The Clinical Application of Pulmonary Function Testing

Mechanisms Leading to Hypoventilation in Extrapyramidal Disorders, With Special Reference to Parkinson's Disease

“…These studies have shown that expiration is a passive phenomenon, and that during the inspiration of quiet breathing, only the diaphragm and scalene muscles are active. In dyspnea or forced breathing, there is no activity in a large group of inspiratory 1 and expiratory 2 muscles (18).…”

“…In affections of the nervous system, derangement of the bellows action is usually produced by impaired function of the respiratory muscles. This abnormality of ventilation, frequently called restrictive ventilatory dysfunction, has been defined as “an impairment of the ability to move air into and out of the lungs as a result of a defect in the thoracic bellows or pulmonary distensibility” (2). A nervous system lesion capable of producing an alteration in ventilation may be located at any one of various levels and yet produce similar manifestations.…”

“…It may also occur in the peripheral nervous system or in the myoneural junction, as in the Guillain‐Barré syndrome (6) or myasthenia gravis (7). Restrictive ventilatory dysfunction may be caused by a muscular disease such as progressive muscular atrophy (8), or by loss of mobility of the bony structure as in kyphoscoliosis where the loss of volume of the thoracic bellows is often associated with loss of its mobility (2).…”