semantic dementia
A form of frontotemporal dementia characterized by progressive loss of semantic knowledge and word meaning.
Full Definition
Semantic dementia is a subtype of frontotemporal dementia characterized by the progressive deterioration of semantic memory, resulting in loss of word meaning and conceptual knowledge while initially preserving phonology, syntax, and episodic memory. Patients typically present with fluent but empty speech, surface dyslexia, and difficulty with object recognition and categorization. The condition is associated with asymmetric atrophy of the anterior temporal lobes, particularly the left temporal pole, and represents one of the primary progressive aphasia variants.
Usage
Usage note: Also known as semantic variant PPA (svPPA) in current diagnostic criteria.
In Context
- "The patient's semantic dementia manifested as profound word-finding difficulties with preserved sentence structure." — dementia differential diagnosis