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Background/objective: We assessed the metabolic and heart rate (HR) responses to a single session of circuit resistance training (CRT) in six subjects with complete paraplegia (T5-T12 levels) in order to determine the caloric cost of the exercise., Methods: Subjects underwent isoinertial weight training exercises with interspersed periods of high-cadence, low-resistance arm ergometry (AE). Following protocol familiarization, subjects completed one session of CRT during which continuous monitoring of HR, oxygen uptake (VO2), and respiratory exchange ratio (RER = VCO2/VO2) was performed. Caloric cost was calculated from the exercise VO2 values across the CRT session. A peak arm exercise test allowed data to be expressed as percentages of peak VO2 and HR., Results: Subjects displayed mean VO2 values of 11.6 +/- 2.4 ml/kg/min (mean +/- SD) and a mean HR of 136 +/- 17 beats/min across the CRT session, corresponding with 49.0% of peak VO2 and 76.8% of peak HR. The RER values ranged from 0.96 to 1.19 and averaged above unity throughout the CRT session., Conclusion: Despite the modest absolute VO2 during exercise, CRT satisfies operational criteria developed for cardiorespiratory exercise prescriptions in persons without disability. The RER values recorded indicate that CRT is intense work that relies primarily on glycolytic metabolism.

Previous reports have described significant limitations in the daily use of functional neuromuscular stimulation (FNS) ambulation systems by persons with spinal cord injuries (SCI). The potential application of these devices to provide physiological benefits as an exercise modality has prompted a reconsideration of the technology. However, the acute physiological effects related to the use of FNS systems have not been thoroughly examined. The purpose of this study was to investigate the relationships of oxygen consumption (VO2), heart rate (HR), and ratings of perceived exertion (RPE) during FNS ambulation by persons with SCI paraplegia. Eleven persons with thoracic level paraplegia, aged 21.5 to 38.0 years, participated in an incremental FNS ambulation test. Metabolic measures were collected continuously via open circuit spirometry as the subjects performed a series of ambulation passes of progressively increasing pace. At the end of each ambulation pass, HR and RPE measures were collected. The test was terminated when either the subjects judged the effort to be maximal or when the investigators deemed the effort to be maximal based on HR. A strong linear relationship was documented between the VO2 and HR measures of all subjects throughout subpeak levels of FNS ambulation. RPE did not vary proportionally with VO2 until relatively high levels of exercise intensity were reached. This study indicates that HR, but not RPE, is an appropriate indicator of exercise intensity for persons with SCI paraplegia using a FNS ambulation system. [ABSTRACT FROM AUTHOR]

The rationale for implantation of autologous human Schwann cells (SCs) in persons with subacute spinal cord injury (SCI) is based on evidence that transplanted SCs are neuroprotective, support local axonal plasticity, and are capable of myelinating axons. A Phase I clinical trial was conducted to evaluate the safety of autologous human SC transplantation into the injury epicenter of six subjects with subacute SCI. The trial was an open-label, unblinded, non-randomized, non-placebo controlled study with a dose escalation design and standard medical rehabilitation. Participants were paraplegics with neurologically complete, trauma-induced spinal lesions. Autologous SCs were cultured in vitro from a sural nerve harvested from each participant and injected into the epicenter of the spinal lesion. Outcome measures for safety were protocol compliance, feasibility, adverse events, stability of neurological level, absence of detectable mass lesion, and the emergence of clinically significant neuropathic pain or muscle spasticity no greater than expected for a natural course cohort. One year post-transplantation, there were no surgical, medical, or neurological complications to indicate that the timing or procedure for the cell transplantation was unsafe. There were no adverse events or serious adverse events related to the cell therapy. There was no evidence of additional spinal cord damage, mass lesion, or syrinx formation. We conclude that it is feasible to identify eligible candidates, appropriately obtain informed consent, perform a peripheral nerve harvest to obtain SCs within 5-30 days of injury, and perform an intra-spinal transplantation of highly purified autologous SCs within 4-7 weeks of injury. [ABSTRACT FROM AUTHOR]