To define the clinical and radiological features of patients with the combination of hemidystonia (HD) and hemiatrophy (HA), the HD-HA syndrome. HD is a very disabling neurological condition that is rarely associated with HA of the affected body part, similar to the hemiparkinsonism-hemiatrophy syndrome.
Method: We reviewed the medical records of 26 patients with the HD-HA syndrome and the data was entered into a database and analyzed. Video recordings as well as imaging studies were also reviewed. Twenty six patients (14 female) with a mean age at onset of HD at 14.9 years (1-46 years) were followed for a mean of 3.4 years. Fourteen (53%) had HD and HA on the left side and 23 (88%) had hemiparesis preceding the onset of HD. The mean latency from the onset of hemiparesis to the onset of HD was 14.7 years (2 weeks-46 years). All patients with hemiparesis had marked improvement in their weakness prior to the onset of HD. Common causes leading to hemiparesis and subsequent HD were birth or perinatal complications (N = 13) and stroke (N = 10). Seven patients (26%) had associated seizures. Twenty two patients (85%) had abnormal brain MRI: eight had lesions directly involving the basal ganglia and nine had cerebral hemiatrophy or non specific diffuse atrophy. Sixteen patients received botulinum toxin injections and responded well to treatment. HD-HA is usually associated with static encephalopathy originating at very young age, but the syndrome may also represent delayed sequelae of a stroke or brain injury.