Which statement best distinguishes semantic dementia from the logopenic variant of primary progressive aphasia?

• A. Semantic dementia presents with early loss of semantic memory.
• B. Semantic dementia features early loss of semantic memory; logopenic PPA features prominent word-finding problems and impaired phonological working memory with relatively preserved single-word semantics early on.
• C. Semantic dementia shows relatively preserved semantic memory; logopenic PPA shows early semantic loss.
• D. Semantic dementia is associated with posterior cortical atrophy; logopenic PPA with anterior temporal lobe atrophy.

Answer: (B)