Acute intermittent hypoxia in people living with chronic stroke - a preliminary study to examine safety and efficacy as a neurorehabilitation intervention.

Background and Purpose: Acute intermittent hypoxia (AIH) is a novel therapeutic intervention that has the potential to facilitate recovery of function, but its safety and efficacy have not been tested in people with stroke. The purpose here was to examine whether AIH is safe and effective in people with stroke. Methods: Participants (n=10) with a unilateral, ischemic, hemispheric stroke were assessed before and following 4 sessions of AIH. Clinical tests and upper limb strength were assessed before, ~15-30 minutes, and ~60 minutes after the intervention. Results: AIH was well-tolerated and there were no adverse events observed. Although no changes in strength were detected for the less-affected limb, grip strength and elbow flexion force of the more-affected limb was increased after AIH. Conclusions: AIH appears to be potentially safe and effective for improving strength in the more-affected limb in people with stroke. Future work should explore the use of AIH to enhance task-specific training-induced plasticity. ### Competing Interest Statement The authors have declared no competing interest. ### Clinical Trial NCT04019522 ### Funding Statement This study was funded by the American Heart Association (AHA GRANT #18IPA34170025) ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: IRB of Northwestern University gave ethical approval for this work I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors