Mild to Moderate Sleep Apnea Is Linked to Hypoxia-induced Motor Recovery after Spinal Cord Injury

• Authors: Isabelle Vivodtzev, Harvard Medical School; Andrew Q Tan, Harvard Medical School; Megan Hermann, Shirley Ryan AbilityLab; Arun Jayaraman, Shirley Ryan AbilityLab; Victoria Stahl, Emory University; William Zev Rymer, Shirley Ryan AbilityLab; Gordon S Mitchell, University of Florida; Heather Hayes, Emory University; Randy Trumbower, Emory University
• Journal Title: AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE
• Volume: Volume 202, Number 6
• Publisher: AMER THORACIC SOC | 2020-09-15, Pages 887-890
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1164/rccm.202002-0245LE
• Subjects: Health Sciences, Medicine and Surgery; Health Sciences, Rehabilitation and Therapy
• Keywords: Science & Technology; Life Sciences & Biomedicine; Critical Care Medicine; Respiratory System; General & Internal Medicine; REPETITIVE INTERMITTENT HYPOXIA; ENHANCES WALKING

Abstract

To the Editor: Acute intermittent hypoxia (AIH) is a novel treatment to enhance respiratory and nonrespiratory motor function after chronic incomplete spinal cord injury (SCI) (1–3). Despite promising findings, uncertainties in optimal AIH delivery to a heterogeneous population of persons with SCI remain a challenge to clinical translation. Beneficial AIH responses are variable between individuals, and we lack useful biomarkers to determine which individuals benefit most from treatment. AIH-induced functional benefits rely on mechanisms of AIH-induced neuroplasticity. Multiple factors modify AIH-induced plasticity in rodent models, including intermittent hypoxia preconditioning and systemic inflammation, among others (4, 5). One factor not accounted for in human AIH trials, to date, is the incidence of sleep-disordered breathing (SDB). Many individuals with SCI exhibit mild to moderate SDB (6), leading to extended periods of nocturnal high-dose intermittent hypoxia. Because chronic intermittent hypoxia (CIH) elicits both neuroplasticity and inflammation (5), SDB after SCI may contribute to between-person variations in response to AIH therapy.