The Japanese journal of neuropsychology

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ArticleTitle	Primary progressive aphasia: changes in 10 years since 2011 diagnostic criteria
Language	J
AuthorList	Nanayo Ogawa^1)～3), Kyoko Suzuki¹⁾
Affiliation	¹⁾Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University Graduate School of Medicine ²⁾Department of Psychiatry, Nagoya University Hospital ³⁾Department of Rehabilitation, Kasugai City Hospital
Publication	Japanese Journal of Neuropsychology: 37 (4), 238-250, 2021
Received
Accepted
Abstract	Ten years ago, the international consensus criteria for primary progressive aphasia (PPA) were proposed by Gorno-Tempini et al. (2011), establishing both diagnosis and classification criteria for nonfluent and agrammatic variant (nfvPPA), semantic variant PPA (svPPA), and logopenic variant PPA (lvPPA). These guidelines boosted interest in the PPA field, and over 1,200 studies have been published in English language during the past decade. Some problems of the current diagnostic criteria include lvPPA being defined as neither svPPA nor nfvPPA, and PPA patients not matching the classification criteria of any variant. The diagnostic features of each PPA variant do not fully reflect the complexity of language alterations, resulting in PPA patients with either unclassifiable or mixed PPA type. We suggest three new advancements on PPA variant classification. First, primary progressive apraxia of speech (PPAOS) is differentiated from nfvPPA, when only apraxia of speech manifests as an isolated symptom for several years (Josephs et al. 2012). Second, progressive word deafness with speech disorders (Matsuda 2019) is a new variant of PPA, which is characterized by word deafness and speech disorders including anarthria, dysprosody, and foreign accent syndrome. Finally, we outline subtypes of lvPPA based on language features or etiology, thereby reducing the ambiguity of lvPPA diagnosis. Research on PPA pathology and genetics has significantly advanced during the past decade. Etiologies of the three variants have been associated with different pathological processes. There are strong relationships between svPPA and the transactive-response DNA binding protein 43 kDa (TDP-43) Type C and between lvPPA and Alzheimer's disease (AD) pathology; however the neuropathological profile of nfvPPA is heterogeneous. More than 50% of nfvPPA patients have tauopathy. PPA is usually sporadic, but it may have an underlying genetic basis in some cases. Long-term follow-up studies will provide valuable insights into the etiology and prognosis of PPA progression.
Keywords	primary progressive aphasia (PPA), progressive nonfluent aphasia (nonfluent/agrammatic variant PPA, nfvPPA), semantic dementia (semantic variant PPA, svPPA), logopenic progressive aphasia (logopenic variant PPA, lvPPA), primary progressive apraxia of speech (PPAOS)