The relationship between arm dystonia in corticobasal degeneration and handedness.

Corticobasal degeneration is a progressive neurodegenerative disease involving the cerebral cortex and basal ganglia and leads primarily to motor symptoms and cognitive dysfunction. Unilateral arm dystonia is a common presenting symptom in many patients with corticobasal degeneration. This study attempts to determine if a relationship exists between arm dystonia in corticobasal degeneration and the handedness of the patient. A chart review of 12 right-handed patients (six males and six females) diagnosed with corticobasal degeneration seen in a Parkinson's disease clinic was conducted. With the exception of a single individual who was afflicted in her dominant arm, all had dystonia in their left arm. The ages of the female patients were substantially lower than their male counterparts. Although the sample size of the patient population is small, the results raise an interesting question: is arm dystonia in corticobasal degeneration more commonly seen on the contralateral side of the dominant hand. Further observation is needed to establish a correlation.