DEVICES FOR THE TREATMENT OF TINNITUS WITH ELECTRIC STIMULATION

Description

BACKGROUND 1. Technical Field

[0001] This document relates to devices for treating tinnitus. For example, this document relates to implantable electrodes and stimulation devices for delivering electrical stimulation to the otic capsule, cochlear region, vestibular region (e.g., vestibule or semicircular canals), the vestibulocochlear nerve, or the brainstem to treat tinnitus. An electrode for delivering electrical stimulation is configured to be placed intraosseously, within the bone of the cochlea, including the promontory.2. Background Information

[0002] Subjective tonal tinnitus (i.e., ringing in the ear) is the phantom perception of sound when no external generating stimulus is present. Tinnitus may be unilateral, bilateral or non-localizing, and may present intermittently or continuously.

[0003] Subjective tonal tinnitus affects approximately a fourth of the US population and is a major source of disability affecting many domains of life. For some, tinnitus is merely a fleeting annoyance; however for many individuals, tinnitus may cause audiological, neurological or cognitive impairment resulting in poor attention, increased distractibility, anxiety, depression, and even suicide. Tinnitus remains the number one disability experienced by U.S. veterans. In 2011 alone, more than 10 percent of all veteran disability claims were due to tinnitus, making it a top research priority of the U.S. Department of Defense and the Veterans Health Administration.

[0004] Despite substantial clinical research in humans and study of animal models, the exact mechanism(s) behind tinnitus remain largely unknown. It is currently held that tinnitus likely reflects inadequate reorganization within the central nervous system following a peripheral auditory system injury. The theory of cochlear deafferentation as a cause for tinnitus parallels phantom limb pain, where cortical maladaptation develops in response to loss of sensory input.

[0005] WO 2015 / 085135 Al describes an electrode lead with an integrated attachment mechanism for use with a cochlear implant system.

[0006] WO 2010 / 120979 Al describes an electrode apparatus for neurostimulation implants.

[0007] WO 2010 / 028152 A2 describes systems for stimulation of the cochlea that mimic or replace the spontaneous background neural activity of the cochlea.

[0008] Currently, there are no FDA approved pharmacological therapies or surgical devices available for the treatment of tinnitus. Current treatment methods largely focus on counseling, cognitive behavioral therapy, masking, and sound therapy. Such strategies may help render tinnitus more tolerable, but such strategies do not abolish the symptom or reverse the underlying pathophysiological process.SUMMARY

[0009] The present invention is defined by independent claim 1. The dependent claims depict additional embodiments of the invention.

[0010] This document provides devices for treating tinnitus. For example, this document provides implantable electrodes and stimulation devices for delivering electrical stimulation to the cochlea region, such as on the surface of the cochlear bone including the promontory, or endosteally and / or intraosseously within the cochlear bone, to treat tinnitus.

[0011] In one aspect an electrode device for delivering electrical pulse stimuli to a patient's cochlear region includes: a lead including a single elongate insulated electrical conductor; a single electrode disposed at a distal end of the lead and in electrical communication with the insulated electrical conductor, where the electrode is configured to be intraosseously placed within a hole created in target tissue to deliver the electrical pulse stimuli to the patient's cochlear region; and an anchor element disposed adjacent to the electrode, where: i) the electrode is an electrode screw including an electrode core, the anchor element including a fenestration, wherein the electrode screw is configured to be passed through the fenestration in the anchor element into the hole created in the target tissue and to anchor the electrode device intraosseously to the target tissue, and wherein the electrode core is configured to deliver the electrical pulse stimuli intraosseously to the target tissue with which it makes contact; or ii) the electrode is an electrode lug including an electrode core, wherein the electrode lug is configured to be placed in the hole created in the target tissue, and wherein the electrode core is configured to deliver the electrical pulse stimuli intraosseously to the target tissue with which it makes contact.

[0012] In some embodiments, the electrode device further includes an implantable stimulator device in electrical communication with the lead and configured to generate the electrical pulse stimuli.

[0013] In some embodiments, the implantable stimulator device includes a magnet for aligning with an external device.

[0014] In some embodiments, the implantable stimulator device includes a receiver coil configured to wirelessly communicate through the patient's scalp with an external device.

[0015] In some embodiments, the electrode is an electrode screw that has a length selected to be suitable for the patient.

[0016] In some embodiments, the electrode is an electrode lug that has a length that is selected to be suitable for the patient.

[0017] In some embodiments, the electrode is an electrode lug that is configured to be fixed in the hole using an adhesive.

[0018] The subject matter described in this document can be implemented to realize one or more of the following advantages. Cochlear surface electrode(s), intraosseous electrode(s), endosteal electrode(s), subendosteal electrode(s) or short intracochlear electrode(s) (or a combination thereof), connected to a receiver / stimulator electronics package, can provide an effectual long-term treatment of tinnitus in many patients. Some embodiments described herein include a grid array, linear array, paired array or single stimulation electrode(s). A multi-electrode array can advantageously provide broad spatial coverage of the cochlear region. Additionally, various electrode pairs or groupings within the multi-electrode array can be activated (while others are deactivated) to provide a customized stimulation treatment that is effective for a particular patient's needs. In some embodiments, one or more electrodes can be placed intraosseously (e.g., in the cochlear bone). Such intraosseous placement can provide the advantage of delivering electrical stimulation in closer proximity to the cochlea (as compared to promontory surface placement). Other devices provided herein can advantageously deliver electrical stimulation to the vestibulocochlear nerve to treat tinnitus.

[0019] 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 pertains. Although methods and materials similar or equivalent to those described herein can be used to practice the invention, suitable methods and materials are described herein. In case of conflict between the present specification and a reference mentioned herein, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.

[0020] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description herein. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 is an illustration of an example implantable receiver / stimulator device in accordance with some examples. FIG. 2 depicts an example electrode device in accordance with some examples. FIG. 3 depicts another example electrode device examples. FIG. 4 depicts another example electrode device in accordance with some examples. FIG. 5 depicts an example drilling tool in accordance with some examples. FIG. 6 depicts another example electrode device in accordance with some embodiments provided herein. FIG. 7 depicts another example electrode device in accordance with some embodiments provided herein. FIG. 8 depicts another example electrode device in accordance with some examples. FIG. 9 depicts another example electrode device in accordance with some examples. FIG. 10 depicts another example electrode device in accordance with some examples. FIG. 11 depicts another example electrode device in accordance with some examples. FIG. 12 depicts the electrode device of FIG. 11 in a second configuration. FIG. 13 depicts another example electrode device in accordance with some examples.

[0022] Like reference numbers represent corresponding parts throughout.DETAILED DESCRIPTION

[0023] This document provides devices for treating tinnitus and methods of using the devices to treat tinnitus. For example, this document provides implantable electrodes and stimulation devices for delivering electrical stimulation to the cochlear region to treat tinnitus. Cochlear surface electrode(s), endosteal electrode(s), subendosteal electrode(s), intraosseous electrode(s), or short intracochlear electrode(s) (or a combination thereof), connected to existing but modified cochlear implant receiver / stimulator technology, can provide a successful model for long-term treatment of tinnitus in a large number of patients. In some cases, patients can simply turn on the tinnitus implant when experiencing troublesome tinnitus and gain instant relief. With increasing use, it is likely many patients will enjoy lasting tinnitus suppression, hours and even days after the device is turned off (i.e., residual inhibition).

[0024] Using surface, endosteal, subendosteal, intraosseous, or short intracochlear electrodes (or a combination thereof), customized monopolar or bipolar stimulation can be performed to target specific patterns and frequencies of tinnitus. A surface grid of electrodes has the advantage of improved cochlear coverage. Endosteal and / or intraosseous electrodes in the promontory can place the electrical stimulation in closer proximity to the modiolus (the conical central axis of the cochlea) without risking sensorineural hearing loss. A short intracochlear electrode offers a direct method of cochlear stimulation. Devices and methods for each of the aforementioned treatment modalities are described further herein.

[0025] Referring to FIG. 1, an implantable receiver / stimulator device 100 can be used in conjunction with the various types of electrode devices provided herein. Receiver / stimulator device 100 can be functionally akin to an implantable receiver / stimulator device used for cochlear implant electrical stimulation. Accordingly, receiver / stimulator device 100 is implanted under the post-auricular scalp and the lead wire(s) can travel through the mastoid and facial recess to the target electrode location(s). In some cases, for treating tinnitus, the target electrode location may be the bony cochlea, otic capsule, and / or promontory (e.g., endosteally and / or intraosseously). In some cases, for treating balance disorders, the target electrode location may be the bony labyrinth (e.g., surface, intraosseous, or intra-labyrinthine) including the semicircular canals and vestibule. For example, surface, intraosseous, and intra-labyrinthine electrodes can be placed in the region of the semicircular canals and vestibule to stimulate labyrinthine function. Electrical stimulation of this organ may be used to rehabilitate vestibular hypofunction or treat ongoing or recurrent vestibular diseases, such as Meniere's disease.

[0026] An external device (not shown) can be used to wirelessly communicate (through the patient's scalp) with the implanted receiver / stimulator device 100. Such an external device can function to activate, program, power, control, and / or otherwise interact with receiver / stimulator device 100. In some cases, receiver / stimulator device 100 can be programmed according to pulse width, current amplitude, stimulus rate, stimulation mode, and the like.

[0027] In the depicted receiver / stimulator device 100, the receiver / stimulator device 100 includes a magnet 110, a receiver coil 120, a stimulator 130, a ground lead 140, a lead wire 150, and one or more electrodes 160. Magnet 110 can be used to magnetically couple and align receiver / stimulator device 100 with an external device. Receiver coil 120 is used to wirelessly communicate with an external device. Stimulator 130 controls the operations of receiver / stimulator device 100 and is the source of electrical stimuli. Lead wire 150 conducts the electrical stimuli to electrode 160.

[0028] Electrode 160 delivers the electrical stimuli to tissue of the patient. It should be understood that electrode 160 is representative of any of the embodiments of electrodes described herein. That is, any electrode embodiment described herein can be used for electrode 160. Ground lead 140 provides a path for the electrical stimuli to flow after the stimuli has been passed from electrode 160 to the tissue. It should be understood that the depicted receiver / stimulator device 100 provides just one nonlimiting example of the types of implantable receiver / stimulator devices that can be used in conjunction with the various types of electrode devices provided herein.

[0029] In some cases, prior to permanent electrode 160 placement, test electrodes can be placed on the patient's cochlea region via a transcanal tympanotomy using local anesthetic with the patient awake. An instrument set can be used to apply varying patterns of electrical stimulation, and the patient can convey which pattern resulted in greatest tinnitus reduction. Individual instruments will vary based on the number of electrodes and the distance between electrodes. Additionally, "pitch-masking" (also referred to as frequency matching) and CT imaging may assist in determining optimal electrode 160 positioning.

[0030] Referring to FIG. 2, an example cochlear surface electrode device 200 can be used to deliver electrical pulses in a patient's cochlear region to treat tinnitus. Electrode device 200 includes a lead 250, an electrode 260, and an anchor element 270. Lead 250 is an insulated conductor that puts electrode 260 in electrical communication with a source of electrical pulse stimuli (e.g., receiver / stimulator device 100). Electrode 260 is an uninsulated conductive element that, when placed in contact with tissue, can deliver electrical stimuli to the tissue. Surface electrode device 200 is an example of a monopolar electrode device that can be used to treat tinnitus. Anchor element 270 is attached to lead 250 and / or electrode 260.

[0031] In some cases, cochlear surface electrode device 200 is implanted such that electrode 260 is in contact with the patient's cochlear bone (e.g., promontory). Anchor element 270 can be used to couple electrode device 200 to the patient's tissue at the target site, and to provide migration resistance. In some cases, an adhesive (e.g., bone cement and the like) can be used to tack anchor element 270 to tissue (e.g., bone, cartilage, or soft tissue). In some cases, a mechanical anchor such as a screw or barbed member can be used to couple anchor element 270 to tissue. In the depicted example cochlear surface electrode device 200, anchor element 270 defines a fenestration that can receive adhesive and / or a mechanical anchor.

[0032] Referring to FIG. 3, another example cochlear surface electrode device 300 can be used to deliver electrical pulses in a patient's cochlear region to treat tinnitus. Electrode device 300 includes a lead 350, an electrode pair 360, and an anchor element 370. In some examples, surface electrode device 300 is an example of a bipolar electrode device that can be used to treat tinnitus. That is, electrode pair 360 includes two electrodes. In some cases, one of the two electrodes functions as a cathode and the other functions as an anode. Hence, in some cases electrode pair 360, when placed in contact with tissue, can deliver electrical stimuli to the tissue without the need for a separate ground lead (e.g., ground lead 140 as described above in reference to FIG. 1). In some cases, both electrodes of electrode pair 360 are used as a cathode and a separate ground lead is used.

[0033] Similar to anchor element 270 described above, anchor element 370 defines a fenestration or other type of attachment feature that can receive adhesive and / or a mechanical anchor.

[0034] Referring to FIG. 4, another example cochlear surface electrode device 400 can be used to deliver electrical pulses in a patient's cochlear region to treat tinnitus. Electrode device 400 includes a lead 450, an electrode array 460, and an anchor element 470. Electrode array 460 can include any number of electrodes arranged in any configuration. Electrode array 460 can comprise a compliant material that can conform to the topography of the patient's tissue (including bone tissue such as the promontory). In some cases, a heat source (e.g., warm water) can be applied to electrode array 460 at the time of placement to increase the compliance of electrode array 460.

[0035] Surface electrode device 400 is an example of a grid electrode device that can be used to treat tinnitus. That is, grid electrode array 460 includes two or more electrode pairs. In some cases, one electrode of each of the electrode pair(s) functions as a cathode and the other functions as an anode.

[0036] In some cases, individual electrode pairs of the two or more electrode pairs of electrode array 460 can be activated individually. That is, while some electrode pairs are utilized to deliver electrical stimuli, other electrode pairs can be selectively deactivated. In that manner, particular areas or zones of the patient's target tissue (e.g., cochlear region) can receive pulse stimuli, while other areas or zones do not. This functionality can be used to customize the treatment to best suit a particular patient. For example, various electrode pairs (or combinations of electrode pairs) can be experimentally activated to determine which electrode pairs provide the patient with the most relief from tinnitus symptoms.

[0037] Referring to FIGS. 5-7, in some cases one or more electrodes can be placed endosteally and / or intraosseously to treat tinnitus. For example, in some cases one or more electrodes of the present disclosure can be placed intraosseously in the bone tissue of the otic capsule (e.g., without penetrating through the endostium of the cochlea or cochlear lumen). Endosteal and / or intraosseous electrodes can place the electrical stimulation in close proximity to the modiolus (the conical central axis of the cochlea) without risking sensorineural hearing loss. The devices depicted in FIGS. 5-7 can be used for such an implementation.

[0038] FIG. 5 depicts a drill device 500 that can be used with a rotary driver instrument. Drill device 500 includes a shank 510, a depth limiter 520, and a working portion 530. Working portion 530 includes cutting edges that can remove tissue such as bone tissue to create a hole (e.g., such as a blind hole or through hole) in the target tissue layer (e.g., anywhere on the promontory including near or at the oval window, near or at the round window, etc.). The maximum depth of the hole can be controlled by depth limiter 520 (e.g., a flange portion). Depth limiter 520 can advantageously prevent the hole created from being a through-hole (i.e., from penetrating completely through the opposite side of the tissue layer, or into the cochlear lumen).

[0039] Patient populations naturally have differing anatomical features (such as promontory thicknesses and the like). Accordingly, a variety of differently sized drill devices 500 can be available so as to suit an individual patient's anatomy. For example, a set of drill devices 500 with depth limiter 520 at differing positions can be provided so that a particular drill device 500 can be used for a particular patient to make a hole of the proper depth for the particular patient's anatomy.

[0040] In most cases, the most suitable drill device 500 and / or electrode device for a particular patient can be determined in advance of the implant procedure. For example, in some cases a patient can undergo a pre-operative imaging procedure, such as a computerized tomography (CT) scan, to determine the patient's anatomical features such as, but not limited to, promontory thickness. Based on the inventor's investigations, minimal promontory thickness is about 0.4-0.5 mm and maximal promontory thickness is about 2.0-2.2 mm. Thus, a desirable hole depth (and intraosseous electrode length) can be about 0.3 mm to about 0.7 mm, or about 0.5 mm to about 0.9 mm, or about 0.7 mm to about 1.1 mm, or about 0.9 mm to about 1.3 mm, or about 1.1 mm to about 1.5 mm, or about 1.3 mm to about 1.7 mm, or about 1.5 mm to about 1.9 mm, or about 1.7 mm to about 2.1 mm, and / or anywhere within such ranges. In some cases, a set of multiple drill devices 500 will be made available in 0.2 mm depth increments, or 0.1 mm depth increments.

[0041] Referring to FIG. 6, when a hole (e.g., a blind hole that does not completely break through the bone) has been created using drill device 500, electrode device 600 can be attached to the target tissue using the hole. Electrode device 600 includes a lead 650, an electrode screw 660, and an anchor element 670. To install electrode device 600, electrode screw 660 is passed through a fenestration in anchor element 670 and into the hole created using drill device 500.

[0042] Electrode screw 660 can serve multiple purposes. First, electrode screw 660 can anchor electrode device 600 endosteally and / or intraosseously to the target tissue (e.g., bony cochlea or labyrinth). Secondly, electrode screw 660 can include an electrode core that can deliver electrical pulse stimuli to the tissue with which it makes contact. A set of electrode screws 660 having differing lengths can be available so that a particular electrode screw 660 having a suitable length can be selected for a particular patient. Hence, in some cases, electrode device 600 can deliver electrical stimuli endosteally and / or intraosseously (e.g., to the promontory) to treat tinnitus. In some cases, an adhesive such as bone cement can be used in conjunction with electrode screw 660.

[0043] Referring to FIG. 7, when a hole has been created using drill device 500, electrode device 700 can be attached to the target tissue within the hole. Electrode device 700 includes a lead 750 and an electrode lug 760. To install electrode device 700, electrode lug 760 is placed into the hole created using drill device 500. In some cases, an adhesive (e.g., bone cement) can be used to fixate electrode lug 760 in the blind hole. Electrode lug 760 can include an electrode core that can deliver electrical pulse stimuli to the tissue with which it makes contact. A set of electrode devices 700 having differing lengths of electrode lugs 760 can be available so that a particular electrode device 700 having a suitable length of electrode lug 760 can be selected for a particular patient. Hence, in some cases, electrode device 700 can deliver electrical stimuli endosteally and / or intraosseously to a cochlear bone (e.g., to the promontory) to treat tinnitus.

[0044] Referring to FIG. 8, another example electrode device 800 can be used to deliver electrical pulses in a patient's cochlear region to treat tinnitus. Electrode device 800 includes a lead 850, one or more electrodes 860, and an anchor element 870.

[0045] Electrode device 800 is configured for delivering electrical stimuli shallowly within the patient's cochlea lumen. That is, in some cases a distal end portion 880 of electrode device 800 can be inserted within the patient's cochlea (e.g., through the round window or oval window). In such a case, anchor element 870 can act as a soft, flexible barb member to retain distal end portion 880 shallowly within the patient's cochlea. In that arrangement, electrode(s) 860 can thereafter deliver electrical pulses to the patient's cochlea to treat tinnitus.

[0046] Referring to FIGS. 9 and 10, in some cases devices having one or more electrodes can deliver electrical stimulation to the vestibulocochlear nerve to treat tinnitus. The devices depicted in FIGS. 9 and 10 can be used for such an implementation.

[0047] Referring to FIG. 9, another example electrode device 900 can be used to deliver electrical pulses in a patient's vestibulocochlear nerve region (e.g., vestibulocochlear nerve or cochlear nerve or vestibular nerve) to treat tinnitus. Electrode device 900 includes a lead 950 and an electrode array 960 disposed on a flexible band 970. Electrode array 960 can include any number of electrodes arranged in any configuration. Electrode array 960 can be monopolar or bipolar.

[0048] Flexible band 970 can comprise a compliant material that can be wrapped around the patient's vestibulocochlear nerve. In some cases, a heat source (e.g., warm water) can be applied to flexible band 970 at the time of placement to increase the compliance of flexible band 970. In some cases, flexible band 970 is malleable so that it retains its shape after being wrapped around the patient's vestibulocochlear nerve. Thereafter, electrical pulse stimuli can be delivered to the patient's vestibulocochlear nerve via electrode array 960.

[0049] Referring to FIG. 10, another example electrode device 1000 can be used to deliver electrical pulses in a patient's vestibulocochlear nerve region to treat tinnitus. Electrode device 1000 includes a lead 1050 and an electrode hook 1060. Electrode hook 1060 can include one or more than one electrodes arranged in any configuration. Electrode hook 1060 can be monopolar or bipolar.

[0050] In some cases, electrode hook 1060 can comprise a shape-memory material that tends to seek a curved or spiral shape such that electrode hook 1060 will be wrapped around the patient's vestibulocochlear nerve. In some cases, a heat source (e.g., electrical current, a laser, and the like) can be applied to electrode hook 1060 at the time of placement to activate the shape-memory property of electrode hook 1060. Thereafter, electrode hook 1060 will tent to retain its shape after being wrapped around the patient's vestibulocochlear nerve. Electrical pulse stimuli can then be delivered to the patient's vestibulocochlear nerve via electrode hook 1060.

[0051] Referring to FIGS. 11-13, in some cases devices having one or more electrodes can deliver electrical stimulation within the vestibulocochlear nerve to treat tinnitus. The devices depicted in FIGS. 11-13 can be used for such an implementation. That is, distal end portions of the electrode devices can penetrate and remain within the patient's vestibulocochlear nerve to treat tinnitus.

[0052] Referring to FIGS. 11 and 12, another example electrode device 1100 can be used to deliver electrical pulses in a patient's vestibulocochlear nerve region to treat tinnitus. Electrode device 1100 includes a lead 1150, an electrode needle 1160, and an anchor element 1170. Electrode needle 1160 can include one or more than one electrodes arranged in any configuration. Electrode needle 1160 can be monopolar or bipolar.

[0053] Electrode device 1100 includes a distal end portion 1180. Distal end portion 1180 can be inserted within the patient's vestibulocochlear nerve while electrode device 1100 is configured as shown in FIG. 11. Thereafter, anchor element 1170 can be pivoted to the configuration shown in FIG. 12. In that configuration, anchor element 1170 acts as an anchor to provide migration resistance. Electrical pulse stimuli can then be delivered to within the patient's vestibulocochlear nerve via electrode needle 1160.

[0054] Referring to FIG. 13, another example electrode device 1300 can be used to deliver electrical pulses in a patient's vestibulocochlear nerve region to treat tinnitus. Electrode device 1300 includes a lead 1350 and an electrode needle 1360. Electrode needle 1360 can include one or more than one electrodes arranged in any configuration. Electrode needle 1360 can be monopolar or bipolar.

[0055] Electrode device 1300 includes a distal end portion 1380. In some cases, distal end portion 1380 is malleable. Distal end portion 1380 can be inserted within and / or through the patient's vestibulocochlear nerve. Thereafter, a portion of distal end portion 1380 can be bent to wrap distal end portion 1380 around the patient's vestibulocochlear nerve. In that configuration, distal end portion 1380 acts as an anchor to provide migration resistance. Electrical pulse stimuli can then be delivered to within and / or on the patient's vestibulocochlear nerve via electrode needle 1360.

Claims

1. An electrode device (600, 700) for delivering electrical pulse stimuli to a patient's cochlear region, the electrode device comprising: a lead (650, 750) comprising a single elongate insulated electrical conductor; a single electrode disposed at a distal end of the lead (650, 750) and in electrical communication with the insulated electrical conductor, wherein the electrode is configured to be intraosseously placed within a hole created in target tissue to deliver the electrical pulse stimuli to the patient's cochlear region; and an anchor element (670) disposed adjacent to the electrode, characterised in that the electrode is an electrode screw (660) including an electrode core, the anchor element (670) including a fenestration, wherein the electrode screw (660) is configured to be passed through the fenestration in the anchor element into the hole created in the target tissue and to anchor the electrode device (600) intraosseously to the target tissue, and wherein the electrode core is configured to deliver the electrical pulse stimuli intraosseously to the target tissue with which it makes contact.

2. The electrode device (600, 700) of claim 1, further comprising an implantable stimulator device (100) in electrical communication with the lead and configured to generate the electrical pulse stimuli.

3. The electrode device (600, 700) of claim 2, wherein the implantable stimulator device (100) includes a magnet (110) for aligning with an external device.

4. The electrode device (600, 700) of claim 2, wherein the implantable stimulator device (110) comprises a receiver coil (120) configured to wirelessly communicate through the patient's scalp with an external device.

5. The electrode device (600) of claim 1, wherein the electrode screw (660) has a length that is selected to be suitable for the patient.