POSSIBILI IMPLICAZIONI DEL SISTEMA SEROTONINERGICO NELLA PATOGENESI DELLE MIOCLONIE: DATI PRELIMINARI DI UNO STUDIO CLINICO

Eight patients affected by various myoclonic syndromes (myoclono-epilepsy in 3 cases, clinical picture at the borderline between myoclono-epilepsy and Ramsay Hunt syndrome in 1 case, progressive myoclonia of unknown etiology in 2 cases, symmetrical bilateral non progressive myoclonia in 1 case, action and intention myoclonia symptomatic of thalamic angioma in 1 case) were given acutely in a single dose, L-5-hydroxytryptophan combined with carbidopa and drugs with a serotonergic action: quipazine, phenfluoramine and trazodone; they were given as well methysergide, that is supposed to be a blocker of the serotonergic receptors, and clonazepam. The basic levels of 5HIAA and HVA in the liquor were determined. During the pharmacological tests clinical and polygraphic monitoring was carried out. The L-5-hydroxytryptophan and the drugs with a serotonergic action had a positive effect in patients affected by the myoclono-epileptic syndrome with characteristics that trend towards the Ramsay-Hunt syndrome; but they clearly increased the incidence of EEG paroxysms in 1 of the patients affected by myoclono-epilepsy, while they had a doubtful or no effect in the other patients. The methysergide clearly aggravated the clinical symptomatology of a patient affected by progressive erratic myoclonus of unknown etiology. Clonazepam was efficacious, when given acutely, in all of the patients. Nevertheless there was confirmation of its efficacy in chronic therapy especially in patients with myoclonus associated with epilepsy. There is a discussion on the possible relationships between the efficacy of drugs that are active on the metabolism of the serotonin among the possible physiopathological mechanisms that underlie the various types of myoclonia.