Progressive nonfluent aphasia
Progressive nonfluent aphasia (PNFA) is one of three clinical syndromes associated with frontotemporal lobar degeneration. PNFA has an insidious onset of language deficits over time as opposed to other stroke-based aphasias, which occur acutely following trauma to the brain. The specific degeneration of the frontal and temporal lobes in PNFA creates hallmark language deficits differentiating this disorder from other Alzheimer-type disorders by the initial absence of other cognitive and memory deficits. This disorder commonly has a primary effect on the left hemisphere, causing the symptomatic display of expressive language deficits (production difficulties) and sometimes may disrupt receptive abilities in comprehending grammatically complex language.
Presentation
The main clinical features are signature language 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:
- Hesitant, effortful speech
- Apraxia of speech
- Stutter (including return of a childhood stutter)
- Anomia
- Phonemic paraphasia (sound errors in speech e.g. 'gat' for 'cat')
- Agrammatism (using the wrong tense or word order)
As the disease develops, speech quantity decreases and many patients 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.
Diagnosis
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. 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.
Classification
Some confusion exists 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 progressive nonfluent (aphasia, semantic dementia, and logopenic progressive aphasia.
Management
No cure or treatment for this condition has been found. Supportive management is helpful.
See also
Further reading
- Gliebus G (March 2010). "Primary progressive aphasia: clinical, imaging, and neuropathological findings". American Journal of Alzheimer's Disease and Other Dementias. 25 (2): 125–127. doi:10.1177/1533317509356691. PMID 20124255. S2CID 29195502.
- Gorno-Tempini ML, Dronkers NF, Rankin KP, Ogar JM, Phengrasamy L, Rosen HJ, et al. (March 2004). "Cognition and anatomy in three variants of primary progressive aphasia". Annals of Neurology. 55 (3): 335–346. doi:10.1002/ana.10825. PMC 2362399. PMID 14991811.
- Henry ML, Gorno-Tempini ML (December 2010). "The logopenic variant of primary progressive aphasia". Current Opinion in Neurology. 23 (6): 633–637. doi:10.1097/WCO.0b013e32833fb93e. PMC 3201824. PMID 20852419.
- Mesulam MM (October 2003). "Primary progressive aphasia--a language-based dementia". The New England Journal of Medicine. 349 (16): 1535–1542. doi:10.1056/NEJMra022435. PMID 14561797.
- Reilly J, Rodriguez AD, Lamy M, Neils-Strunjas J (2010). "Cognition, language, and clinical pathological features of non-Alzheimer's dementias: an overview". Journal of Communication Disorders. 43 (5): 438–452. doi:10.1016/j.jcomdis.2010.04.011. PMC 2922444. PMID 20493496.
- Rohrer JD, Knight WD, Warren JE, Fox NC, Rossor MN, Warren JD (January 2008). "Word-finding difficulty: a clinical analysis of the progressive aphasias". Brain. 131 (Pt 1): 8–38. doi:10.1093/brain/awm251. PMC 2373641. PMID 17947337.