A DOUBLE-BLIND RANDOMIZED SHAM-CONTROLLED STUDY TO ASSESS THE EFFICACY AND TOLERABILITY OF HIGH DEFINITION TRANSCRANIAL DIRECT CURRENT STIMULATION (HD-tDCS) ON COGNITIVE FUNCTIONING IN MODERATE TO SEVERE TRAUMATIC BRAIN INJURY (TBI)

Worldwide, there is high prevalence of Traumatic Brain Injury (TBI) and of individuals who are struggling with persistent TBI-related cognitive deficits. Pharmacological treatment strategies to manage these cognitive deficits are limited by effectiveness as well as tolerability Issues. Only cognitive training is available at present, however it is often time consuming and ineffective. Synaptic plasticity has been a good prognostic factor for patients who have suffered Traumatic Brain Injury. Transcranial Direct Current Stimulation (tDCS) is a form of cheaper, safer, and feasible method and literature has reported its effectiveness in improving synaptic plasticity. However there has been a paucity of studies both worldwide as well as in India which investigates the utility of tDCS for cognitive impairment after TBI.

Consultants and Senior Residents in the outpatient department (OPD) of Psychiatry, Neuropsychiatry, Neurosurgery, Trauma Psychiatry and at tDCS Facility of AIIMS, New Delhi shall be requested to refer all the patients with chronic TBI (more than 6m since TBI). Out of the referred patients, those of 18-45 years of age, right-handed, and with moderate to severe TBI (as per Mayo TBI severity classification system) with at least one cognitive symptom on the NSI will be chosen by a purposive method for participation in the study. Diagnosis of moderate to severe TBI will be confirmed using the Mayo TBI severity classification and participants fulfilling the inclusion and exclusion criteria will be recruited. Participants will be screened for psychiatric comorbidities using clinical interview. Physical, neurological and substance use comorbidity as well as pregnancy or lactation will be ruled out by history and clinical examination. Written consent will be taken prior to participation in the study. After conducting the semi-structured interview and collecting the clinical data and examining the patient for recruitment, participants will be allocated into 2 groups – one which will receive Active HD-tDCS and another which will receive Sham HD-tDCS. Allocation concealment and double blinding will be done to prevent selection bias and observer bias. For participant blinding, computer generated block randomization list will be prepared by the guide for grouping participants into 2 groups (active tDCS or sham tDCS) mentioning alphanumeric code for consecutive recruitment. Investigator after recruiting, will send the participant to tDCS Facility with the alphanumeric code. For investigator blinding, the technician will be allocating the participant to protocol A-tDCS or B-tDCS. Investigator will not be informed whether the participant receives protocol A-tDCS or B-tDCS. For technician blinding, the technician would be unaware of the interim protocol details. The protocols (A-tDCS or B-tDCS) would be prepared by the guide.

A total of 20 sessions of active or sham HD-tDCS would be provided to each participant in respective groups. Gaps between sessions would be allowed (24-48 hours) but if a participant misses 3 consecutive days, then the participant would be considered drop out. Participants would keep receiving the medications as prescribed by the treating clinician without any alteration during the study period and a record of it would be made. For both the groups baseline assessment/pre intervention assessment (ACE-III, TMTApp, qEEG, fNIRS, CGI, WHODAS 2.0, NSI, tSEC) will be done within 2 days of assessments by sociodemographic and clinical data using semi structured datasheet. And following that both groups will be called for 10 sessions of tDCS (2 sessions per day for the next 5 days). After completion of 10 sessions by both groups, a mid-intervention assessment will be done for both groups using TMTApp, qEEG, CGI, WHODAS 2.0, NSI, tSEC. The participants of both the groups will be provided another 10 sessions of tDCS (2 sessions per day for the next 5 days), allowing a maximum gap of 72 hours between prior 10 sessions and the next 10 sessions. After completion of 20 sessions of tDCS, both groups will be subjected to post intervention assessment (ACE-III, TMTApp, qEEG, fNIRS, CGI, WHODAS 2.0, NSI, tSEC). The data obtained from the assessments will be analyzed.