Sleep disturbances and respiratory dysfunction in amyotrophic lateral sclerosis.

OBJECTIVE

To investigate how respiratory dysfunction and site of onset influences changes in sleep architecture in people with ALS (pwALS).

METHODS

We conducted a retrospective observational study, analyzing demographic data, lung function tests, and polysomnography (PSG) measures. Descriptive statistics, correlation analyses, and survival analyses were performed.

RESULTS

Our cohort had 240 pwALS, 63% male, median age at onset 59.3 (IQR 16.5) years. Median time from onset to PSG was 27.5 (IQR 25) months. Most pwALS had spinal onset (79%). Spirometry at time of PSG showed a reduced Forced Vital Capacity (FVC) (58; (IQR 26) %). We saw a significant FVC decline (3.9; (IQR 4) % per month) in the months before PSG. The sleep quality assessment in pwALS revealed a reduced total sleep time (339; (IQR 144.7) minutes), diminished sleep efficiency (62.8; (IQR 26.5)%) and increased wake after sleep onset (172; (IQR 130.2) minutes) when compared to normal values of healthy age-matched adults. The spinal onset group had a higher number of arousals. In the multivariate linear regression model adjusted for age and sex, FVC is a significant predictor for sleep efficiency (β = 3.359, p = 0.0059). Spinal onset, a slower rate of FVC decline in the months preceding PSG and a preserved FVC (≥ 70%) at the time of PSG were associated with improved survival.

CONCLUSION

We observed substantial sleep disturbances in our cohort overall with substantially increased arousals in the spinal group. FVC is a significant predictor for sleep efficiency and the decline in FVC is linked to survival.