Acute respiratory failure in motor neuron disease.

Five patients with sudden deterioration in respiratory function were studied. In three a history of motor neuron disease was known but in two the first evidence of the disease was severe hypoventilation. No other cause for the respiratory difficulty could be detected in any, and all eventually achieved important partial or even complete independence from mechanical support. Severe hypoventilation can be the initial symptom of motor neuron disease, and not all patients with this complication of the disease have the poor prognosis usually expected.