Paraneoplastic motor neuron disease with type 1 Purkinje cell antibodies.

Autoimmune serological testing is a useful aid for identifying a paraneoplastic basis for sporadic motor neuron disease. A 67-year-old woman with ovarian carcinoma presented with progressive weakness. Neurological examination was suggestive of motor neuron disease with signs of upper motor neuron disorder. Electromyography revealed severe motor neuronopathy of the upper extremities. Characteristic type 1 Purkinje cell antibodies (anti-Yo antibody) was detected in the serum diluted at 1:61,400.