タンザニアからの混合非流暢/失語症型原発性進行性失語症および行動変異型前頭側頭型認知症の症例報告

Frontotemporal dementia (FTD) comprises neurodegenerative syndromes causing progressive deterioration in behavior, language, and executive function, with relative preservation of memory early on. Overlap between the behavioral variant (bvFTD) and nonfluent/agrammatic primary progressive aphasia (nfvPPA) reflects shared frontotemporal network pathology but remains rarely documented in Sub-Saharan Africa, where Alzheimer disease predominates. We describe a 61-year-old Tanzanian man who initially presented with effortful, halting speech, agrammatism, and impaired syntax consistent with nfvPPA. Over 4 years, he developed mutism, apathy, loss of initiative, and pica-like behaviors, indicative of bvFTD progression. MRI showed asymmetric frontotemporal atrophy, predominantly in the left hemisphere, with relative posterior sparing. Laboratory tests were unremarkable. This case highlights the evolution from language-predominant to behavioral FTD, illustrating the clinical continuum of frontotemporal lobar degeneration. It underscores the need for awareness, longitudinal assessment, and accessible neuroimaging to improve FTD recognition and management in resource-limited settings.