Transcranialis egyenáram-stimuláció a kognitív idegtudományban – buktatók és megoldások

2021 ◽  
Vol 74 (5-6) ◽  
pp. 171-182
Author(s):  
Orsolya Pesthy ◽  
Karolina Janacsek ◽  
Dezső Németh

Transcranial direct current stimulation (tDCS) is a promising brain stimulation tool which is non-invasive, easy to use and relatively cheap. Since it can change brain activity in a temporal manner, it can contribute to both clinical practice and neuroscientific research. However, the effectiveness of tDCS has been questioned considering the lack of full understanding of its mechanism of action and the seemingly contradictory results. In this review, we aim to provide a summary of potential problems and possible solutions. Our main focus is on the inter-individual differences in the effect of tDCS which can explain the noisy data, thus, controlling for them is important in order to show reliable results. This review is hoped to contribute to maximizing the potential of tDCS by helping future researchers to design replicable studies.

Author(s):  
Anagha S. Deshmukh ◽  
Samir Kumar Praharaj ◽  
Shweta Rai ◽  
Asha Kamath ◽  
Dinesh Upadhya

Background: Alcohol dependence is a significant public health problem, contributing to the global health burden. Due to its immense socio-economic burden, various psychosocial, psychological, and pharmacological approaches have attempted to alter the behaviour of the patient misusing or abusing alcohol, but their efficacy is modest at best. Therefore, there is a search for newer treatment approaches, including noninvasive brain stimulation in the management of alcohol dependence. We plan to study the efficacy of Prefrontal Cortex Transcranial direct current stimulation Treatment in Alcohol dependence syndrome (PreCoTTA). Methods: Two hundred twenty-five male patients with alcohol dependence syndrome will be randomized into the three study arms (2 active, left dorsolateral prefrontal cortex and left orbitofrontal cortex, and 1 sham) to receive a total of 14 tDCS sessions (10 continuous and 4 booster sessions). Data will be collected from them at five different time points on clinical, neuropsychological and biochemical parameters. In addition, 225 healthy age and education matched controls will be administered the neuropsychological test battery at baseline for comparison with the patient group. Discussion: The proposed study aims to explore the use of non-invasive brain stimulation; tDCS as a treatment alternative. We also aim to overcome the methodological gaps of limited sample sizes, fewer tDCS intervention sessions, lack of long term follow ups to measure the sustainability of gains and lack comprehensive measures to track changes in functioning and abstinence after tDCS intervention. The main outcomes include clinical (reduction in cue-induced craving, time to first drink and QFI); neuropsychological (risk-taking, impulsivity, and other neuropsychological domains) and biochemical markers (BDNF, leptin and adiponectin). The findings of the study will have translational value as it may help to improve the clinician’s ability to effectively manage craving in patients with alcohol dependence syndrome. Furthermore, we will have a better understanding of the neuropsychological and biochemical effects of non-invasive brain stimulation techniques which are of interest in the comprehensive treatment of addiction disorders. Trial registration: The study has been registered with the Clinical Trials Registry-India (CTRI/2020/09/027582) on September 03rd 2020.


2020 ◽  
Author(s):  
Davinia Fernández-Espejo ◽  
Davide Aloi ◽  
Antonio Incisa della Rocchetta ◽  
Damon Hoad ◽  
Richard Greenwood ◽  
...  

Abstract Background: Therapeutic options for patients with prolonged disorders of consciousness (PDOC) are very limited, and patients often show little to no progress over time. It is widely recognized that some PDOC patients retain a higher level of cognition that may be apparent on the basis of their external responses, and simply are unable to produce purposeful motor behaviours. This dissociation has been linked to specific impairments in the motor network that lead to a reduction in thalamo-cortical coupling. Here, we will assess whether transcranial direct current stimulation (tDCS) can modulate thalamo-cortical coupling and improve patients’ responsiveness. We will focus on characterising the mechanisms of action of tDCS and the bases for potential individual differences in responsiveness to the stimulation across participants.Methods: This is a multi-centre double-blind randomised crossover feasibility study. It is divided into two streams: (a) MRI stream: 5 PDOC patients will complete 5 anodal, cathodal, and sham stimulation sessions (paired with passive mobilisation of the thumb) in separate weeks. We will measure brain activity and connectivity with functional magnetic resonance imaging and electroencephalography (EEG). We will look at brain structures to assess differences associated with responsiveness. (b) Bedside stream: 10 patients will complete one session of anodal or cathodal stimulation and one session of sham. We will measure brain activity and connectivity with EEG and we will conduct follow up assessments at 3 and 6 months. In both streams we will also look at changes in the clinical profile of patients with the Coma Recovery Scale Revised and in command following behaviour with electromyography and motion tracking. We will assess feasibility on measures of eligibility, recruitment, retention, and completion of tests.Discussion: This feasibility study is the first step towards developing personalised tDCS interventions to restore external responsiveness in PDOC patients. Our results will inform the design of a future trial fully powered for characterising neural, behavioural, and clinical effects of tDCS in PDOC as well as the mechanisms underlying individual differences in responsiveness.


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