Effects of Transcranial Direct Current Stimulation (tDCS) in Spoken and Written Production in Primary Progressive Aphasia (PPA)
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 61
- 试验地点
- 2
- 主要终点
- Absolute Percent Change in Written Naming (Trained Items)
研究概览
简要总结
Primary progressive aphasia (PPA) is a neurodegenerative disease that affects first and foremost language abilities. Mild cognitive impairment (MCI) is slowly progressive decline in a single domain of cognition (e.g. language) not attributable to motor or sensory loss, without impediment of social or occupational function. MCI can be an early sign of neurodegenerative disease, or can be due to normal aging. When language is the prominent affected domain in MCI, the person may later meet criteria for PPA or may progress to the clinical syndrome of Alzheimer's dementia. Spelling, naming, and working memory (e.g. repetition) are among the language abilities affected early in the course of PPA or language-centered MCI, and different variants have distinct deficits in these domains. This research project investigates the behavioral and neuromodulatory effects of high definition transcranial direct current stimulation (HD-tDCS) during language therapy in PPA participants over time. Anodal HD-tDCS targeting the left inferior frontal gyrus (IFG) administered in combination with language therapy is expected to be more beneficial when compared to language therapy alone. It will 1) improve language performance or decrease rate of decline, 2) have better-sustained effects at 2 weeks and 2 months post-treatment, and 3) produce generalization to untrained language items and some other cognitive functions. Resting-state fMRI, diffusion tensor imaging (DTI), and volumetric data are also collected to investigate changes in functional brain connectivity associated with HD-tDCS in individuals with PPA. A better understanding of the therapeutic and neuromodulatory mechanisms of HD-tDCS as an adjunct to language therapy in PPA may have a significant impact on the development of effective therapies for PPA and MCI, and may offer insight into ways of impeding neurodegeneration that may improve patients' quality of life, as well as extend their ability to work and manage their affairs.
详细描述
A. Evaluation Tasks
Language Tasks:
Participants will be administered baseline language and cognitive tasks, including 1 or more of the following, depending on their residual language and cognitive skills:
a) writing to dictation b) oral spelling c) oral and written naming of pictures d) word-picture matching f) written and oral picture description g) digit span h) spatial span i) verbal learning j) grammatical sentence production k) oral word repetition l) sentence comprehension
Quality of Life questionnaires:
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Treatment
- 盲法
- Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 50 Years 至 90 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Must be clinically diagnosed with semantic variant PPA (svPPA), non-fluent variant PPA (nfvPPA), or logopenic variant PPA (lvPPA), unclassifiable PPA, or MCI. Diagnosis will be based on neuropsychological testing, language testing (most commonly the Western Aphasia Battery), MRI and clinical assessment.
- •Must be right-handed.
- •Must be speakers of English.
- •Must have at least 9th grade education.
排除标准
- •Uncorrected visual or hearing impairment by self report.
- •Stroke/other premorbid neurological disorder affecting the brain.
- •Any other language-based learning disorder other than PPA.
- •Inability to follow directions for baseline tasks.
- •Western Aphasia Battery Aphasia Quotient (AQ) <30 (indicating severe language impairment).
- •Exclusion Criteria for MRI Participation:
- •Severe claustrophobia.
- •Cardiac pacemakers or ferromagnetic implants.
- •Pregnant women.
结局指标
主要结局
Absolute Percent Change in Written Naming (Trained Items)
时间窗: Change from Baseline to Immediately after treatment (3 weeks), 2 weeks post treatment (5 weeks), and 2 months post-treatment (11 weeks) for each period of intervention
The primary outcome measure was the absolute percentage change in the number of correct letters in the written response, compared to the target response in the trained word lists. This calculation reflects the change in accuracy between two timepoints. For letter accuracy scoring, a rule-based system was used where each letter was assigned one point if correct. Points were deducted for errors such as deletions, additions, substitutions, transpositions, or movements of letters. A second reviewer independently scored the responses and resolved any discrepancies through discussion to ensure consensus. Interrater reliability for letter accuracy scoring was 95%. Average letter accuracy per word was calculated for all trained items. Then the absolute percentage change was calculated by subtracting the earlier time point value (e.g., baseline) from the later one (e.g., immediately after treatment, 2 weeks post, and 2 months post), reflecting the change in accuracy.
Absolute Percent Change in Written Naming (Untrained Items)
时间窗: Change from Baseline to Immediately after treatment (3 weeks), 2 weeks post treatment (5 weeks), and 2 months post-treatment (11 weeks) for each period of intervention
The primary outcome measure was the absolute percentage change in the number of correct letters in the written response, compared to the target response in the untrained word lists.This calculation reflects the change in accuracy between two timepoints. For letter accuracy scoring, a rule-based system was used where each letter was assigned one point if correct. Points were deducted for errors such as deletions, additions, substitutions, transpositions, or movements of letters. A second reviewer independently scored the responses and resolved any discrepancies through discussion to ensure consensus. Interrater reliability for letter accuracy scoring was 95%. Average letter accuracy per word was calculated for all untrained items. Then the absolute percentage change was calculated by subtracting the earlier time point value (e.g., baseline) from the later one (e.g., immediately after treatment, 2 weeks post, and 2 months post), reflecting the change in accuracy.
Absolute Percent Change in Oral Naming (Trained Items)
时间窗: Change from Baseline to Immediately after treatment (3 weeks), 2 weeks post treatment (5 weeks), and 2 months post-treatment (11 weeks) for each period of intervention
The percent accuracy for each participant's trained oral naming list was calculated, with scores ranging from 0% to 100%. A score of 0% indicates no correct responses, while 100% represents perfect accuracy. Higher percentages reflect better performance. To assess changes in performance from pre- to post-treatment, the percent accuracy for untrained items was compared before and after the intervention. The absolute percentage change was then calculated by subtracting the accuracy at the baseline time point (e.g., baseline) from the accuracy at the later time points (e.g., immediately after treatment, 2 weeks post, and 2 months post). This reflects the change in the participant's ability to name trained items, expressed as absolute percent change. A positive difference indicates improvement in naming accuracy, with a larger change reflecting greater improvement. A negative difference indicates a decline, with a larger change reflecting greater deterioration in naming ability.
Absolute Percent Change in Oral Naming (Untrained Items)
时间窗: Change from Baseline to Immediately after treatment (3 weeks), 2 weeks post treatment (5 weeks), and 2 months post-treatment (11 weeks) for each period of intervention
The percent accuracy for each participant's untrained oral naming list was calculated, with scores ranging from 0% to 100%. A score of 0% indicates no correct responses, while 100% represents perfect accuracy. Higher percentages reflect better performance. To assess changes in performance from pre- to post-treatment, the percent accuracy for untrained items was compared before and after the intervention. The absolute percentage change was then calculated by subtracting the accuracy at the baseline time point (e.g., baseline) from the accuracy at the later time points (e.g., immediately after treatment, 2 weeks post, and 2 months post). This reflects the change in the participant's ability to name trained items, expressed as absolute percent change. A positive difference indicates improvement in naming accuracy, with a larger change reflecting greater improvement. A negative difference indicates a decline, with a larger change reflecting greater deterioration in naming ability.
次要结局
- Change in Sentence Comprehension as Measured by the Subject Object Active Passive (SOAP) Test(Change from baseline to immediate follow-up (3 weeks).)
- Change in Functional Connectivity(Change from before treatment to immediate follow up (3 weeks))