Chronic inflammatory demyelinating polyneuropathy and respiratory failure due to phrenic nerve involvement.

In this article, 2 patients with chronic inflammatory demyelinating polyneuropathy (CIDP) are presented. These patients developed respiratory failure which could not be explained by any cardiac or pulmonary pathology. The first case had pure motor involvement and probable CIDP, and the second case had severe sensorial dysfunction and an ataxic picture in addition to motor symptoms. His clinical picture was compatible with distal acquired demyelinating sensory neuropathy without M protein. Electrophysiologic investigations of both patients disclosed impaired phrenic nerve conduction and neurogenic motor unit changes in the diaphragm. Both patients showed a moderate response to immunotherapy. Distal acquired demyelinating sensory and pure motor variant of CIDP can be a cause of respiratory dysfunction. Different clinical patterns of CIDP should be evaluated for phrenic nerve involvement.