David R. Dolbow

Effects of spinal cord injury on body composition and metabolic profile – Part I

Abstract Several body composition and metabolic-associated disorders such as glucose intolerance, insulin resistance, and lipid abnormalities occur prematurely after spinal cord injury (SCI) and at a higher prevalence compared to able-bodied populations. Within a few weeks to months of the injury, there is a significant decrease in total lean mass, particularly lower extremity muscle mass and an accompanying increase in fat mass. The infiltration of fat in intramuscular and visceral sites is associated with abnormal metabolic profiles. The current review will summarize the major changes in body composition and metabolic profiles that can lead to comorbidities such as type 2 diabetes mellitus and cardiovascular diseases after SCI. It is crucial for healthcare specialists to be aware of the magnitude of these changes. Such awareness may lead to earlier recognition and treatment of metabolic abnormalities that may reduce the co-morbidities seen over the lifetime of persons living with SCI.

Functional electrical stimulation therapies after spinal cord injury.

The use of electricity for therapeutic purposes dates back to 15 AD, when Scribonius Largus, a court physician to the Roman emperor Claudius began using electric shocks from the torpedo ray fish to treat gout pain and headaches [1]. Although the phenomenon of electricity had been used for centuries the actual word “electricity” was not in use until the 1600’s, when William Gilbert, an English physician, coined the new Latin word “electricus” meaning like amber. The Creek word amber refers to the property of attracting small objects after being rubbed [2]. In 1780, Luigi Galvani, an Italian physician and physicist showed that impulses from nerve cells pass to muscles by demonstrating the electrical stimulation of a frog’s leg muscles [3]. Italian physicist and nephew of Luigi Galvani, Giovanni Aldini, carried on the work of his uncle by demonstrating the ability to stimulate brain tissue by applying electrical stimulation to the heads of decapitated prisoners [4]. In 1874, physician Robert Bartholow, stimulated muscle contractions while working on the cancerous brain of a live woman [5]. Research into the uses of electricity continued through the 19th and 20th centuries allowing the development of numerous inventions i.e. galvanometer, micro-electrodes, cathode ray oscilloscope, pacemakers and defibrillators [6,7]. These and other advances

The effects of spinal cord injury and exercise on bone mass: A literature review

INTRODUCTION Bone loss is a common and often debilitating condition that accompanies spinal cord injury. Because bone loss after spinal cord injury is multifactorial, it can be difficult to assess and treat. This process becomes even more complex as secondary conditions associated with aging are introduced. PURPOSE There are two purposes of this literature review. The first is to summarize information concerning the mechanisms of bone loss and osteoporosis after spinal cord injury. The second is to summarize existing data concerning the effects of exercise on bone loss after spinal cord injury. METHOD Literature was reviewed concerning the bone loss process and the non-pharmacological treatment options for ameliorating bone loss after spinal cord injury. RESULTS (Part One) Osteoporosis is universal in persons with chronic complete spinal cord injury, which increases the risk of bone fracture. Bone loss after spinal cord injury is both sublesional and regional with the greatest areas of bone demineralization being in the sublesional trabecular laden areas of the distal and proximal epiphyses of the femur and tibia. (Part Two) While passive weight bearing of paralyzed lower extremities appears to be ineffective, stressing the bones through muscular contractions initiated by electrical stimulation (FES) have yielded positive results in some cases. The intensity, frequency, and duration of stress to the bones appear to be important determinants of improved bone parameters. Although further quantification of these components is needed, some generalized guidelines can be deduced from completed research. Intensities showing positive results have been loads of one to one and a half times body weight for FES exercise or having participants FES cycle at their highest power output. Safety precautions must be used to decrease risk of bone fracture. Generally, the frequency is effective with three or more weekly exercise sessions. Studies of duration suggest that several months to one or more years of FES are necessary. DISCUSSION In order to promote healthy and independent aging in patients with spinal cord injury, it is important to understand the processes, consequences and effective treatments involved with bone loss.

The effects of electrical stimulation on body composition and metabolic profile after spinal cord injury – Part II

Abstract Diet and exercise are cornerstones in the management of obesity and associated metabolic complications, including insulin resistance, type 2 diabetes, and disturbances in the lipid profile. However, the role of exercise in managing body composition adaptations and metabolic disorders after spinal cord injury (SCI) is not well established. The current review summarizes evidence about the efficacy of using neuromuscular electrical stimulation or functional electrical stimulation in exercising the paralytic lower extremities to improve body composition and metabolic profile after SCI. There are a number of trials that investigated the effects on muscle cross-sectional area, fat-free mass, and glucose/lipid metabolism. The duration of the intervention in these trials varied from 6 weeks to 24 months. Training frequency ranged from 2 to 5 days/week. Most studies documented significant increases in muscle size but no noticeable changes in adipose tissue. While increases in skeletal muscle size after twice weekly training were greater than those trials that used 3 or 5 days/week, other factors such as differences in the training mode, i.e. resistance versus cycling exercise and pattern of muscle activation may be responsible for this observation. Loading to evoke muscle hypertrophy is a key component in neuromuscular training after SCI. The overall effects on lean mass were modest and did not exceed 10% and the effects of training on trunk or pelvic muscles remain unestablished. Most studies reported improvement in glucose metabolism with the enhancement of insulin sensitivity being the major factor following training. The effect on lipid profile is unclear and warrants further investigation.

A report of anticipated benefits of functional electrical stimulation after spinal cord injury

Abstract Background Functional electrical stimulation (FES) has been regularly used to offset several negative body composition and metabolic adaptations following spinal cord injury (SCI). However, the outcomes of many FES trials appear to be controversial and incoherent. Objective To document the potential consequences of several factors (e.g. pain, spasms, stress and lack of dietary control) that may have attenuated the effects on body composition and metabolic profile despite participation in 21 weeks of FES training. Participant A 29-year-old man with T6 complete SCI participated in 21 weeks of FES, 4 days per week. Methods Prior to and following training, the participant performed arm-crank-graded exercise testing to measure peak VO2. Tests conducted included anthropometrics and dual energy X-ray absorptiometry body composition assessments, resting energy expenditure, plasma lipid profiles and intravenous glucose tolerance tests. Results The participant frequently reported increasing pain, stress and poor eating habits. VO2 peak decreased by 2.4 ml/kg/minute, body mass increased by 8.5 kg, and body mass index increased from 25 to 28 kg/m2. Waist and abdominal circumferences increased by 2–4 cm, while %fat mass increased by 5.5%. Absolute increases in fat mass and fat-free mass of 8.4 and 1 kg, respectively, were reported. Fasting and peak plasma glucose increased by 12 and 14.5%, while lipid panel profiles were negatively impacted. Conclusion Failure to control for the listed negative emerging factors may obscure the expected body composition and metabolic profile adaptations anticipated from FES training.

Neuromuscular electrical stimulation attenuates thigh skeletal muscles atrophy but not trunk muscles after spinal cord injury

The current study examined the effects of 12weeks of surface neuromuscular electrical stimulation (NMES) and ankle weights on the cross-sectional areas (CSAs) of three thigh [Gracilis (Gra), Sartorious (Sar) and Adductor (Add)] as well as two trunk [hip flexor (HF) and back extensor (BE)] muscle groups in men with spinal cord injury (SCI). Seven individuals with chronic motor complete SCI were randomly assigned into a resistance training +diet (RT+diet; n=4) or diet control (n=3) groups. The RT+diet group underwent twice weekly training with surface NMES and ankle weights for 12weeks. Training composed of four sets of 10 repetitions of leg extension exercise while sitting in their wheelchairs. Both groups were asked to monitor their dietary intake. Magnetic resonance images were captured before and after 12weeks of interventions. Gra muscle CSA showed no change before and after interventions. A significant interaction (P=0.001) was noted between both groups as result of 9% increase and 10% decrease in the Gra muscle CSA of the RT+diet and diet groups, respectively. Sar muscle CSA increased [1.7±0.4-2.5±0.5cm(2); P=0.029] in the RT+diet group with no change [2.9±1.4-2.6±1.3cm(2)] in the diet group; with interaction noted between both groups (P=0.002). Analysis of covariance indicated that Add muscle CSA was 38% greater in the RT+diet compared to the diet group (P=0.025) after 12weeks; a trend of interaction was also noted between both groups (P=0.06). HF and BE muscle groups showed no apparent changes in CSA in both groups. The results suggested that surface NMES can delay the process of progressive skeletal muscle atrophy after chronic SCI. However, the effects are localized to the trained thigh muscles and do not extend to the proximal trunk muscles.

Exercise adherence during home-based functional electrical stimulation cycling by individuals with spinal cord injury.

ObjectiveThe typically sedentary spinal cord injured population has limited physical activity options because of muscle paralysis, difficulties in transportation, and barriers to access rehabilitation/wellness facilities. It is important to investigate physical activity alternatives to increase physical activity levels and decrease the risk of inactivity-derived diseases. The goal of this study was to determine the effects of a home-based functional electrical stimulation cycling program on exercise adherence of those with spinal cord injury. DesignSeventeen Veterans with posttraumatic C4–T11 American Spinal Injury Association Impairment Scale A–C spinal cord injury participated in two 8-wk exercise periods of home-based functional electrical stimulation lower extremity cycling. Exercise adherence and the effects of six factors thought to influence exercise adherence were studied during both exercise periods. ResultsExercise adherence rates for exercise periods 1 and 2 were 71.7% and 62.9%, respectively. Age, history of exercise, and pain not associated with the exercise activity were determined to have significant impact on exercise adherence rates. ConclusionsExercise adherence rates were well above the reported 35% in the able-bodied population, which provides evidence for the feasibility of a home-based functional electrical stimulation lower extremity cycling program. Younger adults with a history of being physically active have the highest potential for exercise adherence.

Feasibility of home-based functional electrical stimulation cycling: case report

Study design:Single-subject (male, 64 years of age) case.Objectives:To determine the feasibility of a home-based FES-LEC (functional electrical stimulation lower extremities cycling) program and effects on body composition, quality of life (QOL) and seat pressure mapping in an older individual with spinal cord injured (SCI).Setting:Home-based FES-LEC with internet connection. Southeastern United States.Methods:FES-LEC three sessions per week for 9 weeks in the participants home and monitored by the research staff via internet connection. Pre- and post-exercise program testing of seat pressure mapping, QOL and body composition including percent body fat (%BF), fat mass (FM), lean mass (LM) and bone mineral density (BMD).Results:The participant completed 25 of 27 recommended exercise sessions over 9 weeks for a 93% compliance rate. Cycling distance increased from 3.98 to 9.00 km (126%). Total body LM increased from 48.94 to 53.02 kg (8.3%). The %BF decreased from 29.6 to 28.4(−1.2%). Total body weight, FM and BMD remained unchanged. Average static seat pressure decreased from 55.5 to 52.59 mm Hg (5%), whereas maximum seat pressure decreased from 120.76 to 91.5 mm Hg (24%). The psychological domain (perception of body image, appearance and self-esteem) of the QOL questionnaire improved from 12.67 to 14.Conclusion:Positive changes in this study regarding body composition, QOL and seat pressure mapping support results of clinical studies using FES-LEC training on younger adults with SCI. The high percentage of exercise adherence and positive results on body composition, QOL and seat pressure provide support for the feasibility of home-based FES-LEC.

A model of prediction and cross-validation of fat-free mass in men with motor complete spinal cord injury.

OBJECTIVES To establish and validate prediction equations by using body weight to predict legs, trunk, and whole-body fat-free mass (FFM) in men with chronic complete spinal cord injury (SCI). DESIGN Cross-sectional design. SETTING Research setting in a large medical center. PARTICIPANTS Individuals with SCI (N=63) divided into prediction (n=42) and cross-validation (n=21) groups. INTERVENTION Not applicable. MAIN OUTCOME MEASURE Whole-body FFM and regional FFM were determined by using dual-energy x-ray absorptiometry. Body weight was measured by using a wheelchair weighing scale after subtracting the weight of the chair. RESULTS Body weight predicted legs FFM (legs FFM=.09×body weight+6.1; R(2)=.25, standard error of the estimate [SEE]=3.1kg, P<.01), trunk FFM (trunk FFM=.21×body weight+8.6; R(2)=.56, SEE=3.6kg, P<.0001), and whole-body FFM (whole-body FFM=.288×body weight+26.3; R(2)=.53, SEE=5.3kg, P<.0001). The whole-body FFM(predicted) (FFM predicted from the derived equations) shared 86% of the variance in whole-body FFM(measured) (FFM measured using dual-energy x-ray absorptiometry scan) (R(2)=.86, SEE=1.8kg, P<.0001), 69% of trunk FFM(measured), and 66% of legs FFM(measured). The trunk FFM(predicted) shared 69% of the variance in trunk FFM(measured) (R(2)=.69, SEE=2.7kg, P<.0001), and legs FFM(predicted) shared 67% of the variance in legs FFM(measured) (R(2)=.67, SEE=2.8kg, P<.0001). Values of FFM did not differ between the prediction and validation groups. CONCLUSIONS Body weight can be used to predict whole-body FFM and regional FFM. The predicted whole-body FFM improved the prediction of trunk FFM and legs FFM.

Differences in current amplitude evoking leg extension in individuals with spinal cord injury

OBJECTIVES To investigate the effects of regional thigh composition that result in different responses to current amplitude among individuals with spinal cord injury (SCI) during applications of surface neuromuscular electrical stimulation (NMES) to evoke dynamic leg extension. DESIGN Cross-sectional. SETTINGS Academic Settings. METHODS Five males with chronic motor complete SCI completed 3 visits of NMES to determine the current amplitude required to evoke full knee extension. The participants underwent magnetic resonance imaging of both thighs to measure skeletal muscle cross-sectional area (CSA), thigh subcutaneous adipose tissue (SAT) and intramuscular fat (IMF). Applicants were classified into high (n = 3) and low-responders (n = 2) based on the determined current amplitude. RESULTS The low-responders required 48-59% greater current amplitude to complete the same task as the high-responders. Low-responders had greater thigh SAT CSA (51-56%) than the high-responders with SCI. After adjusting to whole thigh CSA, IMF CSA was significantly greater in the low- responders; whereas skeletal muscle CSA was lower compared to the high-responders. CONCLUSION The findings suggest that thigh SAT and IMF act as insulation against propagation of current during surface NMES applications in individuals with SCI.