Abstract
Introduction Amyotrophic lateral sclerosis (ALS) is an incurable and highly disabling progressive neurodegenerative disease. The muscle weaknesses encompass all skeletal muscles, including the respiratory muscles, leading to reduced lung volumes and flows.
Aims and objectives Study respiratory muscle strength and lung function in a cross-sectional population based study of ALS patients with different phenotypes treated at Haukeland University Hospital, Bergen, Norway.
Methods ALS was sub-classified according to bulbar involvement and severity was scored. Forced vital capacity (FVC) and peak expiratory flow (PEF) was performed both seated and supine. Maximal inspiratory (MIP) and expiratory (MEP) pressure, and sniff nasal inspiratory pressure (SNIP) were measured seated.
Results
ALS without bulbar symptoms (n=6) Mean(SD) | ALS with bulbar symptoms (n=14) Mean(SD) | t-test p-value | |
---|---|---|---|
Gender: Male/Female | 6/0 | 7/7 | - |
Age, years | 65.8(9.2) | 69.9(9.4) | .385 |
Body Mass Index, kg/cm2 | 23.5(1.8) | 23.6(5.1) | .935 |
ALSFRS-r, 0-48 | 39.0(7.5) | 35.6(8.9) | .433 |
Bulbar Impairment Scale, 0-8 | 8.0(0) | 5.0(2.27) | .005* |
SEATED: | |||
FVC, l | 3.38(0.93) | 2.34(0.91) | .034* |
FVC, % of predicted | 73.5(18.8) | 64.5(23.7) | .428 |
PEF, l/min | 461.7(140.3) | 234.6(109.1) | .001* |
MIP, cmH2O | 54.2(18.9) | 38.6(20.5) | .129 |
MEP, cmH2O | 80.2(32.1) | 37.6(18.3) | .001* |
SNIP, cmH2O | 47.7(22.2) | 33.6(13.8) | .126 |
SUPINE: | |||
FVC, l | 2.97(0.50) | 2.36(1.20) | .353 |
FVC, % of predicted | 63.5(20.1) | 66.3(24.8) | .845 |
PEF, l/min | 395.8(167.7) | 233.1(126.1) | .069 |
*=statistic significant. ALSFRS-r=ALS Functional rating scale-revised
Conclusions ALS patients had decreased lung function and respiratory muscle strength, and those with bulbar involvement had lower lung volumes, and generated lower pressure and flow during expiration.
- Copyright ©ERS 2015