Search

US-20260124459-A1 - SYSTEM AND METHOD FOR TRANSCRANIAL CURRENT LOOP BRAIN STIMULATION

US20260124459A1US 20260124459 A1US20260124459 A1US 20260124459A1US-20260124459-A1

Abstract

A method and device is described, which provides electrical stimulation to the brain of a person, where the device comprises an external portion and at least one implantable portion. The external portion provides the energy source for stimulation to the implantable portions. The implantable portions provide at least two conductive paths through the skull and use the skull's high impedance to generate a current loop with the focus of stimulation lying in the current path.

Inventors

  • James William Phillips

Assignees

  • EPIC Neuro, Inc.

Dates

Publication Date
20260507
Application Date
20250613

Claims (15)

  1. 1 . (canceled)
  2. 2 . A device for electrical stimulation of a person's brain, the device comprising: a first conductor implantable through the person's skull at first location and having a subcutaneous portion disposed over the skull and a subcranial portion which at least partially penetrates the skull to electrically couple with the brain; a second conductor implantable through the person's skull at a second location and having a subcutaneous portion disposed over the skull and a subcranial portion which at least partially penetrates the skull to electrically couple with the brain; an energy source connected to circuitry configured to deliver an alternating current to one of the first and second conductors, wherein the first and second conductors provide a conductive path through the skull in the first and second locations and the skull's high impedance completes a current loop which allows current to flow interior and exterior to the skull and through at least one stimulation target in the person's brain.
  3. 3 . The device of claim 2 , wherein the energy source is a battery.
  4. 4 . The device of claim 2 , wherein the circuitry comprises a pulse generator coupled to at least one of the first or second conductors, wherein the pulse generator is configured to transfer energy through conduction.
  5. 5 . The device of claim 2 , wherein the circuitry operates at a frequency between 1 Hz and 20 Hz.
  6. 6 . The device of claim 2 , wherein the circuitry operates at a frequency between 20 Hz and 100 Hz.
  7. 7 . The device of claim 2 , wherein the circuitry operates at a frequency between 100 Hz and 500 Hz.
  8. 8 . The device of claim 2 , wherein the circuitry operates at a frequency between 500 Hz and 5000 Hz.
  9. 9 . The device of claim 2 , wherein the circuitry operates at a frequency greater than 5000 Hz.
  10. 10 . The device of claim 2 , further including a resistive barrier surrounding the first conductor and configured to fill the first burr hole such that electric current is not allowed to shunt between the subcranial portion and the external portion of the first conductor when current flows between the two first and second conductors.
  11. 11 . The device of claim 2 , wherein the first location comprise a first burr hole and the second location comprises a second burr hole, wherein one of the first or second conductors comprises a conductive fluid configured to fill one of the first or second burr holes.
  12. 12 . The device of claim 2 , further comprising a conductive wire that connects the subcutaneous portions of the first and second conductors together.
  13. 13 . The device of claim 2 , wherein the circuitry is configured to limit a maximum current delivered to the person.
  14. 14 . The device of claim 1 , wherein one or both of the first or second conductors are configured to record an EEG of the person's brain.
  15. 15 . The device of claim 14 , wherein the first or second conductors are configured to control energy delivery based upon the presence or absence of abnormalities in the recorded EEG.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a continuation of U.S. patent application Ser. No. 18/351,338, filed Jul. 12, 2023, which is a continuation of U.S. patent application Ser. No. 17/009,635, filed Sep. 1, 2020, now U.S. Pat. No. 11,738,203, which is a continuation of U.S. patent application Ser. No. 15/856,764, filed Dec. 28, 2017, now U.S. Pat. No. 10,780,286, which is a continuation of U.S. patent application Ser. No. 14/595,118, filed Jan. 12, 2015, now U.S. U.S. Pat. No. 9,872,996, which claims the benefit of provisional application 61/926,206 filed on Jan. 10, 2014, the full disclosure of which is incorporated herein by reference. BACKGROUND OF THE INVENTION Electric brain stimulation has been shown to be as potentially effective treatment for a number of brain disorders, including epilepsy, migraine, fibromyalgia, major depression, stroke rehabilitation, and Parkinson's disease, and is also used in electrocorticography and Cortical Stimulation Mapping (CSM). In epilepsy, the generally accepted treatment method involves locating the epileptic focus in the brain, which is found using EEG analysis of epileptiform discharges and resultant spike or seizure voltage fields at the scalp. The temporal lobe is often the location of epileptogenesis, though the position and orientation may vary between individuals. In treating major depression, the target is often the left dorsolateral prefrontal cortex. In treating migraine, the visual cortex or motor cortexes are generally targeted, as well as the occipital nerves. In stroke recovery for reduced limb movement, the area of the motor cortex associated with the limb is the usual target. Once the target site is located, electrical stimulation is applied to provide therapy for the specific indication. Electric brain stimulation may be accomplished by several means. Repetitive Transcranial Magnetic Stimulation (TMS) is a noninvasive technique that uses a coil to deliver a series of high energy magnetic pulses to the brain, thereby inducing current to flow in the cortex underneath the coil. rTMS has been shown to be effective in the treatment of major depression, and other mental disorders. However, it is not easily directed to a particular location, and involves a large, expensive device to generate the high current pulse to the coil. rTMS is not portable and requires a treatment administrator to deliver therapy to the patient. Transcranial Direct Current Stimulation (tDCS) uses electrodes on the outside of the head to deliver small amounts of current to the brain. tDCS was originally used for stroke recovery, and has shown promise in the treatment of some mental disorders and for cognitive improvement. Electrodes are located near the region of interest for stimulation. The vast majority of current is shunted between the electrodes since the skull is a very effective electrical insulator. However, a portion of the current does result in intracerebral current flow, which may increase or decrease neuronal excitability and alter brain function. The exact method of action is unclear. tDCS current strength is limited due to the excitability of nerves in the scalp, which can cause discomfort to the patient if the current is set too high. Vagus nerve stimulation involves electrically stimulating the vagus nerve in the neck of the patient. This can be done either using electrodes on the skin, which may involve painful sensation of the patient, or surgically implanting electrodes near the vagus nerve, generally with a power source implanted elsewhere in the body. This involves a significant surgical procedure and has shown efficacy in treatment of epilepsy and depression. Deep brain stimulation (DBS) uses electrodes implanted and placed bilaterally into the basal ganglia, cerebellum, anterior principal nucleus, the centromedian nucleus, caudate nucleus, thalamic, or subthalamic region. Stimulation may also be delivered subcortically. Stimulus trains are delivered for treatment of a number of disorders, including epilepsy, Parkinson's disease, and major depression. DBS is generally a very invasive procedure, requiring a long lead that penetrates the skull with multiple electrodes near the tip. The procedure is considered major surgery and is not generally used unless other methods have been exhausted. Direct cortical stimulation (DCS) is similar to DBS, except that the lead lies on the surface of the cortex, either subdural or epidural. The location of the electrodes is generally near the seizure foci. The electrodes are secured in place using sutures. This technique often involves removing a portion of the skull to gain access to the cortical surface, and possibly to make room for the power source. DCS has been shown to have efficacy in treatment of epilepsy and neuropathic pain. It is possible to perform electrical stimulation of the brain utilizing a current loop through a conductive path involving probes that penetrate the skull at two or mo