Logopenic Variant of Primary Progressive Aphasia (LPA)

The goal of this clinical trial is to learn whether home-based brain stimulation combined with virtual speech-language therapy can improve communication abilities in adults with logopenic variant primary progressive aphasia (lvPPA), a language disorder most often caused by Alzheimer's disease. The main questions the study aims to answer are: * Is combining remotely supervised transcranial direct current stimulation (tDCS) with virtual speech-language therapy feasible and acceptable for people with lvPPA? * Does this combined treatment lead to improvements in communication compared to speech-language therapy with sham (placebo) stimulation? * Do individual brain characteristics help predict who benefits most from this treatment? Researchers will compare participants who receive active tDCS plus virtual speech-language therapy to participants who receive sham (placebo) tDCS plus virtual speech-language therapy to see if active brain stimulation enhances communication outcomes. Participants will: * Complete speech-language therapy sessions delivered by video visit. * Receive either active or sham tDCS that is remotely supervised and completed at home. * Complete language and cognitive testing before and after treatment. * Undergo brain imaging and other assessments to help understand treatment response.

The goal of this clinical trial is to learn whether a personalized, multi-component, virtual speech language treatment program can improve communication and quality of life for adults with primary progressive aphasia (PPA) and their primary communication partners. The study will enroll participants who speak English and/or Spanish. The main questions the study aims to answer are: * Is the telerehabilitation program feasible and acceptable for people with PPA and their study partners? * Do participants with PPA and study partners find treatment beneficial? * What patterns of treatment response are seen in participants? * Which outcome measures are most useful for evaluating changes in communication and quality of life? Researchers will compare participants who receive intervention immediately to participants assigned to a waitlist control group (who will receive treatment after a delay) to see whether participation in the treatment program is associated with improvements in communication and quality of life. Participants will: * Take part in speech language therapy sessions delivered by video visit that combine restorative, compensatory, and partner-focused communication strategies. Treatment may take place after a waiting period. * Receive education and communication training together with their partner. * Complete speech, language, and cognitive assessments. * Complete questionnaires about communication abilities, daily functioning, and quality of life.