Neuroendocrine changes during functional electrical stimulation

This study examined the effects of a computerized functional electrical stimulation exercise program on plasma β-endorphin-like immunoreactivity (BEP-ir), cortisol levels and depression parameters in spinal cord-injured individuals. Nine subjects from 1.2 to 33.5 yr postinjury with both motor and sensory complete lesions between C5 and T12 participated. It was determined that patients who sustained spinal cord-injuries <5 yr before this study had lower than normal baseline levels of BEP-ir and flattened circadian rhythms. Patients who sustained their injury >5 yr before this study had higher baseline levels of BEP-ir with some return to normal circadian rhythmicity. Baseline cortisol levels, regardless of time since injury, appeared to be dysregulated. Regular exercise with computerized functional electrical stimulation caused significantly (P < 0.05) sustained increases in BEP-ir in all patients and improved the regulation of cortisol. Furthermore, the more strenuous the exercise training, greater increases in BEP-ir levels were seen. Last, depression scores improved, which suggests a possible association between subjective mood and BEP-ir levels.