[Acute respiratory failure disclosing bilateral diaphragmatic paralysis]

In the case of three patients an acute respiratory failure with alveolar hypoventilation is related to bilateral diaphragmatic paralysis apparently isolated from any other neurologic abnormalities. The current initial diagnosis of pulmonary embolism leading to admission in an intensive respiratory care unit, because of the severity of the acute respiratory failure, has to be rectified then. Bilateral diaphragmatic paralysis is suspected on account of the absence of any patent etiology, on increasing dyspnea in supine position and paradoxic movements of the upper abdomen (whether spontaneously or in attempted weaning of ventilation support). Bilateral diaphragmatic paralysis is asserted by electromyogram with measurement of nerve conduction velocities of the two phrenic nerves. In the first case, it appears early in the course of an amyotrophic lateral sclerosis; in the second case, it occurs before the presence of a herpes-zoster becomes patent. In the third case, paralysis seems to be idiopathic. Evolution is promising in the last two cases, owing to the reversibility of the lesions. The difficulty of diagnosis, the varying nature of etiology and prognosis encountered in these three cases are also apparent in the 15 cases published in medical literature. The small number of cases published up to now, contrasting with the cases we have witnessed over the last 3 years, leads us to think that this disease must exist more often and may remain unknown to us.