Cortical excitability in patients with juvenile myoclonic epilepsy and praxis-induced seizures - study by transcranial magnetic stimulation

Abstract

This study aims to investigate cortical excitability in patients with Juvenile Myoclonic Epilepsy (JME) and praxis-induced seizures. It was designed as a transversal controlled study, with total sample of 60 subjects who should be submitted to Transcranial Magnetic Stimulation (TMS). The sample will be composed by three groups: healthy controls (n=20), JME patients with praxis-induced seizures (n=10) and JME patients without reflex-seizures (n=30). JME patients are outpatients regularly treated at Generalized Epilepsy Clinic of Neurology Department in Universidade Federal de São Paulo. Inclusion Criteria: diagnostic of JME according to the International League Against Epilepsy criteria (COMMISSION, 1989) and stable dosing of antiepileptic drugs (AED) for at least thirty days. Exclusion Criteria: pacemaker use; metallic implants in skull; cardiomyopathy; structural lesion in neuroimaging evaluation; diagnosis of psychiatric disturbances; pregnancy; persistent occurrence of any undesirable effect (migraine, vertigo and buzzing) or increase of epileptic discharges in relation to admission EEG during TMS. Included patients will be evaluated by a neurologist and should have AED level determination. Cortical excitability will be assessed by specific parameters of the single pulse TMS such as motor threshold, silent period, central motor conduction time, M wave, F wave, motor evoked potential amplitude and latency, and somatosensitive evoked potential, including N13 and N20 latencies (FREGNI et al., 2006; MANGANOTTI et al., 2004; REUTENS et al., 1993).Patients should receive all sessions in the same time schedule in order to obtain homogeneity regarding performance and AED use. This study is according to Guidelines and Regulation Norms of Research of Human Beings (resolution 196/1996 of National Council of Health) and was approved by Ethics Committee of Research, Project Nº. 1972/10. (AU)