Methods and apparatus for effectuating a lasting change in a neural-function of a patient

• US 20060200206A1
• Filed: 02/15/2006
• Published: 09/07/2006
• Est. Priority Date: 07/13/2000
• Status: Active Grant

• Current Assignee: Advanced Neuromodulation Systems Incorporated (Abbott Laboratories)
• Original Assignee: Northstar Neuroscience, Inc.
• Inventors: Morgan, Carlton B., Firlik, Andrew D., Gliner, Bradford E., Levy, Alan J., Balzer, Jeffrey
• Granted Patent: US 7,577,481 B2
• Time in Patent Office: Days
• US Class Current: 607/45
• CPC Class Codes: A61N 1/0531 Brain cortex electrodes
• CPC Class Codes: A61N 1/0534 Electrodes for deep brain stimulation
• CPC Class Codes: A61N 1/0539 Anchoring of brain electrode systems, e.g. within burr hole
• CPC Class Codes: A61N 1/36017 with leads or electrodes penetrating the skin
• CPC Class Codes: A61N 1/36025 for treating a mental or cerebral condition
• CPC Class Codes: A61N 1/36082 Cognitive or psychiatric applications, e.g. dementia or Alzheimer's disease
• CPC Class Codes: A61N 1/36103 Neuro-rehabilitation; Repair or reorganisation of neural tissue, e.g. after stroke
• CPC Class Codes: A61N 1/37514 Brain implants
• CPC Class Codes: A61N 1/37518 Anchoring of the implants, e.g. fixation
• CPC Class Codes: A61N 1/3756 Casings with electrodes thereon, e.g. leadless stimulators

Abstract

The following disclosure describes several methods and apparatus for intracranial electrical stimulation to treat or otherwise effectuate a change in neural-functions of a patient. Several embodiments of methods in accordance with the invention are directed toward enhancing or otherwise inducing a lasting change in neural activity to effectuate a particular neural-function. Such lasting change in neural activity is defined as “neuroplasticity.” The methods in accordance with the invention can be used to treat brain damage (e.g., stroke, trauma, etc.), brain disease (e.g., Alzheimer'"'"'s, Pick'"'"'s, Parkinson'"'"'s, etc.), and/or brain disorders (e.g., epilepsy, depression, etc.). The methods in accordance with the invention can also be used to enhance neural-function of normal, healthy brains (e.g., learning, memory, etc.), or to control sensory functions (e.g., pain). Certain embodiments of methods in accordance with the invention electrically stimulate the brain at a stimulation site where neuroplasticity is occurring. The stimulation site may be different than the region in the brain where neural activity is typically present to perform the particular neural function according to the functional organization of the brain. In one embodiment in which neuroplasticity related to the neural-function occurs in the brain, the method can include identifying the location where such neuroplasticity is present. In an alternative embodiment in which neuroplasticity is not occurring in the brain, an alternative aspect is to induce neuroplasticity at a stimulation site where it is expected to occur. Several embodiments of these methods that are expected to produce a lasting effect on the intended neural activity at the stimulation site use electrical pulses that increase the resting membrane potential of neurons at the stimulation site to a subthreshold level.

Claims

1-123. -123. (canceled)

124. A method for providing cortical stimulation to a patient, comprising:

identifying a cortical location at which a patient-specific intrinsic neural activity occurs or is expected to occur;

applying an electromagnetic signal at a cortical stimulation site corresponding to the cortical location using at least one electrode; and

selectively activating a set of neural pathways exposed to the electrical signal by way of a patient activity expected to reinforce the intrinsic neural activity, concurrent with applying the electromagnetic signal to the cortical stimulation site.

125. The method of claim 124 wherein the patient activity includes an adjunctive therapy.

126. The method of claim 124 wherein the patient activity includes a behavioral therapy.

127. The method of claim 124 wherein the patient activity includes a physical activity.

128. The method of claim 124 wherein applying an electromagnetic signal includes applying an electrical signal.

129. The method of claim 124 wherein applying an electromagnetic signal includes applying an electrical signal at a subthreshold level.

130. The method of claim 124 wherein applying an electromagnetic signal includes applying an electrical signal at a level below a level that causes an acute patient response that is measurable, observable or both measurable and observable.

131. The method of claim 124 wherein selectively activating the set of neural pathways by way of a patient activity occurs generally coincident with applying the electrical signal to the cortical location.

132. The method of claim 124 wherein identifying the cortical location includes performing a non-invasive procedure.

133. The method of claim 124 wherein identifying the cortical location includes identifying a location corresponding to a hemodynamic behavior associated with the neurologic dysfunction.

134. The method of claim 124 wherein identifying the cortical location includes performing a neural function localization procedure while the patient is engaged in a task that elicits the intrinsic neural activity.

135. The method of claim 124 wherein the neural function localization procedure includes a neural imaging procedure.

136. The method of claim 124, further comprising discontinuing applying an electromagnetic signal to the cortical stimulation site after a therapy period of several weeks.

137. The method of claim 124, further comprising discontinuing applying an electromagnetic signal to the cortical stimulation site after a therapy period of approximately one year.

138. The method of claim 124, further comprising discontinuing applying an electromagnetic signal to the cortical stimulation site after a therapy period of approximately two years.

139. The method of claim 124, further comprising assessing an extent to which the neural function has been reinforced in the absence of applying the electrical signal.

140. The method of claim 124, further comprising discontinuing application of the electromagnetic signal, or the patient activity, or both, in response to an indication that an extent to which the neural function has been promoted has plateaued.

141. A method for providing cortical stimulation to a patient, comprising:

performing a noninvasive neurofunctional localization procedure to determine a cortical location at which a patient-specific intrinsic neural activity occurs;

positioning a first electrode beneath the scalp at a cortical stimulation site corresponding to the cortical location;

positioning a second electrode at a location remote from the cortical stimulation site;

applying an electromagnetic signal to the patient using the first and second electrodes; and

modulating a neuroplastic activity with the applied signal to affect a patient symptom.

142. The method of claim 141 wherein the electrical signal has a parameter that varies in a pseudorandom manner.

143. The method of claim 141 wherein modulating the neuroplastic activity includes decreasing the neuroplastic activity.

144. The method of claim 143 wherein modulating a neuroplastic activity with the applied signal to affect a patient symptom includes at least reducing symptoms associated with phantom limb pain.

145. The method of claim 141 wherein modulating the neuroplastic activity includes increasing the neuroplastic activity.

146. The method of claim 141 wherein the neuroplastic activity corresponds to a neural process that facilitates at least partial functional recovery following neural damage.

147. The method of claim 141 wherein the neural damage arises in association with at least one of a stroke and a traumatic brain injury.

148. The method of claim 141 wherein identifying the cortical location comprises performing a neural function localization procedure while the patient is engaged in a task expected to facilitate detection of the neuroplastic activity.

149. The method of claim 141, further comprising selectively activating a set of neural pathways exposed to the electrical signal by way of a patient activity expected to promote a neural function subserved by the neuroplastic activity, concurrent with applying the electrical signal to the patient.

150. A method for providing cortical stimulation to a patient, comprising:

identifying a brain location at which a neuroplastic activity occurs or is expected to occur;

positioning an electrode beneath the scalp at a cortical stimulation site corresponding to the identified brain location;

applying an aperiodically varying electrical signal to the patient using the electrode; and

modulating the neuroplastic activity with the applied signal to affect a patient symptom.

151. The method of claim 150 wherein identifying a brain location includes identifying a brain location at which a patient-specific neuroplastic activity occurs.

152. The method of claim 150 wherein applying an aperiodically varying electrical signal includes applying a pseudorandomly varying signal.

153. The method of claim 150 wherein modulating the neuroplastic activity includes increasing the neuroplastic activity.

154. The method of claim 150 wherein modulating the neuroplastic activity includes decreasing the neuroplastic activity.

155. The method of claim 150 wherein identifying the brain location includes performing a neural function localization procedure while the patient is engaged in a task expected to facilitate detection of the neuroplastic activity.

156. A method for treating a patient condition, comprising:

identifying a cortical location at which a patient-specific intrinsic neural activity occurs or is expected to occur;

applying an electromagnetic signal at a cortical stimulation site corresponding to the cortical location;

concurrently with applying the electromagnetic signal, selectively generating a neural activity corresponding to a neural function via a patient activity; and

determining whether to apply a further electromagnetic signal to the cortical location, based at least in part on an extent to which the neural function of the patient has changed.

157. The method of claim 156 wherein applying an electromagnetic signal includes applying the electromagnetic signal at a subthreshold level.

158. The method of claim 156 wherein identifying a cortical location includes identifying a cortical location at which a facilitatory adaptive response is expected to occur.

159. The method of claim 156 wherein selectively generating neural activity includes engaging the patient in an adjunctive therapy.

160. The method of claim 159 wherein engaging the patient in an adjunctive therapy includes engaging the patient in a physical therapy.

161. The method of claim 159 wherein engaging the patient in an adjunctive therapy includes engaging the patient in a physical therapy, and wherein applying an electromagnetic signal includes applying an electromagnetic signal at a subthreshold level.

162. The method of claim 156 wherein determining whether to apply a further electromagnetic signal includes determining whether to apply a further electromagnetic signal after applying an electromagnetic signal and concurrently selectively generating the neural activity.

163. The method of claim 156 wherein determining whether to apply a further electromagnetic signal includes waiting for a period of at least several weeks after applying the electromagnetic signal.

164. The method of claim 156 wherein determining whether to apply a further electromagnetic signal includes waiting for a period of from at least several weeks to less than one year after applying the electromagnetic signal.

165. The method of claim 156 wherein determining whether to apply a further electromagnetic signal includes determining whether to apply a further electromagnetic signal after multiple therapy sessions.

166. The method of claim 156 wherein determining whether to apply a further electromagnetic signal includes determining whether to apply a further electromagnetic signal after a time period corresponding to long-term neural changes has elapsed

167. A method for providing cortical stimulation to a patient, comprising:

identifying a cortical location at which an intrinsic neural activity occurs or is expected to occur to effectuate a first neural function;

applying a first electromagnetic signal to a cortical stimulation site corresponding to the cortical location at a level that triggers the first neural function as a result of the first signal alone;

applying a second electromagnetic signal to the cortical stimulation site at a level that fails to trigger the first neural function in the absence of additional neural input; and

engaging the patient in a behavioral activity that selectively generates a neural activity corresponding to a second neural function different than the first neural function, concurrent with applying the second electrical signal to the cortical stimulation site.

168. The method of claim 167 wherein the intrinsic neural activity is patient specific.

169. The method of claim 167 wherein at least one of the first and second signals is an electrical signal.

170. The method of claim 167 wherein at least one of the first and second signals is an electrical signal applied using an implanted electrode.

171. The method of claim 167 wherein the first neural function is subsumed by the second neural function.

172. The method of claim 167 wherein the signal is applied in a manner that is independent of the behavioral activity.

173. A method for providing cortical stimulation to a patient, comprising:

identifying a cortical location at which a patient-specific intrinsic neural activity occurs or is expected to occur to effectuate a first neural function;

applying an electromagnetic signal to a cortical stimulation site corresponding to the cortical location at a level that fails to trigger the first neural function in the absence of additional neural input;

engaging the patient in a behavioral activity that selectively generates neural activity corresponding to a second neural function, concurrent with applying the electrical signal to the cortical stimulation site.

174. The method of claim 173 wherein the second neural function is facilitated by the intrinsic neural activity.

175. The method of claim 173 wherein the first neural function is subsumed by the second neural function.

176. The method of claim 173 wherein the signal is applied in a manner that is independent of the behavioral activity.

177. The method of claim 173 wherein the first and second neural functions are different.

178. A method for treating a patient condition, comprising:

identifying a cortical location having a first neural population at which a patient-specific intrinsic neural activity corresponding to a first neural function occurs or is expected to occur;

determining a threshold level of a second neural population different than the first neural population;

based at least in part on the threshold level of the second neural population, applying an electromagnetic signal to the cortical location at a level below the threshold level of the second neural population; and

modulating a neuroplastic activity with the applied signal to affect a patient symptom.

179. The method of claim 178, further comprising concurrently with applying the electromagnetic signal, selectively generating a neural activity corresponding to a second neural function via a patient activity.

180. The method of claim 178 wherein applying an electromagnetic signal includes applying an electromagnetic signal in an aperiodic manner.

181. The method of claim 178 wherein applying an electromagnetic signal includes applying an electromagnetic signal in a pseudorandom manner.

182. The method of claim 178, further comprising engaging the patient in an adjunctive therapy concurrently with applying an electromagnetic signal.

183. The method of claim 178 wherein applying an electromagnetic signal includes applying an electrical signal.

184. The method of claim 178 wherein modulating a neuroplastic activity includes decreasing a neuroplastic activity.

185. The method of claim 178 wherein modulating a neuroplastic activity includes ineasing a neuroplastic activity.