Acquired hemidystonia in childhood: a clinical and neuroradiological study of thirteen patients.

A retrospective study of 13 patients (4 males/9 females) with acquired hemidystonia in childhood is reported. The mean age of onset of hemidystonia was 6.4 years (range 1-13.4 years); the mean duration of dystonia at the time of last follow-up was 11.4 years (range 3.6-23 years). Hemidystonia was caused by ischemic infarction in 9 patients and was attributed to perinatal trauma in 1; in 4 of the 9 patients with stroke and in the remaining 3 patients laboratory investigations were suggestive of primary antiphospholipid syndrome. Eleven of the 13 patients had delayed onset of dystonia: between 1 month and 8.9 years (mean 3.4 years). Ten patients had neuroradiological evidence of contralateral basal ganglia damage. A history of hemiparesis and evidence of striatal damage on CT or MRI were important risk factors for the development of dystonia. Response to medical treatment (trihexyphenidyl dose as high as 40 mg daily) in 5 patients was disappointing; 4 of the 5 patients who underwent functional stereotaxic operations were improved, but dystonia was still present at the end of the follow-up. Our study provides additional evidence that lesions of the striatum may induce dystonia, supporting the theory of striatopallido-thalamic disconnection. Furthermore, our results indicate that the occurrence of delayed dystonia must be considered in the diagnostic approach to childhood-onset dystonia.