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.