Unrecognized Motor Neuron Disease: An Uncommon cause of Ventilator Dependency in the Intensive Care Unit

Abstract

A previously healthy woman developed ventilatory failure leading to ventilatory support. We ruled out primary cardiovascular and pulmonary etiologies for the ventilatory failure. Multiple attempts to wean ventilatory support were unsuccessful. Eventually, findings consistent with upper and lower motor neuron involvement were discovered, as well as paradoxical movement of the abdominal wall during inspiration. Nerve conduction studies and needle electromyographic examination showed signs of motor neuron degeneration such as those seen in amyotrophic lateral sclerosis (ALS). ALS should be considered a possible diagnosis in patients with otherwise unexplained ventilator dependence and paradoxical movements of the abdominal wall.