A sham-controlled, phase II trial of transcranial direct current stimulation for the treatment of central pain in traumatic spinal cord injury. Improved naming after transcranial direct current stimulation in aphasia. Transcranial DC stimulation coupled with TENS for the treatment of chronic pain: a preliminary study. Cathodal transcranial direct current stimulation of the right Wernicke's area improves comprehension in subacute stroke patients. Improved picture naming in aphasia patients treated with cathodal tDCS to inhibit the right Broca's homologue area. Efficacy of anodal transcranial direct current stimulation (tDCS) for the treatment of fibromyalgia: results of a randomized, sham-controlled longitudinal clinical trial. Effects of anodal transcranial direct current stimulation on chronic neuropathic pain in patients with multiple sclerosis. Short-term anomia training and electrical brain stimulation. Electrical stimulation over the left inferior frontal gyrus (IFG) determines long-term effects in the recovery of speech apraxia in three chronic aphasics.
Past evidence has shown that motor cortical stimulation with invasive and non-invasive brain stimulation is effective to relieve central pain. Here we aimed to study the effects of another, very safe technique of non-invasive brain stimulation--transcranial direct current stimulation (tDCS)--on pain control in patients with central pain due to traumatic spinal cord injury. Patients were randomized to receive sham or active motor tDCS (2mA, 20 min for 5 consecutive days). A blinded evaluator rated the pain using the visual analogue scale for pain, Clinician Global Impression and Patient Global Assessment. Safety was assessed with a neuropsychological battery and confounders with the evaluation of depression and anxiety changes. There was a significant pain improvement after active anodal stimulation of the motor cortex, but not after sham stimulation. These results were not confounded by depression or anxiety changes. Furthermore, cognitive performance was not significantly changed throughout the trial in both treatment groups. The results of our study suggest that this new approach of cortical stimulation can be effective to control pain in patients with spinal cord lesion. We discuss potential mechanisms for pain amelioration after tDCS, such as a secondary modulation of thalamic nuclei activity. Transcranial direct current stimulation (tDCS) has been proposed as an adjuvant technique to improve functional recovery after ischaemic stroke. This study evaluated the effect of tDCS over the left frontotemporal areas in eight chronic non-fluent post-stroke aphasic patients. The protocol consisted of the assessment of picture naming (accuracy and response time) before and immediately after anodal or cathodal tDCS (2 mA, 10 minutes) and sham stimulation. Whereas anodal tDCS and sham tDCS failed to induce any changes, cathodal tDCS significantly improved the accuracy of the picture naming task by a mean of 33.6% (SEM 13.8%). Based on evidence showing that electrical stimulation of the nervous system is an effective method to decrease chronic neurogenic pain, we aimed to investigate whether the combination of 2 methods of electrical stimulation-a method of peripheral stimulation [transcutaneous electrical nerve stimulation (TENS)] and a method of noninvasive brain stimulation [transcranial direct current stimulation (tDCS)]-induces greater pain reduction as compared with tDCS alone and sham stimulation.
                We performed a preliminary, randomized, sham-controlled, crossover, clinical study in which 8 patients were randomized to receive active tDCS/active TENS ("tDCS/TENS" group), active tDCS/sham TENS ("tDCS" group), and sham tDCS/sham TENS ("sham" group) stimulation. Assessments were performed immediately before and after each condition by a blinded rater.
                The results showed that there was a significant difference in pain reduction across the conditions of stimulation (P=0.006). Post hoc tests showed significant pain reduction as compared with baseline after the tDCS/TENS condition [reduction by 36.5% (+/-10.7), P=0.004] and the tDCS condition [reduction by 15.5% (+/-4.9), P=0.014], but not after sham stimulation (P=0.35). In addition, tDCS/TENS induced greater pain reduction than tDCS (P=0.02).
                The results of this pilot study suggest that the combination of TENS with tDCS has a superior effect compared with tDCS alone. Previous studies have shown the appearance of right-sided language-related brain activity in right-handed patients after a stroke. Non-invasive brain stimulation such as transcranial direct current stimulation (tDCS) and repetitive transcranial magnetic stimulation (rTMS) have been shown to modulate excitability in the brain. Moreover, rTMS and tDCS have been found to improve naming in non-fluent post-stroke aphasic patients. Here, we investigated the effect of tDCS on the comprehension of aphasic patients with subacute stroke. We hypothesized that tDCS applied to the left superior temporal gyrus (Wernicke's area) or the right Wernicke's area might be associated with recovery of comprehension ability in aphasic patients with subacute stroke. Participants included right-handed subacute stroke patients with global aphasia due to ischemic infarct of the left M1 or M2 middle cerebral artery. Patients were randomly divided into three groups: patients who received anodal tDCS applied to the left superior temporal gyrus, patients who received cathodal tDCS applied to the right superior temporal gyrus, and patients who received sham tDCS. All patients received conventional speech and language therapy during each period of tDCS application. The Korean-Western Aphasia Battery (K-WAB) was used to assess all patients before and after tDCS sessions. After intervention, all patients had significant improvements in aphasia quotients, spontaneous speech, and auditory verbal comprehension. However, auditory verbal comprehension improved significantly more in patients treated with a cathode, as compared to patients in the other groups. These results are consistent with the role of Wernicke's area in language comprehension and the therapeutic effect that cathodal tDCS has on aphasia patients with subacute stroke, suggesting that tDCS may be an adjuvant treatment approach for aphasia rehabilitation therapy in patients in an early stage of stroke.
                Copyright © 2011 Elsevier Inc. All rights reserved. Previous reports have suggested that noninvasive cortical stimulation could influence speech production in patients with chronic stroke. Here, we evaluated the hypothesis that cathodal transcranial DC stimulation (ctDCS), a technique that decreases excitability of stimulated cortical sites, applied over a healthy right Broca's homologue area could improve picture naming in patients with post-stroke aphasia.
                Ten right-handed patients with post-stroke aphasia were enrolled in this double blind, counterbalanced sham-controlled, crossover study. Each patient received an intervention of ctDCS (2 mA for 20 min) and of sham tDCS (2 mA for 1 min) daily for 5 consecutive days in a randomized crossover manner with a minimum interval of one week between interventions, over a healthy right Broca's homologue area using a left supraorbital anode and simultaneous daily sessions of conventional word-retrieval training. The primary endpoint measure of this study was a standardized, validated Korean version of the Boston Naming Test, which is a measure of picture naming skills.
                ctDCS was not found to have any adverse effects. Furthermore, significantly improved picture naming (p = 0.02) was observed at 1 hour following the last (5th) ctDCS treatment session, but no changes were observed after sham tDCS.
                These results demonstrate that cathodal tDCS over the right healthy Broca's homologue area with a left supraorbital anodal location can improve picture naming task performance in post-stroke aphasia. Fibromyalgia has been recognized as a central pain disorder with evidence of neuroanatomic and neurophysiologic alterations. Previous studies with techniques of noninvasive brain stimulation--transcranial direct current stimulation (tDCS) and repetitive transcranial magnetic stimulation (rTMS)--have shown that these methods are associated with a significant alleviation of fibromyalgia-associated pain and sleep dysfunction. Here we sought to determine whether a longer treatment protocol involving 10 sessions of 2 mA, 20 min tDCS of the left primary motor (M1) or dorsolateral prefrontal cortex (DLPFC) could offer additional, more long-lasting clinical benefits in the management of pain from fibromyalgia. METHODS: Forty-one women with chronic, medically refractory fibromyalgia were randomized to receive 10 daily sessions of M1, DLPFC, or sham tDCS. RESULTS: Our results show that M1 and DLPFC stimulation both display improvements in pain scores (VAS) and quality of life (FIQ) at the end of the treatment protocol, but only M1 stimulation resulted in long-lasting clinical benefits as assessed at 30 and 60 days after the end of treatment. CONCLUSIONS: This study demonstrates the importance of the duration of the treatment period, suggesting that 10 daily sessions of tDCS result in more long lasting outcomes than only five sessions. Furthermore, this study supports the findings of a similarly designed rTMS trial as both induce pain reductions that are equally long-lasting. Neuropathic pain in patients with MS is frequent and is associated with a great interference with daily life activities. In the present study, we investigated whether anodal transcranial direct current stimulation (tDCS) may be effective in reducing central chronic pain in MS patients. Patients received sham tDCS or real tDCS in a 5-day period of treatment in a randomized, double blind, sham-controlled study. Pain was measured using visual analog scale (VAS) for pain and the short form McGill questionnaire (SF-MPQ). Quality of life was measured using the Multiple Sclerosis Quality of Life-54 scale (MSQoL-54). Depressive symptoms and anxiety were also evaluated as confounding factors using the Beck Depression Inventory (BDI) and VAS for anxiety. Evaluations were performed at baseline, immediately after the end of treatment, and once a week during a 3-week follow-up period. Following anodal but not sham tDCS over the motor cortex, there was a significant pain improvement as assessed by VAS for pain and McGill questionnaire, and of overall quality of life. No depression or anxiety changes were observed. Our results show that anodal tDCS is able to reduce pain-scale scores in MS patients with central chronic pain and that this effect outlasts the period of stimulation, leading to long-lasting clinical effects.
                This article presents a new, noninvasive therapeutic approach to chronic, central neuropathic pain in multiple sclerosis, poorly responsive to current conventional medications. tDCS is known to cause long-lasting changes of neuronal excitability at the site of stimulation and in the connected areas in healthy subjects. This led us to hypothesize that pain decrease may be the result of functional plastic changes in brain structures involved in the pathogenesis of chronic neuropathic pain.
                Copyright 2010 American Pain Society. Published by Elsevier Inc. All rights reserved. Language training success in chronic aphasia remains only moderate. Electric brain stimulation may be a viable way to enhance treatment efficacy.
                In a randomized, double-blind, sham-controlled crossover trial, we assessed if anodal transcranial direct current stimulation compared to cathodal transcranial direct current stimulation and sham stimulation over the right temporo-parietal cortex would improve the success of short-term high-frequency anomia training. Twelve chronic poststroke aphasia patients were studied. Naming outcome was assessed after training and 2 weeks later.
                All training conditions led to a significant increase in naming ability, which was retained for at least 2 weeks after the end of the training. Application of anodal transcranial direct current stimulation significantly enhanced the overall training effect compared to sham stimulation. Baseline naming ability significantly predicted anodal transcranial direct current stimulation effects.
                Anodal transcranial direct current stimulation applied over the nonlanguage dominant hemisphere can enhance language training outcome in chronic aphasia. Clinical Trial Registration- URL: www.clinicaltrials.gov/. Unique identifier: NCT00822068. A number of studies have shown that modulating cortical activity by means of transcranial direct current stimulation (tDCS) affects the performance of both healthy and brain-damaged subjects. In this study, we investigated the potential of tDCS for the recovery of apraxia of speech in 3 patients with stroke-induced aphasia. Over 2 weeks, three aphasic subjects participated in a randomized double-blinded experiment involving intensive language training for their articulatory difficulties in two tDCS conditions. Each subject participated in five consecutive daily sessions of anodic tDCS (20 min, 1 mA) and sham stimulation over the left inferior frontal gyrus (referred to as Broca's area) while they performed a repetition task. By the end of each week, a significant improvement was found in both conditions. However, all three subjects showed greater response accuracy in the anodic than in the sham condition. Moreover, results for transfer of treatment effects, although different across subjects, indicate a generalization of the recovery at the language test. Subjects 2 and 3 showed a significant improvement in oral production tasks, such as word repetition and reading, while Subjects 1 and 2 had an unexpected significant recovery in written naming and word writing under dictation tasks. At three follow-ups (1 week, 1 and 2 months after the end of treatment), response accuracy was still significantly better in the anodic than in sham condition, suggesting a long-term effect on the recovery of their articulatory gestures.
                Copyright © 2011 Elsevier B.V. All rights reserved.
Currently there is no evidence of the effectiveness of tDCS (anodal tDCS, cathodal tDCS) versus control (sham tDCS). However, it appears that cathodal tDCS over the non-lesioned hemisphere might be the most promising approach.