Repetitive sensory stimulation in stroke rehabilitation – perspectives and potential

Sensorimotor impairment resulting from stroke can have extensive physical, psychological, economic, and social implications despite available neurorehabilitative treatments. Intact somatosensory input is not only crucial for tactile perception but also for sensorimotor performance. Loss of sensory abilities further complicates the individual’s ability for functional tasks in spite of possible recovery of motor functions. Generally, rehabilitation following stroke based on neuroplasticity mechanisms utilizes task specific training and massed practice to drive reorganization and improve sensorimotor function. However, since many patients suffer from restricted mobility, development of additional and alternative approaches that could supplement, enhance, or even replace conventional training procedures would be advantageous. Therefore, in the past, many attempts have been made to implement additional rehabilitative approaches that make use of repetitive sensory stimulation. We use high-frequency intermittent electrical stimulation on all fingers of the affected hand. The rational is to induce plasticity processes within and around those brain areas that became dsyfunctional. A major advantage of repetitive stimulation is its passive nature, which does not require active participation or attention. Therefore, it can be applied in parallel to other occupations, making it easier to implement and more acceptable to the individual. Our data from subacute and long-term chronic patients showed that repetitive stimulation induced substantial improvement of tactile and sensorimotor performance long lasting when applied over weeks. Furthermore, positive effects in long-term chronic patients might emerge only after months of intervention. Accordingly, this effectiveness together with the advantage of usage under everyday conditions by laypeople at their homes, make repetitive sensory stimulation-based principles prime candidates for interventions in impaired populations.