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Effect of levetiracetam on cortical excitability: a transcranial magnetic stimulation study
Author(s) -
Solinas C.,
Lee Y. C.,
Reutens D. C.
Publication year - 2008
Publication title -
european journal of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.881
H-Index - 124
eISSN - 1468-1331
pISSN - 1351-5101
DOI - 10.1111/j.1468-1331.2008.02110.x
Subject(s) - transcranial magnetic stimulation , levetiracetam , medicine , motor cortex , silent period , stimulation , anesthesia , neuroscience , psychology , epilepsy , psychiatry
Background and purpose: We studied the effect of levetiracetam (LEV), an anticonvulsant with a novel mechanism of action, on cortical excitability, measured using transcranial magnetic stimulation (TMS). For this purpose, 38 healthy volunteers were assessed in two TMS sessions, before and after an oral dose of 3000 mg LEV. Methods: Resting motor threshold (RMT), intracortical facilitation (ICF) and intracortical inhibition (ICI), cortical silent period (CSP) threshold and duration and motor‐evoked potential (MEP) amplitude were calculated. Results: After treatment with LEV, RMT was increased (mean ± SD: 63 ± 14% of the maximum stimulator output) compared with baseline (58 ± 11%). CSP threshold was decreased after LEV (54 ± 10%; baseline, 57 ± 11%). CSP duration was increased after LEV (116 ± 37 ms; baseline: 102 ± 33 ms). LEV did not affect ICF or ICI or mean MEP amplitude significantly. Conclusions: Our results indicate that LEV modulates some aspects of cortical excitability. Whereas the increase in the RMT most probably reflects the effect of LEV on ion channel activity, effects on the CSP might represent a modulation of GABA receptors at cortical and spinal level.