Trial Outcomes & Findings for Combined tDCS and Cognitive Training in Alzheimer's (NCT NCT06861231)

Combined tDCS and Cognitive Training in Alzheimer's

The Mini-Mental State Examination (MMSE) was used as an index of global cognitive functioning. MMSE scores range from 0 to 30, with higher scores indicating lower cognitive impairment and therefore a better outcome. This test was designed to estimate the existence and severity of cognitive impairment. Participants with scores equal to or below 23 will be considered cognitively impaired. Assessments were conducted at baseline, immediately post-intervention at 2 weeks, and follow-up at 6 weeks (4 weeks after post-intervention assessment). Post-intervention minus baseline difference scores were calculated, with a possible range from -30 to 30; positive scores reflect improvement.

Direct and inverse digits of the Wechsler Intelligence Scale for Adults-III (Wechsler, 2001) were used to assess attentional capacity by exposing participants to increasing amounts of information. On the direct digits task, which assesses immediate recall, participants repeated the sequence of numbers in the same order in which they were presented by the examiner. On the inverse digits task, which assesses working memory and mental flexibility, participants repeated the digits in reverse order. Both tests are scored by assigning one point for each correct item, with scores ranging from 0 to 16; higher scores indicate better attentional performance and therefore a better outcome. Assessments were conducted at baseline, immediately post-intervention at 2 weeks, and follow-up at 6 weeks (4 weeks after post-intervention assessment). Post-intervention minus baseline difference scores were calculated, with a possible range from -16 to 16; positive scores reflect improvement.

The Complutense Verbal Learning Test (TAVEC) presents a list of 16 words that, after being read by the evaluator, must be repeated by the participant. The list is repeated five times (trials), and the participant is asked to recall the 16 words after each trial. The test was administered to evaluate immediate memory (Trial 1) and learning ability (Trial 5). Scores for each trial range from 0 to 16, with higher scores indicating better memory performance and therefore a better outcome. Assessments were conducted at baseline, immediately post-intervention at 2 weeks, and follow-up at 6 weeks (4 weeks after post-intervention assessment). Post-intervention minus baseline difference scores were calculated, with a possible range from -16 to 16; positive scores reflect improvement.

The Memory Alteration Test (M@T) provides efficient and valid screening for amnestic mild cognitive impairment (A-MCI) and early-stage Alzheimer's disease (AD). The test evaluates different cognitive abilities including encoding, orientation, semantic memory, and free recall. Scores range from 0 to 50, with higher scores indicating better memory performance and therefore a better outcome. The optimal cut-off point for distinguishing amnestic mild cognitive impairment from subjective memory complaints is 37 points, while the optimal cut-off point for Alzheimer's disease is 31 points. Assessments were conducted at baseline, immediately post-intervention at 2 weeks, and follow-up at 6 weeks (4 weeks after post-intervention assessment). Post-intervention minus baseline difference scores were calculated, with a possible range from -50 to 50; positive scores reflect improvement.

Barcelona Test (BT) assesses lexical and semantic retrieval through two subtests: semantic fluency (animals, 1 minute) and phonological fluency (words beginning with "p", 3 minutes). Scores correspond to the number of correctly produced words, with higher scores indicating better lexical-semantic performance and therefore a better outcome. Good performance is defined as more than 16 animals and more than 19 words beginning with "p". Scores are reported separately for each subtest, with no combined score. This test assesses lexical and semantic memory, processing speed, cognitive flexibility, and working memory. Assessments were conducted at baseline, immediately post-intervention at 2 weeks, and follow-up at 6 weeks (4 weeks after post-intervention assessment). Post-intervention minus baseline difference scores were calculated, with positive scores reflecting improvement.