Variazioni dell'eccitabilità corticale da trattamento cronico con acido valproico

In the normal subject, transcranial magnetic stimulation (TMS) was able to detect acute changes of cortical excitability due to loading doses of antiepileptic drugs. We explored if TMS was sensitive to changes of cortical excitability in 14 epileptic patients chronically treated with VPA. Ours TMS findings, i.e. an increase in relaxed threshold and a reduction of intracortical facilitation, reflect the basic mechanisms of action of VPA on membrane permeability and on the GABAergic tone. TMS is likely useful to detect antiepileptic properties of drugs.