Idiopathic dystonia-parkinsonism with marked diurnal fluctuation of symptoms.

Studies were performed on 5 patients with idiopathic dystonia-parkinsonism, each of whom had minor dystonic movements and parkinsonian symptoms with marked diurnal fluctuation. Levels of homovanillic acid and 5-hydroxyindoleacetic acid were not different from those in controls. Considerable improvement in dystonic movements and parkinsonian symptoms was obtained with a small dose of L-dopa, trihexyphenidyl hydrochloride, amantadine, or bromocriptine hydrochloride. Electrophysiological investigation confirmed that the dystonic movements, which became remarkably worsened on attempted movement, contributed importantly to the diurnal fluctuation of symptoms.