Methods and Systems Employing Intracranial Electrodes for Neurostimulation and/or Electroencephalography

Abstract

Aspects of the invention relate to intracranial electrodes and methods for implanting and using intracranial electrodes. In one particular example, an intracranial electrode includes a shaft having a distal contact surface adapted to electrically contact a surface of a patient's brain, a head associated with the shaft, and threads adapted to fix the electrode with respect to the patient's skull. This electrode may have an adjustable length adapted to change a contact force of the distal contact surface against the surface of the brain by adjusting the length of the electrode.

1 . An intracranial electrode comprising: 
 a shaft including a distal contact surface adapted to electrically contact a surface of a patient's brain;    a head associated with the shaft, the head being sized to be positioned subcutaneously adjacent the patient's skull; and    threads carried by at least one of the head and the shaft, the threads being adapted to fix the electrode with respect to the patient's skull;    the electrode having an adjustable length adapted to change a contact force of the distal contact surface against the surface of the brain by adjusting the length of the electrode.    
     
     
         2 . The intracranial electrode of  claim 1  wherein the shaft is moveable with respect to the head to adjust the length of the electrode.  
     
     
         3 . The intracranial electrode of  claim 1  further comprising a spring adapted to move the shaft with respect to the head to adjust the length of the electrode.  
     
     
         4 . The intracranial electrode of  claim 1  further comprising a resilient elastomer adapted to move the shaft with respect to the head to adjust the length of the electrode.  
     
     
         5 . The intracranial electrode of  claim 1  wherein the shaft and the head include mating threads such that rotation of the shaft relative to the head adjusts the length of the electrode.  
     
     
         6 . The intracranial electrode of  claim 1  further comprising an abutment adapted to selectively engage the shaft, the abutment restricting movement of the shaft with respect to the head when engaged with the shaft and permitting movement of the shaft with respect to the head to adjust the length of the electrode when disengaged from the shaft.  
     
     
         7 . The intracranial electrode of  claim 1  wherein the shaft has a threaded length and a nonthreaded surface and the distal contact surface comprises at least a portion of the nonthreaded surface of the shaft.  
     
     
         8 . The intracranial electrode of  claim 1  wherein at least a portion of the head is adapted to be received in a bore in the patient's skull.  
     
     
         9 . The intracranial electrode of  claim 1  wherein the head includes a threaded member adapted to be received in a bore in the patient's skull and the shaft is adapted to move axially along a length of the threaded member.  
     
     
         10 . The intracranial electrode of  claim 1  wherein the head includes a threaded member adapted to be received in a bore in the patient's skull, the threaded member having internal threads that mate with external threads on the shaft such that rotation of the shaft relative to the head adjusts the length of the electrode.  
     
     
         11 . The intracranial electrode of  claim 1  wherein the shaft is electrically conductive and the head is electrically insulative.  
     
     
         12 . The intracranial electrode of  claim 1  wherein the shaft is electrically conductive and the head includes a length adapted to be received in the patient's skull and electrically insulate the patient's skull from the shaft.  
     
     
         13 . The intracranial electrode of  claim 1  wherein the head is electrically conductive, further comprising a dielectric cap adapted to electrically insulate the patient's scalp from the head.  
     
     
         14 . The intracranial electrode of  claim 1  further comprising a lead electrically coupled to the contact surface and adapted to carry an electrical signal to or from the contact surface.  
     
     
         15 . The intracranial electrode of  claim 1  further comprising a lead electrically coupled to the contact surface and adapted to carry an electrical signal subcutaneously from a pulse system to the contact surface.  
     
     
         16 . The intracranial electrode of  claim 1  further comprising a lead electrically coupled to the contact surface and adapted to be subcutaneously implanted adjacent a skull.  
     
     
         17 . The intracranial electrode of  claim 1  further comprising a lead electrically coupled to the contact surface, the lead being adapted for subcutaneous implantation and to deliver an electrical signal to or from the contact surface.  
     
     
         18 . An intracranial electrode comprising: 
 a shaft including a distal contact surface adapted to electrically contact a surface of a patient's brain;    a head associated with the shaft, the head being sized to be positioned subcutaneously adjacent the patient's skull;    threads carried by at least one of the head and the shaft, the threads being adapted to fix the electrode with respect to the patient's skull; and    adjustment means adapted to adjust a length of the electrode to change a contact force of the distal contact surface against the surface of the brain.    
     
     
         19 . An intracranial electrode, comprising: 
 an electrically conductive member having a blunt contact surface;    a dielectric member having an interior in which the electrically conductive member is received; and    an anchor carried by the electrically conductive member or the dielectric member and adapted to anchor at least one of the electrically conductive member and the dielectric member with respect to a patient's skull adjacent a brain surface such that the contact surface is in electrical contact with the brain surface and the dielectric member electrically insulates the skull from the electrically conductive member.    
     
     
         20 . The intracranial electrode of  claim 19  further comprising a dielectric cap adapted to electrically insulate the patient's scalp from the electrically conductive member.  
     
     
         21 . The intracranial electrode of  claim 19  further comprising a cap including an electrically conductive portion adapted to be electrically coupled to the electrically conductive member and a dielectric portion adapted to electrically insulate the patient's scalp from the electrically conductive member.  
     
     
         22 . The intracranial electrode of  claim 19  further comprising an electrical lead electrically coupled to the electrically conductive member.  
     
     
         23 . The intracranial electrode of  claim 19  wherein the anchor comprises an external surface of the dielectric member, an external surface of the electrically conductive member includes threads, and the dielectric member is adapted to urge the external surface outwardly into engagement with a lumen of a bore in the skull when the electrically conductive member is threaded into the interior of the dielectric member.  
     
     
         24 . The intracranial electrode of  claim 19  wherein the anchor is carried by the dielectric member and the electrically conductive member is adapted to move the contact surface with respect to the dielectric member.  
     
     
         25 . The intracranial electrode of  claim 19  wherein the anchor comprises threads carried by a threaded portion of the dielectric member and the electrically conductive member is slidable along a length of the threaded portion.  
     
     
         26 . The intracranial electrode of  claim 25  further comprising a spring adapted to push the contact surface of the electrically conductive member against the brain surface.  
     
     
         27 . The intracranial electrode of  claim 19  wherein the anchor comprises threads carried by the dielectric member and the electrically conductive member is fixed with respect to the dielectric member.  
     
     
         28 . The intracranial electrode of  claim 19  wherein the anchor comprises threads carried by the dielectric member and the electrically conductive member is splined for rotation with the dielectric member.  
     
     
         29 . The intracranial electrode of  claim 19  wherein the anchor member comprises an engagement surface of the dielectric member and the dielectric member comprises a compressible collar adapted to expand outwardly to engage the engagement surface with a lumen of a bore in the patient's skull.  
     
     
         30 - 51 . (canceled)