Progressive Non-fluent Aphasia
Progressive non-fluent aphasia (PNFA) is the least common form of Frontotemporal Dementia and affects the ability to speak fluently. Patients present with difficulty communicating due to slow and laboured production of words often with distortion of speech and a tendency to produce the wrong word.
Some patients have slurring of speech whereas others are able to articulate words but produce frequent near misses (e.g. they say “silter” for “sister”). Understanding of word meaning is preserved, but patients with PNFA have problems comprehending sentences and following conversations, especially if there are a number of speakers. Using the telephone and communicating with groups of people is particularly difficult.
Spelling is frequently impaired from an early stage and some patients develop difficulties reading (so called dyslexia). Subtle deficits in problem solving, mental flexibility and decision making are often present from an early stage. Changes in behaviour are uncommon in the early stages but do occur later.
Some people develop clumsiness of handuse, known as apraxia. In later stages, the disease spreads to the frontal lobes, so that many of the features described above, especially the changes in emotional responses and empathy occur. There is considerable overlap between progressive nonfluent aphasia and corticobasal degeneration (see section on Overlap with Corticobasal Degeneration).
