Amyotrophic lateral sclerosis presenting with respiratory insufficiency as the primary complaint. Clinicopathological study of a case.

A 59-year-old man presented with dyspnoea, hypersomnia followed by acute respiratory failure necessitating mechanical ventilation. There were no signs of cardiopulmonary disease and on the first few days, extubation was impossible. Further neurological evaluation supported the diagnosis of amyotrophic lateral sclerosis. The neuropathological examination corroborated this diagnosis, and showed a preponderance of lesions in the phrenic nuclei and axonal alterations associated with a fast evolution.