Ortopneia não cardiogénica. A propósito de dois casos de esclerose lateral amiotrófica

SUMMARYVery few cases of motor neuron diseases presenting with dispnea as the first symptom have been reported in literature.On the other hand, it is very difficult to identify a diaphragmatic paralysis as a cause of respiratory failure in patients without other evidence of muscular weakness.The authors describe two cases of amiatrophic laterat sclerosis in which the presenting symptoms were orthopnea and exertional dispnea. In both cases the cardiological evaluation was irremarkable. The identification of a paradoxial abdominal respiration associated to the radiological evidence of diaphragmatic elevation and a functional pattern of alveolar hypoventilation led us to the clinical suspicion of a primary neuromuscular disease with diaphragmatic involvement. This hypothesis was, in both cases, confirmed by electromiography.At the present, both patients are in a home ventilation program (the first one through a tracheostomy and the second one under nasal non invasive ventilation with BIPAP).The authors conclude drawing some considerations about the difficulties in the diagnosis of diaphragmatic paralysis as a cause of respiratory failure in patients with amiotrophic lateral sclerosis