Management of hypoventilation in motor neuron disease presenting with respiratory insufficiency.

A 57-year-old man presented with a three-month history of somnolence, hypoventilation, cor pulmonale, and episodes of apnea during sleep. Neurological studies revealed motor neuron disease, mainly confined to the muscles of respiration, that was causing respiratory insufficiency in the supine position. Nighttime treatment of respiratory insufficiency has permitted independent activity during wakefulness.