[Lung function in the course of amyotrophic lateral sclerosis].

We report a case of a 26 year old man who was diagnosticated of ALS. This case is a graphic example of the pulmonary function evolution through the flow-volume loop. In the first study the espirometric values were in the normal range. The Static pulmonary pressures were weackle decreased. This was the only sign of respiratory muscle impairement. Its important to study close enough the pulmonary function through the flow/volume loop, maximal respiratory pressures and maximal voluntary Ventilation in order to know the empairment rate, and also to detect intercurrent procedures as bulbar involvement, that can affect the prognosis of the disease.