Open AccessSpinal Cord Stimulation Inhibits Cortical Somatosensory Evoked Potentials Significantly Stronger than Transcutaneous Electrical Nerve Stimulation
Author(s) -
Tilman Wolter
Publication year - 2013
Publication title -
pain physician
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.31
H-Index - 99
eISSN - 2150-1149
pISSN - 1533-3159
DOI - 10.36076/ppj.2013/16/405
Subject(s) - medicine , stimulation , somatosensory evoked potential , somatosensory system , anesthesia , transcutaneous electrical nerve stimulation , spinal cord , neuropathic pain , central nervous system , nociception , neuroscience , psychology , receptor , psychiatry , alternative medicine , pathology
Background: Despite the good clinical results elicited by spinal cord stimulation (SCS), thephysiological basis of action of SCS is widely unknown. Inhibition of somatosensory evokedpotential (SEP) amplitudes by SCS has been described, but it is unclear whether this displaysdose dependency. Moreover, it is unknown whether the pain-relieving effect elicited by SCScorrelates with the inhibition of SEPs. Finally, this study aimed to answer the question whetherthere is a difference in the effect on SEPs between SCS and transcutaneous electrical nervestimulation (TENS), thus between central nervous system stimulation and peripheral nervoussystem stimulation.Methods: Ten patients (4 men and 6 women, age range 40-77 years) with neuropathic lowerlimb pain were included in the study. All patients had implanted SCS systems with percutaneoustype electrodes. Cortical SEPs under SCS and TENS were measured without stimulation, understimulation at perception threshold (PT), and at maximal threshold (MT) in a crossover design.Results: Cortical SEP amplitudes were significantly inhibited by SCS. Stimulation at PT and atMT both led to a statistically significant inhibition of the SEP amplitude. The difference betweenamplitude reduction at PT and MT showed a tendency towards significance. The degree of SEPamplitude inhibition did not correlate with pain relief. Inhibition of SEP amplitudes by TENS wasweaker than that elicited by SCS. The average percentage of amplitude reduction at MT wastwice as high under SCS as it was under TENS. No effects on SEP latencies were seen.Conclusions: SCS exerts a significantly stronger inhibition of SEP amplitudes than TENS. Thedata hint at a dose dependency of SCS-induced SEP amplitude inhibition. No correlation betweenSEP amplitude inhibition and pain relief was found.Key words: spinal cord stimulation, SCS, transcutaneous electrical nerve stimulation, TENS,neuropathic pain, somatosensory evoked potentials, SEP