low oxygen therapy to enhance walking recovery after sci.

Conditions: Spinal Cord Injuries

Summary: the purpose of this study is to determine how combining bouts of low oxygen, transcutaneous spinal cord stimulation, and walking training may improve walking function for people with chronic spinal cord injury of different age groups.

the goal of the study is to determine the optimal dosage for different age groups of repeatedly breathing mild bouts of low oxygen for brief periods (termed acute intermittent hypoxia (aih)) combined with transcutaneous spinal cord stimulation (tstim) to improve recovery of walking and strength after spinal cord injury. preliminary studies have shown that combining aih and tstim with walking training can enhance individuals walking training greater than just aih or tstim. by using low oxygen as a pre-treatment to tstim during walking training, functional independence and quality of life may improve. despite exciting preliminary results supporting the efficacy of aih and tstim to enhance walking recovery after sci, understanding factors that may enhance or undermine treatment responsiveness is warranted. factors include establishing the role of age and sex dependency on appropriate dosing (number of sessions) aih to provide the greatest plasticity-promoting effects on walking recovery for our aging population of persons living with sci.

Eligibility criteria:
inclusion criteria: * 18 to 80 years of age * medically stable with medical clearance from study physician to participate * sci at or below c1 and at or above l2 with at least some sensory or motor function preserved below the neurologic level * non-progressive etiology of spinal injury * american spinal injury association (asia) scores of c-d at initial screen * ambulatory (able to complete the 10-meter walk test without support from another person) * chronic injury (define as \> 12 months post-injury) to avoid potential for spontaneous neurological plasticity and recovery exclusion criteria: * severe concurrent illness or pain, including unhealed decubiti, severe neuropathic or chronic pain syndrome, severe infection (e.g., urinary tract), hypertension, cardiovascular disease, pulmonary disease, severe osteoporosis, active heterotopic ossification in the lower extremities, severe systemic inflammation * \< 24 on mini-mental exam * severe recurrent autonomic dysreflexia * history of severe cardiovascular/pulmonary complications including hypertension (systolic blood pressure \> 150 mmhg) * pregnancy because of unknown effects of aih or tstim on a fetus (individuals of childbearing potential will not otherwise be excluded) * botulinum toxin injections in lower extremity muscles within the prior three months * history of tendon or nerve transfer surgery in the lower extremity * untreated severe sleep-disordered breathing characterized by uncontrolled hypoxia and sleep fractionation that may impact the outcome of this study. * active implanted devices (e.g., intrathecal baclofen pump) * receiving concurrent electrical stimulation * motor threshold evoked by transcutaneous spinal stimulation \>200 ma

Keywords: walk rehabilitation strength movement low oxygen electrical stimulation gait training