Selective dorsal column stimulation in SCS, using conditioning pulses

• US 20020128694A1
• Filed: 05/07/2002
• Published: 09/12/2002
• Est. Priority Date: 04/30/1998
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Holsheimer, Jan
• Granted Patent: US 6,675,046 B2
• Time in Patent Office: Days
• US Class Current: 607/46
• CPC Class Codes: A61N 1/3604 for correcting spinal deformities, e.g. scoliosis

Abstract

A system and method is described for preferentially stimulating dorsal column fibers while avoiding stimulation of dorsal root fibers. The invention applies hyperpolarizing pre-pulses and depolarizing pre-pulses to neural tissue, such as spinal cord tissue, through a lead placed over the spinal cord having the electrodes arranged on a line approximately transverse to the axis of the spine. To increase the threshold needed to stimulate dorsal root fibers, the anodal pulse given by each lateral contact of the electrodes has to be preceded by a depolarizing pre-pulse and simultaneously, the central electrode contact gives a hyperpolarizing pre-pulse, thereby reducing the stimulation threshold for the dorsal column fibers to subsequent depolarizing pulses.

Claims

1. A method of electrically stimulating neural tissue of the spinal cord comprising the steps of:

providing a source of electrical pulses;

providing a first electrode and an electrical return path;

connecting the first electrode to the source of electrical pulses;

placing the first electrode near a patient'"'"'s spinal cord;

applying a hyperpolarizing electrical pre-pulse to the tissue through the first electrode and source of electrical pulses whereby the tissue is more susceptible to subsequent electric stimulation.

2. The method of claim 1 further comprising the step of applying a subsequent depolarizing electrical pulse to the tissue through the first electrode.

3. The method of claim 1 wherein the step of providing an electrical return path includes the step of providing an electrical return path that includes a second electrode.

4. The method of claim 1 wherein the step of providing an electrical return path includes the step of providing an electrical return path that includes the source of electrical pulses.

5. The method of claim 1 wherein the step of placing the first electrode near a patient'"'"'s spinal cord includes the step of placing the first electrode near a patient'"'"'s spinal cord so that the first electrode is generally over a midline of the patient'"'"'s spinal cord.

6. The method of claim 1 wherein the step of placing the first electrode includes the step of implanting the first electrode within the patient'"'"'s body near a patient'"'"'s spinal cord.

7. The method of claim 1 wherein the step of providing the first electrode includes the step of providing a second electrode spaced from the first electrode and further comprising the step of connecting the second electrode to the source of electrical pulses.

8. The method of claim 7 further comprising the step of:

applying a depolarizing electrical pre-pulse to the tissue through the second electrode and source of electrical pulses whereby the tissue near the second electrode is less susceptible to subsequent electric stimulation.

9. The method of claim 8 wherein the step of placing the first electrode near a patient'"'"'s spinal cord includes the step of placing the second electrode near a dorsal root of the patient'"'"'s spinal cord.

10. The method of claim 8 wherein the step of providing a first electrode and a second electrode spaced from the first electrode includes the step of providing a third electrode spaced from the first electrode opposite the second electrode so that the first electrode is generally between the second and third electrodes and further comprising the step of connecting the third electrode to the source of electrical pulses.

11. The method of claim 10 further comprising the step of:

applying a depolarizing electrical pre-pulse to the tissue through the third electrode and source of electrical pulses whereby the tissue near the third electrode is less susceptible to subsequent electric stimulation.

12. The method of claim 1 wherein the step of placing the first electrode near a patient'"'"'s spinal cord includes the step of placing the third electrode near a dorsal root of the patient'"'"'s spinal cord wherein the dorsal root near the third electrode is different than the dorsal root near the second electrode.

13. The method of claim 7 wherein the step of providing a first electrode and a second electrode spaced from the first electrode includes the step of providing a third electrode spaced from the first electrode opposite the second electrode so that the first electrode is generally between the second and third electrodes and further comprising the step of connecting the third electrode to the source of electrical pulses.

14. The method of claim 13 further comprising the step of:

applying a depolarizing electrical pre-pulse to the tissue through the third electrode and source of electrical pulses whereby the tissue near the third electrode is less susceptible to subsequent electric stimulation.

15. The method of claim 14 wherein the step of placing the first electrode near a patient'"'"'s spinal cord includes the step of placing the third electrode near a dorsal root of the patient'"'"'s spinal cord wherein the dorsal root near the third electrode is different than the dorsal root near the second electrode.

16. The method of claim 13 wherein the step of providing a first, second and third electrode includes the step of providing a first, second and third electrode on a single lead.

17. The method of claim 7 wherein the step of providing a first and second electrode includes the step of providing a first and second electrode on a single lead.

18. The method of claim 1 further comprising the step of implanting the source of electrical pulses within the patient'"'"'s body.

20. The method of claim 19 further comprising the step of applying a subsequent depolarizing electrical pulse to the tissue through the first electrode.

21. The method of claim 19 further comprising the step of applying a subsequent hyperpolarizing electrical pulse to the tissue through the second electrode.

22. The method of claim 19 wherein the step of placing the lead near a patient'"'"'s spinal cord includes the step of placing the second electrode near a dorsal root of the patient'"'"'s spinal cord.

23. The method of claim 19 wherein the step of providing a lead having a first electrode and a second electrode spaced from the first electrode includes the step of providing a third electrode spaced from the first electrode opposite the second electrode so that the first electrode is generally between the second and third electrodes and wherein the step of connecting the lead to the source of electrical pulses also includes the step of connecting the third electrode to the second output of the source of electrical pulses.

24. The method of claim 23 further comprising the step of:

applying a depolarizing electrical pre-pulse to the tissue through the third electrode of the lead and source of electrical pulses whereby the tissue near the third electrode is less susceptible to subsequent electric stimulation; and

,

applying a subsequent hyperpolarizing electrical pulse to the tissue through the third electrode.

25. The method of claim 24 wherein the step of placing the lead near a patient'"'"'s spinal cord includes the step of placing the third electrode near a dorsal root of the patient'"'"'s spinal cord wherein the dorsal root near the third electrode is different than the dorsal root near the second electrode.

26. The method of claim 19 further comprising the step of implanting the source of electrical pulses within the patient'"'"'s body.

28. The method of claim 27 further comprising the step of applying a subsequent depolarizing electrical pulse to the tissue through the first electrode.

29. The method of claim 27 further comprising the step of applying a subsequent hyperpolarizing electrical pulse to the tissue through the second and third electrodes.

30. The method of claim 27 further comprising the step of implanting the source of electrical pulses within the patient'"'"'s body.

19. A method of electrically stimulating neural tissue of the spinal cord comprising the steps of:

providing a source of electrical pulses having a first and a second output;

providing a lead having a first electrode and a second electrode spaced from the first electrode;

connecting the lead to the source of electrical pulses so that the first and second electrodes are connected to the first and second outputs, respectively, of the source of electrical pulses;

placing the lead within a patient'"'"'s body near a patient'"'"'s spinal cord so that the first electrode is generally over a midline of the patient'"'"'s spinal cord;

applying a hyperpolarizing electrical pre-pulse to the tissue through the first electrode of the lead and source of electrical pulses whereby the tissue is more susceptible to subsequent electric stimulation;

applying a depolarizing electrical pre-pulse to the tissue through the second electrode of the lead and source of electrical pulses whereby the tissue near the second electrode is less susceptible to subsequent electric stimulation.

27. A method of electrically stimulating neural tissue of the spinal cord comprising the steps of:

providing a source of electrical pulses having a first and a second output;

providing a lead having a first electrode, a second electrode spaced from the first electrode and a third electrode spaced from the first electrode opposite the second electrode so that the first electrode is generally between the second and third electrodes;

connecting the lead to the source of electrical pulses so that the first electrode is connected to the first output of the source of electrical pulses and the second and third electrodes are connected to the second output of the source of electrical pulses;

placing the lead within a patient'"'"'s body near a patient'"'"'s spinal cord so that the first electrode is generally over a midline of the patient'"'"'s spinal cord and so that the second and third electrodes are near different dorsal roots of the patient'"'"'s spinal cord;

applying a hyperpolarizing electrical pre-pulse to the tissue through the first electrode of the lead and source of electrical pulses whereby the tissue is more susceptible to subsequent electric stimulation;

applying a depolarizing electrical pre-pulse to the tissue through the second and third electrodes of the lead and source of electrical pulses whereby the tissue near the second and third electrodes is less susceptible to subsequent electric stimulation.

31. A method of electrically stimulating neural tissue of the spinal cord comprising the steps of:

providing a source of electrical pulses;

providing a first electrode and an electrical return path;

connecting the first electrode to the source of electrical pulses;

placing the first electrode near a patient'"'"'s spinal cord;

applying a depolarizing electrical pre-pulse to the tissue through the first electrode and source of electrical pulses whereby the tissue is less susceptible to subsequent electric stimulation;

applying a subsequent hyperpolarizing electrical pulse to the tissue through the first electrode.

32. The method of claim 31 wherein the step of providing an electrical return path includes the step of providing an electrical return path that includes a second electrode.

33. The method of claim 31 wherein the step of providing an electrical return path includes the step of providing an electrical return path that includes the source of electrical pulses.

34. The method of claim 31 wherein the step of placing the first electrode near a patient'"'"'s spinal cord includes the step of placing the first electrode near a patient'"'"'s spinal cord so that the first electrode is generally over a dorsal root of the patient'"'"'s spinal cord.

35. The method of claim 31 wherein the step of placing the first electrode includes the step of implanting the first electrode within the patient'"'"'s body near a patient'"'"'s spinal cord.

36. The method of claim 31 wherein the step of providing a first electrode includes providing a second electrode spaced from the first electrode and further comprising the step of connecting the second electrode to the source of electrical pulses.

37. The method of claim 36 further comprising the step of:

applying a depolarizing electrical pre-pulse to the tissue through the second electrode and source of electrical pulses whereby the tissue near the second electrode is less susceptible to subsequent electric stimulation.

38. The method of claim 37 wherein the step of placing the first electrode near a patient'"'"'s spinal cord includes the step of placing the second electrode near a dorsal root of the patient'"'"'s spinal cord.

39. The method of claim 38 wherein the step of providing a first electrode and a second electrode spaced from the first electrode includes the step of providing a third electrode spaced from the first electrode opposite the second electrode so that the first electrode is generally between the second and third electrodes and further comprising the step of connecting the third electrode to the source of electrical pulses.

40. The method of claim 39 further comprising the step of:

applying a depolarizing electrical pre-pulse to the tissue through the third electrode and source of electrical pulses whereby the tissue near the third electrode is less susceptible to subsequent electric stimulation.

41. The method of claim 40 wherein the step of placing the first electrode near a patient'"'"'s spinal cord includes the step of placing the third electrode near a dorsal root of the patient'"'"'s spinal cord.

42. The method of claim 37 wherein the step of placing the first electrode near a patient'"'"'s spinal cord includes the step of placing the first electrode near a patient'"'"'s spinal cord so that the first electrode is generally over a first dorsal root of the patient'"'"'s spinal cord and so that the second electrode is placed near a second dorsal root of the patient'"'"'s spinal cord wherein the first dorsal root is different than the second dorsal root.

43. The method of claim 36 wherein the step of providing a first electrode and a second electrode spaced from the first electrode includes the step of providing a third electrode spaced from the first electrode opposite the second electrode so that the first electrode is generally between the second and third electrodes and further comprising the step of connecting the third electrode to the source of electrical pulses.

44. The method of claim 31 further comprising the step of implanting the source of electrical pulses within the patient'"'"'s body.

46. The method of claim 45 further comprising the step of applying a subsequent depolarizing electrical pulse to the tissue through the first electrode.

47. The method of claim 45 wherein the step of providing an electrical return path includes the step of providing an electrical return path that includes a second electrode.

48. The method of claim 45 wherein the step of providing an electrical return path includes the step of providing an electrical return path that includes the source of electrical pulses.

49. The method of claim 45 wherein the step of providing a first electrode having a first electrode includes providing a second electrode spaced from the first electrode and further comprising the step of connecting the second electrode to the source of electrical pulses.

50. The method of claim 49 further comprising the step of:

applying a depolarizing electrical pre-pulse to the tissue through the second electrode and source of electrical pulses whereby the tissue near the second electrode is less susceptible to subsequent electric stimulation.

51. The method of claim 50 wherein the step of providing a first electrode and a second electrode spaced from the first electrode includes the step of providing a third electrode spaced from the first and second electrodes and further comprising the step of connecting the third electrode to the source of electrical pulses.

52. The method of claim 51 further comprising the step of:

applying a depolarizing electrical pre-pulse to the tissue through the third electrode and source of electrical pulses whereby the tissue near the third electrode is less susceptible to subsequent electric stimulation.

53. The method of claim 51 further comprising the step of:

applying a hyperpolarizing electrical pre-pulse to the tissue through the third electrode and source of electrical pulses whereby the tissue near the third electrode is more susceptible to subsequent electric stimulation.

54. The method of claim 45 further comprising the step of implanting the source of electrical pulses within the patient'"'"'s body.

45. A method of electrically stimulating neural tissue of the brain comprising the steps of:

providing a source of electrical pulses;

providing a first electrode;

providing an electrical return path;

connecting the first electrode to the source of electrical pulses;

placing the first electrode in tissue of a patient'"'"'s brain;

applying a hyperpolarizing electrical pre-pulse to the tissue through the first electrode and source of electrical pulses whereby the tissue is more susceptible to subsequent electric stimulation.

55. A method of electrically stimulating neural tissue of the brain comprising the steps of:

providing a source of electrical pulses;

providing a first electrode;

providing an electrical return path;

connecting the first electrode to the source of electrical pulses;

placing the first electrode in tissue of a patient'"'"'s brain;

applying a depolarizing electrical pre-pulse to the tissue through the first electrode and source of electrical pulses whereby the tissue is less susceptible to subsequent electric stimulation.

56. The method of claim 55 further comprising the step of applying a subsequent hyperpolarizing electrical pulse to the tissue through the first electrode.

58. The method of claim 57 wherein the step of providing an electrical return path includes the step of providing an electrical return path that includes a second electrode.

59. The method of claim 57 wherein the step of providing an electrical return path includes the step of providing an electrical return path that includes the source of electrical pulses.

60. The method of claim 57 wherein the step of providing a first electrode includes the step of providing a second electrode spaced from the first electrode and further comprising the step of connecting the second electrode to the source of electrical pulses.

61. The method of claim 60 further comprising the step of:

applying a depolarizing electrical pre-pulse to the tissue through the second electrode and source of electrical pulses whereby the tissue near the second electrode is less susceptible to subsequent electric stimulation.

62. The method of claim 61 wherein the step of providing a first electrode and a second electrode spaced from the first electrode includes the step of providing a third electrode spaced from the first and second electrodes and further comprising the step of connecting the third electrode to the source of electrical pulses.

63. The method of claim 62 further comprising the step of:

applying a depolarizing electrical pre-pulse to the tissue through the third electrode and source of electrical pulses whereby the tissue near the third electrode is less susceptible to subsequent electric stimulation.

64. The method of claim 62 further comprising the step of:

applying a hyperpolarizing electrical pre-pulse to the tissue through the third electrode and source of electrical pulses whereby the tissue near the third electrode is more susceptible to subsequent electric stimulation.

65. The method of claim 57 further comprising the step of implanting the source of electrical pulses within the patient'"'"'s body.

57. A method of electrically stimulating neural tissue of the brain comprising the steps of:

providing a source of electrical pulses;

providing a first electrode;

providing an electrical return path;

connecting the first electrode to the source of electrical pulses;

placing the first electrode on the surface of a patient'"'"'s brain;

applying a hyperpolarizing electrical pre-pulse to the tissue through the first electrode and source of electrical pulses whereby the tissue is more susceptible to subsequent electric stimulation;

applying a subsequent depolarizing electrical pulse to the tissue through the first electrode.

66. A method of electrically stimulating neural tissue of the brain comprising the steps of:

providing a source of electrical pulses;

providing a first electrode;

providing an electrical return path;

connecting the first electrode to the source of electrical pulses;

placing the first electrode on the surface of a patient'"'"'s brain;

applying a depolarizing electrical pre-pulse to the tissue through the first electrode and source of electrical pulses whereby the tissue is less susceptible to subsequent electric stimulation.

67. The method of claim 66 further comprising the step of applying a subsequent hyperpolarizing electrical pulse to the tissue through the first electrode.

69. The method of claim 68 further comprising the step of applying a subsequent depolarizing electrical pulse to the tissue through the first electrode.

70. The method of claim 68 further comprising the step of implanting the source of electrical pulses within the patient'"'"'s body.

68. A method of electrically stimulating neural tissue of the brain comprising the steps of:

providing a source of electrical pulses;

providing a first electrode, a second electrode spaced from the first electrode and a third electrode spaced from the first electrode opposite the second electrode so that the first electrode is generally between the second and third electrodes;

providing an electrical return path;

connecting the first, second and third electrodes to the source of electrical pulses;

placing the first, second and third electrodes within a patient'"'"'s body in a patient'"'"'s brain;

applying a hyperpolarizing electrical pre-pulse to the tissue through the first electrode and source of electrical pulses whereby the tissue is more susceptible to subsequent electric stimulation;

applying a depolarizing electrical pre-pulse to the tissue through the second and third electrodes and source of electrical pulses whereby the tissue near the second and third electrodes is less susceptible to subsequent electric stimulation.

71. A method of electrically stimulating peripheral nerve neural tissue, the peripheral nerve tissue having an axis generally aligned with the elongated dimension of the tissue, the method comprising the steps of:

providing a source of electrical pulses;

providing a first electrode and a second electrode, the first and second electrodes located along a line;

providing an electrical return path;

connecting the first and second electrodes to the source of electrical pulses;

placing the first electrode near a patient'"'"'s peripheral nerve so that the line including the first and second electrodes is generally transverse to the axis of the peripheral nerve;

applying a hyperpolarizing electrical pre-pulse to the tissue through the first electrode and source of electrical pulses whereby the tissue is more susceptible to subsequent electric stimulation;

applying a depolarizing electrical pre-pulse to the tissue through the second electrode and source of electrical pulses whereby the tissue near the second electrode is less susceptible to subsequent electric stimulation;

applying a subsequent depolarizing electrical pulse to the tissue through the first electrode.

72. The method of claim 71 wherein the step of providing an electrical return path includes the step of providing an electrical return path that includes the source of electrical pulses.

73. The method of claim 71 wherein the step of providing a first electrode and a second electrode includes the step of providing a third electrode and further comprising the step of connecting the third electrode to the source of electrical pulses.

74. The method of claim 73 wherein the step of providing a third electrode includes the step of providing a third electrode located generally along the line containing the first and second electrodes on the side of the first electrode opposite the second electrode.

75. The method of claim 74 wherein the step of applying a depolarizing electrical pre-pulse to the tissue through the second electrode and source of electrical pulses also includes the step of applying a depolarizing electrical pre-pulse to the tissue through the third electrode and source of electrical pulses whereby the tissue near the third electrode is less susceptible to subsequent electric stimulation.

76. The method of claim 74 wherein the step of applying a depolarizing electrical pre-pulse to the tissue through the second electrode and source of electrical pulses also includes the step of applying a hyperpolarizing electrical pre-pulse to the tissue through the third electrode and source of electrical pulses whereby the tissue near the third electrode is more susceptible to subsequent electric stimulation.

77. The method of claim 73 wherein the step of applying a depolarizing electrical pre-pulse to the tissue through the second electrode and source of electrical pulses also includes the step of applying a depolarizing electrical pre-pulse to the tissue through the third electrode and source of electrical pulses whereby the tissue near the third electrode is less susceptible to subsequent electric stimulation.

78. The method of claim 73 wherein the step of applying a depolarizing electrical pre-pulse to the tissue through the second electrode and source of electrical pulses also includes the step of applying a hyperpolarizing electrical pre-pulse to the tissue through the third electrode and source of electrical pulses whereby the tissue near the third electrode is more susceptible to subsequent electric stimulation.

80. The method of claim 79 further comprising the step of applying a subsequent depolarizing electrical pulse to the tissue through the second electrode.

81. The method of claim 79 further comprising the step of applying a hyperpolarizing electrical pre-pulse to the tissue through the third electrode and source of electrical pulses whereby the tissue near the third electrode is more susceptible to subsequent electrical stimulation.

82. The method of claim 81 further comprising the step of applying a subsequent depolarizing electrical pulse to the tissue through the third electrode.

79. A method of electrically stimulating peripheral nerve neural tissue comprising the steps of:

providing a source of electrical pulses;

providing a first electrode, a second electrode and a third electrode located on the side of the first electrode opposite the second electrode, the first, second and third electrodes located generally along a line;

providing an electrical return path;

connecting the first, second and third electrodes to the source of electrical pulses;

placing the first, second and third electrodes near a patient'"'"'s peripheral nerve so that the line including the first, second and third electrodes is generally transverse to the axis of the peripheral nerve;

applying a depolarizing electrical pre-pulse to the tissue through the first electrode and source of electrical pulses whereby the tissue is less susceptible to subsequent electric stimulation;

applying a hyperpolarizing electrical pre-pulse to the tissue through the second electrode and source of electrical pulses whereby the tissue near the second electrode is more susceptible to subsequent electric stimulation.

83. The method of claim further comprising the step of applying a depolarizing electrical pre-pulse to the tissue through the third electrode and source of electrical pulses whereby the tissue near the third electrode is less susceptible to subsequent electrical stimulation.