Premium
Early and Late Intracortical Inhibition in Juvenile Myoclonic Epilepsy
Author(s) -
Manganotti Paolo,
Bongiovanni Luigi Giuseppe,
Zanette Gianpietro,
Fiaschi Antonio
Publication year - 2000
Publication title -
epilepsia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.687
H-Index - 191
eISSN - 1528-1167
pISSN - 0013-9580
DOI - 10.1111/j.1528-1157.2000.tb00318.x
Subject(s) - juvenile myoclonic epilepsy , transcranial magnetic stimulation , inhibitory postsynaptic potential , epilepsy , neuroscience , silent period , excitatory postsynaptic potential , psychology , motor cortex , stimulation , anesthesia , audiology , medicine
Summary:Purpose : We investigated 15 patients with juvenile myoclonic epilepsy (JME) by subjecting them to single and paired transcranial magnetic stimulation to test the hypothesis that motor cortical inhibition may be abnormal in this form of benign epilepsy. Methods : Different conditioning paradigms of paired transcranial magnetic stimulation were used with interstimulus intervals (ISIs) of varying lengths (1 to 400 milliseconds) to investigate changes in balance between excitatory and inhibitory intracortical circuits. Results : Motor evoked potential (MEP) inhibition at ISIs of 1 to 4 milliseconds was significantly lower in JME patients than in age‐matched healthy controls (p < 0.001), whereas no significant differences in MEP inhibition were noted at long ISIs (100 to 150 milliseconds). This pattern was observed in both hemispheres in seven of seven patients studied bilaterally and was present in both treated and untreated patients. There were no group differences between JME patients and controls in intracortical facilitation, motor threshold, MEP amplitude, and cortical silent period. Conclusions : We documented a different pattern of MEP inhibition in JME patients, suggesting impaired functioning of inhibitory interneuronal circuits, which may account for the hyperexcitability of the motor system in this form of epilepsy.