Language, cognitive and neuroimaging determinants of Primary Progressive Aphasia in Hebrew Speakers, a case series

Abstract

AbstractBackgroundPrimary progressive aphasias (PPA) are a group of neurocognitive disorders caused by neurodegenerative diseases and defined by progressive deterioration of language capabilities. PPA are traditionally classified into three predominant variants: nonfluent‐agrammatic, semantic, and logopenic. Emerging studies suggest an individual’s spoken language impacts the clinical presentation of PPA variants, potentially leading to misdiagnosis in languages underrepresented in research. We aimed at phenotyping PPA in native speakers of Hebrew, a Semitic language, with unique characteristics such as: under‐representation of vowels in the orthography, which makes it easier to detect various types of dyslexia, rich inflectional and derivational morphology, making it easier to identify morphosyntactic impairments, and, together with object case, making word order more flexible, enabling the examination of various syntactic deficits (e.g. in syntactic‐movement).MethodsFour native Hebrew speakers diagnosed with PPA (Mesulam 2001 criteria), aged 58‐68, complaint duration prior to assessment 10‐60 months, underwent assessment in Rabin Medical Center, Israel. Each participant underwent neurological evaluation, brain magnetic resonance imaging (MRI), and multi‐domain cognitive testing. Regional brain atrophy on T1 weighted MRI was rated with validated visual atrophy scales. All participants subsequently underwent Hebrew language evaluation using Norm‐referenced tests, assessing syntax, lexical retrieval, reading (including words and nonwords sensitive to various dyslexia types), semantic and conceptual abilities tasks, and phonology.ResultsParticipant’s presenting complaint was word finding difficulty (n = 3) and non‐fluent speech (n = 1). All participants exhibited deficits in the comprehension and production of syntactic movement including one participant with no other language deficits on formal testing and no brain atrophy. Three participants exhibited various dyslexias including morphological deficits,attentional dyslexia, vowel dyslexia, and surface dyslexia. As expected, poor scores on tests of lexical retrieval and syntax were observed in subjects with severe left anterior‐temporal and left fronto‐insular atrophy respectively.ConclusionTo our knowledge, this is the first case series of PPA in native Hebrew speakers. Errors in syntactic movement and various dyslexia types were common in all subjects suggesting they may be useful in early‐stage diagnosis. Full results (language, cognitive and neuroimaging), including additional eight cases will be presented in the AAIC conference.