Cerebral PalsyNo data available OA, MA > CA, hypoventilation, Abn REM No data available Spinal muscular atrophy ↓ TLC, FRC ↓ MIP, MEP CA, MA, hypoventilation ↑ occlusion pressure Duchenne muscular dystrophy ↓ TLC, FRC ↓ MIP, MEP OA, MA, CA, hypoventilation, Nonapneic hypoxemia ↓ HVR, Hypercapnic VR N or ↑ occlusion pressure Myotonic dystrophy N or ↓ FRC ↓ MIP, MEP CA>OA, MA, REM-related hypoxemia, hypoventilation, EDS, sleep- onset REM ↓ HVR, Hypercapnic VR N or ↑ occlusion pressure Disease Pulmonary Function Sleep Abnormalites Ventilatory Control

Clinical Manifestation (SDB) Asymptomatic Morning headaches, fatigue, exertional dyspnea, irritability, hyperactivity, impaired learning, vomiting, difficulty tolerating supine position, restless sleep [Heckmatt et al 1989, Labanowski et al 1996] Failure to thrive, nocturnal sweating, developmental delay, cor-pulmonale [Beckerman and Hunt 1992] These symptoms may be erroneously attributed to the NMD rather than SDB [Gozal 2000] Nonrestorative sleep and EDS may be the early sign of SDB

Clinical manifestation PE: Bell shaped chest, tachypnea, use of accessory muscles and paradoxical breathing Even patients with mild symptoms may have significant unrecognized SDB [Labanowski et al 1996] Investigations PFT Ventilatory control Polysomnography Others: Fluoroscopy, CXR, CBC, HCO3

Clinical assessment PFT Spirometry, lung volumes, muscle strength assessment Restrictive physiology Periodic assessment of PFT especially when lung volumes < 60% [Gozal 2000] PFT may not be predictive of SDB [Smith et al 1988, Heckmatt et al 1989, Manni et al 1989, White et al 1995] Other factors contributing to SDB : upper airway, intercostal and diaphragmatic hypotonia, poor airway clearance, pulmonary atelectasis, abdominal distention, GER, pulmonary aspiration, progressive malnutrition or obesity [Givan 2000]

PFT

Critical Pulmonary Function Values in NMD Pulmonary Function FVC < 20 ml/kg ~30% V t < 5 ml/kg FVC < 3 x V t MIP < 30 cm H 2 O MEP < 40 cm H 2 O p a CO 2 > 45 mm Hg Correlation may correlate with elevation of p a CO 2 awake or asleep

Clinical assessment Polysomnography Indication [ATS consensus 1996] : impaired PFT snoring, morning headaches, cor-pulmonale, polycythemia and elevated bicarbonate Planning and implementation of NIPPV Pre and post-operative evaluation DMD: annual PSG starting when wheelchair [ATS consensus statement 2004]

Oximetry vs Full PSG  May be useful as a screening test in DMD [Labonowski et al 1996]  In areas where full PSG is not readily available [ATS consensus 2004]

Management General supportive care : adequate hydration, nutritional support, airway clearance Scoliosis correction and spinal stabilization Specific Rx Elevation of upper body in beds Rocking bed Protryptyline: decrease REM-related respiratory disturbances in DMD [Smith et al 1989]