Respiratory muscle weakness and respiratory muscle training in severely disabled multiple sclerosis patients.
OBJECTIVE
To evaluate the contribution of respiratory muscle weakness (part 1) and respiratory muscle training (part 2) to pulmonary function, cough efficacy, and functional status in patients with advanced multiple sclerosis (MS).


METHODS
Survey (part 1) and randomized controlled trial (part 2).


METHODS
Rehabilitation center for MS.


METHODS
Twenty-eight bedridden or wheelchair-bound MS patients (part 1); 18 patients were randomly assigned to a training group (n = 9) or a control group (n = 9) (part 2).


METHODS
The training group (part 2) performed three series of 15 contractions against an expiratory resistance (60% maximum expiratory pressure [PEmax]) two times a day, whereas the control group performed breathing exercises to enhance maximal inspirations.


METHODS
Forced vital capacity (FVC), inspiratory, and expiratory muscle strength (PImax and PEmax), neck flexion force (NFF), cough efficacy by means of the Pulmonary Index (PI), and functional status by means of the Extended Disability Status Scale (EDSS).


RESULTS
Part 1 revealed a significantly reduced FVC (43% +/- 26% predicted), PEmax (18% +/- 8% predicted), and PImax (27% +/- 11% predicted), whereas NFF was only mildly reduced (93% +/- 26% predicted). The PI (median score, 10) and EDSS (median score, 8.5) were severely reduced. PEmax was significantly correlated to FVC, EDSS, and PI (r = .77, -.79, and -.47, respectively). In stepwise multiple regression analysis. PEmax was the only factor contributing to the explained variance in FVC (R2 = .60), whereas body weight (R2 = .41) was the only factor for the PI. In part 2, changes in PImax and PEmax tended to be higher in the training group (p = .06 and p = .07, respectively). The PI was significantly improved after 3 months of training compared with the control group (p < .05). After 6 months, the PI remained significantly better in the training group.


CONCLUSIONS
Expiratory muscle strength was significantly reduced and related to FVC, cough efficacy, and functional status. Expiratory muscle training tended to enhance inspiratory and expiratory muscle strength. In addition, subjectively and objectively rated cough efficacy improved significantly and lasted for 3 months after training cessation.
Gosselink
R
R
Respiratory Rehabilitation and Respiratory Division, University Hospitals, Katholieke Universiteit Leuven, Belgium.
Kovacs
L
L
Ketelaer
P
P
Carton
H
H
Decramer
M
M
D015992:Body Mass Index; D001945:Breathing Exercises; D003371:Cough; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000145:classification / Q000503:physiopathology / Q000534:rehabilitation*; D009119:Muscle Contraction; D012044:Regression Analysis; D012129:Respiratory Function Tests; D012720:Severity of Illness Index; D016896:Treatment Outcome