Progressive non-fluent aphasia

A disorder that begins with deficits in speech or language, progressive non-fluent aphasia (PNFA) has an insidious onset. Often, the patient becomes aware of his or her deficits before others have noticed changes. Nonfluent aphasia emerges associated with decreased word output, while soon thereafter, shortened phrase length and deficits in articulation develop. The use of nouns remains intact, but deficits in the understanding of grammar and the use of verbs are common. Many patients exhibit speech apraxia, which is characterized by a deficit in articulatory planning resulting in an inability to command the speech musculature to produce sounds in a proper sequence. Social decorum remains intact throughout most of the illness, although some patients evolve to a bvFTD syndrome. Motor disorders characteristic of corticobasal degeneration (CBD) or progressive supranuclear palsy (PSP) are common several years after the onset of PNFA. Some patients evolve from PNFA to classical CBD or PSP over a fairly short period of time. Most patients with PNFA show tau pathology at autopsy.