Non-invasive brain stimulation and computational models in post-stroke aphasic patients: single session of transcranial magnetic stimulation and transcranial direct current stimulation. A randomized clinical trial

ABSTRACT CONTEXT AND OBJECTIVE: Patients undergoing the same neuromodulation protocol may present different responses. Computational models may help in understanding such differences. The aims of this study were, firstly, to compare the performance of aphasic patients in naming tasks before and after one session of transcranial direct current stimulation (tDCS), transcranial magnetic stimulation (TMS) and sham, and analyze the results between these neuromodulation techniques; and secondly, through computational model on the cortex and surrounding tissues, to assess current flow distribution and responses among patients who received tDCS and presented different levels of results from naming tasks. DESIGN AND SETTING: Prospective, descriptive, qualitative and quantitative, double blind, randomized and placebo-controlled study conducted at Faculdade de Ciências Médicas da Santa Casa de São Paulo. METHODS: Patients with aphasia received one session of tDCS, TMS or sham stimulation. The time taken to name pictures and the response time were evaluated before and after neuromodulation. Selected patients from the first intervention underwent a computational model stimulation procedure that simulated tDCS. RESULTS: The results did not indicate any statistically significant differences from before to after the stimulation.The computational models showed different current flow distributions. CONCLUSIONS: The present study did not show any statistically significant difference between tDCS, TMS and sham stimulation regarding naming tasks. The patients'responses to the computational model showed different patterns of current distribution.

The Escitalopram versus Electric Current Therapy for Treating Depression Clinical Study (ELECT-TDCS): rationale and study design of a non-inferiority, triple-arm, placebo-controlled clinical trial / Estudo clínico Escitalopram versus Eletroterapia no Tratamento da Depressão (ELECT-TDCS): racional e desenho de estudo de um ensaio de não inferioridade, de três braços, placebo-controlado

CONTEXT AND OBJECTIVE: Major depressive disorder (MDD) is a common psychiatric condition, mostly treated with antidepressant drugs, which are limited due to refractoriness and adverse effects. We describe the study rationale and design of ELECT-TDCS (Escitalopram versus Electric Current Therapy for Treating Depression Clinical Study), which is investigating a non-pharmacological treatment known as transcranial direct current stimulation (tDCS). DESIGN AND SETTING: Phase-III, randomized, non-inferiority, triple-arm, placebo-controlled study, ongoing in São Paulo, Brazil. METHODS: ELECT-TDCS compares the efficacy of active tDCS/placebo pill, sham tDCS/escitalopram 20 mg/day and sham tDCS/placebo pill, for ten weeks, randomizing 240 patients in a 3:3:2 ratio, respectively. Our primary aim is to show that tDCS is not inferior to escitalopram with a non-inferiority margin of at least 50% of the escitalopram effect, in relation to placebo. As secondary aims, we investigate several biomarkers such as genetic polymorphisms, neurotrophin serum markers, motor cortical excitability, heart rate variability and neuroimaging. RESULTS: Proving that tDCS is similarly effective to antidepressants would have a tremendous impact on clinical psychiatry, since tDCS is virtually devoid of adverse effects. Its ease of use, portability and low price are further compelling characteristics for its use in primary and secondary healthcare. Multimodal investigation of biomarkers will also contribute towards understanding the antidepressant mechanisms of action of tDCS. CONCLUSION: Our results have the potential to introduce a novel technique to the therapeutic arsenal of treatments for depression. .

CONTEXTO E OBJETIVO: O transtorno depressivo maior (TDM) é uma condição psiquiátrica comum, tratada com medicamentos antidepressivos, os quais são limitados devido à refratariedade e efeitos adversos. Descrevemos o racional e o desenho do Estudo Clínico Escitalopram versus Eletroterapia no Tratamento da Depressão (ELECT-TDCS), que investiga um tratamento não farmacológico, conhecido como estimulação transcraniana por corrente contínua (ETCC). DESENHO E LOCAL: Ensaio de fase III, randomizado, de não inferioridade, de três braços, placebo-controlado, em execução em São Paulo, Brasil. MÉTODOS: O estudo compara a eficácia da ETCC ativa/pílula placebo, ETCC simulada/escitalopram 20 mg/dia e ETCC simulada/pílula placebo durante 10 semanas, randomizando 240 pacientes em uma proporção 3:3:2, respectivamente. O objetivo principal é demostrar que a ETCC não é inferior ao escitalopram com uma margem de não inferioridade de pelo menos 50% do efeito de escitalopram em relação ao placebo. Como objetivos secundários, investigamos biomarcadores como polimorfismos genéticos, marcadores séricos, excitabilidade cortical motora, variabilidade da frequência cardíaca e neuroimagem. RESULTADOS: Provar que ETCC é igualmente eficaz a antidepressivos teria um tremendo impacto na psiquiatria clínica, uma vez que a ETCC é praticamente isenta de efeitos adversos. Sua facilidade de uso, portabilidade e preço baixo são outras características atraentes para uso na atenção primária e secundária de saúde. A investigação multimodal de biomarcadores também contribuirá para a compreensão dos mecanismos de ação antidepressivos da ETCC. CONCLUSÃO: Os nossos resultados podem introduzir uma nova técnica no arsenal terapêutico do tratamento da depressão. .