Regression of cerebellar syndrome with long-term administration of 5-HTP or the combination 5-HTP-benserazide.

A quantitative evaluation of cerebellar ataxia, with an ataxia score (total, static, kinetic) and the measurement of objective values relating to the major symptoms, was used in 21 patients with hereditary ataxias treated for 12 months with high doses (16 mg/kg/day) of d-l-5-HTP, l-5-HTP or the combination d-l-5-HTP (16 mg/kg/day)--benserazide (6 mg/kg/day). The data obtained from regular examination were processed by computer. The ataxia showed a significant regression at the 12th month, mainly in the static forms and speed of speech. l-5-HTP appeared to be more effective than d-l-5-HTP. Regression of the cerebellar ataxia was also observed in non-degenerative conditions such as multiple sclerosis and surgical lesion of the anterior lobe vermis, showing that 5-HTP was active on the cerebellar syndrome in general. The regression of the cerebellar ataxia was very slow in inherited diseases and continued for 2 or 4 months after the treatment stopped. A serotoninergic cerebellar control of movement is discussed.