Jessica R. Mitchell, DO
Medical Student
Rowan-Virtua School of Osteopathic Medicine
Somerdale, New Jersey, United States
Brandon Goodwin, DO
Resident
Ocean University Medical Center TY/ John’s Hopkins
Toms River, New Jersey, United States
Timothy Gelatt, BS
Medical Student
Rowan-Virtua School of Osteopathic Medicine
middletown, New Jersey, United States
Gilbert Siu, DO
Medical Director, Brain Injury and Stroke Rehabilitation
Encompass Health
Vineland, New Jersey, United States
Incomplete cervical spinal cord injury (c-SCI) results in the partial severance of neural transmission below the site of injury, resulting in complete or partial loss of gross and fine motor skills. Acute intermittent hypoxia (AIH) has been recently studied as a technique for improving motor function in limb musculature and spinal synaptic plasticity in individuals with c-SCI. This review aims to assess the upper extremity functional outcomes in randomized, controlled trials (RCTs) of individuals with c-SCI before and after AIH treatment.
Design:
The initial database query of 6 databases (PubMed, ProQuest, Embase, Scopus, Web Of Science, Cochrane Library) yielded 308 articles, of which 225 were duplicates. After title and abstract appraisal by two authors (with a third breaking ties), 10 articles remained for full-text appraisal. Of these 10, four were included in qualitative analysis.
Results:
A crossover RCT found AIH to elicit increased bilateral grip and pinch strength compared to placebo groups. Two studies found improvements in the Box and Block Test, a measurement of hand dexterity, after AIH. One study utilized high-density surface electromyography (sEMG) to compare motor unit discharge after AIH from baseline, finding increased elbow flexion and extension torque by 54% and 59%, respectively. This study found no change in the non-AIH group. Another protocol found AIH to potentiate paired corticospinal-motorneuronal stimulation, which was demonstrated by increased motor evoked potentials in the first dorsal interosseous. A different crossover RCT found improvement in hand function, quantified by Jebsen-Taylor tests, and hand opening, using sEMG coactivity motion analysis of the extensor digitorum and flexor digitorum superficialis, after daily AIH.
Conclusions:
The qualitative analysis of these articles depict the beneficial effect of AIH on upper extremity function, strength, dexterity, and grip. Further RCTs are necessary to investigate the full effect, optimal dosage, and effect duration of AIH in patients with incomplete c-SCI.
