Zhila Mohammadi - Department of Humanities, Nationa University of skills (NUS), Tehran, Iran

Progressive and relatively circumscribed loss of semantic knowledge, referred to as semanticdementia (SD) which falls under the broader umbrella of frontotemporal dementia, was officiallyidentified as a clinical syndrome less than ۵۰ years ago. Here, we review recent neuroimaging,pathological, and genetic research in SD. From a neuroimaging perspective, SD is characterisedby hallmark asymmetrical atrophy of the anterior temporal pole and anterior fusiform gyrus, whichis usually left lateralised. Functional magnetic resonance imaging (fMRI) studies have revealedwidespread changes in connectivity, implicating the anterior temporal regions in semantic deficitsin SD. Task-related fMRI have also demonstrated the relative preservation of frontal and parietalregions alongside preserved memory performance

Semantic-variant primary progressive aphasia, Frontotemporaldementia, Primary progressive aphasia