NeuroRehabilitation

Therapeutic strategies to promote recovery from stroke are now beginning to utilize current knowledge of neural plasticity and the neuromodulatory role of physical rehabilitation. Current interests are also focused on adjuvant therapies that may enhance plasticity associated with recovery and rehabilitation. Amphetamine was one of the earliest pharmacological interventions and continues to show promising results as an adjuvant treatment for recovery of function in pre-clinical animal studies. This drug is a potent modulator of neurological function and cortical excitation, acting primarily through norepinephrine and dopamine mechanisms to enhance arousal and attention, and thus, to facilitate learning of motor skills. Although the results from the pre-clinical studies have been primarily positive, they have not translated well to clinical trials, which have yielded mixed results. This review addresses some of the conflicting evidence from pre-clinical studies conducted between 1982 and 2008 in order to better understand how to optimize the clinical application of amphetamine as an adjuvant therapy for stroke recovery. Among many of the factors that relate to differences in outcome, it is likely that both amphetamine dose and the timing of the intervention with respect to the time of injury affected the outcome.

Several disorders that involve motor and sensory disturbances such as chronic pain, tinnitus, stroke or dystonia are also characterized by changes in the sensory and motor maps in the sensorimotor cortices. This article reviews training procedures that target these maladaptive changes and the behavioral and cortical changes that accompany them. In addition, we will discuss factors that influence these training procedures and discuss new developments. These procedures include training of perceptual abilities, motor function, direct cortical stimulation as well as behavioral approaches and have been shown to reorganize the altered sensory and motor maps. Treatments that combine several modalities such as imagery or mirror treatment as well as use of prostheses also have beneficial effects. Further research must elucidate the mechanisms of these plastic changes and relate them to disorders and treatments.

Recent experimental evidence suggests that rapid advancement of virtualreality (VR) technologies has great potential for the development of novelstrategies for sensorimotor training in neurorehabilitation. We discuss whatthe adaptive and engaging virtual environments can provide for massive andintensive sensorimotor stimulation needed to induce brain reorganization.Second, discrepancies between the veridical and virtual feedback can beintroduced in VR to facilitate activation of targeted brain networks, whichin turn can potentially speed up the recovery process. Here we review theexisting experimental evidence regarding the beneficial effects of trainingin virtual environments on the recovery of function in the areas of gait,upper extremity function and balance, in various patient populations. Wealso discuss possible mechanisms underlying these effects. We feel thatfuture research in the area of virtual rehabilitation should follow severalimportant paths. Imaging studies to evaluate the effects of sensorymanipulation on brain activation patterns and the effect of various trainingparameters on long term changes in brain function are needed to guide futureclinical inquiry. Larger clinical studies are also needed to establish theefficacy of sensorimotor rehabilitation using VR in various clinicalpopulations and most importantly, to identify VR training parameters thatare associated with optimal transfer to real-world functionalimprovements.

This review presents technologies used in and assesses the main clinical outcomes of electrical therapies designed to speed up and increase functional recovery in stroke patients. The review describes methods which interface peripheral systems (e.g., cyclic neural stimulation, stimulation triggered by electrical activity of muscles, therapeutic functional electrical stimulation) and transcranial brain stimulation with surface and implantable electrodes. Our conclusion from reviewing these data is that integration of electrical therapy into exercise-active movement mediated by electrical activation of peripheral and central sensory-motor mechanisms enhances motor re-learning following damage to the central nervous system. Motor re-learning is considered here as a set of processes associated with practice or experience that leads to long-term changes in the capability for movement. An important suggestion is that therapeutic effects are likely to be much more effective when treatment is applied in the acute, rather than in the chronic, phase of stroke.

In global terms, cerebrovascular stroke is the leading cause of long-term disability. Despite improved acute phase management of stroke, the majority of survivors are disabled and many require effective rehabilitation. Constraint-induced movement therapy (CIMT) is one of the recently emerging therapies for subjects with stroke. The effects of two-week long CIMT on behavioural, neurophysiologic and neuroimaging measures in subjects with chronic stroke were studied. Furthermore, the effects of combined upper limb exercise and peripheral preprogrammed multichannel electrical stimulation, i.e. functional electrical therapy (FET), were evaluated. Behavioral gains were obtained in hand function and functional MRI activations, and, in addition, TMS responses appeared more laterally and/or bilaterally in the affected hemisphere in the subjects after CIMT. Neurophysiologic and functional imaging results were supportive evidence for the benefits of use-dependent plasticity in subjects with chronic stroke.

Neuroprostheses electrically stimulate paralyzed muscles to provide functional enhancement for individuals with neurological disorders, especially among persons with spinal cord injuries. Fully implanted neuroprostheses are reliable, require minimal maintenance and are user-friendly. These systems provide a variety of functions, including reaching, hand grasp and release, standing and stepping, bladder and bowel function and respiratory assist. Based on a representative review of the literature, this article presents and evaluates the development, clinical implementation and clinical efficacy and effectiveness of the various implanted neuroprostheses. Directions for future development are also presented.