Zonisamide decreases cortical excitability in patients with idiopathic generalized epilepsy.
OBJECTIVE
To evaluate changes in cortical excitability after long-term zonisamide (ZNS) administration.


METHODS
Fifteen drug-naïve idiopathic generalized epilepsy (IGE) patients (8 male, mean age 24.9 years) were enrolled. The transcranial magnetic stimulation (TMS) parameters obtained using two Magstim 200 stimulators were resting motor threshold (RMT), motor evoked potential (MEP) amplitudes, cortical silent period (CSP), intracortical inhibition (ICI), and intracortical facilitation (ICF). TMS parameters were compared before and after ZNS administration.


RESULTS
All patients were administered ZNS monotherapy (200 mg/day) for 8 weeks. No patient reported seizures during the study period. After ZNS treatment MEP amplitudes were significantly reduced in right (-34.2%) and left hemispheres (-37.0%) (Wilcoxon's signed rank test after Bonferroni's correction for multiple comparisons, P < 0.05). Mean RMT, CSP, and ICI/ICF were not changed by ZNS (P > 0.05).


CONCLUSIONS
These findings suggest that ZNS decreases cortical excitability in patients with IGE and a MEP amplitude is a useful TMS parameter for evaluating changes in cortical excitability induced by ZNS.


CONCLUSIONS
The findings in this study are helpful to understand how ZNS affects the excitability of the motor cortex in patients with IGE.
Joo
Eun Yeon
EY
Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul 135-710, Republic of Korea.
Kim
Sun Hwa
SH
Seo
Dae Won
DW
Hong
Seung Bong
SB
D000293:Adolescent; D000328:Adult; D000927:Anticonvulsants / Q000627:therapeutic use*; D004558:Electric Stimulation / Q000379:methods; D004829:Epilepsy, Generalized / Q000188:drug therapy*; D019054:Evoked Potentials, Motor / Q000187:drug effects* / Q000528:radiation effects; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007555:Isoxazoles / Q000627:therapeutic use*; D008297:Male; D009044:Motor Cortex / Q000187:drug effects* / Q000503:physiopathology / Q000528:radiation effects; D009433:Neural Inhibition; D018709:Statistics, Nonparametric; D050781:Transcranial Magnetic Stimulation; D000078305:Zonisamide
D000927:Anticonvulsants; D007555:Isoxazoles; D000078305:Zonisamide