Atypical motor neuron disease with supranuclear vertical gaze palsy and slow saccades.

In amyotrophic lateral sclerosis (ALS), eye movements are usually preserved even after the long-term use of respirators. The present study evaluated a 57-year-old male patient who showed clinical findings compatible with ALS but exhibited disorders of eye movements before he needed to be on an artificial respiration system. The patient had noted clumsiness and weakness in all extremities 5 years before presentation of abnormal eye movements. The results of electromyography and muscle biopsy were compatible with ALS. However, supranuclear vertical gaze palsy and slow saccades are seen. The present case might be representative of a distinct clinical entity, motor neuron disease with disorders of eye movement.