Targeting Language-specific and Executive-control Networks With Transcranial Direct Current Stimulation in Aphasic Alzheimer's Disease (Logopenic Variant PPA)

What this Trial Is About

Researchers are investigating transcranial direct current stimulation (tDCS) combined with language therapy to improve language and cognitive functions in people with logopenic variant Primary Progressive Aphasia (lvPPA), a form of Alzheimer's disease that severely affects language and communication. This condition typically begins between the ages of 50 and 65, impacting work and family life. The study builds on previous findings that tDCS over a brain language center enhances therapy effects and explores stimulation of two brain areas to test how benefits may generalize to different language and executive functions. Participants will undergo two treatment periods separated by a three-month break. They will receive either active high-definition tDCS (HD-tDCS) combined with language and cognitive interventions or a sham (inactive) stimulation combined with the same interventions. The stimulation targets either the left supramarginal gyrus (involved in phonological memory) or the left dorsolateral prefrontal cortex (involved in executive control). Each stimulation session lasts up to 20 minutes with 2 milliamperes of current. During the study, participants will be assessed before, immediately after, and up to three months following each intervention. Assessments include language tests measuring word and sentence repetition, memory spans, naming, spelling, and connected speech, along with brain imaging scans to monitor functional connectivity and neurotransmitter levels. The study also collects data on cognitive, clinical, physiological, and demographic factors to identify predictors of treatment response. Total participation includes both treatment phases and follow-up evaluations.

Targeting Language-specific and Executive-control Networks With Transcranial Direct Current Stimulation in Logopenic Variant PPA