The effects of concurrent M1 anodal tDCS and physical therapy interventions on function of ankle muscles in patients with stroke: a randomized, double-blinded sham-controlled trial study.

One of the most common symptoms in stroke patients is spasticity. The aims were to investigate the effects of anodal trans-cranial direct current stimulation (a-tDCS) over the affected primary motor cortex (M1) on ankle plantar flexor spasticity and dorsiflexor muscle activity in stroke patients. The design of this study was a randomized sham-controlled clinical trial. Thirty-two participants with stroke were randomly assigned to three groups (experimental, sham, control groups). Participants in the experimental and sham groups received 10-session 20-min M1 a-tDCS concurrent with physical therapy (PT), while the control group only received 10-session PT. All groups were instructed to perform home stretching exercises and balance training. Berg Balance Scale (BBS), Modified Ashworth Scale (MAS) of plantar flexors, and EMG activity of lateral gastrocnemius (LG) and tibialis anterior (TA) were recorded during active and passive ankle dorsiflexion immediately and 1 month after interventions. A significant reduction was shown in MAS and EMG activity of LG during dorsiflexion, immediately and 1 month after intervention in the M1 a-tDCS group (p <0.001). BBS also significantly increased only in the M1 a-tDCS group (p <0.001). In addition, EMG activity of TA during active dorsiflexion increased immediately and 1 month after intervention in the M1 a-tDCS group (p <0.001). However, in the sham and control groups, EMG activity of TA increased immediately (p<0.001), while this was not maintained 1 month after intervention (p >0.05). PT concurrent with M1 a-tDCS can significantly prime lasting effects of decreasing LG spasticity, increasing TA muscle activity, and also balance in stroke patients.

Concurrent postural training and M1 anodal transcranial direct current stimulation improve postural impairment in patients with chronic low back pain.

Changes in different regions of the brain due to postural disturbances were found in patients with chronic low back pain (LBP). The aims of the current study were to investigate the short- and long-term enhancing effects of concurrent postural training and primary motor cortex (M1) anodal transcranial direct current stimulation (a-tDCS) on balance, postural stability and pain in chronic LBP patients with postural impairment. In this clinical trial study, thirty eight patients with chronic LBP were randomly assigned to a-tDCS and training, sham a-tDCS and training,and training only groups. All groups received identical postural training for 20 min, three sessions per week for two weeks. The length of stimulation, which used concurrent with postural training in the active a-tDCS group was also 20 min. Before, immediately and one-month after the interventions, postural stability, balance and pain were assessed using Biodex Balance System, Berg Balance Scale (BBS) and Visual Analog Scale (VAS), respectively. The postural stability indices, BBS and VAS scores significantly improved immediately and one-month after the intervention in the a-tDCS and training group (P < 0.001), while there were significant differences between active a-tDCS and other two groups (P < 0.001). Postural stability indices, the BBS and VAS scores were not significantly different between the sham and training only groups after the interventions (P > 0.05). M1 a-tDCS significantly improves the effects of postural training on postural stability, balance and pain in patients with chronic LBP. Two-week postural training alone cannot improve postural impairment in patients with chronic LBP.

The effects of trans-cranial direct current stimulation intervention on fear: A systematic review of literature.

Intensifying fear and fear of pain may lead to some diseases such as panic disorder, phobias, post-traumatic stress disorder (PTSD), anxiety disorders, depression, etc. A number of studies indicated positive effect of transcranial direct current stimulation (tDCS) on controlling fear and some studies did not observe any effect or even negative effect on decreasing fear. Due to lack of consensus in the findings of research, we aimed to systematically review studies, which investigated the effect of tDCS on fear. A literature search was conducted using the databases of PubMed, Science Direct, OVID, CINAHL, PEDro, Cochrane, Scopus and MEDLINE. Fear, fear memory, fear of pain, anxiety, post-traumatic stress disorder, electrical brain stimulation were applied as keywords. The valid assessment scale was used to evaluate the methodological quality of the included studies. The results of this systematic review revealed that the cathodal tDCS (c-tDCS) on the left dorsolateral prefrontal cortex (DLPFC) as compared to anodal tDCS (a-tDCS) could significantly reduce fear and modulate the fear memory. In addition, the findings of this study showed that the c-tDCS has positive effect on behavioural parameters of fear, while it cannot change biochemical parameters of fear during limited sessions of intervention. Application of c-tDCS on the left DLPFC could significantly reduce fear and modulate the fear memory.

Multi-session anodal tDCS enhances the effects of postural training on balance and postural stability in older adults with high fall risk: Primary motor cortex versus cerebellar stimulation.

BACKGROUND: Postural control impairment is a key target for rehabilitation of older adults with high fall risk. OBJECTIVE: To investigate whether anodal transcranial direct current stimulation (a-tDCS) over primary motor cortex (M1) or cerebellum can enhance the positive effects of postural training on balance and postural stability in older adults with high fall risk. METHOD: In this randomised, double-blinded sham-controlled study, 65 participants were randomly assigned into five groups; M1 a-tDCS with postural training, bilateral cerebellar a-tDCS with postural training, sham a-tDCS with postural training, postural training alone and cerebellar a-tDCS alone. Participants in the first two a-tDCS groups received 2 mA stimulation for 20 min concurrently with postural training. Postural training was conducted for three sessions of 20 min per week for two weeks. The Berg Balance Score (BBS) and the stability indices at both static and dynamic levels of the Biodex Balance System were evaluated before and after intervention. A general linear model repeated measure ANOVA was used to assess the effects of variables among groups. RESULT: Simultaneous postural training with M1 or bilateral cerebellar a-tDCS significantly improved postural stability indices (p < 0.05) and BBS scores (p < 0.05). Besides, the effects of bilateral cerebellar a-tDCS were significantly higher than that of M1 stimulation on these indices (p < 0.05). Moreover, two weeks postural training alone or cerebellar a-tDCS alone is not an adequate intervention to improve the postural stability indices (p > 0.05). CONCLUSION: Postural training with M1 or bilateral cerebellar a-tDCS, especially bilateral cerebellar a-tDCS, can significantly improve postural control or balance in older adults with high fall risk, while two weeks of postural training alone or two weeks cerebellar a-tDCS alone is not a sufficient intervention.