Teaching video neuroimages: muscle cramps and a raised creatine kinase.

A 40-year-old man presented with a 25-year history of cramps affecting the abdomen, neck, and limbs. Examination revealed fasciculation in the forearms, abdomen, and chin (video on the ® Web site at Neurology.org). There was shoulder girdle wasting with bilateral mastectomy scars (figure, B and C). Creatine kinase (CK) was 1,650 U/L (normal < 310 U/L). Electrodiagnostic studies revealed sensory neuronopathy with neurogenic changes on EMG. Genetic testing demonstrated excess CAG repeats in the androgen receptor gene, confirming Kennedy disease. This X-linked disorder is the most common adult-onset spinal muscular atrophy. CK can be markedly raised. Gynecomastia results from androgen insufficiency and can precede the development of neurologic symptoms.