Primary progressive aphasia: A dementia of the language network

Abstract

Primary progressive aphasia (PPA) is a clinical syndrome diagnosed when three core criteria are met. First, there should be a language impairment (i.e., aphasia) that interferes with the usage or comprehension of words. Second, the neurological work-up should determine that the disease is neurodegenerative, and therefore progressive. Third, the aphasia should arise in relative isolation, without equivalent deficits of comportment or episodic memory. The language impairment can be fluent or non-fluent and may or may not interfere with word comprehension. Memory for recent events is preserved although memory scores obtained in verbally mediated tests may be abnormal. Minor changes in personality and behavior may be present but are not the leading factors that bring the patient to medical attention or that limit daily living activities. This distinctive clinical pattern is most conspicuous in the initial stages of the disease, and reflects a relatively selective atrophy of the language network, usually located in the left hemisphere. There are different clinical variants of PPA, each with a characteristic pattern of atrophy. The underlying neuropathological diseases are heterogeneous and can include Alzheimer’s disease as well as frontotemporal lobar degeneration. The clinician’s task is to recognize PPA and differentiate it from other neurodegenerative phenotypes, use biomarkers to surmise the nature of the underlying neuropathology, and institute the most fitting multimodal interventions.

Syndromes dominated by apraxia of speech show distinct characteristics from agrammatic PPA

“…3,4 Unlike PPAOS, the term primary progressive aphasia (PPA) is reserved for a neurodegenerative disorder in which the most salient feature is language dysfunction. [5][6][7] Agrammatic PPA (agPPA) is one subtype of PPA, characterized by specific abnormalities that affect grammar and syntax in verbal or written expression. 8,9 Although it is recognized that many subjects with agPPA may have AOS, the most salient feature of agPPA is aphasia.…”

“…In fact, to be diagnosed with any variant of PPA, 8 language difficulty must be the most prominent clinical feature at symptom onset and for the initial phases of the disease; deficits cannot be due to "disruption of the formation of words." 7 Over the past 2½ years, we have encountered subjects with AOS and agrammatic aphasia in whom AOS is the dominant feature. Such cases are difficult to classify.…”

Naming vs knowing faces in primary progressive aphasia

“…PPA is a predominantly young-onset clinical dementia characterized by selective language disruption and relative preservation of other cognitive abilities during the initial disease stages. 1 Atrophy in PPA is initially asymmetrically concentrated within the language-dominant (usually left) hemisphere but eventually extends to adjacent and contralateral areas with individual variations from patient to patient. Although the most severe face identification impairments in PPA are encountered in its semantic subtype, this study included all subtypes, thereby providing a subject group with a spectrum of deficits and atrophy sites so that the anatomical substrates of face naming and recognition deficits could be explored more objectively.…”

A fluência na afasia progressiva primária logopênica

“…Primary Progressive Aphasia (PPA) is characterized by progressive deterioration of language through gradual atrophy, which can remain isolated from language for up to ten years (1) . PPA is considered part of a group of rare neurodegenerative diseases, including frontotemporal dementia that appears in individuals aged between 45 and 70.…”

“…PPA is considered part of a group of rare neurodegenerative diseases, including frontotemporal dementia that appears in individuals aged between 45 and 70. Although Progressive Aphasia subtypes were described more than 100 years ago, in the cases studied by Pick, Sérieux, Dejerine, Franceschi, and Rosenfeld (1,2) , it was not until the 1980s that more systematic studies started being conducted on the subject.…”