Progressive nonfluent aphasia (PNFA) is one of three clinical syndromes associated with

frontotemporal lobar degeneration Frontotemporal lobar degeneration (FTLD) is a pathological process that occurs in frontotemporal dementia. It is characterized by atrophy in the frontal lobe and temporal lobe of the brain, with sparing of the parietal and occipital lobes. Com ...

. 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 lobe The temporal lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The temporal lobe is located beneath the lateral fissure on both cerebral hemispheres of the mammalian brain. The temporal lobe is involved in pr ...

s in PNFA creates hallmark language deficits differentiating this disorder from other

Alzheimer Alzheimer's disease (AD) is a neurodegenerative disease and the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in remembering recent events. As the disease advances, symptoms can include problems wit ...

-type disorders by the initial absence of other cognitive and memory deficits. This disorder commonly has a primary effect on the

left hemisphere The lateralization of brain function (or hemispheric dominance/ lateralization) is the tendency for some neural functions or cognitive processes to be specialized to one side of the brain or the other. The median longitudinal fissure separates ...

, 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 Stuttering, also known as stammering, is a speech disorder characterized externally by involuntary repetitions and prolongations of sounds, syllables, words, or phrases as well as involuntary silent pauses called blocks in which the person who ...

(including return of a childhood stutter) *

Anomic aphasia Anomic aphasia, also known as dysnomia, nominal aphasia, and amnesic aphasia, is a mild, fluent type of aphasia where individuals have word retrieval failures and cannot express the words they want to say (particularly nouns and verbs). By cont ...

(word retrieval failures) * Phonemic

paraphasia Paraphasia is a type of language output error commonly associated with aphasia and characterized by the production of unintended syllables, words, or phrases during the effort to speak. Paraphasic errors are most common in patients with fluent for ...

(sound errors in speech e.g. 'gat' for 'cat') *

Agrammatism Agrammatism is a characteristic of non-fluent aphasia. Individuals with agrammatism present with speech that is characterized by containing mainly content words, with a lack of function words. For example, when asked to describe a picture of ch ...

(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 Frontotemporal dementia (FTD), also called frontotemporal degeneration disease or frontotemporal neurocognitive disorder, encompasses several types of dementia involving the progressive degeneration of the brain's frontal lobe, frontal and tempor ...

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 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 In neurology, semantic dementia (SD), also known as semantic variant primary progressive aphasia (svPPA), is a progressive neurodegenerative disorder characterized by loss of semantic memory in both the verbal and non-verbal domains. However, t ...

, and

logopenic progressive aphasia Logopenic progressive aphasia (LPA) is a variant of primary progressive aphasia. It is defined clinically by impairments in naming and sentence repetition. It is similar to conduction aphasia and is associated with atrophy to the left posterior ...

Management

No cure or treatment for this condition has been found. Supportive management is helpful.

Presentation

Diagnosis

Classification

Management

See also

References

Further reading