Progressive nonfluent aphasia is one of three clinical syndromes associated with frontotemporal lobar degeneration. The major symptom is progressive difficulties with the production of speech.
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The main clinical features are progressive difficulties with speech production. There can be problems in different parts of the speech production system, hence patients can present with articulatory breakdown, phonemic breakdown (difficulties with sounds) and other problems. However, it is rare for patients to have just one of these problems and most people will present with more than one problem. Features include:
As the disease develops, speech quantity decreases and many patients will become mute.
Cognitive domains other than language are rarely affected early on. However, as the disease progresses other domains can be affected. Problems with writing, reading and speech comprehension can occur as can behavioural features similar to frontotemporal dementia.
There is some confusion in the terminology used by different neurologists. Mesulam's original description in 1982 of progressive language problems caused by neurodegenerative disease (which he called primary progressive aphasia - PPA) included patients with both progressive non-fluent aphasia (PNFA) and semantic dementia (SD). The Neary criteria for PNFA and SD are therefore different from the Mesulam criteria for PPA. This is further confused by some doctors using the term primary progressive aphasia to mean patients with progressive non-fluent aphasia only.[1]
Imaging studies have shown differing results which probably represents the heterogeneity of language problems than can occur in PNFA. However, classically atrophy of left perisylvian areas is seen. Comprehensive meta-analyses on MRI and FDG-PET studies identified alterations in the whole left frontotemporal network for phonological and syntactical processing as the most consistent finding.[2] Based on these imaging methods, progressive nonfluent aphasia can be regionally dissociated from the other subtypes of frontotemporal lobar degeneration, frontotemporal dementia and semantic dementia.
There is no curative treatment for this condition. Supportive management is helpful.