Vagal nerve stimulation for treating or preventing stroke or transient ischemic attack

Abstract

Devices, systems and methods are disclosed for reducing inflammation associated with an aneurysm in a patient. The methods comprise transmitting impulses of energy non-invasively to selected nerve fibers, particularly those in the vagus nerve. Vagus nerve stimulation is used to modulate the release of neurotransmitters in the brain and to reduce inflammation that may lead to the formation, growth, rupture or hemorrhage of an aneurysm.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of U.S. patent application Ser. No. 16 / 693,088, filed Nov. 22, 2019, which is a divisional of U.S. patent application Ser. No. 13 / 952,859, filed Jul. 29, 2013, which is a Continuation in Part of U.S. patent application Ser. No. 13 / 603,781 filed Sep. 5, 2012; which is a Continuation in Part of U.S. patent application Ser. No. 13 / 222,087 filed Aug. 31, 2011; which is a Continuation in Part of U.S. patent application Ser. No. 13 / 183,765 filed Jul. 15, 2011; which is a: (1) Continuation in Part of U.S. patent application Ser. No. 13 / 183,721 filed Jul. 15, 2011; which claims the benefit of priority to U.S. Provisional Application No. 61 / 488,208 filed May 20, 2011 and U.S. Provisional Application No. 61 / 487,439 filed May 18, 2011; (2) a Continuation in Part of U.S. patent application Ser. No. 13 / 109,250 filed May 17, 2011; which claims the benefit of priority to U.S. Provisional Application No. 61 / 471,405 file...

AI Technical Summary

Benefits of technology

This invention is about a device and method for reducing inflammation associated with an aneurysm in a patient. The device contains a housing with a contact surface for transmitting an electric impulse to a nerve fiber in the patient non-invasively through the outer skin surface. The electric impulse has been found to modify the nerve fiber and reduce inflammation associated with the aneurysm. The device can induce a peak pulse voltage sufficient to produce an electric field in the vicinity of a nerve to cause it to depolarize and reach a threshold for action potential propagation. The stimulator produces an elongated electric field of effect that can be oriented parallel to a long nerve, such as a vagus. The device is designed to avoid substantially stimulating nerves and tissue other than the target nerve to prevent pain.

Problems solved by technology

Stroke also causes a substantial medical burden for those individuals who survive a stroke.

The estimated annual number of TIAs in the U.S. is about 200 to 500 thousand, although the number is difficult to estimate because TIAs may be under-reported, considering that they typically last less than an hour.

In amaurosis fugax, cholesterol from ruptured atherosclerotic plaques in the common or internal carotid artery or other types of emboli transiently occludes flow to the retinal artery, causing a sudden onset of monocular blindness.

However, such imaging may produce a false negative if it is performed too soon, so measurement of the patient's EEG may also be performed as a companion to the imaging, or in lieu of the imaging if CT or MRI imagers are not available.

It is impossible to know whether stroke symptoms are due to ischemia or hemorrhage based on clinical characteristics alone.

The major risk of intravenous rtPA treatment is symptomatic intracranial hemorrhage (sICH).

An older neuroprotective strategy is the use of hyperbaric oxygen, but clinical data concerning its use are inconclusive, and some data imply that the intervention may be harmful.

In these reports, AI et al note that the clinical relevance of such findings is limited because the stimulation methods are invasive.

Although non-invasive stimulation at this location can be effective for treating an inflammatory disorder, such stimulation may raise the risk of stroke.

To summarize the foregoing background information, stroke and transient ischemic attacks cause major medical and public health problems.

Current methods for treating them are only partially successful, either acutely or in the rehabilitative patient.

Although animal experiments suggest that treatment of a stroke in its acute phase using vagus nerve stimulation may be neuroprotective, methods used in those experiments are of limited utility because they are invasive.

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