Non-fluent/Agrammatic Variant of Primary Progressive Aphasia With Generalized Auditory Agnosia

Case Report: Semantic Variant Primary Progressive Aphasia With Impaired Verbal Word Discrimination

“…Several studies have reported that most of the patients with PPA complicated with impaired verbal sound recognition eventually demonstrate apraxia of speech, suggesting nfvPPA ( 6 – 8 , 10 – 12 , 31 – 37 ). In addition, some of them demonstrated behavioral disorders and were considered to have frontotemporal dementia ( 6 – 8 , 10 , 32 , 38 ).…”

“…In addition, the case of lvPPA with pure word deafness ( 9 ) had cortical thinning in bilateral Heschl's gyri, PT, and superior temporal sulcus (STS), compared with healthy controls. The case of nfvPPA with auditory agnosia had hypoperfusion mainly in the left superior temporal and inferior frontal gyri ( 12 ). A recent study using activation likelihood estimation meta-analysis of 23 fMRI experiments identified significant activation likelihoods in the left mid-posterior STS with phonetic and phonological processes ( 43 ).…”

“…We performed ROI-based analyses for gray matter volumes using the computational anatomy toolbox (CAT12, http://www.neuro.uni-jena.de/cat/ ) for SPM ( 26 ). The ROIs were defined based on the previous studies that have reported lesions that were associated with the manifestation of word deafness or auditory agnosia ( 12 – 16 , 27 – 29 ). These ROIs were as follows: (i) left and right STG; (ii) left and right PT; (iii) left and right Heschl's gyri; (iv) left and right angular gyri; and (v) left and right SMG.…”

“…However, several patients do not meet the diagnostic criteria for PPA, which suggests the existence of atypical PPA ( 2 – 5 ). The previous studies have reported that some patients with PPA present with impaired recognition of auditory stimuli, including progressive word deafness ( 6 – 10 ), auditory agnosia in its broader sense ( 6 – 8 , 11 , 12 ), and pure auditory agnosia restricted to non-verbal sounds ( 13 ).…”

Primary progressive aphasia: six questions in search of an answer

“…lvPPA is particularly associated with impaired perception of phonemes [ 71 , 78 ], while performance on hearing tasks more generally is modulated by auditory working memory capacity [ 70 ]. Atypical PPA presentations with prominent auditory impairments have also been identified, including progressive phonagnosia [ 79 , 80 ], progressive word deafness (disproportionately impaired comprehension of spoken versus written words) [ 1 , 81 – 83 ], and generalised auditory agnosia [ 84 ]. Taken together, these diverse non-linguistic auditory deficits suggest that PPA syndromes might be best characterised as pervasive ‘communication’ disorders: language output deficits in all three major PPA syndromes are likely to be influenced by disordered complex sound processing.…”