Compositions and methods for treatment of neurological disorders

Abstract

To provide a method that selectively targets peripheral nerves without damaging the surrounding tissue and provides sustained treatment of pains.SOLUTION: A method includes injecting a biocompatible ice slurry into one or more peripheral nerves of a subject or to its surrounding area, for a duration sufficient to inhibit the peripheral nerves. The injected biocompatible ice slurry cools the peripheral nerves, and the inhibition is reversible.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 62 / 042,979, filed August 28, 2014, U.S. Provisional Patent Application No. 62 / 121,472, filed February 26, 2015, and U.S. Provisional Patent Application No. 62 / 121,329, filed February 26, 2015. The entire disclosures of the aforementioned provisional applications are incorporated herein by reference. This application contains related disclosures in International Application No. PCT / US2015 / 015 (Attorney Docket No. 051588-22211WO1(000386)), filed August 27, 2015, the entire disclosure of which is incorporated herein by reference. [Background technology]

[0002] Chronic peripheral nerve pain is a common problem in the general population, especially among veterans. It can arise from many causes, such as surgery, trauma, neuromas, metabolic or genetic disorders, and infection, or it can be idiopathic. It is estimated that 20-30% of all limb injuries in U.S. military personnel involve peripheral nerve injury. Severe peripheral nerve injury and amputation can have a devastating impact on quality of life due to intractable neuropathic pain. Treatment of intractable nerve pain has been attempted using oral pain medications, including narcotics and nonsteroidal anti-inflammatory drugs (NSAIDs), surgery, and various percutaneous approaches, including radiofrequency and alcohol ablation. However, these treatments are associated with numerous complications, including narcotic addiction and the need for multiple procedures. Overall, current treatment options for chronic peripheral nerve pain have not produced satisfactory results.

[0003] Cryoneurolysis is the application of cold to targeted nerves. It is a specialized technique for providing long-term pain relief in interventional pain management settings. The application of cold to nerves creates a conduction block similar to the effects of local anesthesia, and freezing the nerve causes Wallerian degeneration of the nerve. Cryoneurolysis has been used for years to treat, among other things, phantom limb pain, pain secondary to trigeminal neuralgia, chest wall pain after thoracotomy, pain from peripheral neuritis, and post-herpetic neuralgia. This technique involves a 1.4- to 2-mm-sized probe, utilizing pressurized gas (e.g., nitrous oxide or carbon dioxide) at 600-800 psi to create a cold temperature of -89°C or below at the probe tip through adiabatic cooling based on the Joule-Thompson effect, thereby creating an ice ball in the target area. The probe is placed directly on the nerve and any tissue that comes into contact with the probe and is destroyed due to the extreme cold temperatures used. Because surrounding tissue is almost always injured or damaged, this procedure is not selective. Additionally, nerve damage in these temperature ranges may be permanent.

[0004] Procedures involving cryoneurolysis, which selectively target peripheral nerves and provide sustained pain treatment without damaging surrounding tissue, are particularly desirable. Summary of the Invention

[0005] In one aspect, the present invention provides a method for reversibly inhibiting a peripheral nerve in a subject in need thereof. The method comprises administering a biocompatible ice slurry to the peripheral nerve in the subject for a duration sufficient to inhibit the peripheral nerve, wherein the inhibition is reversible. In some embodiments, the inhibition resolves after a period of about five months or less. The peripheral nerve targeted for inhibition may be a subcutaneous nerve; a somatic nerve, including a sensory nerve, a motor nerve, a cranial nerve, or a spinal nerve; or an autonomic nerve, including a sympathetic nerve, a parasympathetic nerve, or an enteric nerve. In some embodiments, the biocompatible ice slurry is administered along the perineural sheath of the peripheral nerve.

[0006] In one embodiment, the biocompatible ice slurry comprises ice particles and lactated Ringer's solution or a lactated electrolyte solution.

[0007] In another embodiment, the biocompatible ice slurry further comprises hetastarch or dextrose.

[0008] In yet another embodiment, the biocompatible ice slurry further comprises about 0.1% to about 20% glucose.

[0009] In yet another embodiment, the biocompatible ice slurry further comprises about 0.1% to about 20% glycerol.

[0010] In yet another embodiment, the biocompatible ice slurry further comprises about 0.1% to about 6% hetastarch.

[0011] In yet another embodiment, the biocompatible ice slurry comprises ice particles and saline.

[0012] In yet another embodiment, the biocompatible ice slurry further comprises about 0.1% to about 20% glycerol.

[0013] In yet another embodiment, the biocompatible ice slurry further comprises about 0.1% to about 20% dextrose.

[0014] In yet another embodiment, the biocompatible ice slurry further comprises about 0.1% to about 5% ethanol.

[0015] In yet another embodiment, the biocompatible ice slurry further comprises about 0.1% to about 10% polyvinyl alcohol.

[0016] In yet another embodiment, the biocompatible ice slurry further comprises at least one ion, sugar, polysaccharide, lipid, oil, lysolecithin, amino acid, caffeine, surfactant, antimetabolite, or combination thereof. The at least one ion includes, but is not limited to, calcium, potassium, hydrogen, chloride, magnesium, sodium, lactate, phosphate, zinc, sulfur, nitrate, ammonium, carbonate, hydroxide, iron, barium, salts thereof, or combinations thereof, including salts thereof. The at least one sugar includes, but is not limited to, glucose, sorbitol, mannitol, hetastarch, sucrose, or combinations thereof. The at least one oil includes, but is not limited to, canola oil, coconut oil, corn oil, cottonseed oil, linseed oil, olive oil, palm oil, peanut oil, safflower oil, soybean oil, sunflower oil, or combinations thereof.

[0017] In yet another embodiment, the surfactant is a detergent, including, but not limited to, deoxycholate, sodium tetradecyl sulfate, polidocanol, polysorbates (including polysorbate 20 (polyoxyethylene(20) sorbitan monolaurate), polysorbate 40 (polyoxyethylene(20) sorbitan monopalmitate), polysorbate 60 (polyoxyethylene(20) sorbitan monostearate), polysorbate 80 (polyoxyethylene(20) sorbitan monooleate)), sorbitan esters, poloxamers, or combinations thereof.

[0018] In yet another embodiment, the biocompatible ice slurry comprises a peritoneal dialysis solution.

[0019] In yet another embodiment, the biocompatible ice slurry cools the nerve to about 5°C to about -40°C.

[0020] In yet another embodiment, the biocompatible ice slurry has a first equilibrium temperature of about 4°C to about -30°C.

[0021] In yet another embodiment, the biocompatible ice slurry has a second equilibrium temperature of about 2°C to about -30°C.

[0022] In yet another embodiment, the ice particles are spherical or round with a diameter of about 1 mm to about 0.01 mm.

[0023] In yet another embodiment, the biocompatible ice slurry further comprises a drug, including but not limited to, a vasoconstrictor, a corticosteroid, an NSAID, an anesthetic, a glucocorticoid, a lipoxygenase inhibitor, and combinations thereof. Vasoconstrictors include, but are not limited to, epinephrine or norepinephrine. Anesthetics include, but are not limited to, lidocaine, bupivacaine, prilocaine, tetracaine, procaine, mepivicaine, QX-314, etidocaine, or combinations thereof.

[0024] In yet another embodiment, a biocompatible ice slurry is injected. The injection may be administered into or around any peripheral nerve, including but not limited to, subcutaneous nerves, trigeminal nerve, ilioinguinal nerve, intercostal nerve, interscalene nerve, intercostal nerve, supraclavicular nerve, infraclavicular nerve, axillary nerve, paraspinal nerve, transversus abdominis nerve, lumbar plexus, femoral nerve, pudendal, celiac plexus, and sciatic nerve, any nerve that conducts pain sensation, or any damaged nerve that causes pain or disease.

[0025] In yet another embodiment, the biocompatible ice slurry is applied to a peripheral nerve of a subject by tumescent pumping of the slurry.

[0026] In yet another embodiment, pressure is applied to the injection site to reduce blood flow.

[0027] In yet another embodiment, the tissue containing the peripheral nerves is cooled externally before, during, or after application of the biocompatible ice slurry.

[0028] In yet another embodiment, the ice content of the biocompatible ice slurry is monitored by ultrasound or imaging.

[0029] In yet another embodiment, the subject in need of treatment is suffering from a disorder including, but not limited to, neuropathic pain, diabetic neuropathy pain, trigeminal neuralgia, post-herpetic neuralgia, phantom limb pain, cancer-related itch or pain, burn itch or pain, lichen sclerosus et atrophicus, scalp itch, paresthesia back pain, atopic dermatitis, eczema, psoriasis, lichen planus, vulvar itch, vrvodynia, lichen simplex chronicus, prurigo nodularis, sensory-mediated itch, peripheral neuropathy, peripheral nerve injury, post-thoracotomy pain, incision pain, chest pain, coccygodynia, lower back pain (with or without radiculopathy), scar, neuroma, acute post-operative pain, lumbar facet syndrome, and skin pain disorders.

[0030] Cutaneous pain disorders include, but are not limited to, reflex sympathetic dystrophy (RSD), phantom limb pain, neuroma, post-herpetic neuralgia, headache, occipital neuralgia, tension headache, and vrvodynia.

[0031] In yet another embodiment, the subject in need of treatment suffers from a movement disorder including, but not limited to, hemifacial spasm, bladder spasm, laryngospasm, and gustatory hyperhidrosis.

[0032] Other features and advantages of the invention will be apparent from the detailed description and claims. Accordingly, other aspects of the invention are set forth in the following disclosure and are included within the scope of the invention.

[0033] The following detailed description is given by way of example and is not intended to limit the invention to the specific embodiments described, and should be understood in conjunction with the accompanying drawings, which are incorporated herein by reference. [Brief explanation of the drawings]

[0034] [Figure 1] Figure 1 shows a quantitative model to illustrate the behavior of injected slurries. [Figure 2] FIG. 2 shows the three stages of heat exchange after the slurry is injected into the tissue. [Figure 3] FIG. 3 shows the sciatic nerve of a rat exposed by surgical incision. [Figure 4] Figure 4 shows a thermocouple placed under the rat sciatic nerve to record tissue temperature. [Figure 5] FIG. 5 shows tissue temperature after injection of 6% hetastarch in lactated Ringer's slurry above the sciatic nerve in live rats. [Figure 6] FIG. 6 shows tissue temperature after injection of a 6% hetastarch lactate Ringer slurry above the sciatic nerve in live rats. [Figure 7] FIG. 7 shows tissue temperature after injection of a 6% hetastarch lactate Ringer slurry above the sciatic nerve in live rats. [Figure 8] Figure 8 shows blunt exposure of the common sciatic nerve over the entire biceps femoris muscle and separation from adjacent tissue. [Figure 9] Figure 9 shows the injection of an ice slurry. [Figure 10] Figure 10 shows the thermal paw withdrawal latency in rats subjected to chronic constriction sciatic nerve injury. After constriction sciatic nerve injury, responding rats were either treated with slurry or left untreated (no slurry). At 20, 25, and 42 days after slurry injection, rats exposed to slurry showed increased thermal withdrawal latency responses to heat exposure, indicating reduced pain in response to thermal stimuli. [Figure 11] FIG. 11 shows the results of the study by comparing the difference in thermal withdrawal latencies of responding rats while normalizing to the internal control. [Figure 12] FIG. 12 shows the effect of increasing glycerol concentration (in saline) on slurry temperature. [Figure 13] Figure 13 confirms the invisible injection of ice slurry adjacent to the rat sciatic nerve, stained with tattoo ink for visualization. [Figure 14]Figure 14 shows thermal paw withdrawal latencies in rats with chronic constriction sciatic nerve injury classified as "severe." The difference in paw withdrawal latencies from baseline after injection of room temperature slurry and ice slurry indicates that ice slurry induces a decrease in pain sensation after injury. [Figure 15] Figure 15 shows thermal paw withdrawal latencies in rats subjected to a chronic constriction sciatic nerve injury classified as "moderate." The difference in paw withdrawal latencies from baseline after injection of room temperature slurry and ice slurry indicates that ice slurry induces a decrease in pain sensation after injury. [Figure 16] Figure 16 shows thermal paw withdrawal latencies in rats subjected to chronic constriction sciatic nerve injury classified as "mild." The difference in paw withdrawal latencies from baseline after injection of room temperature slurry and ice slurry indicates that ice slurry induces a decrease in pain sensation after injury. [Figure 17] FIG. 17 shows a method for removing the slurry. [Figure 18] Figure 18 shows the difference in thermal withdrawal latency of the left hind paw at follow-up compared to baseline measurements. Positive values ​​indicate increased thermal pain tolerance due to decreased sensation. [Figure 19] Figure 19 shows the mean thermal withdrawal latency of rats injected with slurry, which was injected by needle around the left sciatic nerve, and the right sciatic nerve was left untreated to serve as a control. DETAILED DESCRIPTION OF THE INVENTION

[0035] definition Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present application, including definitions, will control.

[0036] Unless expressly stated or apparent from the context, the term "about" as used herein is understood to mean within a range common to those skilled in the art, for example, within two standard deviations of the mean. "About" is understood to mean within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. Unless otherwise apparent from the context, all numerical values ​​given herein are modified by the term "about."

[0037] As used herein, the term "biocompatible" refers to a substance or solution that has the ability to exist with living tissue or organisms without causing harm.

[0038] As used herein, the term "ice" refers to water in the solid state (i.e., frozen water).

[0039] As used herein, the term "water" refers to H2O and all isotopes of H2O, including D2O, T2O, etc., and mixtures thereof.

[0040] As used herein, the term "aqueous solution / slurry" refers to a solution / slurry containing HO and all isotopes of HO, including DO, TO, etc., and mixtures thereof. Such solutions may contain water in the solid, semi-solid, and / or liquid state.

[0041] As used herein, the term "equilibrium" or "equilibrium temperature" refers to a temperature between the temperature of the slurry and the temperature of the tissue upon initial contact of the slurry with the tissue.

[0042] As used herein, "reversibly inhibiting" a peripheral nerve refers to loss of function of the nerve that recovers over time. Loss of function may include, for example, a decrease in thermal or mechanical sensation of the nerve.

[0043] Ranges given herein are understood to be shorthand notations for all values ​​within that range. For example, a range of 1 to 50 is understood to include any number, combination of numbers, or subrange (and portions thereof, unless the context clearly dictates otherwise) from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50.

[0044] "Slurry" refers to solid particles (e.g., ice particles) suspended in a biocompatible liquid solution. The slurry may also contain gas bubbles.

[0045] A "subject" is a vertebrate, and includes any member of the mammalian group, including humans, livestock, farm animals, zoo animals, sport animals or pets, such as horses, cats, dogs, mice, rabbits, pigs, sheep, goats, cows and higher primates.

[0046] As used herein, the terms "treat," "treating," "treatment," and the like refer to reducing or alleviating a disorder and / or symptoms associated with the disorder. Although not excluded, it will be understood that treating a disorder or condition does not require that the disorder, condition, or symptoms associated with the disorder be completely eliminated.

[0047] In this disclosure, the words "comprise," "comprising," "containing," "having," and the like may have the meaning assigned to them in U.S. patent law, and "include," "including," and the like, and "consisting essentially of" or "consisting essentially of" likewise have the meaning assigned to them in U.S. patent law, and the terms are inclusive and permit the presence of more than what is recited, provided that the basic or novel characteristics of the recited thing are not altered by the presence of more than what is recited, but excluding prior art embodiments.

[0048] Other definitions appear throughout the text of this disclosure.

[0049] Compositions and methods of the present invention In one aspect, the present invention involves introducing a composition comprising a cold slurry (e.g., ice slurry) directly into interstitial tissue, i.e., into the tissue rather than via natural pathways within the body, such as arteries, veins, or the gastrointestinal tract. When a volume of ice slurry is introduced directly into a volume of soft tissue, rapid heat exchange occurs between the tissue and the slurry. Rapid, localized injection creates a pool of slurry that mixes with the targeted volume of local tissue. In contrast, when the slurry is injected more slowly into a larger volume, the slurry penetrates and flows through spaces within the tissue, creating widespread slurry-filled pathways in a process similar to the administration of tumescent anesthetics. Injection allows for continuous flow of the slurry through the tissue, particularly tissues proximal to the injection site. Continuous or prolonged flow of the slurry can cool the tissue to the exact same temperature as the slurry itself.

[0050] Typically, when a slurry is injected directly into tissue, there are two heat exchange phases: rapid equilibration of the slurry with the local tissue, followed by slow warming to body temperature. During rapid equilibration, the slurry warms and the local tissue cools until an equilibrium temperature is reached between the initial temperature of the slurry and the tissue. During this rapid tissue cooling by heat exchange, three events occur: 1) heat stored by the heat capacity of the slurry and the tissue is exchanged; 2) heat released by lipid crystallization in the tissue is exchanged; and 3) heat absorbed by ice melting in the slurry is exchanged. Depending on the tissue and slurry parameters, some or all of the ice in the slurry melts, and some or all of the lipids in the tissue crystallize. Targeted pain relief occurs through lipid crystallization within the nerve myelin sheath or direct cooling of unmyelinated nerves.

[0051] Rapid heat exchange with the slurry is followed by gradual warming through heat exchange with the body. Gradual warming occurs through a combination of thermal diffusion from surrounding warm tissue and convective heating from blood flow. Blood flow can be reduced in local tissues by pressure or drugs; for example, blood flow can be stopped or significantly reduced by applying pressure to cold tissue or by adding epinephrine or other vasoconstrictors to the slurry. The desired level of pain relief will vary depending on the temperature, cooling rate, cooling duration, and number of cooling cycles.

[0052] The effectiveness of the treatment is related to the amount of lipid crystallization, the amount and number of epidermal nerve fibers, the reduction of myelinated nerve fibers in the dermis, the minimum temperature achieved, the duration of cold, and the number of cold cycles (slurry injections can be easily repeated in one treatment session). All these parameters can be controlled in local tissue volumes by varying the amount and rate of introduction of slurries containing fractions of various ice contents.

[0053] I. Preparation Predictable cooling of the target tissue may be achieved by selecting the liquid-containing slurry components, the chilled particle content (e.g., ice content), and application parameters (including injection location, rate, and volume). During melting of the ice component of the slurry, the temperature of the slurry is at or near its melting point, keeping the slurry cool during and after injection into the tissue. Depending on the composition and osmolality of its liquid components, this melting temperature can be selected to impart the desired effect on the tissue, and may be about -30 to about 10°C, particularly about -30 to about 4°C, and more particularly about -30 to about 2°C.

[0054] The temperature of solutions, including slurries, can be adjusted by selection of liquid phase components, including various solvents and solutes and ions that cause controlled freezing point depression (including, for example, aqueous solutions of NaCl and other biocompatible salts, other electrolytes such as potassium or chloride, glycerol, sugars, polysaccharides, lipids, surfactants, antimetabolites, and detergents).

[0055] The solution comprising the slurry may comprise or consist essentially of lactated Ringer's solution, saline solution, or hetastarch solution. Dextrose, mannitol, glucose, sorbitol, hetastarch, sucrose, glycerol, or ethanol or polyvinyl alcohol may be used to prepare the slurry formulation. Freezing point depression to about -40°C may be achieved using saline, glycerol, glucose, sorbitol, or mixtures thereof. In specific embodiments, the slurry formulation may be prepared using about 0.1% to about 5% ethanol or about 0.1% to about 20% glycerol (e.g., particularly about 5% to about 10% glycerol).

[0056] In a specific embodiment, the solution comprising the slurry comprises lactated Ringer's solution with or without about 0.1% to about 20% glucose or glycerol; saline with or without about 0.1% to about 20% dextrose or glycerol; or lactated Ringer's solution in 6% hetastarch. In another specific embodiment, the solution comprising the slurry may comprise about 0.1% to about 6% hetastarch in a lactated electrolyte solution.

[0057] Glycerol is desirable for use as a cryoprotectant and / or surfactant. Freezing point depression of glycerol-water solutions can be achieved as described in Table 1 below. [Table 1]

[0058] Ions that may be included in the slurry to obtain a controlled freezing point depression include, but are not limited to, calcium, potassium, hydrogen, chloride, magnesium, sodium, lactate, phosphate, zinc, sulfur, nitrate ions, ammonium, carbonate ions, hydroxide ions, iron, barium, or combinations thereof, including salts made therefrom.

[0059] Local blood flow is an important factor, and agents that limit or eliminate local blood flow may be used, for example, when extended treatment times are desired. The solution containing the slurry may also contain a vasoconstrictor to reduce local tissue blood flow. Suitable vasoconstrictors include, but are not limited to, epinephrine (e.g., 1 / 10,000 or less) and norepinephrine. Blood flow can also be reduced by the use of tourniquets, pressure / compression, or suction on the area to be treated. Vasoconstriction can also be achieved by pre-cooling the tissue to be treated by applying topical cooling in the form of Peltier cooling, or by applying ice or cold packs to the skin surface.

[0060] The addition of physiologically compatible surfactant molecules can enhance flow and tissue effectiveness. The surfactant may also act as a foaming agent. Suitable surfactant molecules include, but are not limited to, sodium tetradecyl sulfate, polysorbate, polysorbate 20 (polyoxyethylene (20) sorbitan monolaurate), polyoxyethylene sorbitan monooleate, sorbitan monooleate polyoxyethylene sorbitan monolaurate, lecithin, and polyoxyethylene-polyoxypropylene copolymers, polysorbate, polysorbate 20 (polyoxyethylene (20) sorbitan monolaurate), polysorbate 40 (polyoxyethylene (20) sorbitan monopalmitate), polysorbate 60 (polyoxyethylene (20) sorbitan monostearate), polysorbate 80 (polyoxyethylene (20) sorbitan monooleate), sorbitan esters, poloxamers, or combinations thereof.

[0061] Adding agents such as lysolecithin, deoxycholate, or other surfactants or detergents to the slurry may allow targeting of nonmyelinated nerves. For example, lysolecithin is known to cause reversible degeneration of nonmyelinated axons (Mitchell J. Degeneration of Nonmyelinated Axons in the Rat Sciatic Nerve Following Lysolecithin Injection. Acta Neuropathol (Berl) (1982) 56:187-193). This combination allows the slurry injection to target both myelinated and nonmyelinated nerve fibers, resulting in complete nerve block.

[0062] Therefore, the solution containing the slurry may contain a detergent that can function as a freezing point depressant or a myelin dissolving agent. Such detergents include, but are not limited to, TWEEN® polysorbate, deoxycholate, cholate, phosphatidylcholine, and sodium deoxycholate. An exemplary slurry formulation is shown in Table 2. [Table 2]

[0063] The solution containing the slurry may contain agents to reduce inflammation, including but not limited to corticosteroids, glucocorticoids, lipoxygenase inhibitors and NSAIDs.

[0064] The solution containing the slurry may contain an anesthetic to further reduce pain, including but not limited to polidocanol, lidocaine, bupivacaine, prilocaine, tetracaine, procaine, mepivicaine, and etidocaine.

[0065] In one embodiment, the anesthetic is QX-314, N-ethyl bromide, a quaternary lidocaine derivative, a permanently charged molecule capable of providing long-lasting (greater than 24 hours) anesthesia. Unlike lidocaine, QX-314 can more selectively block nociceptors, has a longer duration of action, and has fewer side effects. QX-314 is a charged molecule that must enter cells and block sodium channels intracellularly. The ability of QX-314 to block nerve membranes from the inside rather than the outside could be exploited to block only the desired neurons. Combining QX-314 with the cold slurry injection described herein selectively targets cold-sensitive nociceptive sensory neurons to provide selective, long-lasting anesthetics.

[0066] In another specific embodiment, the slurry may be composed of a lipid emulsion (e.g., Intralipid), an emulsion of soybean oil, egg phospholipids, and glycerin, available in concentrations of 10%, 20%, and 30%. The lipid emulsion may be mixed with amino acids and dextrose as part of the total nutrient mixture.

[0067] In another specific embodiment, the slurry may comprise a peritoneal dialysis solution.

[0068] The slurry-containing solution may contain chilled particles, e.g., ice particles smaller than the inner diameter of medical cannulas, catheters, and needles, e.g., ice particles smaller than about 1 mm, preferably smaller than about 0.1 mm. The volume percent, size, and / or shape (preferably less than about 0.5 mm, nominally spherical or ellipsoidal) of the chilled particles can be adjusted to optimize the flow of the slurry through the needle, catheter, or cannula and through various target tissues during injection. See, e.g., Kauffeld, M. et al., Int J Refrig. 2010.33(8):1491-1505. The volume percent of chilled particles (e.g., ice particles) in the injected slurry and the volume of the injected slurry determine the cooling capacity of the injection. In a specific embodiment, the volume percent of ice in the injected slurry may range from about 0.1% to about 50% of the solution.

[0069] II. Treatment method For a given volume of target tissue into which a slurry is injected, there are three stages of heat exchange. Initially, when the slurry is injected into and / or through the tissue, the slurry is significantly cooler than the tissue. A strong thermal gradient exists between the tissue and the slurry, which rapidly equilibrates until a local equilibrium temperature is achieved. During this rapid equilibrium phase, the ice in the slurry melts. The amount of melting that occurs depends on other factors, including the initial ice content, the local volume fraction of the slurry mixing with the tissue, the starting tissue temperature, the lipid content of the tissue, and the injection volume and rate of the slurry. These factors can be modeled using many conventional fluid and heat exchange approximations (e.g., using finite element models) (see Example 1). If ice remains after this initial equilibration period, the equilibrium temperature will be very close to the melting point of the ice in the slurry; that is, it may be between about -20°C and about 4°C. The composition of the slurry liquid components sets a lower temperature boundary for this equilibrium temperature; that is, the equilibration temperature cannot be lower than the reduced melting point of the ice in the slurry.

[0070] After local equilibrium is reached, a second phase begins, in which the ice continues to melt as heat is removed from the surrounding tissue. This second phase may last from a few seconds to several minutes, depending on many factors. These factors include the amount of ice per unit volume remaining after the initial equilibrium, the size of the tissue volume containing the ice, the heat transfer and composition of the target and surrounding tissue, and local blood flow. The second phase can be viewed as providing a "therapeutic temperature and duration" to the target tissue, since the temperature remains relatively stable in the target tissue during this phase until all of the ice in the slurry has melted. The therapeutic temperature is primarily set by the composition of the slurry liquid and the volume fraction of the slurry injected into and around the target tissue. The therapeutic duration is primarily set by the ice content and blood flow within the target tissue, by injection variables including volume, rate, and distribution, and by the size and shape of the target tissue. For example, a higher ice content in the slurry will result in a longer second phase; the larger the volume fraction of the injected slurry (the ratio of locally injected slurry to the target tissue and injected slurry), the longer this second phase will be; the larger the dimensions of the injected slurry and target tissue, the longer this phase will be, approximately proportional to the square of the dimensions; blood flow within the target tissue will shorten treatment time by melting the ice in the slurry more quickly. Heat transfer from surrounding (non-slurry-filled) tissue and heat transfer due to blood flow will melt the ice in the slurry during this second phase.

[0071] In a specific embodiment, the biocompatible ice slurry has a first equilibrium temperature of about 4°C to about -30°C and / or a second equilibrium temperature of about 2°C to about -30°C. These equilibrium temperatures are achieved, for example, as follows: A slurry composition of hetastarch in lactate electrolyte (500 ml), saline (500 ml), and glycerol (100 ml) can be used to achieve a slurry temperature of -5°C. A single bolus injection of about 25 ml of the slurry composition into tissue at a starting temperature of 29°C can rapidly reduce the tissue temperature to -3.2°C and maintain it below 0°C for about 10 to 15 minutes. A slurry composition of hetastarch in lactate electrolyte (500 ml), saline (500 ml), and glycerol (50 ml) can be used to achieve a slurry temperature of -2.1°C. A single bolus injection of about 50 ml into tissue using a 15-gauge needle can achieve a tissue temperature of about -2°C to -1.3°C. The temperature within the tissue can be maintained below 0°C for approximately 15 minutes. If the tissue temperature is approximately -0.1°C, a second bolus injection of 40-60 ml of slurry can be administered to reduce the tissue temperature to approximately -1.1°C and maintain this temperature for more than 15 minutes. A third bolus injection can maintain the tissue temperature below 0°C for more than 20 minutes. Approximately four to five injections of the slurry composition can maintain a cool temperature below 0°C for 60 minutes to achieve hypoesthesia. Exposing peripheral nerves to temperatures below 0°C for approximately 60 minutes can result in hypoesthesia for several weeks (e.g., 6-8 weeks). This multiple cycle of slurry injections can be administered to prolong the cooling effect of the slurry injection.

[0072] The rate of ice melting can be monitored for a given application and anatomical situation. For example, ice is readily visible through medical ultrasound imaging, which can be used to monitor ice content, size and shape, and the rate of ice melting from the target tissue. In some applications, the ice content in the treated tissue can be monitored using ultrasound during and after slurry injection. Treatment can be significantly prolonged by repeated or continuous injection of the slurry during the second phase. Ultrasound guidance can be used to monitor the ice content and adjust the repeated or continuous injection of the slurry accordingly.

[0073] To target the desired nerve, the location of the slurry placement can be monitored using ultrasound. For example, while the slurry is being injected, the target nerve can be monitored using ultrasound to ensure proper placement of the slurry. This allows for precise delivery of the slurry and targeting of the desired nerve.

[0074] If a longer treatment time is desired, methods to temporarily restrict or eliminate local blood flow may be used. For example, mechanical force can be applied to restrict blood flow, including simply applying pressure after slurry injection, or, where appropriate, a tourniquet can be applied before, during, or after slurry injection. Pre-cooling the tissue before slurry injection can also induce vasoconstriction. Continuous external cooling after slurry injection can be used to increase the duration of the slurry's effectiveness within the tissue.

[0075] The method of the present invention reversibly inhibits peripheral nerves. Inhibition can last up to about 5 months after administration of the slurry. For example, peripheral nerve inhibition can be achieved for several minutes, several days, several weeks, or several months after a single administration of the slurry. If necessary, treatment can be extended by administering multiple cycles of the slurry. The tissue can also be pre-cooled or pre-chilled before slurry injection, allowing the tissue temperature to remain cool for an extended period of time.

[0076] The third phase, following slurry injection, occurs after the ice contents have melted. Here, the temperature of the target tissue can gradually return to body temperature by the same processes that melted the ice during the second phase (heat conduction, heat convection through blood flow). Again, depending on the size, anatomy, and blood flow involved, it may take minutes or even hours for the target tissue to return to normal body temperature. As all the ice in the slurry melts, the temperature within the target tissue increases in the third phase. These phases are illustrated diagrammatically in Figure 2.

[0077] Lipid crystallization is one mechanism for the temporary and long-term loss of nerve conduction after nerve cooling. The myelin sheath surrounding nerve axons contains a high concentration of lipids. The primary mechanism of the lipid-rich sheath is to isolate the axon, thereby enabling the propagation of action potentials (i.e., nerve signals). The destruction and / or loss of myelin sheath after localized cooling appears to follow a similar mechanism, with stress and degeneration occurring after myelin lipid crystallization. Myelin sheaths are extensions of Schwann cell cytoplasm, and this type of damage is slow to repair. Therefore, the reduction of anesthesia, pain, or itch over a long period (up to approximately three months or more) is an application of the present invention. For example, the slurry may be used for long-term nerve blocks after injection / infusion at many anatomical sites traditionally used for temporary nerve blocks using anesthetic injections.

[0078] The methods of the invention can reduce or eliminate pain or itch from neuropathy such as, for example, neuropathic pain, diabetic neuropathy pain, trigeminal neuralgia, post-herpetic neuralgia, phantom limb pain, cancer-related itch or pain, burn itch or pain, lichen sclerosus et atrophicus, scalp itch, paresthesia back pain, atopic dermatitis, eczema, psoriasis, lichen planus, vulvar itch, vrvodynia, lichen simplex chronicus, prurigo nodularis, sensory-mediated itch, peripheral neuropathy, peripheral nerve injury, post-thoracotomy pain, incision pain, chest pain, coccygologic pain, lower back pain (with or without radiculopathy), scarring, neuroma, acute post-operative pain, lumbar facet joint syndrome, and cutaneous pain disorders.

[0079] Cutaneous pain disorders include, but are not limited to, reflex sympathetic dystrophy (RSD), phantom limb pain, neuroma, post-herpetic neuralgia, headache, occipital neuralgia, tension headache, and vrvodynia.

[0080] The methods of the invention can also be used to reduce or eliminate pain disorders caused by peripheral neuropathy, symptoms associated with peripheral nerve damage from metabolic, infectious, traumatic, genetic, or chemical processes. The methods of the invention can also be used to reduce or eliminate cutaneous pain.

[0081] The methods of the present invention can also be used to reduce or eliminate symptoms associated with pain disorders caused by surgery (e.g., surgery that involves making an incision through the skin to induce pain). This includes post-operative thoracic pain caused by thoracic surgery (e.g., treatment of pain from open surgery). The slurry can be injected before, during, or after the incision.

[0082] In a specific embodiment, after thoracic surgery, approximately 3 cm 3 The slurry may be used to inhibit pain by injecting the slurry into the subcostal space. The lipid content of an exemplary subcostal nerve is about 20% (f tlip =0.2). Before injection, ice packs are applied to cool the local tissue to 20°C (T t =20). 30% ice (I o = 0.3), a slurry containing 0.001% epinephrine is added for vasoconstriction, and injected around the nerve so that approximately equal volumes of slurry and tissue are created (f s After rapid exchange based on heat capacity, the temperature of the slurry-tissue mixture is T m =(1-f s )T=10℃. T m = 10°C, so no new ice melts to reach 10°C, i.e., Q to10C =(T m-10)ρC = 0. The latent heat is exchanged as ice in the melt of the slurry-tissue mixture while lipids crystallize in the myelin sheath of the target nerve. The initial ice content of the slurry-tissue mixture is I o =f s I s where I o =(0.5)(0.3)=0.15% or 15%. At this ice content, the value Q icetotal =f s I s H ice or (0.5)(0.3)(74)=11 cal / cm 3 The lipid content of the slurry-tissue mixture is f inlip =(1-f s )f tliP where (0.5)(0.2)=0.10 or 10%. Crystallization of all lipids in the slurry-tissue mixture (an exothermic process) results in a heat of fusion, H, that depends on the lipid content and volume of lipid, as described above. lipid The thermal energy Q is equal to the product of liptotal The lipid content f mlip =0.1, H lipid value = 34 cal / cm 3 , the energy associated with lipid crystallization in the target nerve is Q liptotal =f mlip H lipid =(0.1)(34)=3.4 cal / cm 3 Q icetotal >Q liptotal Therefore, all lipids in the nerve crystallize, leaving residual ice. When this residual ice melts, Q iceresidual =Q icetotal -Q liptotal The temperature decreases according to the value of Q iceresidual value = 11 - 3.4 = 7.6 cal / cm 3 The final temperature is T final ~10-Q iceresidual / ρC. As mentioned above, the value of ρC for most soft tissues is 1 cal / °C-cm 3 As a result, T final ~10-7.6, or 2.4°C. Then, about 6cm3 A volume of slurry-tissue mixture is gradually heated. The diameter of a sphere of volume v is d = (6v / □) 1 / 3 Therefore, 6cm 3 For a spherical volume of slurry-tissue mixture, the diameter is approximately 22 mm. The cold slurry-tissue mixture has a diameter of approximately (22) 2 = 480 seconds, or approximately 8 minutes, of gradual warming. A second or further injection of slurry may also be performed, and the effectiveness of multiple cooling cycles is typically greater than a single cycle.

[0083] The methods of the present invention may also be used to reduce muscle spasms caused by abnormal nerve firing, such as bladder spasms or facial spasms.

[0084] The methods of the present invention can also target motor nerves when long-term paralysis of the motor nerve is desired.

[0085] The methods of the present invention can also be used to reduce, eliminate, or alter functions controlled by the autonomic nervous system. For example, the sympathetic nervous system controls excessive sweating through sympathetic nerve fibers that innervate the eccrine glands in the axilla. The methods of the present invention can be used to target autonomic nerve fibers to reduce excessive sweating.

[0086] The peripheral nerves of a subject may be administered by injecting, infusing or tumescently pumping the slurry into one or more nerves, such as peripheral, subcutaneous or autonomic nerves of the subject, by injecting a solution containing the slurry into one or more nerves selected from the group consisting of cutaneous nerves, trigeminal nerve, ilioinguinal nerve, intercostal nerve, interscalene nerve, supraclavicular nerve, subclavian nerve, axillary nerve, pudendal nerve, paraspinal nerve, nerves of the transversus abdominis plane, lumbar plexus, femoral nerve and sciatic nerve.

[0087] The methods of the present invention may also reduce or eliminate pain associated with nerve plexuses (i.e., groups of crossing nerves), including, but not limited to, the cervical plexus, which serves the head, neck, and shoulders; the brachial plexus, which serves the chest, shoulders, arms, and hands; the lumbar plexus, which serves the back, abdomen, groin, thighs, knees, and calves; the sacral plexus, which serves the pelvis, buttocks, genitals, thighs, calves, and feet; the celiac plexus (solar plexus), which serves the internal organs; the coccygeal plexus, which serves the small area above the tailbone; the Auerbach plexus, which serves the gastrointestinal tract; and the Meissner plexus (submucosal plexus), which serves the gastrointestinal tract.

[0088] The methods of the present invention can also be used for renal sympathetic denervation, an emerging therapy for treating severe and / or resistant hypertension.

[0089] Flowing the slurry through tissue can provide cooling over large distances from the injection point, particularly through tissue structures that offer minimal resistance to fluid flow, such as along the perineural sheath of a sensory or motor nerve. The solution can also be administered percutaneously by syringe needle or via the circulatory system to any peripheral or subcutaneous nerve accessible by catheter.

[0090] The means for injecting the slurry (e.g., a needle) may include additional features (e.g., a sensor that can read temperature and monitor the temperature of the target tissue). The means for injecting the slurry may optionally have the ability to withdraw the molten components of the slurry while allowing for the injection of new slurry, as shown in FIG.

[0091] The injection location can be confirmed, for example, by MRI or x-ray imaging, for example, if the slurry contains an imaging agent known in the art. Preactivation of the nerve with electrical or chemical stimulation and / or confirmation of needle location can also be performed in combination with the methods of the present invention. Here, correct placement of the slurry can be facilitated by injecting an anesthetic or electrical stimulus to create sensation or anesthesia along the targeted nerve before injecting the slurry.

[0092] The duration for which the slurry is administered can be determined by a physician or other skilled professional or technician and adjusted, if necessary, to suit the observed effects of the treatment, or adjusted, if necessary, depending on the formulation of the slurry being administered. Adjusting the duration of treatment according to the methods described herein is well within the knowledge of one of ordinary skill in the art.

[0093] The method of the present invention can also be used to treat urinary incontinence. In a recent survey of women aged 25-84 in the United States, approximately 15% reported experiencing stress incontinence, and 13% reported experiencing urge incontinence / "overactive bladder." The causal relationship between these two incontinence types is due to separate mechanisms, but a single patient may experience both mechanisms.

[0094] Stress incontinence is the most common type of incontinence in young women and is often due to insufficient bladder support from the pelvic floor, often due to urethral hypermobility. This lack of support is due to loss of connective tissue. This lack of support is also associated with other conditions, such as pelvic organ prolapse and bowel problems (both constipation and incontinence). Currently, the primary treatment strategies include pharmacological treatment, pessaries, and surgical intervention, with varying success rates. Parasympathetic, sympathetic, and somatic nerves play important roles in controlling lower urinary tract function. More specifically, the smooth muscle of the bladder (deuric muscle) is primarily innervated by parasympathetic nerves. The smooth muscle of the bladder neck and urethra (internal sphincter) is innervated by sympathetic nerves. The striated muscle of the external urethral sphincter (EUS) receives primary stimulation from somatic nerves. The slurry described herein could be used as an injectable treatment to treat stress incontinence while targeting one or more of these nerves.

[0095] Urge incontinence results from overactivity of the detrusor muscle. Therapies for treating urge incontinence are primarily pharmacological (e.g., botulinum toxin) and target reducing nerve input to the bladder muscle to prevent frequent bladder spasms. Due to the ability of the ice slurries described herein to reduce nerve function, another embodiment of the present invention provides a treatment for urge incontinence by inhibiting nerve input to the bladder. In one embodiment, this treatment involves an injectable treatment in which an ice slurry is administered, for example, to the neuromuscular junction to inhibit nerve input to the bladder.

[0096] The present invention is further described by the following illustrative, non-limiting examples, which will provide a better understanding of the present invention and its many advantages. [Example]

[0097] The following examples illustrate some embodiments and aspects of the present invention. It will be apparent to those skilled in the art that various modifications, additions, substitutions, etc. can be made without altering the spirit or scope of the present invention, and such modifications and variations are encompassed within the scope of the present invention as defined in the following claims. The following examples do not limit the present invention in any manner.

[0098] Example 1: Quantitative model to describe the behavior of injected slurries A simplified and reasonable estimate is made in the quantitative model to describe the behavior of injected slurries, as shown in FIG.

[0099] Heat capacity is an important factor in the heat exchange between the slurry and the tissue. The first heat exchange to consider is that of the energy stored by the heat capacity of the slurry and the tissue. The energy stored per unit volume in the medium by the heat capacity is given by H = TρC, where H is the energy density (cal / cm 3 ), T is the temperature (°C), and p is the density (gm / cm 3 ) and C is the specific heat capacity (cal / °C gm). Assume that ρC is the same for slurry, tissue, and water (i.e., ρC = 1 cal / gm-°C). This assumption is approximately correct for all soft tissues except fat, where ρC is approximately two times smaller.

[0100] Consider the local volume of tissue into which the slurry is introduced. The slurry is introduced into the local tissue at a volume fraction f s When introduced with, this local organization is (1-f s ) volume fraction. Due to the heat capacity of the slurry, the heat stored per unit volume of the resulting slurry-tissue mixture is H s =f s T s ρC, and the heat stored per unit volume due to the heat capacity of the tissue is H t =(1-f s )T t ρC. After the rapid exchange of thermal energy due to the heat capacity, the new temperature T mThe heat energy due to the heat capacity of this mixture is m =T m The conservation of energy in local heat exchange is given by H s +H t =H m Combining these equations, we get f s T s ρC+(1-f s )T t ρC=T m ρC T m Solving for, the temperature of the slurry-tissue mixture after this initial portion of heat exchange is T m =f s T s +(1-f s )T t Since the temperature of the physiological ice slurry is close to 0, this is T m =(1-f s )T t The rapid heat exchange during mixing due to heat capacity alone is the volume-weighted average of the two starting temperatures. For example, f s = 0, no slurry is added, and T m =T t is the starting temperature of the tissue. s When f = 1, the mixture is entirely a slurry and Tm = 0. s For f = 0.5, it is a 50-50 mixture of slurry and tissue, and the temperature obtained after mixing is the average of the starting temperatures of the slurry and tissue. s Typical values ​​of f range from about 0.2 to about 0.8, i.e., the volume of the mixed slurry-tissue may have a slurry content of about 20 to about 80%. s Consider the case where T = 0.5. t is 37°C, then after heat exchange from the heat capacity, Tm=18.5°C.

[0101] The ice volume fraction of the physiological slurry in this model is I s is defined as the volume of ice per unit volume of slurry. Thus, immediately after injection into the tissue, the initial volume fraction of ice in the local slurry-tissue mixture is I o =f s I s and I o is the total amount of ice available for melting per unit volume of slurry-tissue mixture.

[0102] After rapid heat exchange from the heat capacity, the ice in the slurry component of the slurry-tissue mixture begins to melt, absorbing heat and cooling the slurry-tissue mixture. Before the gradual warming period due to internal heat exchange, briefly discussed above, the ice in the slurry-tissue mixture melts until it is gone or reaches an equilibrium temperature. In pure water, ice and liquid water may exist together at an equilibrium temperature of 0°C to 4°C. In tissue, many solutes exist that depress the freezing point, resulting in ice and water existing together over a somewhat lower temperature range (e.g., about -8°C to 0°C in skin). Lipids in tissue are in a liquid state at normal body temperature. Cooling of the slurry-tissue mixture due to ice melting can cause lipid crystallization below a certain temperature. Essentially, there is a heat exchange between the latent heat of fusion from the melting ice and the latent heat of fusion from the crystallization of lipids. Because lipid crystallization occurs at temperatures well above the freezing point of water, these two processes run in opposite directions (e.g., water melts and lipids crystallize). Most animal fats crystallize at 10–15°C, depending on the length and degree of saturation of the lipid chains in the triglyceride molecules. Wax esters and free fatty acids crystallize at similar temperatures. Polar lipids crystallize at lower temperatures; for example, the phospholipids of cell membranes can remain somewhat fluid well below 0°C.

[0103] The injected physiological slurry is effective in suppressing pain or itch by affecting the myelin sheath lipids of nerves. The sheath lipids crystallize well above 0°C. Effective treatment requires a starting tissue temperature Tt , the ice content of the slurry I s , in the slurry-tissue mixture, a sufficient slurry fraction f s The volume and rate of slurry injected to achieve the target lipid content of the tissue, L t , its crystallization temperature T c The amount of ice will vary depending on variables including the time the ice remains in the slurry-tissue mixture.

[0104] The enthalpy of fusion (also called the heat of fusion) describes how much heat energy is absorbed (endothermic) or released (exothermic) due to the change from a solid to a liquid state. Melting ice is an endothermic transition that requires a large amount of heat energy. For water, the heat of fusion is 80 cal / gm. The density of ice at 0°C is 0.92, resulting in a volumetric heat of fusion, H ice (Thermal energy required to melt a given volume of ice) is H ice =74 cal / cm 3 is. The total heat per unit volume, Q, that can be absorbed by melting all the ice in the slurry-tissue mixture icetotal is simply the ice content and H ice Multiply by Q icetotal =f s I s H ice is.

[0105] f s Typical values ​​for the above mentioned range from about 0.2 to 0.8, and the ice content of physiological slurries can be up to about 50% (I s ~0.5). Therefore, the appropriate maximum I s = 0.5, Q in the slurry-tissue mixture icetotal The range (no limit) is approximately 7 to 30 cal / cm 3 is.

[0106] The heat of fusion of lipids in animal fats ranges from about 30 to 50 cal / gm (Cooling Technology in the Food Industry; Taylor and Francis, 1976). The density of lipids is approximately 0.8-0.9 gm / cm 3 (e.g., palmitic acid triglyceride in solid state has a viscosity in the range of 0.85 gm / cm 3 Taking an average value of 40 cal / gm as the heat of fusion, the latent heat per unit volume for lipid crystallization is approximately H lipid =34 cal / cm 3 is.

[0107] Therefore, the latent heat for lipid crystallization is less than half the latent heat for melting ice. The slurry-tissue mixture cools by melting some of the ice until the temperature reaches approximately 10°C, the temperature required for lipid crystallization to begin. The heat energy consumed in lowering the temperature of the slurry-tissue mixture to approximately 10°C is: Q to10C =(T m -10)ρC is obtained by

[0108] At approximately this temperature, any remaining ice from the slurry will melt, absorbing the energy required to crystallize nearly twice the volume of lipid itself. If all the lipid in the tissue crystallizes, more ice will melt, and the temperature will drop to below about 10°C, potentially to about -8°C to 0°C, where ice and liquid water can coexist in the tissue. Therefore, the lipid content of the slurry-tissue mixture is another important factor. The lipid content of the tissue can be calculated by f tlip The lipid content of the slurry-tissue mixture is defined as f mlip =(1-f s )f tlip is.

[0109] f tlip The value of f varies depending on the type of tissue. The lipid content of most soft tissues ranges from about 5% (most connective tissues) to about 80% (fat), i.e., ftlip = 0.05-0.8. The energy per unit volume of the slurry-tissue mixture produced by crystallizing all the lipids present is Q liptotal =f mlip H lipid is.

[0110] During the latent heat exchange time between the melting of ice and the crystallization of lipids in the slurry-tissue mixture, the ice in the slurry melts until all the lipids have crystallized or until there is no more ice.

[0111] The fraction of lipid that crystallizes in the slurry-tissue mixture is simply given by the energy balance, f lipxtal =(Q icetotal -Q to10C ) / Q liptotal (Q icetotal -Q to10C ) liptotal In the case of f, some of the lipids crystallize, lipxtal (Q icetotal -Q to10C )=Q liptotal In this case, all of the lipids crystallize, all of the ice melts, and the temperature remains near the phase transition temperature of most animal lipids, about 10°C. (Q icetotal -Q to10C )>Q liptotal In this case, all of the lipids crystallize, and then the temperature drops to less than about 10°C (i.e., in the temperature range of about -8°C to 0°C) until all of the ice melts or until an equilibrium exists between the ice and liquid water in the tissue. The lowest temperature reached is determined by the heat exchange between the melting of the remaining ice and the heat capacity of the slurry-tissue mixture. Therefore, the lowest temperature T final may be estimated by equating the latent heat per unit volume absorbed by melting the remaining ice with the heat associated with a temperature drop of less than about 10°C.

[0112] The latent heat associated with melting the ice remaining after lipid crystallization is Q iceresidual ​=Q icetotal -Q to10C -Q liptotal and the amount of remaining ice per unit volume is I residual =Q iceresidual =H ice The T due to the melting of the remaining ice final The temperature drop to iceresidual ~(10-T final )ρC, and T final ~10-Q iceresidual / ρC.

[0113] The local heat exchange modeled above occurs on a timescale of a few seconds as the slurry is in intimate contact with the tissue by mixing and flowing through and / or cutting through the soft tissue during interstitial injection. After the exchange of latent heat from melting ice and crystallizing lipids, the temperature of the slurry-tissue mixture rises to approximately T final The tissue is then gradually warmed due to conduction and convection. Therefore, the rate of gradual warming varies with the rates of conduction and convection. In the absence of blood flow (convection), conductive warming involves a minimum characteristic time, which is proportional to the square of the diameter of the local slurry-tissue mixture. Typically, in soft tissue, the time in seconds to substantially warm an area by conduction (to 1 / e of the final equilibrium value) is approximately equal to the square of the diameter in millimeters. For example, a 10 mm diameter slurry-tissue mixture typically requires about 100 seconds to substantially warm, and a 30 mm diameter slurry-tissue mixture typically requires about 900 seconds (i.e., 15 minutes) to substantially warm by conduction. Depending on the ice content, some ice may remain even after this estimated period of substantial warming. The model presented here is illustrative and not actual. Direct measurements of slurry and tissue temperatures can be made. As shown below, such measurements are generally consistent with this appropriate model.

[0114] Example 2: Inhibition of sciatic nerve function in rats A 6% hetastarch lactate Ringer's slurry (i.e., hetastarch (500 ml), saline (500 ml), and glycerol (50 ml) blended together) was injected into the upper sciatic nerve of male rats weighing approximately 250-271 g. The procedure was performed as follows: Rats were placed under general anesthesia using inhaled isoflurane and oxygen. The sciatic nerve was exposed through a surgical incision (Figure 3). A starting temperature of -3.2°C to -2.7°C was obtained and maintained throughout the experiment. For each of five injections, 5 ml of the slurry was injected into the upper sciatic nerve. Tissue temperature was recorded using a thermocouple placed under the sciatic nerve (Figure 4).

[0115] The 6% hetastarch lactate Ringer slurry was able to maintain nerve tissue temperatures below 0°C for an average of 5 minutes, and tissue temperature was maintained as long as ice was present in the slurry (Figures 5, 6, and 7). Nerve blocks are expected to last for days, weeks, or months. Once the ice becomes liquid, the tissue temperature quickly rises above 0°C. If the tissue around the nerve was precooled, the ice melted at a slower rate, and the slurry lasted longer (Figure 6).

[0116] Example 3: Sensory testing in rats The efficacy of cold treatment on large motor and sensory nerves (e.g., the sciatic nerve) can be demonstrated in rodent models by assessing nerve tissue staining and performing assays to measure motor and sensory function after injection of cold slurry. Sensory experiments were performed on 12 adult male rats weighing 250 g to 350 g. The rats were housed in a testing environment, labeled 1 to 12, and randomly divided into two groups of six rats each. Baseline sensory testing was performed one day before the procedure.

[0117] All rats underwent chronic constriction injury (CCI) for a chronic neuropathic pain model. Using blunt dissection across the biceps femoris, the common sciatic nerve was exposed and separated from adjacent tissue as shown in Figure 8. 4-0 chromic gut sutures were tied loosely around the nerve at two points approximately 1 mm apart. The desired degree of constriction slowed but did not prevent circulation through the superficial epineurial vasculature.

[0118] Sensory testing was repeated in rats 6 days after CCI, demonstrating the efficacy of the procedure: rats were more sensitive to heat injury in the injured paw than in the uninjured paw, and the injured paw withdrew significantly more quickly when exposed to thermal pain. One week after CCI, the sciatic nerve was exposed in all rats using blunt dissection. Six rats received an injection of ice slurry, as shown in Figure 9. Six rats were opened and closed without slurry injection (no slurry).

[0119] The slurry injected into the six rats in the experimental group consisted of 5% glycerol (by weight) in saline and 5% glycerol added (by weight) before injection. Each rat was injected with 10 cc of slurry around the sciatic nerve. A thermocouple was placed near the nerve to record the temperature. The average temperature of the slurry above the sciatic nerve at the time of injection was approximately -1.1°C. Once the temperature reached +5°C, the area was wiped with sterile gauze, and another 10 cc of slurry was injected around the sciatic nerve. The tissue temperature at the injection site reached an average of +5°C within approximately 5 minutes.

[0120] All rats tolerated the slurry injections well, with no evidence of necrosis, infection, ulceration, or self-injurious behavior.

[0121] Sensory testing was performed to assess the potential analgesic effects of ice slurry 14, 20, 25, 32, 36, and 42 days after slurry injection. All rats were randomized, and as expected, rats in the randomized group responded better to chronic constriction injury by exhibiting greater sensitivity to thermal pain. These rats were used to evaluate the reduction of thermal pain following injection of ice slurry. The results are shown in the figures below.

[0122] Figure 10 shows the thermal paw withdrawal latency of responding rats, showing longer response times to heat exposure in rats 20, 25, and 42 days after slurry injection. A longer response time indicates less pain from the thermal stimulus, demonstrating that the slurry reduces thermal pain.

[0123] Sensory testing in rats is known to be variable, and one way to reduce this variability is to report the difference between the test side (left hind paw) and the internal control (right hind paw), i.e., right hind paw latency minus left hind paw latency. Figure 11 shows the results of the test by comparing the difference in heat-induced withdrawal latencies of responding rats while normalizing to the internal control. Positive values ​​indicate that the left paw withdraws more quickly than the right paw in response to heat-induced pain. A decrease in the difference in latency between the left and right paws was observed after slurry injection, indicating that the slurry reduces heat-induced pain.

[0124] Experiment 4: Tolerance to various slurry compositions The slurries listed in Table 3 were made and successfully injected around the sciatic nerve of rats. "NS" is an abbreviation for "normal saline" (0.90% grams of NaCl per ml of HO). "Hetastarch" is another term for "hydroxyethyl starch" and is a non-ionic starch derivative. HEXTEND® (6% hetastarch lactate electrolyte injection, average molecular weight 670,000 daltons, available from Hospira, Inc., Lake Forest, Illinois) was used for the experiments performed herein. "LR" is an abbreviation for lactated Ringer's solution. Glycerol percentages are expressed in g / ml. [Table 3]

[0125] One week after injection, all rats were examined for tolerable side effects by observation, dissection of the injected area, and gross observation. All animals tolerated the injections well with no signs of infection, ulcers, necrosis, or side effects up to one week after injection.

[0126] Table 4 below details further safety and tolerability testing in rats. Tattoo ink was added to demonstrate localization of the injected slurry around the sciatic nerve. [Table 4]

[0127] No evidence of infection, tissue necrosis, or ulceration was observed in any of the rats 24, 48, or 72 days after injection. The muscles remained generally intact. There were no differences in necropsy between the sides injected with and without slurry one week after injection. The tattoo ink was found to be localized around the nerve, indicating that the slurry was precisely injected around the target tissue (Figure 13).

[0128] Further studies were conducted to determine the safety and tolerability limits of the cold slurry by injecting increasing amounts of glycerol around the sciatic nerve of rats. Rats were observed daily for up to one week after injection, and side effects were assessed by observation, photography, and histology. The results are shown in Table 5. [Table 5]

[0129] All animals tolerated the injections well, with no signs of infection, ulcers, necrosis, or side effects observed up until the time the animals were sacrificed one week after injection. No abnormalities were noted upon necropsy.

[0130] Example 5: Relationship of solute concentration to slurry temperature Figure 12 shows the effect of increasing glycerol concentration (in saline) on slurry temperature. Increasing the amount of glycerol in the slurry significantly reduced the slurry temperature. The slurries shown in Table 5 were injected to test the safety and tolerability limits of the lowest tolerated slurry temperature. All animals tolerated the injections well, with no signs of infection, ulcers, necrosis, or adverse reactions observed up to the time the animals were sacrificed one week after injection. No abnormalities were noted upon necropsy.

[0131] Example 6: Feasibility of blind cryoneurolysis injection Referring now to Figure 13, tattoo ink (black pigment) was added to a slurry composed of saline and 20% glycerol. In Sprague-Dawley rats, this slurry was injected into a dissected pocket containing the sciatic nerve. One week after injection, the rats were sacrificed, and the skin overlying the dissected pocket containing the sciatic nerve was then incised to confirm placement of the slurry adjacent to the sciatic nerve (visible due to the tattoo ink). This image demonstrates the feasibility of delivering a slurry around the sciatic nerve by invisible injection through the skin.

[0132] Example 7: Rat sensory test Sprague-Dawley rats housed in the sensory testing environment for three consecutive days before baseline measurements were obtained were further subjected to sensory testing. A baseline thermal sensory test was performed using withdrawal latencies. Thermal withdrawal latencies represent the amount of time it takes a rat to withdraw its hind paw from an infrared heat source; higher values ​​indicate a higher pain threshold, while lower values ​​indicate increased sensitivity to pain. All rats underwent chronic constriction injury (CCI) for a chronic neuropathic pain model. Using blunt dissection across the biceps femoris, the common sciatic nerve was exposed and separated from adjacent tissue. 4-0 chromic gut sutures were loosely tied around the nerve at two points approximately 1 mm apart. The desired degree of constriction slowed but did not prevent circulation through the superficial epineurial vasculature. Six days after CCI, repeated sensory testing demonstrated the efficacy of this procedure. One week after CCI, the sciatic nerve was exposed in all rats using blunt dissection.

[0133] The slurry injected into experimental rats consisted of 10% glycerol (by weight) in saline and had a mean temperature of -3.9°C. A thermocouple was placed near the nerve to record the temperature. Initially, 5 cc of slurry was injected into each rat's nerve. Using a syringe smaller than the delivery syringe, the slurry was continuously removed from the site as it melted and replaced with fresh iced slurry. A nerve cooling duration of 15 minutes was ensured, defined as a temperature below +5°C at the nerve site. A sample of the slurry was removed from the container and allowed to warm to room temperature. A room-temperature solution with the same composition as the slurry was injected into control (room-temperature slurry) rats.

[0134] All rats tolerated the slurry injections well. No evidence of necrosis, infection, ulcers, or self-injurious behavior was observed. Sensory testing was performed to examine the potential analgesic effects of the ice slurry at intermediate time points (5 and 6 days after slurry injection) and then at a longer time point (28 days after slurry injection). Selected rats were matched based on mean injury severity after CCI. Injury severity was determined by a decrease in thermal withdrawal latency compared to the mean baseline measurement. Injury severity = (baseline thermal withdrawal latency) - (thermal withdrawal latency at time point X). A reading of 0 indicates that the rat had returned to its baseline (pre-injury) pain threshold. Four rats were perfectly matched (difference of 0.2 s or less), and then two additional rats were matched at the highest severity of their group (difference of 0.5 s or less).

[0135] In rats with severe sciatic nerve constriction injury, the addition of ice slurry reduced pain levels in response to heat stimuli 6 and 28 days after injection (Figure 14). Compared to rats injected with room temperature slurry (shown in red), rats injected with ice slurry (shown in blue) showed a 4.4-fold reduction in thermal withdrawal latency 28 days after slurry injection (1.4 s vs. 6.2 s), indicating a significant reduction in thermal pain sensitivity.

[0136] In rats with moderate sciatic nerve constriction injury, the addition of ice slurry reduced pain levels in response to heat stimuli 6 and 28 days after injection (Figure 15). Compared with rats injected with room temperature slurry (shown in red), rats injected with ice slurry (shown in blue) showed a nearly two-fold reduction in thermal withdrawal latency 28 days after slurry injection (2.1 s vs. 4.1 s), indicating a significant reduction in thermal pain sensitivity.

[0137] In rats with mild sciatic nerve constriction injury, the addition of ice slurry reduced pain levels in response to heat stimuli 6 and 28 days after injection (Figure 16). Compared with rats injected with room temperature slurry (shown in red), rats injected with ice slurry (shown in blue) had an 11-fold reduction in thermal withdrawal latency 28 days after slurry injection (0.2 s vs. 2.2 s), indicating a significant reduction in thermal pain sensitivity. Indeed, by 28 days, rats injected with ice slurry had thermal sensitivity equivalent to baseline levels, indicating that the addition of ice slurry reduced pain levels to baseline.

[0138] Example 8: Slurry injection around the sciatic nerve in intact (uninjured) rats Male Sprague-Dawley rats weighing 250-271 g were obtained and subjected to baseline sensory testing. Thermal withdrawal latencies of the hind paws were obtained. The rats were then anesthetized with inhaled isoflurane and oxygen, and their left thighs were shaved and washed. A slurry of the following composition, shown in Table 6, was then injected into the anatomic pocket containing the left sciatic nerve. [Table 6]

[0139] All rats tolerated the procedure well, and no adverse effects were observed at the injection site during follow-up. At 7, 14, and 25 days after slurry injection, rats were subsequently subjected to sensory testing (Figure 18). Compared to baseline, heat withdrawal latencies increased in the slurry-injected hind paw at follow-up 7, 14, and 25 days after slurry injection. Increased heat latency reflects increased tolerance to heat-induced pain and is an indicator of analgesia in the left hind paw. The difference in heat withdrawal latency between the left (slurry-injected) and right (uninjected) hind paws is shown in Figure 19. The left hind paw (receiving the slurry injection) had increased heat withdrawal latency, while the right remained relatively constant (unchanged).

[0140] From the above description, it will be apparent that variations and modifications may be made to the invention described herein to adapt it to various uses and conditions. Such embodiments are also within the scope of the following claims. Reference to a list of elements in a definition of a variable herein includes definition of the variable as any single element or combination (or subcombination) of the listed elements. Reference to an embodiment herein includes that embodiment as any single embodiment or in combination with any other embodiment or portion thereof. literature All patents, patent applications, and publications mentioned in this specification are herein incorporated by reference to the same extent as if each individual patent and publication was specifically and individually indicated to be incorporated by reference. Those incorporated by reference include, but are not limited to, the following: 1.Lenz H, Goertz W, Preussler H. The freezing threshold of the peripheral motor nerve: an electrophysiological and light-microscopical study on the sciatic nerve of the rabbit. Cryobiology 1975;12:486-96. 2.Barnard D.The effects of extreme cold on sensory nerves.Ann R Coll Surg Engl 1980;62:180-7. 3. Kauffeld M, Wang MJ, Goldstein V, Kasza KE. Ice Slurry Applications. Int J Refrig 2010;33:1491-505. 4.Shikanov S,Wille M,Large M,et al.Microparticulate ice slurry for renal hypothermia:laparoscopic partial nephrectomy in a porcine model.Urology 2010;76:1012-6. 5.Vanden Hoek TL,Kasza KE,Beiser DG,et al.Induced hypothermia by central venous infusion:saline ice slurry versus chilled saline.Crit Care Med 2004;32:S425-31. 6.Garbay B,Heape AM,Sargueil F,Cassagne C.Myelin synthesis in the peripheral nervous system.Prog Neurobiol 2000;61:267-304. 7.Halkier-Sorensen,L.and K.Thestrup-Pedersen,The relevance of low skin temperature inhibiting histamine-induced itch to the location of contact urticarial symptoms in the fish processing industry.Contact dermatitis,1989.21(3):p.179-83. 8.Fruhstorfer,H.,M.Hermanns,and L.Latzke,The effects of thermal stimulation on clinical and experimental itch.Pain,1986.24(2):p.259-69. 9.Pradel,W.,et al.,Cryosurgical treatment of genuine trigeminal neuralgia.Br J Oral Maxillofac Surg,2002.40(3):p.244-7. 10.Calandria,L.,Cryoanalgesia for post-herpetic neuralgia:a new treatment.Int J Dermatol.2011.50(6):p.746-50. 11.Hargreaves K,Dubner R,Brown F,Flores C,Joris J(1988).A new and sensitive method for measuring thermal nociception in cutaneous hyperalgesia.Pain 32:77-88. 12.Mitchell J.Degeneration of Non-myelinated Axons in the Rat Sciatic Nerve Following Lysolecithin Injection.Acta Neuropathol(Berl)(1982)56:187-193.

Claims

1. 1. A method of providing reversible inhibition of one or more peripheral nerves to a subject in need thereof, comprising administering a biocompatible ice slurry to the peripheral nerves in the subject for a duration sufficient to inhibit the peripheral nerves, wherein said inhibition is reversible.

2. The method of claim 1 , wherein the biocompatible ice slurry comprises ice particles and a lactated Ringer's solution, an electrolyte solution, or a lactated electrolyte solution.

3. The method of claim 2 , wherein the biocompatible ice slurry further comprises hetastarch or dextrose.

4. The method of claim 2 , wherein the biocompatible ice slurry further comprises about 0.1% to about 20% glucose.

5. The method of claim 2 , wherein the biocompatible ice slurry further comprises about 0.1% to about 20% glycerol.

6. The method of claim 2, wherein the biocompatible ice slurry further comprises about 0.1% to about 6% hetastarch.

7. The method of claim 1 , wherein the biocompatible ice slurry comprises ice particles and saline.

8. The method of claim 7, wherein the biocompatible ice slurry further comprises about 0.1% to about 20% glycerol.

9. 8. The method of claim 7, wherein the biocompatible ice slurry further comprises about 0.1% to about 20% dextrose.

10. The method of claim 7, wherein the biocompatible ice slurry further comprises about 0.1% to about 5% ethanol.

11. The method of claim 7, wherein the biocompatible ice slurry further comprises about 0.1% to about 10% polyvinyl alcohol.

12. 8. The method of claim 7, wherein the biocompatible ice slurry further comprises at least one sugar, ion, polysaccharide, lipid, oil, lysolecithin, amino acid, caffeine, surfactant, antimetabolite, detergent, or combination thereof.

13. 13. The method of claim 12, wherein the at least one sugar is glucose, mannitol, hetastarch, sucrose, sorbitol, or a combination thereof.

14. 13. The method of claim 12, wherein the at least one ion is calcium, potassium, hydrogen, chloride, magnesium, sodium, lactate, phosphate, zinc, sulfur, nitrate, ammonium, carbonate, hydroxide, iron, barium, salts thereof, or combinations thereof.

15. 13. The method of claim 12, wherein the at least one oil is canola oil, coconut oil, corn oil, cottonseed oil, linseed oil, olive oil, palm oil, peanut oil, safflower oil, soybean oil, sunflower oil, or a combination thereof.

16. The method of claim 12 wherein the surfactant is a detergent.

17. 13. The method of claim 12, wherein the detergent is at least one of deoxycholate, sodium tetradecyl sulfate, polidocanol, deoxycholate, sodium tetradecyl sulfate, polidocanol, polysorbate 20 (polyoxyethylene (20) sorbitan monolaurate), polysorbate 40 (polyoxyethylene (20) sorbitan monopalmitate), polysorbate 60 (polyoxyethylene (20) sorbitan monostearate), polysorbate 80 (polyoxyethylene (20) sorbitan monooleate), sorbitan esters, poloxamer, or combinations thereof.

18. The method of claim 1 , wherein the biocompatible ice slurry comprises a peritoneal dialysis solution.

19. 10. The method of claim 1, wherein the biocompatible ice slurry is applied along the perineural sheath of a peripheral nerve.

20. The method of claim 1, wherein the peripheral nerve is a subcutaneous nerve.

21. The method of claim 1, wherein the peripheral nerve is an autonomic nerve.

22. 22. The method of claim 21, wherein the autonomic nerve is a sympathetic nerve, a parasympathetic nerve, or an enteric nerve.

23. 22. The method of claim 21, wherein the peripheral nerve is a somatic nerve.

24. 2. The method of claim 1, wherein the somatic nerve is a sensory nerve, a motor nerve, a cranial nerve, or a spinal nerve.

25. 10. The method of claim 1, wherein the biocompatible ice slurry cools the nerve to about 5°C to about -40°C.

26. The method of claim 1, wherein the biocompatible ice slurry has a first equilibrium temperature of about 4°C to about -30°C.

27. The method of claim 1, wherein the biocompatible ice slurry has a second equilibrium temperature of about 2°C to about -30°C.

28. The method of claim 2, wherein the ice particles are spherical or round with a diameter of about 1 mm to about 0.01 mm.

29. 10. The method of claim 1, wherein the biocompatible ice slurry further comprises a drug selected from the group consisting of a vasoconstrictor, a corticosteroid, a nonsteroidal anti-inflammatory drug (NSAID), an anesthetic, a glucocorticoid, a lipoxygenase inhibitor, and combinations thereof.

30. 30. The method of claim 29, wherein the vasoconstrictor is epinephrine or norepinephrine.

31. 30. The method of claim 29, wherein the anesthetic is selected from the group consisting of lidocaine, bupivacaine, prilocaine, tetracaine, procaine, mepivicaine, etidocaine, QX-314, and combinations thereof.

32. 10. The method of claim 1, wherein a biocompatible ice slurry is injected.

33. 33. The method of claim 32, wherein the biocompatible ice slurry is administered to a peripheral nerve of a subject by injection into or around one or more nerves selected from the group consisting of subcutaneous nerve, trigeminal nerve, ilioinguinal nerve, intercostal nerve, interscalene nerve, intercostal nerve, supraclavicular nerve, inclavian nerve, axillary nerve, paraspinal nerve, transversus abdominis nerve, genitofemoral nerve, lumbar plexus, femoral nerve, pudendal nerve, celiac plexus, and sciatic nerve.

34. 10. The method of claim 1, wherein the biocompatible ice slurry is applied to the peripheral nerve of the subject by tumescent pumping of the slurry.

35. 10. The method of claim 1, further comprising applying pressure to reduce blood flow at the injection site.

36. The method of claim 1 further comprising monitoring the biocompatible ice slurry by ultrasound or imaging.

37. 10. The method of claim 1, wherein the inhibition disappears after a period of about 5 months or less.

38. 10. The method of claim 1, wherein the subject in need of treatment is suffering from a disorder selected from the group consisting of neuropathic pain, diabetic neuropathy pain, trigeminal neuralgia, post-herpetic neuralgia, phantom limb pain, cancer-related itch or pain, burn itch or pain, lichen sclerosus et atrophicus, scalp itch, paresthesia back pain, atopic dermatitis, eczema, psoriasis, lichen planus, vulvar itch, vrvodynia, lichen simplex chronicus, prurigo nodularis, sensory-mediated itch, peripheral neuropathy, peripheral nerve injury, post-thoracotomy pain, incision pain, chest pain, coccygodynia, lower back pain, superficial scarring, neuroma, acute post-operative pain, lumbar facet joint syndrome, skin pain disorders, and urinary incontinence.

39. 39. The method of claim 38, wherein the cutaneous pain disorder is selected from the group consisting of reflex sympathetic dystrophy (RSD), phantom limb pain, neuroma, post-herpetic neuralgia, tension headache, occipital neuralgia, and vrvodynia.

40. 10. The method of claim 1, wherein the subject in need of treatment is suffering from a movement disorder selected from the group consisting of hemifacial spasm, bladder spasm, and laryngospasm.

41. 10. The method of claim 1, wherein the subject in need of treatment is suffering from hyperhidrosis disorder.

42. 10. The method of claim 1, wherein the tissue containing the peripheral nerve is cooled externally before, during, or after application of the biocompatible ice slurry.

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