Semantic dementia

What is Semantic dementia?

Semantic dementia (SD) is a form of frontotemporal dementia (FTD; see this term), characterized by the progressive, amodal and profound loss of semantic knowledge (combination of visual associative agnosia, anomia, surface dyslexia or dysgraphia and disrupted comprehension of word meaning) and behavioral abnormalities, attributable to the degeneration of the anterior temporal lobes.

Other condition names

  • Semantic primary progressive aphasia
  • Semantic variant PPA

Inheritance type

Multigenic/multifactorial, Not applicable

Age of Onset

  • Adult
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