PULMONARY FUNCTION IN PATIENTS WITH NEUROMUSCULAR DISORDERS
Fourteen patients with neuromuscular disorders were studied for changes in lung function, especially in the maximal expiratory flow volume curve (MEFV curve). Comparison was made with findings in patients with PSS. Changes of lung functions were mainly of restrictive type characterized by decrease in vital capacity, total lung capacity and by increase in residual volume with normal value of FEV1.0 and respiratory resistance. Arterial blood gases showed normal oxygen tension and normal or lowered carbon dioxide tension in most of patients. MEFV curve in the neuro-muscular disorders revealed a slow increase of initial ascending limb, lower peak flow and concavity toward the volume axis of terminal portion (normal ・V25), which contrasted with MEFV curves of PSS patients, the curves of which showed convexity of terminal portion (decreased ・V25). The slow increase of ascending limb and lower peak flow in the former may be an expression of the decreased muscle strength, which was demonstrated by the simultaneous slow increase and small change of the transpulmonary pressure. Normal ・V25 of MEFV curves may be the evidence of intact lung in the neuromuscular diseases.
