Amyotrophic lateral sclerosis presenting with respiratory failure. Diaphragmatic paralysis and dependence on mechanical ventilation in two patients.

Described are two patients whose initial symptom was acute respiratory failure requiring mechanical ventilation. Initially, the cause of the respiratory failure in each patient was obscure, but diaphragmatic paralysis was subsequently demonstrated fluoroscopically in each case. Further neurologic evaluation then supported the diagnosis of amyotrophic lateral sclerosis. Postmortem examination corroborated this diagnosis.