Delayed-onset focal dystonia after diffuse cerebral hypoxia--two case reports.

The delayed-onset focal dystonia is a rare sequela of cerebrovascular disease or diffuse cerebral hypoxic damage. The responsible lesion sites for the dystonia are variable and the pathogenesis is uncertain. We describe two children with delayed-onset focal dystonia as a complication of perinatal anoxia. The intervals between hypoxic insult and onset of dystonia were 6 years in one and 3 in the other cases. Our patients did not have a focal lesion; one had scattered white matter lesion and the other had a diffuse frontoparietal atrophy. Delayed-onset dystonia after perinatal anoxia can be also caused by non-focal lesion such as diffuse frontoparietal atrophy or cerebral white matter lesion with long interval delay.