Treating lexical retrieval using letter fluency and tDCS in primary progressive aphasia: a single-case study.
Vânia de Aguiar, Adrià Rofes, Haley Wendt and 3 others
PMID 38765920WHAT IT FOUND
One man with early primary progressive aphasia improved word retrieval after letter fluency therapy combined with brain stimulation.
Gains lasted three months for trained letters and transferred to an untrained naming task, but only with left frontal stimulation.
Key findings
01Letter fluency therapy combined with anodal tDCS to the left inferior frontal gyrus improved word retrieval for trained letters, with gains sustained at three-month follow-up.
02Improvement transferred to an untrained picture naming task, but only after stimulation to the left inferior frontal gyrus, not the left inferior parietal lobule.
03The study had no sham control, so it cannot determine if the brain stimulation added benefit beyond the behavioural therapy alone.
STILL TO COME
How it was doneWhat they foundWhat it means for SLPs
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What it does not show
Single-case design limits generalizability to other patients. No sham control condition was included, so the effect of tDCS cannot be distinguished from the effect of the behavioural therapy. The order of treatment phases (IFG then IPL) was not randomized, so habituation or practice effects may have influenced the results. The participant had mild impairment and high baseline function, so it is unclear if this approach works for more severe cases. Functional communication improvements were only informally reported by family, not formally measured.
Declared interests
The authors report no conflict of interest.
The easy way to misread this
Do not conclude that tDCS is necessary for these improvements. The study lacked a sham control, so the observed gains could be due entirely to the letter fluency therapy itself.