The Impact of Concurrent Brain Stimulation and Working Memory Training on Cognitive Performance in Acquired Brain Injury
试验速览
- 阶段
- 不适用
- 入组人数
- 40
- 主要终点
- Changes in memory capacity, as measured by number of items that are memorised successfully, in the cognitive task used as the training regime;
研究概览
简要总结
Working memory is a limited capacity cognitive system in which information is held temporarily in order to make it available for processing. The amount of information that can be held in mind varies considerably from person to person and changes across the lifespan.
Working memory is frequently affected following brain injury. As working memory is important for cognitive skills such as problem solving, planning and active listening, a deficit in working memory can lead to difficulties with many everyday activities that are necessary for work, study and general functioning. Impaired working memory may consequently have a significant impact on a person's quality of life and ability to participate in previous social roles, with potential for effects on mood and emotional wellbeing.
Evidence shows that non-invasive transcranial direct current brain stimulation (tDCS) can be used in combination with computerized memory training (CT) over multiple days, to enhance working memory in healthy and clinical populations. In patients with an acquired brain injury (ABI), cognitive training or brain stimulation have been used alone to improve attention or memory-related impairment, but the effect of the concurrent used of the two interventions over multiple days is yet to be investigated.
With this research the investigators propose to investigate the effect of the combined use of tDCS and CT to improve memory performance in patients with acquired brain injury. The investigators propose to use a multi-day cognitive training regime to exercise working memory, while stimulating the brain with low intensity direct currents. Success will be measured as improvement in performance in several cognitive domain, before and after training.
详细描述
Participants will be recruited through Northampton Healthcare NHS Foundation Trust Acquired Brain Injury clinics. They will complete 5 weeks of training at home. During the first two weeks they will be visited in their home by a researcher who will administered the current stimulation together with the working memory training program. The remaining 3 weeks the patient will complete the training program at home, while receiving a motivational / catch up call every week. Weekends will be exempt from testing. The working memory training software program is accessed via a password-protected website on a secure server at Dalhousie University. Training data will be saved on the Dalhousie University server and will be downloaded in Birmingham for data analyses.
RECRUITMENT As the aim of this research is to improve spatial working memory, only participants with a working memory impairment will be included in the study. To identify a working memory impairment, cognitive tests from the Wechsler Adult Intelligence Test (WAIS-IV) and the Wechsler Memory Scale (WMS-IV), will be administered in paper and pencil versions or using iPads. These tests are administered to every patient, as part of the routine care protocol.
The investigators will consider the following scores:
- A Full-Scale Intelligent Quotient (FSIQ) obtained from the WAIS-IV higher than 70: this score identifies patients able to follow instructions. The FSIQ will also be used as a covariate in the analysis to control for low average overall ability rather than a specific working memory issue.
- A Working Memory Index (WMI), obtained as a combination of the digit span score and the arithmetic score in the WAIS-IV, smaller than 85: this score identifies a general working memory impairment;
- A Visual Working Memory Index (VWMI), obtained as a combination of the symbol span and the spatial addition score in the WMS-IV, smaller than 85: this score identifies impairment specific to spatial working memory.
These tests are co-normed on a large sample (mean = 100; SD = 15). In order to be included in the study, a patient should have a FSIQ >70 and either a WMI or a SWMI or both < 85. This means that the investigators use a criterion score of one standard deviation below the mean. This score doesn't reflect significant impairment, but it allows us to identify patients with an impairment significant enough to potentially improve with training. See below for a detailed description of the cognitive tasks used. Participants who don't present a working memory impairment, as defined above, will be excluded from further participation. Patients identified as potential participants in the study will be approached with a letter.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Supportive Care
- 盲法
- Triple (Participant, Care Provider, Outcomes Assessor)
盲法说明
A computer programme will generate a random list assigning group allocation to participant numbers. The participant numbers will be given out in order of attendance in the laboratory. The study design is double blind: participants and the researchers who are conducting the behavioural testing will not know until the end of the intervention if the participant received brain stimulation. A researcher from the University of Birmingham (Dr Assecondi) will setup the blind protocol on the brain stimulation device and will keep a record of this.
入排标准
- 年龄范围
- 18 Years 至 69 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Referred to the service
- •Are between 18 and 69 years of age
- •Have capacity and able to provide informed consent
- •Normal or corrected-to-normal vision and hearing
- •Having a working memory impairment (see screening procedure below)
- •At least three months between the injury and the starting of the study
- •Has a computer or has access to a computer
排除标准
- •Pre-injury psychiatric or neurological disease by self-report (e.g., anxiety disorder, ADHD, Parkinson's disease, etc.)
- •History of diagnosed severe depression (diagnosed pre-injury)
- •History of epilepsy (diagnosed pre-injury)
- •Family history of epilepsy
- •Have had fainting spells or syncope in the last three years pre-injury
- •Have significant hearing loss, vision or motor impairment that would prevent them from performing the task
- •Known to be pregnant
- •Assuming medication affecting cortical excitability or recreational drugs
- •Metal (except titanium) or electronic implants in the brain /skull (e.g., splinters, fragments, clips, cochlear implant, deep brain stimulation, medication pump...)
- •Metal (except titanium) or any electronic device at other sites in the participant's body, such as cardiac pacemaker or traumatic metallic residual fragments
- •Have skin problems such as dermatitis, psoriasis or eczema under the stimulation sites
- •Have had brain stimulation in the past six months
- •Have undergone transcranial electric or magnetic stimulation in the past (more than 6 months) which resulted in adverse effects
- •Skull fractures, significant skull defects, skull plates or large vessels occlusions in the site of electrode placement
- •having had a seizure at the time of accident or between the injury and starting of the therapy.
研究组 & 干预措施
Active tDCS
During cognitive training in the first 2 weeks, participants will also received brain stimulation. The investigators will use a total current intensity of 2mA for 20 minutes, preceded by 30 seconds ramping up and followed by 30 seconds ramping down (total stimulation time = 21s).
干预措施: Active tDCS (Device)
SHAM tDCS
During sham stimulation, concurrent with the cognitive training, The investigators will use the same setup as in the active condition but after ramping up, the current will be brought back to zero and the process repeated 30 seconds before the end of the 21 minutes time interval (total sham stimulation time = 21s).
干预措施: SHAM tDCS (Device)
结局指标
主要结局
Changes in memory capacity, as measured by number of items that are memorised successfully, in the cognitive task used as the training regime;
时间窗: On day1, at end of week 2, at end of week 5 and at end of week 9
The difficulty of the training regime is manipulated by increasing N, i.e. the number of items the participant is requested to memorise. As such, N is used to measure individual memory capacity. Changes in memory capacity, as the training regime progresses is the primary outcome measure of this study.
次要结局
- Changes in memory capacity, as measured by number of items that are memorised successfully, in untrained cognitive tasks.(On day1, at end of week 2, at end of week 5 and at end of week 9)
- Persistence of changes in memory capacity through time(On day1, at end of week 2, at end of week 5 and at end of week 9)