[Progressive hereditary dystonia with diurnal fluctuations: report of 2 cases]

We report two patients with diurnally fluctuating hereditary progressive dystonia, that presented with dystonic movements and parkinsonian symptoms with marked diurnal fluctuations. There was a significant and maintained improvement of symptoms with small doses of L-Dopa. The pathogenesis of this disease could be a functional alteration of basal ganglia in the dopaminergic striatonigral region. The diurnal fluctuation of symptoms would be related to the circadian variation of tyrosine hydroxylase function.