Impact of neurological level and spinal curvature on pulmonary function in adults with spina bifida.

PURPOSE: To describe pulmonary function and determine the impact of neurological level, scoliosis, and obesity on pulmonary function in people with spina bifida (SB).

METHODS: Participants with SB (N= 29) (15 females; age, 30 ± 12 years) completed spirometry and body plethysmographic lung volume testing. Univariate and multivariate regression analyses were used to describe the factors associated with pulmonary function in people with SB.

RESULTS: Distribution of category of impairment in pulmonary function was: 55% (n= 16) restricted, 6.9% (n= 2) spirometric restricted, 1 combined obstructed and restricted, and 35.5% (n= 10) normal. In univariate analyses, neurological level was negatively associated with pulmonary function parameters, i.e., forced vital capacity (FVC) (p= 0.005), forced expiratory volume in 1 second (FEV1) (p= 0.008), total lung capacity (TLC) (p= 0.001), and degree of scoliosis were inversely associated with FVC (p= 0.005), FEV1 (p= 0.003), and TLC (p= 0.004). In multivariate models, level of lesion and degree of scoliosis independently contributed to the degree of lung function impairment. Restrictive pulmonary function was observed in 9/10 (90%) of those with thoracic neurological levels and was associated with decreased inspiratory capacity (IC) and expiratory reserve volume (ERV). Lumbar level lesions were associated with either normal lung function or an isolated reduction in FVC due to reduction in only ERV and preserved TLC representing spirometric restriction.

CONCLUSIONS: High prevalence of restrictive pulmonary physiology is present in people with SB, with more rostral neurological levels and greater degree of scoliosis associated with a higher degree of pulmonary function impairment.