All are true about bilateral diaphragmatic paralysis, except :

Answer is B (Causes normocapnic failure): "Most patients with severe diaphragmatic weakness present with hypercapnic respiratory failure"-Harrison Sniff test is a confirmatory test of unilateral diaphragmatic paralysis. Whether sniff test is also useful for bilateral diaphragmatic paralysis is unconfirmed, although it could show a paradoxical diaphragm movement on both sides. (The person is asked to sniff and is observed with fluoroscopy. The paralyzed diaphragm moves paradoxically upwards during inhalation due to negative intrathoracic pressure.) Diaphragmatic pacing may be a ble alternative if the nerve to the diaphragm is intact. Treatment of choice for Bilateral Diaphragmatic Paralysis is assisted ventilation Note: Unilateral paralysis occurs due to more local cause e.g. nerve invasion from bronchogenic carcinoma. Patients are usually asymptomatic. Bilateral paralysis occurs due to more central or generalized causes e.g. high spinal cord injury, muscular dystrophy chest trauma. Patients present with hypercapnic respiratory failure, frequently complicated by cor-pulmonale, right ventricular failure (because of hypoxemic vasoconstriction in the lungs) pneumonia and atelectasis.