HEREDITARY PROGRESSIVE DYSTONIA WITH MARKED DIURNAL FLUCTUATION (SEGAWA SYNDROME) IN TAIWAN

Since 1988, we have diagnosed 6 cases of hereditary progressive dyston ia with marked diurnal fluctuation (HPD) in Taiwan. All cases presente d with clinical features similar to those described by Segawa. They co nsisted of four sporadic and two familial cases. The age at onset rang ed from 18 months to 8 years. There is a female predominance of 4:2. A ll of them showed mild postural tremor and postural dystonia manifeste d initially by flexion-inversion of a foot. However, unlike Segawa's d escription, side preference to the right (4:2) was noticed. Neck and a xial muscles were not or were minimally involved, except a case presen ting with retrocollis and tilting of the neck. These symptoms showed r emarkable diurnal fluctuation which became aggravated towards the even ing and alleviated in the morning or after rest. Response to L-dopa wa s dramatic, independent of the duration of illness, and no adverse eff ect of L-dopa has been observed. Our experience suggested that 10 mg/k g/day of L-dopa may be an optimally effective dose for treatment of pa tients with HPD. Neurophysiological, neuroradiological and biochemical studies were all normal except in one case who showed prolonged somat osensory potential latencies and white matter changes on MRI. Change o f dopamine and its metabolites in CSF, plasma and urine had been inves tigated in one case.