Implantable cortical neural lead and method

• US 20040243205A1
• Filed: 05/30/2003
• Published: 12/02/2004
• Est. Priority Date: 05/30/2003
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: NʼGuyen, Jean Paul, Gielen, Frans L. H., Cross, Thomas E. Jr., Van Venrooij, Paulus, Keravel, Yves
• Granted Patent: US 7,107,104 B2
• Time in Patent Office: Days
• US Class Current: 607/116
• CPC Class Codes: A61N 1/0531 Brain cortex electrodes
• CPC Class Codes: A61N 1/0553 Paddle shaped electrodes, e.g. for laminotomy

Abstract

A neural lead and method of treating neurological disorders by stimulation of the cerebral cortex of the brain is provided. The lead is designed for reduction of strain between the lead body and the lead paddle caused by the position of the lead body above the cranium and the lead paddle beneath the cranium. The lead is also designed to include a two dimensional chronic electrode array for better stimulation coverage of the target area of the cerebral cortex. A method of treating a neurological disorder by stimulating the cerebral cortex is also presented.

Claims

1. An implantable neural lead adapted for use in electrically stimulating the cerebral cortex, the lead comprising:

a paddle having first and second opposite major surfaces, and a plurality of electrically isolated electrodes exposed through the first major surface;

a lead body including a plurality of electrically conductive wires in electrical communication with the electrodes; and

a strain relief connecting the paddle with the lead body, the strain relief offsetting the lead body from the second surface of the paddle a distance sufficient to accommodate the thickness of a patient'"'"'s skull bone.

2. The implantable neural lead of claim 1 in which the lead body has a distal end adjacent the strain relief, the strain relief tends to hold the paddle and the distal end of the lead body in a generally parallel yet displaced relationship.

3. The implantable neural lead of claim 2 in which the paddle has a peripheral edge, the strain relief being connected to the paddle along the peripheral edge.

4. The implantable neural lead of claim 3 in which the strain relief causes the electrically conductive wires to extend along a generally “

S”

shaped path between the lead body and the paddle.

5. The implantable neural lead of claim 4 in which the strain relief provides means for relieving strain as tension is applied between the paddle and the lead body.

6. The implantable neural lead of claim 5 in which the strain relief is molded of elastomeric material, the electrically conductive wires each integrally extending between the electrodes and the proximal end of lead body.

7. The implantable neural lead of claim 6 in which the paddle further includes a fibrous reinforcing layer sandwiched between resiliently-flexible layers.

10. The implantable neural lead of claim 1 in which the plurality of electrically isolated electrodes comprises a two dimensionally distributed electrode array.

11. The implantable neural lead of claim 1 wherein the strain relief comprises a strain relief connector.

8. The implantable neural lead of 1 in which the strain relief offsets the lead body from the first major surface of the paddles a distance between about 4-10 mm.

9. The implantable neural lead of claim 8 in which the strain relief offsets the lead body from the first major surface of the paddle a distance of about 6 mm.

12. An implantable neural lead adapted for use in electrically stimulating the cerebral cortex of the brain, the lead comprising:

at least one lead body having proximal and distal ends and including a plurality of electrically conductive wires, the lead body defining an axial direction; and

a lead paddle having a two dimensionally distributed electrode array including a plurality of electrically isolated electrodes, the plurality of electrodes including a first set of at least three electrodes defining an axis of the paddle, and a second set of electrodes offset in opposite directions from the axis of the paddle.

13. The implantable neural lead of claim 12 in which the at least one lead body includes:

a first lead body containing electrically conductive wires in electrical communication with the first set of electrodes; and

a second lead body containing electrically conductive wires in electrical communication with the second set of electrodes.

14. The implantable neural lead of claim 12 in which the lead paddle comprises a generally round sheet of resiliently-flexible material.

15. The implantable neural lead of claim 12 in which the axis of the paddle is generally parallel with the axial direction of the lead body.

16. The implantable neural lead of claim 13 in which the lead paddle has first and second opposite major surfaces, the first and second set of electrodes being exposed through the first major surface, the lead further comprising:

at least one strain relief connecting the lead paddle with the lead bodies, the at least one strain relief displacing the lead bodies from the first surface of the paddle a distance sufficient to accommodate the thickness of a patient'"'"'s skull bone.

17. The implantable neural lead of claim 16 in which the at least one strain relief comprises first and second strain reliefs corresponding to the first and second lead bodies.

18. The implantable neural lead of claim 17 in which the first and second strain reliefs cause the electrically conductive wires to extend along a generally “

S”

shaped path between the lead bodies and the lead paddle.

19. The implantable neural lead of claim 16 in which the strain relief is molded of elastomeric material, the electrically conductive wires each integrally extending between the electrodes and the proximal end of lead body.

20. The implantable neural lead of claim 12 in which the second set of electrodes comprises an equal number of electrodes offset in opposite directions from the axis of the lead paddle.

21. The implantable neural lead of claim 20 in which the first set of electrodes comprises four electrodes and the second set of electrodes comprises four electrodes.

22. The implantable neural lead of claim 21 in which:

the four electrodes of the first set constitute electrodes 0, 1, 2 and 3 and are substantially equally spaced apart by a distance “

G”

in numerical order; and

the four electrodes of the second set constitute electrodes 4, 5, 6 and 7 laterally spaced apart from electrodes 1 and 2.

23. The implantable neural lead of claim 22 in which:

electrodes 4 and 6 are laterally spaced in opposite directions from electrode 1 by a distance substantially equal to distance “

G”

;

electrodes 5 and 7 are laterally spaced in opposite directions from electrode 2 by a distance substantially equal to distance “

G”

;

electrodes 4 and 5 are spaced apart by a distance substantially equal to distance “

G”

; and

electrodes 6 and 7 are spaced apart by a distance substantially equal to distance “

G”

.

24. The implantable neural lead of claim 12 in which the lead paddle comprises first and second film layers and a fibrous reinforcing web sandwiched between the first and second film layers, the fibrous reinforcing web being relatively inelastic in comparison with the first and second film layers.

25. The implantable neural lead of claim 24 in which the fibrous reinforcing web comprises a woven web.

26. An implantable neural lead adapted for use in electrically stimulating the cerebral cortex, the lead comprising:

at least one lead body having proximal and distal ends and including a plurality of electrically conductive wires, the lead body defining an axial direction; and

a lead paddle having a two dimensionally distributed electrode array including a plurality of electrically isolated electrodes, wherein the lead paddle comprises a peripheral edge defining at least two peninsulas and at least two bays.

27. The implantable neural lead of claim 26 wherein the at least two peninsulas and at least two bays comprise six peninsulas and 6 bays.

28. A method of treating a neurological disorder by stimulation of the cerebral cortex of the brain comprising:

providing an implantable neural lead comprising;

at least one lead body having proximal and distal ends and including a plurality of electrically conductive wires; and

a lead paddle having a two dimensionally distributed electrode array including a plurality of electrically isolated electrodes connected to the plurality of electrically conductive wires;

creating an opening through the skull bone of a patient to access an area adjacent the cortex;

placing the lead paddle within the area;

determining a satisfactory orientation for the lead paddle for reduction in symptoms of the neurological disorder;

based upon the step of determining a satisfactory orientation for the lead paddle, permanently attaching the lead paddle within the area for chronic stimulation; and

implanting a pulse generator in electrical communication with the plurality of electrically conductive wires.

29. The method of claim 28 wherein the area is an epidural area.

30. The method of claim 28 wherein the area is a subdural area.

31. The method of claim 28 wherein creating an opening comprises creating an opening through the skull bone of a patient to access an epidural area adjacent the central sulcus of the cortex.

32. The method of claim 28 wherein the neurological disorder being treated comprises pain.

33. The method of claim 28 wherein the neurological disorder being treated comprises a movement disorder.

34. The method of claim 33 wherein the movement disorder comprises Parkinson'"'"'s disease.

35. The method of claim 33 wherein the movement disorder comprises essential tremor.

36. The method of claim 28 wherein the neurological disorder being treated comprises a psychological disorder.

37. The method of claim 36 wherein the psychological disorder comprises depression.

38. The method of claim 36 wherein the psychological disorder comprises obsessive compulsive disorder.

39. The method of claim 28 wherein the determining a satisfactory orientation comprises stimulating with at least one electrode and determining whether the stimulation results in sufficient relief from a symptom of the neurological disorder.

40. The method of claim 28 wherein the determining a satisfactory orientation comprises stimulating with at least one electrode and observing an evoked response.

41. The method of claim 39 wherein the determining a satisfactory orientation further comprises moving the lead paddle to a different orientation and providing a second stimulation with at least one electrode and determining whether the second stimulation results in sufficient relief from the symptom of the neurological disorder.

42. The method of claim 40 wherein the determining a satisfactory orientation further comprises moving the lead paddle to a different orientation and providing a second stimulation with at least one electrode and observing an evoked response from the second stimulation.

43. The method of claim 28 wherein the permanently attaching comprises suturing the lead paddle to the dura mater.

44. A method of treating a neurological disorder by electrical stimulation of the cerebral cortex comprising:

providing an implantable neural lead comprising;

a lead paddle having a two dimensionally distributed electrode array including a plurality of electrically isolated electrodes, the plurality of electrodes including a first set of electrodes defining an axis of the paddle, and a second set of electrodes offset in opposite directions from the axis of the paddle;

a first lead body containing a first plurality of electrically conductive wires in electrical communication with the first set of electrodes; and

a second lead body containing a second plurality of electrically conductive wires in electrical communication with the second set of electrodes;

creating an opening through the skull bone of a patient to access an area adjacent the cortex;

placing the lead paddle within the area;

determining whether stimulation with the first set of electrodes provides sufficient relief; and

based on the step of determining whether stimulation with the first set of electrodes provides sufficient relief, implanting either a single channel implantable pulse generator in electrical communication with the first set of electrodes or a multiple channel implantable pulse generator in electrical communication with the first and second sets of electrodes.

45. The method of claim 44 wherein creating an opening comprises creating an opening through the skull bone of a patient to access an epidural area adjacent the central sulcus of the cortex.

46. The method of claim 45 wherein placing the lead paddle within the epidural area comprises placing the lead paddle within the epidural area with the first set of electrodes orientated generally parallel to the central sulcus.

47. The method of claim 45 wherein placing the lead paddle within the epidural area comprises placing the lead paddle within the epidural area with the first set of electrodes oriented generally perpendicular to the central sulcus.