Diaphragm paralysis and ventilatory failure in chronic proximal spinal muscular atrophy.

Ventilatory failure occurred in a patient suffering from proximal neurogenic muscular atrophy resembling the adult form of Kugelberg-Welander syndrome. Diaphragmatic paralysis was diagnosed when patient was found to be unable to generate a transdiaphragmatic pressure difference on deep inspiration. Post-mortem examination revealed nearly complete replacement of the diaphragm by fat and fibrous tissue. Although uncommonly reported in the medical literature, ventilatory failure secondary to diaphragm dysfunction should be added to the list of complications encountered in the clinical setting of chronic proximal spinal muscular atrophy.