MOTOR-NEURON DISEASE PRESENTING WITH RESPIRATORY-FAILURE

Respiratory failure accounts for the majority of deaths in amyotrophic lateral sclerosis (ALS) but only rarely is ALS diagnosed on the basis of respiratory insufficiency. We report four ALS patients presenting with acute respiratory failure. In three patients we have performed EM G needle examination of both hemidiaphragms which showed severe denerv ation. We reviewed 25 patients previously described presenting with re spiratory failure. Almost all patients showed upper limbs weakness and diaphragm involvement; few patients had bulbar dysfunction. The progn osis of these patients is not always a permanent ventilator dependence . Rapidly progressive ventilatory failure may be a striking initial si gn of ALS; the main reason is a weakened diaphragm. There are possibil ities of significant improvement after a period of rest with ventilato ry assistance. In the initial phase of the disease, bulbar dysfunction is not the more common reason of acute respiratory failure.