title: Transverse tripolar spinal cord stimulation: results of an international multicenter study.
abstract: Experienced neurosurgeons at eight spinal cord stimulation centers in the United States, Canada, and Europe participated in a study from 1997 to 2000 investigating the safety, performance, and efficacy of a Transverse Tripolar Stimulation (TTS) system invented at the University of Twente, the Netherlands. This device was proposed to improve the ability of spinal cord stimulation to adequately overlap paresthesia to perceived areas of pain. Fifty-six patients with chronic, intractable neuropathic pain of the trunk and/or limbs more than three months' duration (average 105 months) were enrolled with follow-up periods at 4, 12, 26, and 52 weeks. All patients had a new paddle-type lead implanted with four electrodes, three of them aligned in a row perpendicular to the cord. Fifteen of these patients did not undergo permanent implantation. Of the 41 patients internalized, 20 patients chose conventional programming using an implanted pulse generator to drive four electrodes, while 21 patients chose a tripole stimulation system, which used radiofrequency power and signal transmission and an implanted dual-channel receiver to drive three electrodes using simultaneous pulses of independently variable amplitude. On average, the visual analog scale scores dropped more for patients with TTS systems (32%) than for conventional polarity systems (16%). Conventional polarity systems were using higher frequencies on average, while usage range was similar. Most impressive was the well-controlled "steering" of the paresthesias according to the dermatomal topography of the dorsal columns when using the TTS-balanced pulse driver. The most common complication was lead migration. While the transverse stimulation system produced acceptable outcomes for overall pain relief, an analysis of individual pain patterns suggests that it behaves like spinal cord stimulation in general with the best control of extremity neuropathic pain. This transverse tripole lead and driving system introduced the concept of electrical field steering by selective recruitment of axonal nerve fiber tracts in the dorsal columns.
authors.affiliation: Northern Rockies Regional Pain Center, Billings, Montana, USA;              Department of Surgery, Kingston General Hospital, Kingston, Ontario, Canada;              Westfälische Wilhelms-Universität, Klinik für Neurochirurgie, 48149 Münster, Germany;              MacKenzie Health Sciences Centre, Edmonton, Alberta, Canada;              Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon, USA;              Neurosurgery Department, Moncton Hospital, Moncton, New Brunswick, Canada;              Department of Neurosurgery, De Wever Hospital, Heerlen, The Netherlands;              Department of Neurosurgery, U.Z. Gasthuisberg, Leuven, Belgium;              Medtronic Neurological, Columbia Heights, Minn, USA; and              University of Twente, Deptment of Electrical Engineering, Enschede, The Netherlands.
authors.forename: John C
authors.initials: JC
authors.lastname: Oakley
authors.forename: Francisco
authors.initials: F
authors.lastname: Espinosa
authors.forename: Hans
authors.initials: H
authors.lastname: Bothe
authors.forename: John
authors.initials: J
authors.lastname: McKean
authors.forename: Peter
authors.initials: P
authors.lastname: Allen
authors.forename: Kim
authors.initials: K
authors.lastname: Burchiel
authors.forename: Gilbert
authors.initials: G
authors.lastname: Quartey
authors.forename: Geert
authors.initials: G
authors.lastname: Spincemaille
authors.forename: Bart
authors.initials: B
authors.lastname: Nuttin
authors.forename: Frans
authors.initials: F
authors.lastname: Gielen
authors.forename: Gary
authors.initials: G
authors.lastname: King
authors.forename: Jan
authors.initials: J
authors.lastname: Holsheimer