Subject
Child; Humans; Adult; Middle Aged; Sensitivity and Specificity; Predictive Value of Tests; adolescent; Preschool; Q3 Literature Search; REM; Sleep; Polysomnography; Diaphragm/physiopathology; Glycogen Storage Disease Type II/complications; Respiratory Insufficiency/diagnosis/etiology/physiopathology; Sleep Apnea Syndromes/diagnosis/etiology/physiopathology; Vital Capacity
Description
BACKGROUND: Sleep-disordered breathing (SDB) and respiratory failure (RF) are complications of acid maltase deficiency (AMD), a rare hereditary myopathy. OBJECTIVE: To define the relationship between lung and respiratory muscle function, to establish incidence and patterns of SDB, and to determine daytime predictors of SDB. METHODS: Sitting and supine lung and respiratory muscle function tests were obtained in 27 subjects with juvenile and adult AMD (aged 39 +/- 19 years) and compared with outcomes of polysomnography. RESULTS: Ventilatory restriction was present in 17/27 subjects. Inspiratory vital capacity (IVC) correlated (p 50 mm Hg) first in REM sleep, then in non-REM sleep (p < 0.005). SDB was predicted by DW (sensitivity 80%, specificity 86%) and nocturnal hypoventilation by IVC < 40% (sensitivity 80%, specificity 93%). Noninvasive ventilation, instituted for daytime respiratory failure or nocturnal hypoventilation, normalized daytime and nocturnal gas exchange (p < 0.005). CONCLUSION: Vital capacity correlates with respiratory muscle function in AMD. Diaphragm weakness is the major cause of SDB and RF. SDB and nocturnal hypoventilation are predictable from daytime function tests.
2001