semantic dementia
A progressive neurodegenerative condition characterized by loss of semantic memory and knowledge of word meanings while other cognitive abilities remain relatively preserved.
Full Definition
Semantic dementia is a variant of frontotemporal dementia characterized by progressive deterioration of semantic memory - the knowledge of facts, concepts, and word meanings. Patients gradually lose understanding of familiar objects, people, and concepts while maintaining fluent speech patterns and relatively preserved episodic memory and visuospatial skills. The condition typically presents with word-finding difficulties, reduced vocabulary, and progressive inability to understand the meaning of words or recognize familiar objects. Semantic dementia primarily affects the anterior temporal lobes and represents one of the three main variants of primary progressive aphasia. Recognition is important for differential diagnosis and family counseling.
Usage
Usage note: Specific subtype of frontotemporal dementia; emphasize semantic memory loss.
In Context
- "The patient's semantic dementia progressed from word-finding difficulties to complete loss of object recognition." — Longitudinal assessment
- "Semantic dementia was suspected when the patient could no longer identify common household items despite preserved motor skills." — Neuropsychological evaluation