Muscle atrophy is prevented in patients with acute spinal cord injury using functional electrical stimulation

Abstract

Severe muscle atrophy occurs rapidly following traumatic spinal cord injury (SCI). Previous research shows that neuromuscular or`functional' electrical stimulation (FES), particularly FES-cycle ergometry (FES-CE) can cause muscle hypertrophy in individuals with chronic SCI (41 year post-injury). However, the modest degree of hypertrophy in these already atrophied muscles has lessened earlier hopes that FES therapy would reduce secondary impairments of SCI. It is not known whether FES treatments are eective when used to prevent, rather than reverse, muscle atrophy in individuals with acute SCI. This study explored whether unloaded isometric FES contractions (FES-IC) or FES-CE decreased subsequent muscle atrophy in individual with acute SCI (53 months post-injury). Twenty-six subjects, 14 ± 15 weeks posttraumatic SCI, were assigned to control, FES-IC, or FES-CE against progessively increasing resistance. Subjects were involved in the study for 3 or 6 months. Total body lean body mass (TB-LBM), lower limb lean body mass (LL-LBM), and gluteal lean body mass (G-LBM) were determined before the study, and at 3 and 6 months using dual energy X-ray absorptiometry (DEXA). Controls lost an average of 6.1%, 10.1%, 12.4%, after 3 months and 9.5%, 21.4%, 26.8% after 6 months in TB-LBM, LL-LBM and G-LBM respectively. Subjects in the FES-IC group consistently lost less lean body mass than controls, however, only 6 month G-LBM loss was signi®cantly attenuated in this group relative to the controls. In the FES-CE group, LL-LBM and G-LBM loss were prevented at both 3 and 6 months, and TB-LBM loss was prevented at 6 months. In addition, FES-CE signi®cantly increased G-LBM and LL-LBM after 6 months of training relative to pre-training levels. Within the control group, there was no signi®cant relationship between LL-LBM loss (3 and 6 months) and the number of days between injury and baseline measurement. In summary, this study shows that FES-CE, but not FES-IC, training prevents muscle atrophy in acute SCI after 3 months of training, and causes signi®cant hypertrophy after 6 months. The magnitude of dierences in regionalized LBM between controls and FES-CE subject raises hopes that such treatment may indeed be bene®cial in preventing secondary impairments of SCI if employed before extensive post-injury atrophy occurs.

Electrical Stimulation During Gait Promotes Increase of Muscle Cross-sectional Area in Quadriplegics: A Preliminary Study

“…The 15% increase in quadriceps CSA confirms previous studies that showed muscle increase in chronic spinal cord-injured patients using NMES in other modalities of therapy [3,19]. Two studies suggest NMES does not reverse muscle atrophy in chronic spinal cord-injured patients [1,16] but can promote moderate increases after muscle contractions against some external load [20,21]. Scremin et al [23] observed an increase of 31% in the CSA of the rectus femoris after 98.1 ± 9.1 sessions of FES cycle-ergometer training with progressive resistance as shown on CT. Mohr et al reported an increase of 12% in CSA of the thigh after FES cycle-ergometer with progressive load for 12 months three times a week [19].…”

“…However, FES contractions without resistance appear not to prevent muscle atrophy or to increase muscle CSA in the early and chronic phases of spinal cord injury [1,16]. Thus, these studies suggest the muscle hypertrophy is directly associated with the force produced during electrical stimulation training.…”

“…Muscle atrophy is one of many alterations occurring after spinal cord injury; it contributes to various medical complications, such as fractures, deep venous thrombosis [1], cardiovascular deconditioning [5], and early fatigability during neuromuscular electrical stimulation (NMES) [15]. Decrease in average muscle cross-sectional area (CSA) [8], replacement of Type I muscle fibers by Type II fibers [4], infiltration of adipose tissue inside muscles, reduction in the oxidative enzyme level, mitochondria concentration, and number of capillaries are observed in muscles located below the injury level [3,18,21].…”

Physiological effects of lower extremity functional electrical stimulation in early spinal cord injury: lack of efficacy to prevent bone loss

“…Electrical stimulation has a long history in the diagnosis [1][2][3] and treatment of disorders [4][5][6] of the central nervous system. The application of this physical modality in the rehabilitation of people with spinal cord injury (SCI) has been extensively studied as a 'functional therapy'.…”

“…The application of this physical modality in the rehabilitation of people with spinal cord injury (SCI) has been extensively studied as a 'functional therapy'. [4][5][6][7] Clinical and experimental studies indicate that neuromuscular electrical stimulation can both affect and effect changes in muscle fibre contractile properties 4,8 and metabolism, 9,10 as well as responses at physiological 5,6 and functional levels. Although well studied, 7,[11][12][13] there is conflicting evidence about the efficacy of electrically evoked muscle activation in the stimulation of bone metabolism (bone formation and/or reduction of bone loss), and the clinical role of functional electrical stimulation (FES) in the treatment of osteoporosis resulting from neurological damage.…”