Skull implanted electrode assembly for brain stimulation

Abstract

A skull-implantable electrode assembly for delivering pulses of electric current to a patient's brain, comprising an electrode housed in an insulated conduit and threaded through an electrically-conductive cannulated skull screw. Details of the exterior construction are discussed, as well as electrode arrangements and methods of treating a medical ailment of a patient.

1 : An implantable electrode assembly comprising:
 an electrically-conductive cannulated skull screw with a head end and a point end, which is configured to transverse a skull of a patient with the point end located at the interior surface of the skull and the head end at the exterior surface of the skull;   an electronics module comprising a casing, wherein the electronics module is electrically connected to the head end of the skull screw and wherein the casing is in direct contact with the head end of the skull screw; and   a conductor housed in an insulated conduit and threaded through the skull screw, said conductor comprising a connection end and an electrode end, with the connection end located at the head end of the skull screw and electrically connected to the electronics module, and the electrode end configured to form an electrical connection with a brain tissue of the patient.   
     
     
         2 : The assembly of  claim 1  wherein the electrode end of the conductor is configured to form at least two electrical connections with different locations of the patient's brain tissue. 
     
     
         3 : The assembly of  claim 2  further comprising a plurality of conductive discs housed within a flexible insulator with 1-20 mm spacing, wherein the electrode end is electrically connected to the conductive discs to form at least two electrical connections with different locations of the patient's brain tissue. 
     
     
         4 : The assembly of  claim 1  wherein the electronics module further comprises a photovoltaic power supply. 
     
     
         5 : The assembly of  claim 1  wherein the electronics module further comprises a battery and a computer chip, wherein an exterior surface of the casing comprises one or more electrical contacts for linking to the battery and/or computer chip. 
     
     
         6 : The assembly of  claim 1  wherein the electronics module further comprises at least one surface electrode configured to form an electrical connection with a scalp of a patient. 
     
     
         7 : The assembly of  claim 1  wherein the insulated conduit is removably attached to the head end of the skull screw by a first key and keyhole mechanism, wherein the insulated conduit comprises a key and the head end of the skull screw comprises a complementary keyhole. 
     
     
         8 : The assembly of  claim 7  wherein the key and keyhole are triangular. 
     
     
         9 : The assembly of  claim 7  wherein the connection end of the conductor is removably attached to the electronics module by a second key and keyhole mechanism. 
     
     
         10 : The assembly of  claim 1  wherein the head end of the skull screw is removably attached to the electronics module by a key and keyhole mechanism. 
     
     
         11 : The assembly of  claim 10  wherein the head end of the skull screw comprises a key and the electronics module comprises a complementary keyhole. 
     
     
         12 : The assembly of  claim 10  wherein the electronics module comprises a key and the head end of the skull screw comprises a complementary keyhole. 
     
     
         13 : The assembly of  claim 12  wherein the electronics module further comprises a projection with an end comprising an electrically-conductive spring-loaded piston, wherein the projection and the electrically-conductive spring-loaded piston are configured to fit into a cavity in the head end of the skull screw and form a locked position with the skull screw and an electrical connection with the connection end of the electrode. 
     
     
         14 : The assembly of  claim 1  wherein the insulated conduit is removably attached to the electronics module by a key and keyhole mechanism, wherein the insulated conduit comprises a key and the electronics module comprises a complementary keyhole. 
     
     
         15 : The assembly of  claim 1  wherein the electronics module further comprises a wireless transceiver configured to receive a wireless signal encoding a program for brain stimulation and configured to send and receive a wireless signal with a portable wireless device. 
     
     
         16 : A method of treating a medical ailment of a patient with the implantable electrode assembly of  claim 1 , the method comprising:
 implanting the implantable electrode assembly into a skull of the patient;   forming an electrical connection with the brain tissue of the patient and the electrode end of the electrode; and   generating pulses of current between the electrode end of the electrode and the skull screw with pulse widths of 10 μs-300 ms, frequencies of 10-200 Hz, and voltages of 0.1-6 V,   wherein the medical ailment is at least one selected from the group consisting of epilepsy, migraine, depression, anxiety, attention deficit disorder, hyperactivity, bipolar disorder, stroke, dementia, schizophrenia, delirium, neurosis, psychosis, Parkinson's disease, alcohol withdrawal, drug withdrawal, dizziness, motion sickness, insomnia, dystonia, chronic pain, obsessive compulsive disorder, Tourette's syndrome, essential tremor, spasticity, trigeminal neuralgia, and headache.   
     
     
         17 : The method of  claim 16 , wherein the electrode end of the electrode is configured to form at least two electrical connections with different locations of the patient's brain tissue, the method further comprising:
 generating pulses of current between the at least two electrical connections with pulse widths of 10 μs-300 ms, frequencies of 10-200 Hz, and voltages of 0.1-6 V.   
     
     
         18 : The method of  claim 16 , further comprising:
 removing the electronics module while leaving the electrode and cannulated skull screw in place; and   attaching a second electronics module.   
     
     
         19 : A method of monitoring a brain activity of a patient with the implantable electrode assembly of  claim 2  wherein the electronics module further comprises an on/off switch, the method comprising:
 implanting the implantable electrode assembly into a skull of the patient and connecting the electrode end with different locations of the patient's brain tissue; and 
 turning on the electronics module with the on/off switch and receiving electric activity between at least two electrical connections in a brain of the patient. 
 
     
     
         20 : The method of  claim 19  wherein the electronics module further comprises a digital storage medium and a wireless transceiver, the method further comprising:
 converting the electric activity into a set of digital data; 
 storing the set of digital data in the digital storage medium; and 
 wirelessly transmitting the set of digital data with the wireless transceiver.