Sleep alterations in amyotrophic lateral sclerosis.

Purpose of review: This review summarizes recent evidence on sleep disturbances in amyotrophic lateral sclerosis (ALS), emphasizing their role as intrinsic features of the disease process rather than consequence of motor decline.

Recent findings: Emerging data suggest that sleep disturbances such as sleep fragmentation, rapid eye movement sleep (REM) and non rapid eye movement sleep (NREM) alterations and circadian changes often precede classic motor symptoms. Structural and functional hypothalamic changes have been observed in early ALS, suggesting a direct role in sleep-wake dysregulation. In addition, impaired glymphatic clearance during sleep may contribute to neurodegeneration by impairing the removal of protein waste. Polysomnographic studies and cohort data support the presence of prodromal sleep abnormalities in both symptomatic patients and gene mutation carriers. Noninvasive ventilation has shown benefits not only in respiratory management but also in improving sleep quality and overall prognosis.

Summary: Sleep alterations in ALS are increasingly recognized as early indicators and potential modulators of disease progression. The hypothalamus and the glymphatic system emerge as key contributors to these disturbances, highlighting sleep as a therapeutic target. Understanding the role of sleep in ALS pathophysiology may aid in earlier diagnosis and novel intervention strategies aimed at modifying disease course.