BACKGROUND. Amyotrophic lateral sclerosis (ALS), the major adult-onset motor neuron disease, is preceded by an early period unrelated to motor symptoms, including altered sleep, with increased wakefulness and decreased deep NREM. Whether these alterations in sleep macroarchitecture are associated with, or even precede abnormalities in sleep-related EEG features remains unknown. METHODS. Here, we characterised sleep microarchitecture using polysomnography in patients with ALS (n=33) and controls (n=32), and in asymptomatic carriers of SOD1 or C9ORF72 mutations (n=57) and non-carrier controls (n=30). Patients and controls with factors that could confound sleep structure, including respiratory insufficiency, were prospectively excluded. Results were complemented in three ALS mouse models (Sod1G86R , Fus∆NLS/+ and TDP-43Q331K ). RESULTS. We observed a brain-wide reduction in the density of sleep spindles, slow oscillations and K-complexes in both early-stage ALS patients and presymptomatic gene carriers. These defects in sleep spindles and slow oscillations correlate with cognitive performance in both cohorts, particularly with scores on memory, verbal fluency and language function. Alterations in sleep microarchitecture were replicated in three mouse models and decreases in sleep spindles were rescued following intracerebroventricular supplementation of MCH or by the oral administration of a dual orexin receptor antagonist. CONCLUSION. Sleep microarchitecture is associated with cognitive deficits and is causally linked to aberrant MCH and orexin signalling in ALS. FUNDING. This work was funded by Agence Nationale de la Recherche (ANR-24-CE37-4064, ANR-10-IDEX-0002, ANR-20-SFRI-0012), Fondation Thierry Latran, Association Francaise de Recherche sur la sclérose latérale amyotrophique, Association Française contre les Myopathies (#28944), TargetALS and JPND.
Christina Lang, Simon J. Guillot, Dorothee Lule, Luisa T. Balz, Antje Knehr, Patrick Weydt, Johannes Dorst, Katharina Kandler, Hans-Peter Müller, Jan Kassubek, Laura Wassermann, Sandrine Da Cruz, Francesco Roselli, Albert C. Ludolph, Matei Bolborea, Luc Dupuis
The Editorial Board will only consider comments that are deemed relevant and of interest to readers. The Journal will not post data that have not been subjected to peer review; or a comment that is essentially a reiteration of another comment.