Apparatus And Method For Modulating Neurochemical Levels In the Brain

• US 20100312305A1
• Filed: 12/30/2009
• Published: 12/09/2010
• Est. Priority Date: 10/05/2004
• Status: Active Grant

• Current Assignee: The Trustees of Dartmounth College (Dartmouth College)
• Original Assignee: The Trustees of Dartmounth College (Dartmouth College)
• Inventors: Chernov, Mykyta M., Leiter, James C., Roberts, David W.
• Granted Patent: US 8,473,060 B2
• Time in Patent Office: Days
• US Class Current: 607/45
• CPC Class Codes: A61B 5/4094 Diagnosing or monitoring seizure diseases, e.g. epilepsy
• CPC Class Codes: A61N 1/0534 Electrodes for deep brain stimulation
• CPC Class Codes: A61N 1/36082 Cognitive or psychiatric applications, e.g. dementia or Alzheimer's disease

Abstract

A treatment for Parkinson'"'"'s Disease uses a stimulus electrode implanted in a subthalamic nucleus with a chemosensor implanted in a globus pallidus pars interna (GPi) of the subject. A level of a neurochemical is sensed with the chemosensor, and compared to a desired level. When the level of the neurochemical is less than desired, an electrical stimulation is provided to the stimulus electrode. In alternative embodiments, the neurochemical sensed is glutamate or dopamine. An alternative system uses a chemosensor implanted in the striatum instead of the GPi. An alternative system for treating benign essential tremor uses a stimulus electrode implanted in the thalamus with feedback taken from a chemosensor in the striatum.

Claims

1. A treatment for Parkinson'"'"'s Disease comprises:

diagnosing a subject with Parkinson'"'"'s disease;

providing at least one stimulus electrode implanted in a subthalamic nucleus of the subject;

providing at least one chemosensor implanted in the globus pallidus pars interna (GPi) of the subject;

sensing a level of a neurochemical with the chemosensor;

comparing the level of the neurochemical to a desired level of the neurochemical; and

when the level of the neurochemical is less than the desired level, providing an electrical stimulation to the stimulus electrode.

2. The treatment of claim 1 wherein the chemosensor is selected from the group consisting of a chemosensor responsive to glutamate levels and a chemosensor responsive to dopamine levels.

4. The treatment of claim 2 further comprising

providing a second stimulus electrode implanted in a second subthalamic nucleus of the subject;

providing a second chemosensor implanted in a second brain structure selected from the group consisting of a globus pallidus pars interna and a striatum of the subject;

sensing a second level of a neurochemical with the second chemosensor;

comparing the second level of the neurochemical to a desired level of the neurochemical; and

when the second level of the neurochemical is less than the desired level, providing an electrical stimulation to the second stimulus electrode.

3. (canceled)

5. A treatment for a disease in a subject, the disease characterized by low levels of a neurochemical in brain, the treatment comprising:

providing at least one stimulus electrode implanted in a first part of brain of a subject;

providing at least one chemosensor implanted in a second part of brain of the subject;

sensing a level of a neurochemical with the chemosensor;

comparing the level of the neurochemical to a desired level of the neurochemical; and

when the level of the neurochemical is less than the desired level, providing an electrical stimulation to the stimulus electrode;

wherein the electrical stimulation is a high frequency electrical stimulation (HFS) having a pulse rate of at least 100 hertz; and

wherein the HFS pulses are provided in bursts, and the bursts are automatically burst-length-modulated in response to chemosensor readings.

8. The method of treatment of claim 5, wherein the HFS pulses have a selected pulse parameter selected from the group consisting of voltage or current, and wherein an amplitude of the selected pulse parameter is inversely proportional to the neurochemical level.

9. The method of treatment of claim 5, wherein the HFS pulses are provided through a first pair of electrodes in a multiple-electrode assembly when the neurochemical level is low relative to the target level and a second pair of electrodes when the neurochemical level is high.

6-7. -7. (canceled)

10. A deep brain stimulator device comprising:

an implantable chemosensor selected from the group consisting of a dopamine-sensitive chemosensor and a glutamate sensitive chemosensor;

an implantable stimulus electrode for electrical stimulation to a brain;

a programmable feedback controller coupled to the chemosensor and the implantable stimulus electrode;

wherein the feedback controller reads the chemosensor and provides a sequence of high frequency electrical stimulation (HFS) pulses through the stimulus electrode such that a greater number of HFS pulses are provided when levels of a neurochemical measured with the chemosensor are less than a programmed level than a number of HFS pulses provided when levels of the neurochemical measured with the chemosensor are greater than the programmed level;

wherein the chemosensor and the stimulus electrode are adapted for implantation in separate neurological structures of the brain.

11. The deep brain stimulator device of claim 10 wherein the HFS comprises electrical pulses at a rate of between one hundred and one hundred eighty pulses per second.

12. The deep brain stimulator device of claim 11 wherein the HFS pulses are of width between ten and twenty-five microseconds.

13. The deep brain stimulator device of claim 11, wherein the HFS pulses are provided in bursts, and the bursts are burst-length-modulated in response to chemosensor readings of levels of the neurochemical.

14. The deep brain stimulator device of claim 11, wherein the HFS pulses have a selected pulse parameter selected from the group consisting of voltage or current, and wherein an amplitude of the selected pulse parameter is inversely proportional to the neurochemical level as measured by the chemosensor.

15. The deep brain stimulator device of claim 11, wherein the control unit is programmable through signals electromagnetically coupled through skin to determine the pulse parameter for use when the chemosensor indicates the neurochemical level is low and the pulse parameter for use when the chemosensor indicates the neurochemical level is high;

and wherein HFS pulses are provided in bursts, and the bursts are burst-length-modulated in response to chemosensor readings such that fewer pulses are provided when the chemosensor indicates that the neurochemical level is high.

16. The deep brain stimulator device of claim 11, wherein the feedback controller is configurable to provide HFS pulses through a determined first pair of electrodes in a multiple-electrode assembly when the neurochemical level is low and a determined second pair of electrodes when the neurochemical level is high.

17. The deep brain stimulator device of claim 16, wherein the control unit is programmable through signals electromagnetically coupled through skin to determine the pair of electrodes used when the neurochemical level is low.

18. The deep brain stimulator device of claim 11, wherein the control unit is programmable through signals electromagnetically coupled through skin to follow a diurnal rhythm.

19. A treatment for benign essential tremor comprises:

providing at least one stimulus electrode implanted in a thalamus of a subject;

providing at least one chemosensor implanted in a striatum of the subject;

sensing a level of a neurochemical with the chemosensor;

comparing the level of the neurochemical to a desired level of the neurochemical; and

when the level of the neurochemical is less than the desired level, providing an electrical stimulation to the stimulus electrode.

20. The treatment of claim 19 wherein the chemosensor is selected from the group consisting of a chemosensor responsive to glutamate levels and a chemosensor responsive to dopamine levels.

21. The treatment of claim 20 further comprising

providing a second stimulus electrode implanted in a second thalamus of the subject;

providing a second chemosensor implanted in a second striatum of the subject;

sensing a second level of a neurochemical with the second chemosensor;

comparing the second level of the neurochemical to a desired level of the neurochemical; and

when the second level of the neurochemical is less than the desired level, providing an electrical stimulation to the second stimulus electrode.

22. The treatment of claim 20 wherein the electrical stimulation is a high frequency electrical stimulation (HFS) having a pulse rate of at least 100 hertz.

23. The treatment of claim 22 wherein the HFS pulses are provided in bursts, and the bursts are automatically burst-length-modulated in response to chemosensor readings.