Acute offline transcranial direct current stimulation does not change pain or anxiety produced by the cold pressor test.

Transcranial direct current stimulation (tDCS) over the primary motor cortex (M1) has an antalgic effect on acute experimental pain in healthy volunteers. Many published studies have used online stimulation (i.e., tDCS performed during painful stimulation). On the other hand, daily tDCS sessions have been proposed as a therapy for chronic pain (offline tDCS). In such cases, the therapeutic potential depends on the possible aftereffects of each tDCS session. We set out to investigate whether a single tDCS session before application of a classical experimental pain paradigm (the Cold Pressor Test, CPT) would be capable of modulating physiological measures of anxiety as well as pain perception. tDCS was applied to 30 healthy volunteers, 18-28 years old (mean 18.5), with the anode positioned over either the left M1 or the left dorsolateral prefrontal cortex (l-DLPFC), which has been linked to the affective aspects of experienced pain, including anxiety. All volunteers underwent the CPT procedure before and after a tDCS session. Real 2 mA tDCS sessions for 20 min were compared to sham stimulations. No significant difference was found for any variable after real tDCS sessions when compared to the sham stimulations. This result suggests that effective offline tDCS for chronic pain might have different mechanisms of action. Cumulative effects, functional targeting and the unintended simultaneous stimulation of both M1 and the l-DLPFC are likely responsible for the therapeutic effects of tDCS sessions in the clinical setting.

Safety of transcranial direct current stimulation in a patient with deep brain stimulation electrodes.

BACKGROUND: Transcranial direct current stimulation (tDCS) has been investigated in movement disorders, making it a therapeutic alternative in clinical settings. However, there is still no consensus on the most appropriate treatment protocols in most cases, and the presence of deep brain stimulation (DBS) electrodes has been regarded as a contraindication to the procedure. We recently studied the effects of cerebellar tDCS on a female patient already undergoing subthalamic nucleus deep brain stimulation (STN-DBS) for generalized dystonia. She also presented with chronic pain and depression. With STN-DBS, there was improvement of dystonia, and botulinum toxin significantly reduced pain. However, depressive symptoms were worse after STN-DBS surgery. METHODS: Neuromodulation with 2 mA anodal cerebellar tDCS was initiated, targeting both hemispheres in each daily 30 minute session: 15 minutes of left cerebellar stimulation followed by 15 minutes of right cerebellar stimulation. The DBS electrodes were in place and functional, but the current was turned off during tDCS. RESULTS: Although our goal was to improve dystonic movements, after 10 tDCS sessions there was also improvement in mood with normalization of Beck Depression Inventory scores. There were no complications in spite of the implanted STN-DBS leads. CONCLUSION: Our results indicate that tDCS is safe in patients with DBS electrodes and may be an effective add-on neuromodulatory tool in the treatment of potential DBS partial efficacy in patients with movement disorders.

Safety of transcranial direct current stimulation in a patient with deep brain stimulation electrodes / Segurança da estimulação transcraniana por corrente contínua em uma paciente com implante de eletrodos de estimulação cerebral profunda

ABSTRACT Background: Transcranial direct current stimulation (tDCS) has been investigated in movement disorders, making it a therapeutic alternative in clinical settings. However, there is still no consensus on the most appropriate treatment protocols in most cases, and the presence of deep brain stimulation (DBS) electrodes has been regarded as a contraindication to the procedure. We recently studied the effects of cerebellar tDCS on a female patient already undergoing subthalamic nucleus deep brain stimulation (STN-DBS) for generalized dystonia. She also presented with chronic pain and depression. With STN-DBS, there was improvement of dystonia, and botulinum toxin significantly reduced pain. However, depressive symptoms were worse after STN-DBS surgery. Methods: Neuromodulation with 2 mA anodal cerebellar tDCS was initiated, targeting both hemispheres in each daily 30 minute session: 15 minutes of left cerebellar stimulation followed by 15 minutes of right cerebellar stimulation. The DBS electrodes were in place and functional, but the current was turned off during tDCS. Results: Although our goal was to improve dystonic movements, after 10 tDCS sessions there was also improvement in mood with normalization of Beck Depression Inventory scores. There were no complications in spite of the implanted STN-DBS leads. Conclusion: Our results indicate that tDCS is safe in patients with DBS electrodes and may be an effective add-on neuromodulatory tool in the treatment of potential DBS partial efficacy in patients with movement disorders.

RESUMO Descrição: A estimulação transcraniana por corrente contínua (ETCC) tem sido investigada nos distúrbios de movimento, tornando-a uma alternativa terapêutica no contexto clínico. Contudo, não há consenso quanto aos protocolos mais apropriados na maioria dos casos e a presença de eletrodos de estimulação cerebral profunda (ECP) é geralmente considerada uma contraindicação. Recentemente, estudamos os efeitos da ETCC cerebelar em uma paciente do sexo feminino com implante de eletrodos de estimulação cerebral profunda (ECP) para distonia generalizada. Ela também apresentava dor crônica e depressão. A ETCC foi realizada dois anos após o implante de eletrodos de ECP. Com a ECP houve melhora da distonia e a toxina botulínica reduziu a dor. Contudo, os sintomas depressivos pioraram após a cirurgia de ECP. Métodos: Foi proposta ETCC cerebelar anódica de 2mA, sobre os dois hemisférios em cada sessão de 30min: 15 min de ETCC cerebelar esquerda seguida de 15min de ETCC cerebelar direita. Resultados: Embora o nosso objetivo tenha sido melhorar os movimentos distônicos, após 10 sessões de ETCC houve melhora também do humor da paciente. Não houve nenhuma complicação, apesar da presença de eletrodos de ECP. Conclusão: Nossos resultados apontam para a segurança da tDCS e sua aplicação potencial e efetiva como ferramenta neuromodulatória adicional no tratamento de possíveis sintomas persistentes após a ECP em pacientes com distúrbios de movimento.

Effects of Prefrontal Transcranial Direct Current Stimulation and Motivation to Quit in Tobacco Smokers: A Randomized, Sham Controlled, Double-Blind Trial.

Transcranial direct current stimulation (tDCS) applied over the dorsolateral prefrontal cortex (DLPFC) has been shown to reduce cravings in tobacco addiction; however, results have been somewhat mixed. In this study, we hypothesized that motivation to quit smoking is a critical factor of tDCS effects in smokers. Therefore, we conducted a double-blind, randomized clinical trial to evaluate the effects of both tDCS and motivation to quit on cigarette consumption and the relationship between these two factors. DLPFC tDCS was applied once a day for 5 days. Our primary outcome was the amount of cigarettes smoked per day. We collected this information at baseline (d1), at the end of the treatment period (d5), 2 days later (d7) and at the 4-week follow-up (d35). Visual Analog Scale (VAS) for motivation to quit was collected at the same time-points. 36 subjects (45 ± 11 years old; 24.2 ± 11.5 cigarettes daily smoked, 21 women) were randomized to receive either active or sham tDCS. In our multivariate analysis, as to take into account the mediation and moderation effects of motivation to quit, we found a significant main effect of tDCS, showing that tDCS was associated with a significant reduction of cigarettes smoked per day. We also showed a significant interaction effect of motivation to quit and treatment, supporting our hypothesis that tDCS effects were moderated by motivation to quit, indicating that higher levels of motivation were associated with a larger tDCS response. We found that the participants' motivation to quit alone, both at baseline and at follow-up, does not explain the decrease in the average cigarette consumption. Repetitive prefrontal tDCS coupled with high motivation significantly reduced cigarette consumption up to 4-weeks post-intervention. CLINICAL TRIAL REGISTRATION: http://ClinicalTrials.gov, NCT02146014.

Motor Cortex Stimulation for Pain Relief: Do Corollary Discharges Play a Role?

Both invasive and non-invasive motor cortex stimulation techniques have been successfully employed in the treatment of chronic pain, but the precise mechanism of action of such treatments is not fully understood. It has been hypothesized that a mismatch of normal interaction between motor intention and sensory feedback may result in central pain. Sensory feedback may come from peripheral nerves, vision and also from corollary discharges originating from the motor cortex itself. Therefore, a possible mechanism of action of motor cortex stimulation might be corollary discharge reinforcement, which could counterbalance sensory feedback deficiency. In other instances, primary deficiency in the production of corollary discharges by the motor cortex might be the culprit and stimulation of cortical motor areas might then be beneficial by enhancing production of such discharges. Here we review evidence for a possible role of motor cortex corollary discharges upon both the pathophysiology and the response to motor cortex stimulation of different types of chronic pain. We further suggest that the right dorsolateral prefrontal cortex (DLPC), thought to constantly monitor incongruity between corollary discharges, vision and proprioception, might be an interesting target for non-invasive neuromodulation in cases of chronic neuropathic pain.

Learning, memory, and transcranial direct current stimulation.

Transcranial direct current stimulation (tDCS) has been the subject of many studies concerning its possible cognitive effects. One of the proposed mechanisms of action for neuromodulatory techniques, such as transcranial magnetic stimulation and tDCS is induction of long-term potentiation (LTP) and long-term depression (LTD)-like phenomena. LTP and LTD are also among the most important neurobiological processes involved in memory and learning. This fact has led to an immediate interest in the study of possible effects of tDCS on memory consolidation, retrieval, or learning of various tasks. This review analyses published articles describing beneficial or disruptive effects of tDCS on memory and learning in normal subjects. The most likely mechanisms underlying these effects are discussed.

Lack of clinically detectable acute changes on autonomic or thermoregulatory functions in healthy subjects after transcranial direct current stimulation (tDCS).

BACKGROUND: Neuromodulatory techniques, such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS), have been increasingly studied as possible treatments for many neurological and psychiatric disorders. tDCS is capable of inducing changes in regional cerebral blood flow in both cortical and subcortical structures, as shown by positron emission tomography studies, and might conceivably affect hypothalamic and autonomic nervous system functions. However, it remains unknown whether acute changes in autonomic or hypothalamic functions may be triggered by conventional tDCS protocols. OBJECTIVE/HYPOTHESIS: To verify whether tDCS, when performed with a bipolar cephalic montage, is capable of inducing acute changes in autonomic or hypothalamic functions in healthy subjects. METHODS: Fifty healthy volunteers were studied. tDCS was performed with the anode over the C3 position and the cathode over the right supraorbital region. Subjects received either real or sham tDCS. Parameters assessed before and after a 20-minute session included blood pressure, tympanic thermometry, hand skin temperature, heart rate and ventilatory rate. Plasma concentrations of cortisol were also measured in a sub-set of 10 participants. RESULTS: A repeated-measures, mixed-design ANOVA showed significant changes in hand skin temperature (P = .005) and cortisol levels (P < .001) after both real and sham stimulation. There were no statistically significant changes in any of the other measurements. CONCLUSIONS: The changes in hand temperature and cortisol levels, having occurred in both the sham and experimental groups, probably reflect a non-specific stress response to a new procedure. There were no significant changes in autonomic functions, ventilation rate or core body temperature that can be attributed to conventional tDCS applied to healthy volunteers.

Neuromodulation approaches for the treatment of major depression: challenges and recommendations from a working group meeting.

UNLABELLED: The use of neuromodulation as a treatment for major depressive disorder (MDD) has recently attracted renewed interest due to development of other non-pharmacological therapies besides electroconvulsive therapy (ECT) such as transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), deep brain stimulation (DBS), and vagus nerve stimulation (VNS). METHOD: We convened a working group of researchers to discuss the updates and key challenges of neuromodulation use for the treatment of MDD. RESULTS: The state-of-art of neuromodulation techniques was reviewed and discussed in four sections: [1] epidemiology and pathophysiology of MDD; [2] a comprehensive overview of the neuromodulation techniques; [3] using neuromodulation techniques in MDD associated with non-psychiatric conditions; [4] the main challenges of neuromodulation research and alternatives to overcome them. DISCUSSION: ECT is the first-line treatment for severe depression. TMS and tDCS are strategies with a relative benign profile of side effects; however, while TMS effects are comparable to antidepressant drugs for treating MDD; further research is needed to establish the role of tDCS. DBS and VNS are invasive strategies with a possible role in treatment-resistant depression. In summary, MDD is a chronic and incapacitating condition with a high prevalence; therefore clinicians should consider all the treatment options including invasive and non-invasive neuromodulation approaches.

Neuromodulation approaches for the treatment of major depression: challenges and recommendations from a working group meeting / Estratégias de neuromodulação para o tratamento da depressão maior: desafios e recomendações de uma força-tarefa

The use of neuromodulation as a treatment for major depressive disorder (MDD) has recently attracted renewed interest due to development of other non-pharmacological therapies besides electroconvulsive therapy (ECT) such as transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), deep brain stimulation (DBS), and vagus nerve stimulation (VNS). METHOD: We convened a working group of researchers to discuss the updates and key challenges of neuromodulation use for the treatment of MDD. RESULTS: The state-of-art of neuromodulation techniques was reviewed and discussed in four sections: [1] epidemiology and pathophysiology of MDD; [2] a comprehensive overview of the neuromodulation techniques; [3] using neuromodulation techniques in MDD associated with non-psychiatric conditions; [4] the main challenges of neuromodulation research and alternatives to overcome them. DISCUSSION: ECT is the first-line treatment for severe depression. TMS and tDCS are strategies with a relative benign profile of side effects; however, while TMS effects are comparable to antidepressant drugs for treating MDD; further research is needed to establish the role of tDCS. DBS and VNS are invasive strategies with a possible role in treatment-resistant depression. In summary, MDD is a chronic and incapacitating condition with a high prevalence; therefore clinicians should consider all the treatment options including invasive and non-invasive neuromodulation approaches.

O uso de técnicas de neuromodulação para o tratamento do transtorno depressivo maior (TDM) tem despertado um renovado interesse nos últimos anos com o desenvolvimento de outras intervenções não-farmacólogicas além da eletroconvulsoterapia (ECT), como a estimulação magnética transcraniana (EMT), a estimulação transcraniana por corrente continua (ETCC), a estimulação cerebral profunda (DBS) e a estimulação de nervo vago (VNS). MÉTODO: Nós organizamos um grupo de trabalho com vários pesquisadores para discutir os avanços recentes e os principais desafios para o uso da neuromodulação no tratamento do TDM. RESULTADOS: O estado-da-arte da neuromodulação foi revisado e discutido em quatro seções: [1] epidemiologia e fisiopatologia do TDM; [2] uma revisão das técnicas de neuromodulação; [3] o uso das técnicas de neuromodulação na depressão que ocorre associada ou em virtude de condições não-psiquiátricas; [4] os principais desafios da pesquisa na neuromodulação e alternativas para superá-los. DISCUSSÃO: ECT é o tratamento de primeira linha para depressão grave. EMT e ETCC são estratégias com um perfil benigno de efeitos adversos; contudo, enquanto os efeitos da EMT são comparáveis ao das drogas antidepressivas para o tratamento da TDM, a eficácia da ETCC ainda precisa ser estabelecida por mais pesquisas clínicas. DBS e VNS são intervenções invasivas com um papel possível para a depressão refratária. Em resumo, TDM é uma condição crônica, incapacitante e de alta prevalência; portanto na prática clínica todas as opções de tratamento possíveis, incluindo as farmacológicas e não-farmacológicas, devem ser consideradas.

Feeling pain in the rubber hand: integration of visual, proprioceptive, and painful stimuli.

The visual capture phenomenon has recently been explored, especially in the context of the rubber-hand illusion (RHI)--an illusion in which tactile sensations are referred to an illusory limb. We have induced the RHI with the difference that tactile-painful stimuli were added in order to verify the interaction between vision, touch, proprioception, and pain. Thirty volunteers were used. We found that tactile-painful stimuli could cause the same illusion as purely tactile stimuli. This result suggests that localisation of pain may also be distorted by spurious visual cues. The implications of this finding for distorted human proprioception (as in amputees with phantom pain or limbs) are discussed.

Sensory deficits in the unaffected hand of hemiparetic stroke patients.

OBJECTIVE: To evaluate sensory function in the unaffected hand of unilateral stroke patients. BACKGROUND: Ipsilateral motor deficits have been described in stroke patients, but sensory function has usually been reported to be normal in the unaffected limbs. METHOD: Twenty-five patients (19 males, 6 females, 58.24+/-11.11 y old) with first-ever stroke, in the chronic phase (mean interval after stroke: 43.8+/-55.4 mo), who fulfilled the inclusion criteria, and 25 age-matched and sex-matched healthy control subjects (19 males, 6 females, 58.60+/-11.32 y old) participated in the study. Ipsilateral hand sensory function was assessed with a Moving Touch-Pressure test; motor performance was evaluated by the Box and Block test and grip strength. The examiner was not blinded to the subject's neurologic status. RESULTS: Stroke patients had a mean Moving Touch-Pressure score of 79.77%+/-10.74% whereas the control group had a mean score of 89.10%+/-8.09% (P<0.01). Mean Box and Block scores were 58.4+/-8.27 and 68.08+/-8.98, respectively (P<0.01). CONCLUSIONS: In addition to motor dysfunction, decreased sensitivity to moving tactile stimuli may contribute to clumsiness of the unaffected arm of unilateral stroke patients.

Normative study of tympanic infrared thermometry: a non-invasive index of asymmetric cerebral activity.

Human and primate studies have demonstrated that performance of tasks that induce asymmetrical physiological activation of the cerebral hemispheres leads to a reduction of tympanic temperature (TT) ipsilateral to the most active hemisphere. It is possible that diseases that interfere in an asymmetrical fashion with the degree of cerebral activity cause similar TT changes. There are not, however, normative studies of the acceptable interaural difference in TT in normal subjects at rest. This study was done to establish normative values for interaural TT values measured by means of infrared tympanic thermometry in resting normal subjects not engaged in any specific task. TT values were measured in 47 normal volunteers (20 men and 27 women, aged 39.38+/-12.57 years old) at rest; mean interaural differences of TT were calculated. Mean right ear TT was 36.85+/-0.50 degrees C and mean left ear TT was 36.74+/-0.57 degrees C; these values are in agreement with those already reported in the literature. Mean interaural TT difference was 0.25 degrees C (SD 0.21 degrees C). These findings indicate that maximal normal values for interaural TT differences, with confidence levels of 99% and 95%, are, respectively, 0.88 and 0.67 degrees C. The value of interaural differences of TT as a marker of asymmetrical hemispheric activity in neurological patients will have to be established by additional studies.

Normative study of tympanic infrared thermometry: a non-invasive index of asymmetric cerebral activity

Human and primate studies have demonstrated that performance of tasks that induce asymmetrical physiological activation of the cerebral hemispheres leads to a reduction of tympanic temperature (TT) ipsilateral to the most active hemisphere. It is possible that diseases that interfere in an asymmetrical fashion with the degree of cerebral activity cause similar TT changes. There are not, however, normative studies of the acceptable interaural difference in TT in normal subjects at rest. This study was done to establish normative values for interaural TT values measured by means of infrared tympanic thermometry in resting normal subjects not engaged in any specific task. TT values were measured in 47 normal volunteers (20 men and 27 women, aged 39.38±12.57 years old) at rest; mean interaural differences of TT were calculated. Mean right ear TT was 36.85±0.50ºC and mean left ear TT was 36.74±0.57ºC; these values are in agreement with those already reported in the literature. Mean interaural TT difference was 0.25ºC (SD 0.21ºC). These findings indicate that maximal normal values for interaural TT differences, with confidence levels of 99 percent and 95 percent, are, respectively, 0.88 and 0.67ºC. The value of interaural differences of TT as a marker of asymmetrical hemispheric activity in neurological patients will have to be established by additional studies.

Estudos em humanos e outros primatas demonstraram que a realização de tarefas que causam ativação assimétrica fisiológica dos hemisférios cerebrais resulta em redução da temperatura timpânica (TT) ipsilateral ao hemisfério cerebral mais ativo. É possível que patologias que interfiram de modo assimétrico com o grau de atividade cerebral causem alterações similares da TT. Não existem, entretanto, estudos normativos da diferença normal aceitável de TT entre os tímpanos de um mesmo indivíduo em repouso. Este estudo teve como objetivo estabelecer uma normatização dos valores bilaterais da TT, e principalmente das diferenças interauriculares desse parâmetro, obtidas por termometria timpânica por infravermelho, em indivíduos normais, na ausência de execução de tarefas específicas. Foram obtidas medidas da TT em 47 voluntários normais (20 homens e 27 mulheres, com média de idade de 39,38±12,57 anos) em repouso e calculadas as diferenças interauriculares, sua média e desvio-padrão. A TT média foi de 36,85±0,50ºC à direita e de 36,74± 0,57ºC à esquerda, o que está de acordo com dados da literatura. A média das diferenças de TT encontrada foi de 0,25ºC e o desvio padrão (DP) 0,21ºC. Com base nesses achados, os valores máximos considerados normais para a diferença interauricular da TT, com níveis de confiança de 99 por cento e de 95 por cento, são de 0,88ºC e 0,67ºC, respectivamente. A utilidade da medida da diferença interauricular da TT como marcador de assimetria da atividade cerebral em pacientes com patologias neurológicas deverá ser avaliada em estudos adicionais.

Injections of botulinum toxin type a produce pain alleviation in intractable trigeminal neuralgia.

To report the effects of local injections of botulinum toxin type A regarding pain relief and long-term control in a patient with intractable trigeminal neuralgia. The patient was a 75-year-old man with trigeminal neuralgia in the left hemifacial region. His pain was unbearable and could not be controlled by carbamazepine, amitriptyline, or blocked by infiltration of a glycerol solution or phenol. The authors evaluated pain intensity, quality, and location using a Visual Analog Scale to establish the efficacy of botulinum toxin type A injections. Two units of botulinum toxin type A (Botox) were subcutaneously injected once in eight points distributed along the territory of V1 and V2. Visual Analog Scores were measured at baseline and at 7, 30, 60, and 90 days after treatment. The authors also examined the patient's general condition and daily life activities. The Visual Analog values were, respectively, 82, 54, 25, 25, and 45 mm at each follow-up examination. No side effects were observed on the site of injection and on the patient's clinical state. The authors have been able to reduce trigeminal neuralgia pain with botulinum toxin type A injections in the V1, V2 territory during all the period of study, as well as to withdraw all medication. Interestingly, there was concomitant reduction of pain also in V3, which was not injected.

Experimental therapy of epilepsy with transcranial magnetic stimulation: lack of additional benefit with prolonged treatment.

OBJECTIVE: To investigate the effect of three months of low-frequency repetitive transcranial magnetic stimulation (rTMS) treatment in intractable epilepsy. METHODS: Five patients (four males, one female; ages 6 to 50 years), were enrolled in the study; their epilepsy could not be controlled by medical treatment and surgery was not indicated. rTMS was performed twice a week for three months; patients kept records of seizure frequency for an equal period of time before, during, and after rTMS sessions. rTMS was delivered to the vertex with a round coil, at an intensity 5% below motor threshold. During rTMS sessions, 100 stimuli (five series of 20 stimuli, with one-minute intervals between series) were delivered at a frequency of 0.3 Hz. RESULTS: Mean daily number of seizures (MDNS) decreased in three patients and increased in two during rTMS--one of these was treated for only one month; the best result was achieved in a patient with focal cortical dysplasia (reduction of 43.09% in MDNS). In the whole patient group, there was a significant (p<0.01) decrease in MDNS of 22.8%. CONCLUSION: Although prolonged rTMS treatment is safe and moderately decreases MDNS in a group of patients with intractable epilepsy, individual patient responses were mostly subtle and clinical relevance of this method is probably low. Our data suggest, however, that patients with focal cortical lesions may indeed benefit from this novel treatment. Further studies should concentrate on that patient subgroup.

Experimental therapy of epilepsy with transcranial magnetic stimulation: lack of additional benefit with prolonged treatment

OBJETIVO: investigar o efeito de três meses de estimulação magnética transcraniana repetitiva (EMTr) de baixa freqüência, na epilepsia de difícil controle. MÉTODO: Cinco pacientes (quatro homens, uma mulher, idades entre 6 e 50 anos), participaram do estudo; suas crises epilépticas não puderam ser controlados por tratamento medicamentoso e não tinham indicação cirúrgica; a EMTr foi realizada duas vezes por semana durante três meses, sendo que os pacientes anotaram o número diário de crises neste período, assim como nos três meses anteriores e posteriores ao tratamento. A aplicação da EMTr foi feita no vértex com bobina circular, com intensidade 5 por cento abaixo do limiar motor. Durante as sessões de EMTr, 100 estímulos (5 séries de 20 estímulos, com um minuto de intervalo entre as séries) foram realizadas na freqüência de 0,3 Hz. RESULTADOS: A média diária de crises (MDC) decresceu em três pacientes e aumentou em dois durante o uso da EMTr; um destes casos foi tratado somente por um mês; o melhor resultado foi encontrado em um paciente com displasia cortical focal (redução de 43,09 por cento na MDC). Em todo o grupo de pacientes, houve decréscimo significativo na MDC de 22,8 por cento (p<0,01). CONCLUSAO: Embora o tratamento prolongado com a EMTr seja seguro e tenha sido registrado decréscimo moderado da MDC em um grupo de pacientes com epilepsia de difícil controle, respostas individuais de pacientes foram imprevisíveis e a relevância clínica deste método é provavelmente baixa. Nossos dados sugerem, contudo, que pacientes com lesões corticais focais podem ser beneficiar deste novo tipo de tratamento. Estudos futuros devem se concentrar neste grupo de pacientes.