None listed
Conditions
Brief summary
This study evaluates the efficacy of brain stimulation, i.e. Transcranial Direct Current Stimulation (tDCS) to improve attention skills and working memory in people with traumatic brain injury. The study involves placing electrodes on the scalp and passing a weak direct electrical current through the brain that can increase neuronal excitability. The stimulation is non-invasive and painless with few reported side effects such as skin irritation or a mild headache. Individuals received one active/actual tDCS sessions and one sham or placebo session. During both sessions they also completed two computer-based task in which they responded to symbols appearing on the computer monitor. Participants were fully awake and alert during these sessions. Test sessions were approximately an hour in duration and took place approximately 1 week apart. The order of session (active or sham) was unknown to participants and, indeed, people find it very difficult to guess.
Interventions
1. Brief description of intervention:
The intervention for all participants was a 20 minute session of transcranial direct current stimulation (tDCS: 2mA) which was compared to a sham tDCS session delivered to the same participant a week or so apart.
a) Frequency- both active tDCS and sham sessions were delivered once only. Order (sham, active) was randomised across participants. There was approximately one week between the two sessions (M = 8.03, SD = 2.76 days).
b) Parameters- tDCS was adm
1. Brief description of intervention: The intervention for all participants was a 20 minute session of transcranial direct current stimulation (tDCS: 2mA) which was compared to a sham tDCS session delivered to the same participant a week or so apart. a) Frequency- both active tDCS and sham sessions were delivered once only. Order (sham, active) was randomised across participants. There was approximately one week between the two sessions (M = 8.03, SD = 2.76 days). b) Parameters- tDCS was administered using a battery driven, constant current stimulator and a pair of conductive rubber electrodes (7 cm×5 cm, 35 cm2) covered in normal saline-soaked, synthetic sponge which were restrained by a latex headband. tDCS was delivered in a 20 minute session (2mA) with a 5 s fade in and 5 s fade out time by an anode placed on the head over the left parietal lobe with the cathode placed over the same area on the right side. Sham stimulation used the same montage for 20 minutes and consisted of 2 mA of tDCS delivered for 30 s with a 5 s fade in and 5 s fade out time. c) The intervention was administered by a research assistant. d) Treatment adherence was audited by a second researcher during initial training but not thereafter. 2. Procedure: Prior to the first treatment session (Active or sham as randomly allocated), participants completed a brief neuropsychological battery including the the WAIS-IV Digit Span Test (forward, backward and sequencing) (Wechsler, 2008), animals fluency (Tombaugh, Kozak, & Rees, 1999), Digit Symbol Modality test (Smith, 2007) and the Trail Making Test (TMT) (Reitan, 1992). Prior to each session (active and sham) of tDCS they completed a measure of mood state (the Profile of Mood State) and a fatigue and alertness scale. In order to examine arousal levels participants were fitted with skin conductance electrodes and were asked to sit relaxed and (1) close their eyes for two minutes (EC1); (2) open their eyes in response to a beep signal and focus their eyes on a fixation cross for two minutes (EO) and (3) close their eyes again for another two minutes (EC2). During the administration of active (or sham tDCS) participants completed a 1-back and a 2-back working memory task (order counterbalanced across participants). At the completion of the tDCS (active or sham) and the N-back tasks, participants again had their arousal monitored (using the EC1, EO, EC2 procedure) and completed the POMS and the fatigue and alertness scales.
Sponsors
UNSW
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject)
Eligibility
Sex/Gender
All
Age
18 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
- Definite moderate to severe traumatic brain injury according to the Mayo classification criteria (Malec, Brown, Leibson et al, 2007), i.e. a period of post-traumatic amnesia (PTA) of 24 hours or greater and/or loss of consciousness greater than 30 minutes and/or evidence of intracerebral brain pathology on neuroimaging. - Aged between 18 – 70 years, - At least 12 months post-injury, - Discharged from hospital and living in the community, - Functional English reading and writing ability.
Exclusion criteria
-Uncorrected hearing or vision loss. -Current diagnosed drug and/or alcohol addiction - Active psychosis -Psychiatric condition (other than mild to moderate anxiety or depression). -Dementia or other neurodegenerative disease -Aphasia, agnosia, or profound amnesia - Insertion of a metal shunt.
Outcome results
None listed