Lamotrigine and valproic acid have different effects on motorcortical neuronal excitability

Brain Stimulation Laboratory, Department of Psychiatry, Medical University of South Carolina, MUSC IOP, 502 N, 67 President Street, Charleston, SC, 29425, USA.
Journal of Neural Transmission (Impact Factor: 2.4). 03/2009; 116(4):423-9. DOI: 10.1007/s00702-009-0195-z
Source: PubMed


To investigate different cortical effects of lamotrigine and valproic acid, 30 paid healthy adult men were given, in a randomized/blinded fashion on three separate days (separated by a week), either a single dose of lamotrigine 325 mg, or a single dose of valproic acid 1,250 mg, or placebo. Resting motor threshold (RMT), cortical silent period (CSP) and motor evoked potential recruitment curves (RC) were assessed at baseline and 3 h after administration of each medication (or placebo). Lamotrigine caused a significant increase (63.32 vs. 69.25) in the RMT, compared with an insignificant increase following valproic acid (62.50 vs. 63.35), and a decrease (62.60 vs. 62.36) following placebo (F (2,26) = 18.58, P < 0.0001). No significant difference in CSP was found between placebo and drugs (F (2,26) = 0.119, P > 0.05). RCs were significantly suppressed by lamotrigine (t = 2.07, P < 0.05) and enhanced by valproic acid (t = 2.39, P < 0.05). Lamotrigine and valproic acid have different effects on cortical neuronal excitability as demonstrated by TMS.

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Available from: Raffaella Ricci, Nov 12, 2014
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