METHODS FOR ESTABLISHING PARAMETERS FOR NEURAL STIMULATION, INCLUDING VIA PERFORMANCE OF WORKING MEMORY TASKS, AND ASSOCIATED KITS

• US 20070265489A1
• Filed: 04/19/2007
• Published: 11/15/2007
• Est. Priority Date: 10/19/2005
• Status: Active Grant

• Current Assignee: Advanced Neuromodulation Systems Incorporated (Abbott Laboratories)
• Original Assignee: Northstar Neuroscience, Inc.
• Inventors: Fowler, Brad, Sloan, Leif, Borgerding, Joleen
• Granted Patent: US 8,929,991 B2
• Time in Patent Office: Days
• US Class Current: 600/12
• CPC Class Codes: A61N 1/0531 Brain cortex electrodes
• CPC Class Codes: A61N 1/0534 Electrodes for deep brain stimulation
• CPC Class Codes: A61N 1/36082 Cognitive or psychiatric applications, e.g. dementia or Alzheimer's disease
• CPC Class Codes: A61N 1/36096 Mood disorders, e.g. depression, anxiety or panic disorder

Abstract

Methods for establishing parameters for neural stimulation, including via performance of working memory tasks, and associated kits, are disclosed. A method in accordance with one embodiment includes engaging a patient in a function controlled at least in part by a target neural population, and applying electromagnetic signals to the target neural population. A target parameter in accordance with which the electromagnetic signals are applied is adjusted, based at least in part on a characteristic of the patient'"'"'s performance of the function. Electromagnetic signals are applied to the patient with the adjusted target parameter, and the patient'"'"'s response to the electromagnetic signals, including the characteristic of the patient'"'"'s performance, is evaluated. Based at least in part on the evaluation of the patient'"'"'s response, an embodiment of the method includes determining whether to apply further electromagnetic signals to the patient, establishing a value of the target parameter for applying further electromagnetic signals to the patient, and/or adjusting another target parameter in accordance with which the electromagnetic signals are applied to the patient.

Claims

1. A method for treating a patient, comprising:

engaging a patient in a function controlled at least in part by a target neural population;

applying electromagnetic signals to the target neural population;

adjusting a target parameter in accordance with which the electromagnetic signals are applied to the patient, based at least in part on a characteristic of the patient'"'"'s performance of the function;

applying the electromagnetic signals to the patient with the adjusted target parameter;

evaluating the patient'"'"'s response to the electromagnetic signals, including the characteristic of the patient'"'"'s performance; and

based at least in part on the evaluation of the patient'"'"'s response;

(a) determining whether to apply further electromagnetic signals to the patient;

(b) establishing a value of the target parameter for applying further electromagnetic signals to the patient; and

/or

(c) adjusting another target parameter in accordance with which the electromagnetic signals are applied to the patient.

2. The method of claim 1, further comprising:

establishing a baseline value for the characteristic by engaging the patient in the function prior to applying electromagnetic signals to the target neural population; and

comparing the patient'"'"'s response to the baseline value.

3. The method of claim 1, further comprising:

applying therapeutic electromagnetic signals to the patient to address a patient dysfunction using a value of the target parameter based at least in part on the evaluation of the patient'"'"'s response.

4. The method of claim 3 wherein the patient dysfunction includes depression and the function includes a memory task.

5. The method of claim 1 wherein applying the electromagnetic signals to the patient with the adjusted target parameter is performed simultaneously with engaging the patient in the function.

6. The method of claim 1 wherein applying electromagnetic signals with the adjusted parameter includes applying electrical signals from an electrical contact located within the patient'"'"'s skull.

7. The method of claim 1 wherein applying electromagnetic signals with the adjusted parameter includes applying the electromagnetic signals without triggering a seizure response in the patient.

8. The method of claim 1 wherein establishing a value of the target parameter is performed on a patient-by-patient basis.

9. The method of claim 1 wherein applying electromagnetic signals includes applying anodal electromagnetic signals.

10. The method of claim 1, further comprising:

determining a parameter limit based at least in part on a value of the target parameter when the characteristic of the patient'"'"'s performance of the function changes by or to a target level; and

applying additional electromagnetic signals to the patient as treatment for a neurological dysfunction, with a value of the target parameter at or below the parameter limit.

11. The method of claim 10 wherein applying additional electromagnetic signals to the patient includes applying the additional electromagnetic signals to the target neural population.

12. The method of claim 10 wherein the target neural population is a first target neural population, and wherein applying additional electromagnetic signals to the patient includes applying the additional electromagnetic signals to a second target neural population different than the first.

13. The method of claim 10 wherein applying additional electromagnetic signals includes applying additional electromagnetic signals to at least reduce patient depression.

14. The method of claim 13, further comprising engaging the patient in psychological counseling during a treatment regimen that includes applying additional electromagnetic signals to at least reduce the patient'"'"'s depression.

15. The method of claim 10, further comprising engaging the patient in an adjunctive therapy while applying the additional signals.

16. The method of claim 15 wherein the adjunctive therapy is different than the function performed by the patient.

17. The method of claim 10 wherein determining the parameter limit includes determining a first parameter limit based on the characteristic at a first point in time prior to applying the additional signals, and wherein the method further comprises:

determining a second parameter limit based at least in part on a value of the target parameter when the characteristic of the patient'"'"'s performance of the function changes by or to the target level at a second point in time after applying the additional signals.

18. The method of claim 10 wherein applying electromagnetic signals includes applying electromagnetic signals via a first modality, and wherein applying additional electromagnetic signals includes applying additional electromagnetic signals via a second modality different than the first.

19. The method of claim 10 wherein determining whether to apply further electromagnetic signals is based at least in part on the patient'"'"'s response to electromagnetic stimulation provided by a non-implanted device, and wherein applying additional electromagnetic signals includes applying the additional electromagnetic signals via an implanted electrode.

20. The method of claim 1, further comprising:

engaging the patient in the function while the patient is not under the influence of extrinsic electromagnetic signals applied to the target neural population; and

comparing results of the patient'"'"'s performance of the function with and without the influence of electromagnetic signals applied to the target neural population.

21. The method of claim 1 wherein engaging the patient in the function includes engaging the patient in a memory task.

22. The method of claim 1 wherein engaging the patient in the function includes engaging the patient in a mathematical task.

23. The method of claim 1 wherein engaging the patient in the function includes engaging the patient in a phonetic task.

24. The method of claim 1 wherein evaluating the patient'"'"'s response includes identifying a reduced level of performance.

25. The method of claim 1 wherein the characteristic includes the speed with which the patient performs the function.

26. The method of claim 1 wherein the characteristic includes the accuracy with which the patient performs the function.

27. The method of claim 1 wherein the characteristic includes the patient'"'"'s mood while performing the function.

28. The method of claim 1 wherein engaging the patient in the function includes eliciting an emotional response from the patient.

29. The method of claim 1 wherein adjusting a target parameter includes adjusting an intensity with which the electromagnetic signals are applied to the patient.

30. The method of claim 1 wherein adjusting a target parameter includes adjusting a current applied to an electrode.

31. The method of claim 1 wherein adjusting a target parameter includes adjusting a current density of an electromagnetic signal applied to the patient.

32. The method of claim 1 wherein adjusting a target parameter includes adjusting a power level at which electromagnetic energy is applied to the patient.

33. The method of claim 1 wherein adjusting a target parameter includes adjusting a characteristic of an electromagnetic signal waveform applied to the patient.

34. A method for treating a patient, comprising:

applying electromagnetic test signals to a target neural population at the frontal lobe of a patient;

adjusting a current with which the test signals are delivered while engaging the patient in a cognitive function;

ceasing to apply the test signals if the patient'"'"'s performance of the cognitive changes by or to a target level or if the patient exhibits unwanted effects;

determining a current limit based at least in part on a value of the current when the patient'"'"'s performance of the cognitive function changes by or to the target level; and

applying electromagnetic therapy signals to the patient at a current level that is at or below the current limit.

35. The method of claim 34 wherein determining a current limit includes comparing the patient'"'"'s performance of the cognitive function with and without applying electromagnetic signals to the target neural population.

36. The method of claim 34 wherein applying electromagnetic signals includes addressing patient depression, and wherein the cortical function includes a memory task.

37. The method of claim 34 wherein applying electromagnetic therapy signals includes applying electrical signals from an electrical contact located within the patient'"'"'s skull.

38. The method of claim 34 wherein engaging the patient in the cognitive function includes engaging the patient in a memory task.

39. The method of claim 34 wherein engaging the patient in the cognitive function includes engaging the patient in a mathematical task.

40. The method of claim 34 wherein determining a current limit includes identifying a speed with which the patient performs the cognitive function and comparing the speed to a baseline value.

41. The method of claim 34 wherein determining a current limit includes identifying an accuracy with which the patient performs the cognitive function and comparing the accuracy to a baseline value.

42. The method of claim 34 wherein determining a current limit includes identifying a mood with which the patient performs the cognitive function and comparing the mood to a baseline mood.

43. The method of claim 34 wherein ceasing to apply the test signals is triggered by the patient exhibit seizure activity.

44. The method of claim 34 wherein applying electromagnetic therapy signals includes selecting the electromagnetic therapy signals to be within a first range relative to a first current limit if the current is applied with a first polarity, and selecting the electromagnetic therapy signals to be within a second range relative to a second current limit if the current is applied with a second polarity different than the first polarity, the second range being different than the first range.

45. The method of claim 34 wherein adjusting a current includes adjusting a first current with which first test signals are delivered at a first polarity while engaging the patient in a first cognitive function, wherein determining a current limit includes determining a first current limit based at least in part on a value of the current applied at the first polarity when the patient'"'"'s performance changes by or to a first target level, wherein applying electromagnetic therapy signals includes selecting the electromagnetic therapy signals to be within a first range relative to the first current limit, and wherein the method further comprises:

adjusting a second current with which second test signals are delivered at a second polarity different than the first while engaging the patient in a second cognitive function;

ceasing to apply the second test signals if the patient'"'"'s performance of the second cognitive function changes by or to a second target level or if the patient exhibits unwanted effects;

determining a second current limit based at least in part on a value of the current when the patient'"'"'s performance of the second cognitive function changes by or to the second target level; and

applying electromagnetic therapy signals to the patient at a current level that is selected to be within a second range different than the first range relative to the second current limit.

46. The method of claim 45 wherein the first therapy signals are applied without an adjunctive therapy, and wherein the second therapy signals are applied in conjunction with an adjunctive therapy.

47. The method of claim 46 wherein the first range is lower than and overlaps with the second range.

48. The method of claim 34 wherein the target level is a first target level and wherein the current limit is a first current limit, and wherein the method further comprises:

ceasing to apply the test signals if the patient'"'"'s performance of the cognitive function exceeds a second target level or if the patient exhibits unwanted effects;

determining a second current limit based at least in part on a value of the current when the patient'"'"'s performance of the cognitive function by or to the second target level; and

applying electromagnetic therapy signals to the patient at a current level that is at or below the second current limit.

49. A method comprising:

engaging a patient in a set of tasks that involve cognitive or emotional behavior;

applying. electromagnetic signals to the patient;

measuring patient task performance while the patient is affected by the electromagnetic signals;

determining a first neural activation threshold corresponding to a change in a first patient task performance level;

determining a second neural activation threshold corresponding to a second patient task performance level;

determining a first therapy signal intensity based at least in part upon the first neural activation threshold; and

determining a second therapy signal intensity based at least in part upon the second neural activation threshold.

50. The method of claim 49, wherein the first neural activation threshold corresponds to a first type of task, and the second neural activation threshold corresponds to a second type of task different than the first.

51. The method of claim 49, wherein the first and second neural activation thresholds correspond to a single type of task.

52. The method of claim 49, wherein the first patient task performance level corresponds to a task performance degradation, and the second patient task performance level corresponds to a task performance improvement.

53. The method of claim 49, wherein the first and second patient task performance levels correspond to a task performance degradation.

54. The method of claim 49, further comprising:

applying electromagnetic signals to the patient at the first therapy signal intensity in the absence of a first type of adjunctive therapy; and

applying electromagnetic signal to the patient at the second therapy signal intensity in conjunction with the first type of adjunctive therapy.

55. The method of claim 54 wherein determining the first therapy signal intensity includes determining the first therapy signal intensity to be from about 75-95% of the first neural activation threshold.

56. The method of claim 54 wherein determining the second therapy signal intensity includes determining the second therapy signal intensity to be from about 25-95% of the second neural activation threshold

57. The method of claim 49, further comprising selecting the first and second signal intensities to be at different polarities.

58. A kit for treating a non-motor, non-sensory neurological dysfunction in a patient, comprising:

an electrode device having at least one electrode positioned to be implanted beneath a patient'"'"'s skull;

a lead coupled to the electrode device and coupleable to a signal generator having an adjustable output; and

a volitional neurological test administrable to the patient.

59. The kit of claim 58 wherein the electrode device includes a plurality of electrode contacts.

60. The kit of claim 59 wherein the lead includes multiple lead elements, each coupled to one of the electrode contacts, and wherein individual electrode contacts are electromagnetically isolated from each other at the electrode device.

61. The kit of claim 58 wherein the test includes a memory test.

62. The kit of claim 58 wherein the test includes a verbal performance test.

63. The kit of claim 58 wherein the test includes a mathematical test.

64. The kit of claim 58 wherein at least a portion of the test is in the form of a computer-readable medium.

65. A computer-implemented method for establishing patient treatment parameters, comprising:

receiving a baseline value of a characteristic with which a patient performs a function controlled at least in part by a target neural population while the patient is not subject to external electromagnetic signals directed to the target neural population;

receiving multiple values of the characteristic with which the patient performs the function while the patient is subject to external electromagnetic signals directed to the target neural population;

performing a statistical analysis of the multiple values; and

based at least in part on the statistical analysis, determining a probability that the patient'"'"'s performance while subject to the electromagnetic signals is affected by the electromagnetic signals.

66. The method of claim 65 wherein determining a probability includes determining a probability based at least in part on a binomial distribution.

67. The method of claim 65 wherein the characteristic includes a speed with which the patient performs the function

68. The method of claim 65 wherein the characteristic includes an accuracy with which the patient performs the function.

69. The method of claim 65, further comprising providing the probability to a practitioner for determination of a parameter for applying therapeutic stimulation to the patient.