LUNG FUNCTION AND FOUR PHYSICAL PERFORMANCE FUNCTIONAL TESTS IN PERSONS WITH MULTIPLE SCLEROSIS

Purpose/Hypothesis: To describe lung function in ambulatory persons with multiple sclerosis (MS) and evaluate the relationship of respiratory muscle strength and endurance ??: 1 ) pulmonary function tests (PFT), 2) physical performance functional tests (PPFT) and 3) neurological function (EDSS). Number of Subjects: 45 adult, ambulatory, subjects with clinically diagnosed MS participated. Materials/Methods: Multiple factor, cross-sectional design. PFTs !Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 sec. (FEV,), Peak Expiratory Flow (PEF), Total Lung Capacity, Residual Volume] were measured with a VMax metabolic cart (Sensor Medics), lnspiratory and expiratory muscle strength were measured by Maximal lnspiratory and Expiratory Pressure (Plmax, PEmax), and muscle endurance by Maximal Voluntary Ventilation (MVV); functional status by the PPFTs including a 6-Minute Walk Test (6MWT), Functional Stair Test (FST), one-legged Romberg (RMB), 6 repetition Sit to Stand Test (SST); and neurological function by EDSS. Pearson Product Moment Correlations were computed with a level set at p<.05. Results: The FVC, FEV,, TLC, RV, MVV were normal (mean > or = to 80% predicted) whereas FEV/FVC (75 � 10% predicted), PEF (75 � 22%), ER (77 � 47%), PIMAX (72 � 28%), PEMAX (49 � 20%), VT (15 � 4%) were abnormal with mild inspiratory and severe expiratory muscle strength impairment. Mean and standard deviation (X, SD) for the 6MWT were 1101 � 550 ft., FST 12.4� 9.7 sec., RMB 15.4� 9.9 sec. and SST 24.6 � 1 7.0 sec. Average EDSS (3.7 � 1.7) indicate mild to moderate impairment on a scale of O to 10. PEMax was significantly correlated to 6MWT distance (r=0.484, p=0.001 ), FST total time (r=-0.466, p=0.001 ), SST time (r= -0.346, p=0.020), EDSS (r= -0.374, p=0.011), FEV,(r=0.526, p=0.000)and PEF (r=0.627, p=0.000). MVV was significantly correlated to MWT distance (r=0.419, p=0.004), FST total time (r= - 0.492, p=0.001), RMB (r= 0.316, p=0.033), EDSS (r= -0.401, p=0.006), FVC (r=0.749, p=0.000), FEV,(r=0.798 p=0.000), PEF (r=0.727, p=0.000), PIMax (r=0.729, p=0.000), PEMax (r=0.675, p=0.000). Conclusions: Marked expiratory weakness develops in ambulatory persons with MS with minimal to moderate neurological involvement. Clinical Relevance: Several PFT abnormalities are associated with respiratory pump dysfunction, and relate to reduced PPFTs.

[Author Affiliation]

L Pfalzer, D Fry-Welch, E Jackson, A Chokshi, M Wagner. Dept. of Physical Therapy, University of Michigan-Flint, Flint Ml.