Transcranial magnetic stimulation (TMS) methods and apparatus

Abstract

Method and devices are provided for treating subjects with Transcranial Magnetic Stimulation (TMS). According to some approaches, the methods and devices are configured for the treatment of ongoing seizures. Other approaches relate to the use of TMS as an antiepileptogenic or for use in determining preferential placement of intracranial probes.

1 - 21 . (canceled) 
   
   
       22 . A device for treating an ongoing seizure, the device comprising:
 an electromagnetic coil that receives power from a power source to produce a magnetic field;   a controller that controls operation of the electromagnetic coil according to an operating protocol;   a plurality of electrodes configured to receive a signal indicative of brain activity in the subject and to provide the electrical signal to the controller; and   an interface that includes the plurality of electrodes and the electromagnetic coil, the interface configured to position the plurality of electrodes to receive the signal and to position the electromagnetic coil to deliver the magnetic field to a subject's brain.   
   
   
       23 . The system according to  claim 22 , wherein operating protocol comprises:
 delivering an initial magnetic field having an intensity and a duration; and   delivering a subsequent magnetic field after delivering the initial magnetic field, wherein at least one of the intensity and the duration of the subsequent magnetic field is greater than the intensity and the duration of the initial magnetic field, respectively.   
   
   
       24 . The system according to  claim 23 , further comprising:
 a manual activation control that, when activated, causes the controller to initiate the operating protocol.   
   
   
       25 . The system according to  claim 24 , wherein further manual activation of the manual activation control is required before subsequent magnetic fields of the operating protocol are delivered. 
   
   
       26 . The system according to  claim 22 , wherein the controller is configured to identify termination of a seizure and to stop the operating protocol when the seizure has terminated. 
   
   
       27 . The system according to  claim 22 , wherein the controller is configured to perform analysis of the signal and to cause the electromagnetic coil to deliver a magnetic field that is phased to the brain activity. 
   
   
       28 . The system according to  claim 22 , wherein the operating protocol comprises delivering a plurality of subsequent magnetic fields, each of the subsequent magnetic fields having at least one of an intensity and a duration that is greater than intensity and duration of previously delivered magnetic fields, respectively, of the operating protocol. 
   
   
       29 . The system according to  claim 22 , wherein the controller is configured to detect onset of a seizure through analysis of the signal. 
   
   
       30 . The system according to  claim 29 , wherein the controller is configured to compare the signal to a baseline indicative of normal brain activity to detect the onset of a seizure. 
   
   
       31 . The system according to  claim 29 , wherein the controller is configured to monitor root mean squared values of the signal to detect the onset of a seizure. 
   
   
       32 . The system according to  claim 29 , wherein the controller is configured to monitor frequency domain aspects of the signal to detect the onset of a seizure. 
   
   
       33 . A method of non-invasively assessing intracranial electrode positioning, the method comprising:
 positioning an electromagnetic coil at an initial external position about a subject's brain;   applying a magnetic field from the electromagnetic coil positioned at the initial external position about the subject's brain;   identifying any effects exhibited by the subject subsequent to applying the first magnetic field from the electromagnetic coil at the initial external position;   repositioning the electromagnetic coil at a subsequent external position, different than the initial external position, about the subject's brain;   applying a magnetic field from the electromagnetic coil positioned at the subsequent external position about the subject's brain;   identifying any effects exhibited by the subject subsequent to applying the subsequent magnetic field from the electromagnetic coil at the subsequent external position;   comparing any effects associated with applying the magnetic field from the first external position of the electromagnetic coil and any effects associated with applying the magnetic field from the subsequent external position to identify a preferential position among the initial and subsequent external positions.   
   
   
       34 . The method according to  claim 33 , wherein the acts of repositioning the electromagnetic coil at a subsequent external position; applying a magnetic field from the electromagnetic coil positioned at the subsequent external position; and identifying any effects exhibited by the subject subsequent to applying the subsequent magnetic field from the electromagnetic coil are each repeated multiple times. 
   
   
       35 . The method according to  claim 33 , further comprising:
 applying a magnetic field from the electromagnetic coil positioned at the preferential position during an ongoing seizure;   assessing whether applying the magnetic field from the electromagnetic coil positioned at the preferential position terminates the ongoing seizure.   
   
   
       36 . The method according to  claim 33 , further comprising:
 providing a model of the subject's head;   identifying a relationship between external positions of the electromagnetic coil about the subject's brain and a focus of the magnetic field applied by the electromagnetic coil from the external positions through use of the model of the subject's head.   
   
   
       37 . The method according to  claim 36 , wherein positioning the electromagnetic coil at a first external position about a subject's brain comprises positioning the electromagnetic coil in a stereotactic device and further wherein repositioning the electromagnetic coil at the second external position, comprises repositioning the electromagnetic coil in the stereotactic device. 
   
   
       38 . The method according to  claim 33 , wherein the stereotactic device is a helmet fastened to the subject's head. 
   
   
       39 . The method according to  claim 33 , further comprising:
 operatively placing an electrode at the preferential position.   
   
   
       40 . The method according to  claim 33 , wherein applying a magnetic field from the electromagnetic coil positioned at the first external position about the subject's brain comprises applying a magnetic field as a single magnetic pulse. 
   
   
       41 - 43 . (canceled) 
   
   
       44 . A method of terminating an ongoing seizure, the method comprising:
 identifying a subject for treatment;   positioning an electromagnetic coil about the seizing subject's brain; and   energizing the electromagnetic coil to direct a magnetic field from the electromagnetic coil to the seizing subject's brain.   
   
   
       45 - 57 . (canceled)