Primary progressive aphasia.

Neurodegenerative dementia may, in rare cases, initially manifest as isolated language impairments in the absence of other cognitive symptoms. These impairments are often somewhat imprecisely referred to as difficulties with 'word finding'. There are several variants of this form of dementia, each caused by different underlying neuropathologies. Occasionally problems with speech rather than language predominate. Patients may have exclusively language or speech-related symptoms for several years, but eventually all will progress to generalised dementia. This clinical review describes primary progressive aphasia: a collective term for forms of dementia that begin with language impairments.