Spinal Muscular Atrophy, Sleep-Disordered Breathing, and the Effects of Disease-Modifying Therapies: A Narrative Review.

BACKGROUND: This narrative review summarizes the current understanding of the incidence, prevalence, and potential underlying pathological mechanisms of sleep-disordered breathing (SDB) in patients with spinal muscular atrophy (SMA). Additionally, it evaluates the effects of disease-modifying therapies (DMTs) on SDB within this patient population. METHODS: We systematically evaluated the primary literature using the Covidence systematic review program and employed a modified Preferred Reporting Items for Systematic Reviews and Meta-Analyses approach. RESULTS: The incidence and prevalence of SDB in patients with SMA was greatest during the first year of diagnosis, with a notable percentage presenting as central and mixed sleep apnea. DMTs have demonstrated variable to positive effects on improving but not eliminating SDB in patients with SMA, with evidence most strongly favoring nusinersen. The literature search demonstrated a paucity of data for risdiplam. CONCLUSIONS: Much of existing medical literature regarding SDB in SMA and the impact of DMTs is derived from studies of small sample sizes, abstracts, and varying methodologic rigor. To advance our understanding of DMTs' effects on the management and potential prevention of SDB in SMA, rigorous, multicenter, blinded prospective cohort studies with large sample sizes are essential. Furthermore, specific attention should be directed toward assessing the superiority of single-agent therapy versus combination therapy in mitigating the morbidity associated with SDB in SMA.