Effect of a Novel Intervention Using Daily Intermittent Hypoxia and High-Intensity Training on Upper-Limb Function in Individuals with Spinal Cord Injury
Abstract
Despite recent advances in potential therapies, the challenge of regaining function following spinal cord injury (SCI) remains difficult to resolve. As many as 1.2 million individuals, including 70,000 military Service members, are currently living with SCI in the United States. The average lifetime healthcare cost for each individual with SCI is between 2 and 5 million dollars, making it a significant public health concern. The ability to regain strength and function is of highest importance to people with SCI, yet our therapeutic options remain rather limited in scope and in their impact on daily life. Rationale: Most SCIs are incomplete, meaning that some level of motor and sensory function is partially preserved below the level of injury. While in the weeks or months following SCI, a person may spontaneously regain some level of function due to the ability of spared pathways to change and adapt (plasticity), this recovery is modest at best and rarely results in large gains in motor or sensory performance. Most therapies for persons with SCI also focus on enhancing preserved motor functions using rehabilitation training; however, they are limited in efficacy due to limited connections between the brain and spinal cord. The objective of this proposal is to evaluate a new strategy that focuses on strengthening existing neural connections to maximize the benefits of current training methods. During this therapy, called acute intermittent hypoxia (AIH), a person is administered brief bouts of low oxygen through a mask. The oxygen drops from 21% to 10% -- similar to being on the top of a high mountain -- for a brief amount of time (15 bouts of 90 seconds each, alternating with normal oxygen levels). In persons with SCI, daily AIH has been shown to dramatically increase strength in ankle muscles within a few minutes. In addition, coupling daily AIH with walking training significantly enhances walking recovery compared to just training alone. As the next step in this promising therapy, we aim to test the potential of daily AIH to improve upper limb function in persons with incomplete SCI. Regaining upper-limb strength after SCI is necessary in order to achieve independence in activities of daily living. In fact, for most persons with SCI at the cervical level, recovery of hand function is rated as their highest priority. We propose to address a key question concerning SCI rehabilitation: Can we boost the efficacy of traditional rehabilitation training protocol by coupling it with approaches that induce spinal plasticity? Clinical applications, benefits, risks and timeline: This proposal is specifically relevant to persons with chronic, incomplete SCI at the cervical or high thoracic level (C3 - T1). There are two specific aims: First, we will quantify the effect of daily AIH therapy on upper-limb function in persons with SCI. Second, we will determine the impact of daily AIH therapy administered just before upper-limb training on arm and hand function. We aim to recruit 92 research participants who will visit the Rehabilitation Institute of Chicago for 14 training sessions over 1 month and then follow-up assessments for another 3 months. We hypothesize that daily AIH will induce spinal plasticity and improve voluntary hand function. Additionally, when combined with upper limb training, we expect that daily AIH will be significantly more effective in improving hand function compared to training alone. If our combined rehabilitation strategy using AIH is successful, this research will lay the foundation for practical techniques for harvesting spinal plasticity to improve the outcomes of traditional rehabilitation. No adverse effects have been observed in our lower extremity work, preliminary data, and other studies that used a similar mild intermittent hypoxia protocol. However, we will monitor research participants carefully for any adverse effects or unexpected results. Contributions of the P
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 07, 2017
- Source ID
- W81XWH1710340
Entities
People
- William Rymer
Organizations
- Shirley Ryan AbilityLab
- United States Army