There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.
Abstract
In this study, we aimed to evaluate motor cortical excitability changes in patients
with juvenile myoclonic epilepsy (JME) and their asymptomatic siblings (AS) using
single-pulse transcranial magnetic stimulation (spTMS). 21 patients with JME and their
21 AS were compared to 20 healthy controls. All of JME patients were receiving antiepileptic
therapy and their seizures were well controlled. Firstly, standard EEG examinations
and then TMS studies were performed. Resting motor threshold (RMT), motor evoked potential
(MEP) amplitudes, the durations of central motor conduction time (CMCT) and cortical
silent period (CSP) were measured. After TMS studies, EEG recordings were repeated
in an hour to evaluate any effect of TMS study on EEG. There were no significant differences
between the first and second EEG recordings. No seizures were recorded during and
after the TMS study. RMT was found higher in JME patients than AS and normal controls.
There were no significant differences between cortical MEP amplitudes and MEP amplitude/CMAP
(compound muscle action potential) amplitude ratio in all three groups. CMCT duration
was shorter in JME patients than AS. CSP durations of JME patients were found to be
longer than controls. In AS, CSP durations were also found to be longer than controls
but this difference was not found statistically significant. Our results suggested
that although high MT may be related to antiepileptic therapy, the prolongation of
CSP duration may reflect impairment of supraspinal and/or intracortical inhibitory
mechanism in JME. To eliminate the drug effect, further studies are needed in newly
diagnosed JME patients without medication and large series of their asymptomatic siblings.