DOPA-sensitive progressive dystonia of childhood with fluctuations of symptoms--Segawa's syndrome and possible variants. Results of a collaborative study of the European Federation of Child Neurology Societies (EFCNS).

Twenty children with dystonia sensitive to L-Dopa were identified in a collaborative study by 11 European colleagues. Most cases showed clinical characteristics similar to those described by Segawa (age and mode of onset, marked diurnal fluctuations, predominant limb involvement with no or minimal axial dystonia and, in all cases, dramatic relief of symptoms with small doses of L-Dopa). The typical diurnal fluctuation of symptoms was not observed in 7 children. Significant differences in this respect were noted among affected siblings. There were 9 sporadic and 11 familial cases. The pedigrees observed do not contradict nor clearly confirm Segawa's hypothesis that this might be a dominantly inherited disorder with low penetrance. Response to low doses of L-Dopa was usually dramatic, the benefit was maintained over periods ranging from one to eight years without complications. Recurrence of symptoms on withdrawal was observed in all cases in which it was attempted. These cases represent a form of progressive, presumably hereditary, childhood dystonia, similar to that originally described in Japan and different from dystonia musculorum deformans. The absence of fluctuations of symptoms despite good L-Dopa response and the great variability in the severity of the disorder were important features which will require further study as will the homogeneity of the syndrome, the mode of genetic transmission and the need for persistent L-Dopa treatment in adult life.