Progressive nonfluent aphasia explained

See main article: Aphasia and Primary progressive 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.^[1]

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:^[2]

• Hesitant, effortful speech
• Apraxia of speech
• Stutter (including return of a childhood stutter)
• Anomic aphasia (word retrieval failures)
• 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.^[3] 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)^{[4] [5]} included patients with progressive nonfluent (aphasia, semantic dementia, and logopenic progressive aphasia.^{[6] [7] [8]}

Management

No cure or treatment for this condition has been found. Supportive management is helpful.^[9]

See also

• Alzheimer's disease
• Corticobasal degeneration
• Pick's disease

Further reading

• Gliebus G . Primary progressive aphasia: clinical, imaging, and neuropathological findings . American Journal of Alzheimer's Disease and Other Dementias . 25 . 2 . 125–127 . March 2010 . 20124255 . 10.1177/1533317509356691 . 29195502 . 10845457 .
• Gorno-Tempini ML, Dronkers NF, Rankin KP, Ogar JM, Phengrasamy L, Rosen HJ, Johnson JK, Weiner MW, Miller BL . 6 . Cognition and anatomy in three variants of primary progressive aphasia . Annals of Neurology . 55 . 3 . 335–346 . March 2004 . 14991811 . 2362399 . 10.1002/ana.10825 .
• Henry ML, Gorno-Tempini ML . The logopenic variant of primary progressive aphasia . Current Opinion in Neurology . 23 . 6 . 633–637 . December 2010 . 20852419 . 3201824 . 10.1097/WCO.0b013e32833fb93e .
• Mesulam MM . Primary progressive aphasia--a language-based dementia . The New England Journal of Medicine . 349 . 16 . 1535–1542 . October 2003 . 14561797 . 10.1056/NEJMra022435 .
• Reilly J, Rodriguez AD, Lamy M, Neils-Strunjas J . Cognition, language, and clinical pathological features of non-Alzheimer's dementias: an overview . Journal of Communication Disorders . 43 . 5 . 438–452 . 2010 . 20493496 . 2922444 . 10.1016/j.jcomdis.2010.04.011 .
• Rohrer JD, Knight WD, Warren JE, Fox NC, Rossor MN, Warren JD . Word-finding difficulty: a clinical analysis of the progressive aphasias . Brain . 131 . Pt 1 . 8–38 . January 2008 . 17947337 . 2373641 . 10.1093/brain/awm251 . Martin Rossor .

Notes and References

1. Book: M. Hunter Manasco . Introduction to Neurogenic Communication Disorders . 86–88 . 2014. Elsevier Health Sciences . 9780323290920 .
2. Gorno-Tempini ML, Hillis AE, Weintraub S, Kertesz A, Mendez M, Cappa SF, Ogar JM, Rohrer JD, Black S, Boeve BF, Manes F, Dronkers NF, Vandenberghe R, Rascovsky K, Patterson K, Miller BL, Knopman DS, Hodges JR, Mesulam MM, Grossman M . 6 . Classification of primary progressive aphasia and its variants . Neurology . 76 . 11 . 1006–1014 . March 2011 . 21325651 . 3059138 . 10.1212/WNL.0b013e31821103e6 .
3. Schroeter ML, Raczka K, Neumann J, Yves von Cramon D . Towards a nosology for frontotemporal lobar degenerations-a meta-analysis involving 267 subjects . NeuroImage . 36 . 3 . 497–510 . July 2007 . 17478101 . 10.1016/j.neuroimage.2007.03.024 . 130161 .
4. Mesulam MM . Slowly progressive aphasia without generalized dementia . Annals of Neurology . 11 . 6 . 592–598 . June 1982 . 7114808 . 10.1002/ana.410110607 . 29107525 .
5. Mesulam MM . Primary progressive aphasia . Annals of Neurology . 49 . 4 . 425–432 . April 2001 . 11310619 . 10.1002/ana.91 . 35528862 .
6. Gorno-Tempini ML, Hillis AE, Weintraub S, Kertesz A, Mendez M, Cappa SF, Ogar JM, Rohrer JD, Black S, Boeve BF, Manes F, Dronkers NF, Vandenberghe R, Rascovsky K, Patterson K, Miller BL, Knopman DS, Hodges JR, Mesulam MM, Grossman M . 6 . Classification of primary progressive aphasia and its variants . Neurology . 76 . 11 . 1006–1014 . March 2011 . 21325651 . 3059138 . 10.1212/WNL.0b013e31821103e6 .
7. Bonner MF, Ash S, Grossman M . The new classification of primary progressive aphasia into semantic, logopenic, or nonfluent/agrammatic variants . Current Neurology and Neuroscience Reports . 10 . 6 . 484–490 . November 2010 . 20809401 . 2963791 . 10.1007/s11910-010-0140-4 .
8. Harciarek M, Kertesz A . Primary progressive aphasias and their contribution to the contemporary knowledge about the brain-language relationship . Neuropsychology Review . 21 . 3 . 271–287 . September 2011 . 21809067 . 3158975 . 10.1007/s11065-011-9175-9 .
9. Tippett . Donna C. . Hillis . Argye E. . Tsapkini . Kyrana . 2015 . Treatment of Primary Progressive Aphasia . Current Treatment Options in Neurology . en . 17 . 8 . 362 . 10.1007/s11940-015-0362-5 . 1092-8480 . 4600091 . 26062526.