semantic dementia
A progressive language disorder characterized by loss of word meaning and object knowledge, considered a variant of frontotemporal dementia.
Full Definition
Semantic dementia is a form of primary progressive aphasia and a variant of frontotemporal dementia characterized by progressive loss of semantic memory. Patients gradually lose the meaning of words and the ability to recognize objects, faces, and concepts while maintaining fluent speech patterns and relatively preserved syntax. The condition typically begins with difficulty finding words for specific items or concepts and progresses to more generalized comprehension problems. Neuroimaging typically shows predominant atrophy in the anterior temporal lobes, particularly on the left side.
Usage
Usage note: Distinguish from 'vascular dementia' and other dementia subtypes in clinical writing.
In Context
- "The patient's inability to name common objects despite fluent speech suggested semantic dementia." — Neuropsychological report
- "Semantic dementia typically presents with surface dyslexia and regularization errors in reading." — Language assessment