The neurologic features of 47 cases of Williams syndrome were determined and a follow-up study was performed on a subgroup of 27 subjects at the Neurorehabilitation Unit, IRCCS Eugenio Medea, Bosisio Parini, Italy. All the patients showed some neurologic deficit, but none was major, and none affected the cranial nerves or peripheral nerves. Proximal hypotonia was found in all but one (98%), and mild rigidity in 6 (12.8%). Hyperreflexia was elicited in 20 patients (42.6%), and Babinski responses in 2 (4.3%). Soft cerebellar signs were frequent: dysmetria (31.9%), dysdiadochokinesia (95.7%), tandem dyspraxia (93.6%), braking (59.6%), and gait ataxia (6.4%). Extrapyramidal signs were mild and included choreiform movements in 46.8%, dystonia in 42.6%, other involuntary movements in 36.2%, and facial grimacing in 55.3%. Cerebellar signs showed no consistent change whereas extrapyramidal signs, especially dystonia, tended to increase with age from 8 years to 14+ years, during the 4-year follow-up (P<0.01). The extrapyramidal abnormalities are linked to a dysfunction in the nigrostriatal dopaminergic system that increases with the accelerated ageing process, a characteristic of Williams syndrome. 
COMMENT. Williams syndrome is caused by a deletion in chromosome 7ql 1.23 and affects multiple systems, especially cardiac. The patient has an elfin-like facial appearance, infantile hypercalcemia that resolves with age, supravalvular aortic stenosis and hypertension, hyperacusis, and cognitive disorders. Nonverbal functions, visual-motor and spatial perceptions, are weak, whereas expressive language, musical abilities, and facial recognition are relative strengths. The older patient has a “cocktail personality.” Less attention has been given to neurological and behavioral symptoms. Some patients with Williams syndrome (WS) have ADHD and have been treated with methylphenidate . In our ADHD Neurology Clinic, we have seen one patient with WS in the past 10 years. With a structural heart defect, the use of stimulant medication is generally contraindicated. So-called “soft” neurologic signs are a common finding in WS, especially cerebellar and extrapyramidal signs. The present large series of patients with WS, including long-term follow-up observations, documents the changes in neurologic signs with age and the increase in extrapyramidal signs related to an accelerated ageing process.