ELECTROMAGNETIC SIGNAL DELIVERY FOR TISSUE AFFECTED BY NEURONAL DYSFUNCTION, DEGRADATION, DAMAGE, AND/OR NECROSIS, AND ASSOCIATED SYSTEMS AND METHODS

• US 20080039895A1
• Filed: 04/06/2007
• Published: 02/14/2008
• Est. Priority Date: 04/11/2006
• Status: Active Grant

• Current Assignee: Advanced Neuromodulation Systems Incorporated (Abbott Laboratories)
• Original Assignee: Northstar Neuroscience, Inc.
• Inventors: Fowler, Brad, Himes, David, Gliner, Bradford
• Granted Patent: US 7,949,401 B2
• Time in Patent Office: Days
• US Class Current: 607/2
• 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 2/006 for magnetic stimulation of nerve tissue

Abstract

Electromagnetic signal delivery for tissue affected by neuronal dysfunction, degradation, damage, and/or necrosis, and associated systems and methods are disclosed. A method in accordance with one embodiment of the invention includes identifying an affected region, with the affected region including neuronal tissue that, at least during a pre-dysfunctional period, was in neural communication with neuronal tissue in a dysfunctional region. The affected tissue can be functionally adversely affected by neuronal dysfunction in the dysfunctional region. The method can further include applying electromagnetic signals to the neuronal tissue in the affected region. For example, the electromagnetic signals can be applied to a hypo-active neural region that is not physically damaged, and has been identified as likely to recover at least in part as a result of electromagnetic signals. Signals can be applied at sub-threshold levels to cortical and/or subcortical regions.

Claims

1. A method for treating neuronal tissue of a patient, comprising:

identifying an affected region, the affected region including affected neuronal tissue that, at least during a pre-dysfunctional period, was in neural communication with neuronal tissue in a dysfunctional region, the affected tissue being functionally adversely affected by neuronal dysfunction in the dysfunctional region; and

applying electromagnetic signals to the neuronal tissue in the affected region.

2. The method of claim 1 wherein identifying an affected region includes identifying an affected region that is located in the same brain hemisphere as the dysfunctional region.

3. The method of claim 1 wherein identifying an affected region includes identifying an affected region that is likely to recover at least in part as a result of the electromagnetic signals.

4. The method of claim 1 wherein identifying an affected region includes identifying a first affected region that is likely to recover at least in part as a result of the electromagnetic signals, and wherein the method further comprises:

identifying a second affected region that is unlikely to recover as a result of applied electromagnetic signals; and

not applying electromagnetic signals to the second affected region.

5. The method of claim 1, further comprising identifying the location of the dysfunctional region, wherein the dysfunctional region includes neuronal tissue that is subject to or has been subjected to a reduced oxygen supply.

6. The method of claim 1 wherein applying electromagnetic signals includes applying electromagnetic signals to neuronal tissue that has not suffered a loss in oxygen supply.

7. The method of claim 1 wherein applying electromagnetic signals includes applying electromagnetic signals to neuronal tissue that is not physically damaged.

8. The method of claim 1 wherein applying electromagnetic signals includes applying electromagnetic signals to neuronal tissue that receives a reduced number of patient-generated signals, patient-generated signals at a reduced strength, or both, as a result of damage to neuronal tissue in the dysfunctional region.

9. The method of claim 1 wherein applying electromagnetic signals includes applying electromagnetic signals to neuronal structures that include viable projections, viable tracts, or both.

10. The method of claim 1 wherein applying electromagnetic signals includes applying electromagnetic signals resulting in new neuronal pathways, restoration of existing neuronal pathways, or both.

11. The method of claim 1 wherein identifying a dysfunctional region includes identifying a dysfunctional region located in a deep brain region of the patient'"'"'s brain, and wherein identifying an affected region includes identifying an affected region at least proximate to a cortical region of the patient'"'"'s brain.

12. The method of claim 1 wherein applying electromagnetic signals includes applying electromagnetic signals during a post-acute, pre-chronic period of time.

13. The method of claim 1 wherein applying electromagnetic signals includes:

applying electromagnetic signals during a post-acute, pre-chronic period of time using a first set of signal delivery parameters; and

applying electromagnetic signals during a chronic period of time using a second set of signal delivery parameters, wherein a value of at least one of the parameters in the second set is different than a value of the corresponding parameter in the first set.

14. The method of claim 13 wherein the signal delivery parameters for at least one of the first and second sets includes at least one of a signal amplitude and a signal frequency.

15. The method of claim 1 wherein identifying the affected region includes using a diffusion tensor imaging technique.

16. The method of claim 15, further comprising:

re-evaluating neural activity after applying the electromagnetic signals;

detecting a shift in the neural activity using a diffusion sensor imaging technique; and

updating at least one parameter in association with which electromagnetic signals are applied to the patient.

17. The method of claim 1, further comprising directing the patient to engage in an adjunctive therapy.

18. The method of claim 1, further comprising directing the patient to engage in an adjunctive therapy during a chronic phase relative to the onset of the dysfunction, but not during a post-acute, pre-chronic phase.

19. The method of claim 1 wherein applying electromagnetic signals includes applying electromagnetic signals via an electrode implanted at least proximate to the patient'"'"'s cortex.

20. The method of claim 1 wherein applying electromagnetic signals includes applying electromagnetic signals during a post-acute, pre-chronic period relative to the onset of the neuronal dysfunction.

21. The method of claim 1 wherein the dysfunctional region is cortical and wherein identifying the affected region includes identifying a subcortical affected region.

22. The method of claim 1 wherein the dysfunctional region is subcortical and wherein identifying the affected region includes identifying a cortical affected region.

23. The method of claim 1, further comprising delivering electromagnetic signals to neuronal tissue at a location contralateral to the affected region.

24. The method of claim 1 wherein applying electromagnetic signals includes applying electromagnetic signals at subthreshold signal strength levels.

25. The method of claim 1 wherein applying electromagnetic signals includes applying electromagnetic signals at a level below a level that causes an inherent patient response or results in an inherent patient sensation.

26. The method of claim 1 wherein applying electromagnetic signals includes applying electromagnetic signals at from about 10% to about 90% of a threshold level.

27. The method of claim 1 wherein applying electromagnetic signals includes applying electromagnetic signals at from about 25% to about 75% of a threshold level.

28. The method of claim 1 wherein applying electromagnetic signals includes applying electromagnetic signals at about 25% of a threshold level.

29. The method of claim 1 wherein applying electromagnetic signals includes increasing an intensity of the signals relative to a threshold level over the course of a treatment regimen.

30. The method of claim 1 wherein applying electromagnetic signals includes changing at least one of an intensity and a location of the electromagnetic signals over the course of a treatment regimen.

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

32. The method of claim 1 wherein applying electromagnetic signals includes applying cathodal electromagnetic signals.

33. The method of claim 1 wherein applying electromagnetic signals includes applying anodal stimulation followed by cathodal electromagnetic signals.

34. A method for treating neuronal tissue of a patient, comprising:

identifying a target location of the patient'"'"'s central nervous system positioned proximate to damaged neuronal tissue;

applying electromagnetic signals at the target location during a post-acute, pre-chronic period relative to the occurrence of damage to the neuronal tissue; and

directing the patient to engage in an adjunctive therapy during a chronic period relative to the occurrence of damage to the neuronal tissue.

35. The method of claim 34 wherein identifying a target location includes identifying a target location of the patient'"'"'s brain.

36. The method of claim 34 wherein applying electromagnetic signals includes applying electromagnetic signals before the patient'"'"'s naturally occurring recovery processes in response to the damage to the neuronal tissue are complete.

37. The method of claim 34 wherein applying electromagnetic signals includes applying electromagnetic signals during a period when functional degradation of the patient'"'"'s nervous system resulting from damage to the neuronal tissue is occurring.

38. The method of claim 34 wherein identifying a target location includes identifying a target location that includes neuronal tissue that has not undergone a loss of oxygen as a result of damage to the damaged neuronal tissue.

39. The method of claim 34, further comprising applying electromagnetic signals at the target location during a chronic period relative to the occurrence of damage to the neuronal tissue.

40. The method of claim 34 wherein identifying the target location includes identifying the target location using diffusion tensor imaging techniques.

41. A method for treating neuronal tissue of a patient, comprising:

identifying target neuronal tissue that has not suffered a loss of oxygen as a result of a proximate infarct, but at least during a pre-infarct period, was in neural communication with damaged neuronal tissue that suffered a loss of oxygen as a result of the infarct, the target neuronal tissue being functionally adversely affected by dysfunction in the damaged neuronal tissue; and

applying electromagnetic signals to the target neuronal tissue.

42. The method of claim 41, further comprising not applying electromagnetic signals to neuronal cells having hyperactive spontaneous electrical activity levels.

43. The method of claim 41, further comprising preferentially applying electromagnetic signals to neuronal cells having hypoactive spontaneous electrical activity levels.

44. The method of claim 41, further comprising:

preferentially applying electromagnetic signals to first neuronal cells having hypoactive spontaneous electrical activity levels;

not applying electromagnetic signals to second neuronal cells having hyperactive spontaneous electrical activity levels; and

after spontaneous electrical activity levels of the second neuronal cells become hypoactive, applying electromagnetic signals to the second neuronal cells.

45. A method for treating neuronal tissue of a patient, comprising:

identifying a location of an infarct region that includes neuronal tissue subjected to a reduced oxygen supply;

based at least in part on the location of the infarct region, identifying an affected region, the affected region including neuronal tissue that, at least during a pre-infarct period, was in neural communication with neuronal tissue in the infarct region, wherein identifying the affected region includes using diffusion tensor imaging techniques, and wherein neuronal tissue in the affected region has reduced neural signal transmission as a result of tissue loss at the infarct region;

implanting an electrode at least proximate to the affected region;

applying electromagnetic signals to the neuronal tissue in the affected region during a post-acute, pre-chronic period relative to the occurrence of damage to the neuronal tissue;

identifying the onset of a chronic period relative to the occurrence of damage to the neuronal tissue; and

directing the patient to engage in adjunctive therapy during the chronic period.

46. The method of claim 45, further comprising not applying electromagnetic signals to neuronal cells having hyperactive spontaneous electrical activity levels.

47. The method of claim 45, further comprising preferentially applying electromagnetic signals to neuronal cells having hypoactive spontaneous electrical activity levels.

48. The method of claim 45, further comprising:

preferentially applying electromagnetic signals to first neuronal cells having hypoactive spontaneous electrical activity levels;

not applying electromagnetic signals to second neuronal cells having hyperactive spontaneous electrical activity levels; and

after spontaneous electrical activity levels of the second neuronal cells become hypoactive, applying electromagnetic signals to the second neuronal cells.

49. A method for treating neuronal tissue of a patient, comprising:

based at least in part on information obtained via physiologic or physiologic correlate information corresponding to a state of neuronal tissue, identifying the location of an affected region, the affected region including neuronal tissue that, at least during a pre-dysfunctional period, was in neural communication with neuronal tissue in a dysfunctional region, the affected region being functionally adversely affected by neuronal dysfunction in the dysfunctional region; and

applying electromagnetic signals to the neuronal tissue in the affected region.

50. The method of claim 49 wherein applying electromagnetic signals includes:

applying electromagnetic signals during a post-acute, pre-chronic period of time using a first set of signal delivery parameters; and

applying electromagnetic signals during a chronic period of time using a second set of signal delivery parameters, wherein a value of at least one of the signal delivery parameters in the second set is different than a value of the corresponding parameter in the first set.

51. The method of claim 49, further comprising not applying electromagnetic signals to neuronal cells having hyperactive spontaneous electrical activity levels.

52. The method of claim 49, further comprising preferentially applying electromagnetic signals to neuronal cells having hypoactive spontaneous electrical activity levels.

53. The method of claim 49, further comprising:

preferentially applying electromagnetic signals to first neuronal cells having hypoactive spontaneous electrical activity levels;

not applying electromagnetic signals to second neuronal cells having hyperactive spontaneous electrical activity levels; and

after spontaneous electrical activity levels of the second neuronal cells become hypoactive, applying electromagnetic signals to the second neuronal cells.

54. The method of claim 49 wherein identifying the location of an affected region includes identifying the location of an affected region based at least in part on information obtained via diffusion tensor imaging techniques.

55. A computer-readable medium, comprising:

a receiver portion configured to receive physiologic or physiologic correlate information corresponding to a neuronal state of a neuronal structure; and

a processor portion coupled to the receiver portion and configured to identify neuronal tissue at an affected region, the affected region including affected neuronal tissue that, at least during a pre-dysfunctional period, was in neural communication with neuronal tissue in a dysfunctional region, the affected tissue being functionally adversely affected by neuronal dysfunction in the dysfunctional region, the processor portion further being configured to select a target signal delivery site at the affected region based at least in part on the information.

56. The computer-readable medium of claim 55 wherein the receiver portion is configured to receive information resulting from the application of a diffusion tensor imaging technique.

57. The computer-readable medium of claim 55 wherein the receiver portion is configured to receive information corresponding to locations of neural projections extending from the dysfunctional region, and wherein the processor portion is configured to identify the affected region and select the target signal delivery site based at least in part on the locations of the neural projections.

58. A computer-readable medium, comprising:

a receiver portion configured to receive information corresponding to activity levels of neuronal structures; and

a processor portion coupled to the receiver portion and configured to distinguish between hyperactive activity levels and hypoactive activity levels.

59. The computer-readable medium of claim 58 wherein the processor portion is operatively coupleable to multiple electrodes to direct electrical current to electrodes based at least in part on information received from the receiver portion.

60. The computer-readable medium of claim 59 wherein the processor portion is configured to direct electrical current preferentially to electrodes positioned proximate to neuronal structures exhibiting hypoactive activity levels.

61. The computer-readable medium of claim 59 wherein the processor portion is configured to shunt electrical current from electrodes positioned proximate to neuronal structures exhibiting hyperactive activity levels to electrodes positioned proximate to neuronal structures exhibiting hypoactive activity levels.

62. The computer-readable medium of claim 58 wherein the processor portion is programmed with instructions for comparing activity levels received from the receiver portion with target activity levels for normal neuronal cells.

63. A computer-readable medium, comprising:

a receiver portion configured to receive multiple segments of information corresponding to at least one characteristic of neuronal structures obtained at corresponding multiple points in time; and

a processor portion coupled to the receiver portion and being configured to automatically identify when the neuronal structures achieve a steady state based at least in part on the multiple segments of information.

64. The computer-readable medium of claim 63 wherein the receiver portion is programmed with instructions for receiving information corresponding to patient performance levels.