Nutrient supplementation post ambulation in persons with incomplete spinal cord injuries: a randomized, double-blinded, placebo-controlled case series

OBJECTIVE: To examine effects of protein-carbohydrate intake on ambulation performance in persons with incomplete spinal cord injury (SCI). DESIGN: Double-blinded treatment with washout and placebo crossover. SETTING: Academic medical center. PARTICIPANTS: Three subjects aged 34 to 43 years with incomplete SCI at C5-T4. INTERVENTIONS: Subjects walked to fatigue on 5 consecutive days. On fatigue, participants consumed 48g of vanilla-flavored whey and 1g/kg of body weight of carbohydrate (CH(2)O). Weekend rest followed, and the process was repeated. A 2-week washout was interposed and the process repeated using 48g of vanilla-flavored soy. MAIN OUTCOME MEASURES: Oxygen consumed (Vo(2); in L/min), carbon dioxide evolved (Vco(2)), respiratory exchange ratio (RER: Vco(2)/Vo(2)), time (in minutes), and distance walked (in meters) were recorded. Caloric expenditure was computed as Vo(2) by time by 21kJ/L (5kcal/L) of oxygen consumed. Data were averaged across the final 2 ambulation sessions for each testing condition. RESULTS: Despite slow ambulation velocities (range, .11-.34m/s), RERs near or above unity reflected reliance on CH(2)O fuel substrates. Average ambulation time to fatigue was 17.8% longer; distance walked 37.9% longer, and energy expenditure 12.2% greater with the whey and CH(2)O supplement than with the soy drink. CONCLUSIONS: Whey and CH(2)O ingestion after fatiguing ambulation enhanced ensuing ambulation by increasing ambulation distance, time, and caloric expenditure in persons with incomplete SCI.     

Effects of Practice Combined with Somatosensory or Motor Stimulation on Hand Function in Persons with Spinal Cord Injury

Background:

Individuals with chronic tetraplegia prioritize recovery of hand function as an important factor in improving their quality of life. Interventions that may improve hand function and increase corticomotor excitability are functional electrical stimulation (FES), somatosensory stimulation (SS), and task-oriented training.

Objective:

We compared functional and corticomotor outcomes in a control condition to changes associated with FES (triggered via electromygraphic signals) and with SS (constant trains), each combined with either unimanual or bimanual training.

Methods:

Using a randomized, clinical trial design, comparisons were made to a delayed intervention control group. Participants (n = 24) had chronic tetraplegia, with the ability to activate thenar muscles, and were randomly assigned to either the immediate intervention (intervention) or control/ delayed intervention groups. Primary analyses compared intervention (FES or SS) to control/delayed intervention. Secondary analyses compared subgroups of FES versus SS (regardless of uni- or bilateral training) and uni- versus bimanual training (regardless of stimulation type). Outcomes were assessed before and after the control and the intervention period.

Results:

Compared to control/delayed intervention, the intervention group had greater changes in unimanual function and corticomotor area, regardless of whether practice was combined with FES or with SS. Irrespective of stimulation type, the bimanual subgroups improved to a greater extent than the unimanual subgroups on the bimanual hand function test.

Conclusions:

Hand training combined with either SS or FES was associated with improved hand use and corticomotor activity in persons with chronic tetraplegia. Both interventions appear to be equally effective.Key words: functional electrical stimulation, hand function, neuroplasticity, somatosensory stimulation, spinal cord injury, tetraplegiaThere are approximately 259,000 individuals living with chronic tetraplegia due to cervical spinal cord injury (SCI) in the United States.¹ For persons with tetraplegia, recovery of hand function is an important meaningful goal.^2,3 Studies of neuroplasticity have shown that corticomotor reorganization likely contributes to impairment in addition to that imposed by the damaged spinal cord. Maladaptive corticomotor plasticity occurs after SCI, wherein areas of the body affected by the injury have less corticomotor representation^4,5 and less corticomotor excitability to muscles that are paretic as a result of the injury.⁶The repetitive practice of task-specific activities using a massed practice (MP) schedule has been shown to induce corticomotor reorganization and improve the performance of activities in persons with tetraplegia.^7–10 When considering interventions for persons with tetraplegia, the literature indicates that more changes in functional and corticomotor measures are found when MP training is augmented by electrical stimulation.^7,8 Somatosensory stimulation (SS) is a form of low-level, continuous electrical stimulation with a long pulse width wherein the goal is to indirectly activate the corticomotor system through the sensory system.¹¹ There is evidence that the long pulse width has been shown to preferentially activate the Ia afferent fibers.¹² In persons with weakness due to spinal cord injury (SCI)^7,8 or stroke,¹³ prolonged application of SS alone improved pinch force and unimanual hand function. Further, SS is associated with increased corticomotor excitability^5,7,8 and is hypothesized to prepare the system for reorganization.¹⁴Despite the apparent value of SS in augmenting effects of practice, it is conceivable that because the SS provides continuous stimulation, it administers inappropriate sensory information. The individual receives stimulation regardless of the phase of the activity in which they are engaged. As an alternative, functional electrical stimulation (FES) is a form of electrical stimulation wherein the stimulation activates the muscles and acts as a neural prosthesis to improve grasping function.¹⁵ Evidence suggests that improvements in activities persist even when the FES is not in use.^16,17 As the degree of neural reorganization is dependent on the demands of the task in which the individual engages, more opportunities for practice of challenging activities may result in greater improvement in function and corticomotor reorganization. Further, most stimulators used in the clinical setting have a maximal pulse width of 400 microseconds, which is appropriate for FES; it has been suggested that longer pulse durations are required to activate large-diameter sensory fiber, as is the goal of SS.¹¹ If the shorter pulse width used in FES is effective in promoting hand function compared to SS, then there is no need for the more expensive laboratory stimulators with the capability of increasing the pulse width to 1 millisecond.The purpose of this study was to evaluate the effectiveness of FES or SS, each combined with either unimanual (Uni) or bimanual (Bi) MP training, as compared to a control condition on the primary outcome measure, the Jebsen Taylor Hand Function Test (JTHF). Because persons with tetraplegia typically have bilateral deficits, bimanual training may be more beneficial than unimanual training.^9,10 A pilot study comparing these interventions has been published,¹⁰ but it lacked a control condition, which limited the ability to draw conclusions about overall effects of the intervention. We hypothesized that the participants assigned to the FES group would have greater changes in functional outcomes and corticomotor map area. We further hypothesized that participants assigned to the SS group would have a greater increase in corticomotor excitability compared to participants in the FES group.     

Cortical reorganization following bimanual training and somatosensory stimulation in cervical spinal cord injury: a case report

BACKGROUND AND PURPOSE: Deficits in upper-extremity function in individuals with tetraplegia are primarily due to the loss of motor pathways. Detrimental cortical reorganization, however, may create further loss of function. The purpose of this case report is to describe the cortical changes associated with a combination intervention using bimanual massed practice training with somatosensory stimulation. CASE DESCRIPTION: "BR" was a 22-year-old man with C6 tetraplegia and hand impairment who participated in this training intervention for 3 weeks. OUTCOMES: BR demonstrated improvements in sensory function, strength (the force-generating capacity of muscle), and performance of functional hand skills. Following the training, the cortical motor map of the biceps brachii muscle shifted anteriorly and increased in area and volume. DISCUSSION: This is the first documented case in which changes in the size and location of the cortical map were associated with an intervention and improvement in function in an individual with tetraplegia. This case suggests that an intensive training intervention may induce both functional and neurophysiological changes.     

Spinal cord control of movement: implications for locomotor rehabilitation following spinal cord injury

In recent years, our understanding of the spinal cord's role in movement control has been greatly advanced. Research suggests that body weight support (BWS) walking and functional electrical stimulation (FES), techniques that are used by physical therapists, have potential to improve walking function in individuals with spinal cord injury (SCI), perhaps long after the stage of spontaneous recovery. Walking is one of the most desired goals of people with SCI; however, we are obligated to be judicious in our claims of locomotor recovery. There are few controlled studies that compare outcomes of BWS training or FES with those of conventional interventions, and access to services using BWS training or FES may be restricted under managed care.     

Medical Rehabilitation: Guidelines to Advance the Field With High-Impact Clinical Trials

The purpose of this Special Communication is to summarize guidelines and recommendations stemming from an expert panel convened by the National Institutes of Health, National Center for Medical Rehabilitation Research (NCMRR) for a workshop entitled The Future of Medical Rehabilitation Clinical Trials, held September 29-30, 2016, at the NCMRR offices in Bethesda, Maryland. The ultimate goal of both the workshop and this summary is to offer guidance on clinical trials design and operations to the medical rehabilitation research community, with the intent of maximizing the effect of future trials.