Noninvasive Neuromodulation in Poststroke Gait Disorders: Rationale, Feasibility, and State of the Art.

Walking rehabilitation is one of the primary goals in stroke survivors because of its great potential for recovery and its functional relevance in daily living activities. Although 70% to 80% of people in the chronic poststroke phases are able to walk, impairment of gait often persists, involving speed, endurance, and stability. Walking involves several brain regions, such as the sensorimotor cortex, supplementary motor area, cerebellum, and brainstem, which are approachable by the application of noninvasive brain stimulation (NIBS). NIBS techniques, such as repetitive transcranial magnetic stimulation and transcranial direct current stimulation, have been reported to modulate neural activity beyond the period of stimulation, facilitating neuroplasticity. NIBS methods have been largely applied for improving paretic hand motor function and stroke-associated cognitive deficits. Recent studies suggest a possible effectiveness of these techniques also in the recovery of poststroke gait disturbance. This article is a selective review about functional investigations addressing the mechanisms of lower-limb motor system reorganization after stroke and the application of NIBS for neurorehabilitation.

Chieffo R ，Comi G ，Leocani L 《-》

Noninvasive brain stimulation combined with other therapies improves gait speed after stroke: a systematic review and meta-analysis.

Vaz PG ，Salazar APDS ，Stein C ，Marchese RR ，Lukrafka JL ，Plentz RDM ，Pagnussat AS ... -  《-》

Non-invasive brain stimulation (NIBS) and motor recovery after stroke.

Recovery of motor function after stroke occurs largely on the basis of a sustained capacity of the adult brain for plastic changes. This brain plasticity has been validated by functional imaging and electrophysiological studies. Various concepts of how to enhance beneficial plasticity and in turn improve functional recovery are emerging based on the concept of functional interhemispheric balance between the two motor cortices. Besides conventional rehabilitation interventions and the most recent neuropharmacological approaches, non-invasive brain stimulation (NIBS) has recently been proposed as an add-on method to promote motor function recovery after stroke. Several methods can be used based either on transcranial magnetic stimulation (repetitive mode: rTMS, TBS) via a coil, or small electric current via larges electrodes placed on the scalp, (transcranial direct current stimulation tDCS). Depending on the different electrophysiological parameters of stimulation used, NIBS can induce a transient modulation of the excitability of the stimulated motor cortex (facilitation or inhibition) via a probable LTP-LTD-like mechanism. Several small studies have shown feasible and positive treatment effects for most of these strategies and their potential clinical relevance to help restoring the disruption of interhemispheric imbalance after stroke. Results of these studies are encouraging but many questions remain unsolved: what are the optimal stimulation parameters? What is the best NIBS intervention? Which cortex, injured or intact, should be stimulated? What is the best window of intervention? Is there a special subgroup of stroke patients who could strongly benefit from these interventions? Finally is it possible to boost NIBS treatment effect by motor training of the paretic hand or by additional neuropharmacological interventions? There is clearly a need for large-scale, controlled, multicenter trials to answer these questions before proposing their routine use in the management of stroke patients.

Simonetta-Moreau M 《-》

Effect of Dual-Mode and Dual-Site Noninvasive Brain Stimulation on Freezing of Gait in Patients With Parkinson Disease.

To investigate the effect of dual-mode noninvasive brain stimulation (NIBS) with high-frequency repetitive transcranial magnetic stimulation (rTMS) over the primary motor cortex of the lower leg and anodal transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex compared with rTMS alone in patients with Parkinson disease (PD) with freezing of gait (FOG). Randomized, double-blind, controlled study. Outpatient rehabilitation clinics. Patients diagnosed as having PD with FOG (N=32). Patients in the dual-mode group underwent 5 consecutive daily sessions of dual-mode NIBS with high-frequency rTMS and tDCS simultaneously, whereas patients in the rTMS group underwent high-frequency rTMS and sham tDCS. Assessments of FOG and motor, ambulatory, and cognitive function were performed 3 times: at baseline before NIBS, immediately after NIBS, and 1 week after cessation of NIBS. Serious adverse effects were not observed in either group. Significant changes over time were observed in FOG, motor function, and ambulatory function in each group; however, there was no significant difference between the 2 groups. Executive function showed significant improvement after NIBS only in the dual-mode group. These results suggest the potential for dual-mode NIBS to modulate 2 different cortices simultaneously. Dual-mode NIBS might be considered a novel therapeutic approach for patients with PD.

Chang WH ，Kim MS ，Park E ，Cho JW ，Youn J ，Kim YK ，Kim YH ... -  《-》

Application of noninvasive brain stimulation for post-stroke dysphagia rehabilitation.

Noninvasive brain stimulation (NIBS), commonly consisting of transcranial magnetic stimulation (TMS), transcranial direct-current stimulation (tDCS), as well as paired associative stimulation (PAS), has attracted increased interest and been applied experimentally in the treatment of post-stroke dysphagia (PSD). This review presented a synopsis of the current research for the application of NIBS on PSD. The intention here was to understand the current research progress and limitations in this field and to stimulate potential research questions not yet investigated for the application of NIBS on patients with PSD. Here we successively reviewed advances of repetitive TMS (rTMS), tDCS, and PAS techniques on both healthy participants and PSD patients in three aspects, including scientific researches about dysphagia mechanism, applied studies about stimulation parameters, and clinical trials about their therapeutic effects. The techniques of NIBS, especially rTMS, have been used by the researchers to explore the different mechanisms between swallowing recovery and extremity rehabilitation. The key findings included the important role of intact hemisphere reorganization for PSD recovery, and the use of NIBS on the contra-lesional side as a therapeutic potential for dysphagia rehabilitation. Though significant results were achieved in most studies by using NIBS on swallowing rehabilitation, it is still difficult to draw conclusions for the efficacy of these neurostimulation techniques, considering the great disparities between studies.

Wang Z ，Song WQ ，Wang L 《-》