Evolution of neurologic features in Williams syndrome.

As a part of a large multidisciplinary clinical and research follow-up study, 47 Williams syndrome patients underwent detailed neurologic testing. Because previous studies have documented the absence of major neurologic signs in Williams syndrome, the neurologic testing focused on soft signs. Previous findings of impairment of both gross and fine motor coordination were confirmed, and the presence of mild cerebellar and extrapyramidal signs was documented. In a 4-year follow-up study, an age-related pattern was revealed: soft extrapyramidal signs became more evident from 8 years of age and increased in the 14+ age group. The results are discussed according to a hypothesis related to the dopaminergic system involvement in Williams syndrome: anomalous organization or accelerated ageing process.