Objective This study aimed to examine echolalia and its related symptoms and brain lesions in primary progressive aphasia (PPA). Methods Forty‐five patients with PPA were included: 19 nonfluent/agrammatic variant PPA (nfvPPA), 5 semantic variant PPA, 7 logopenic variant PPA, and 14 unclassified PPA patients. We detected echolalia in unstructured conversations. An evaluation of language function and the presence of parkinsonism, grasp reflex, imitation behaviour, and disinhibition were assessed. We also measured regional cerebral blood flow (rCBF) using single‐photon emission computed tomography. Results Echolalia was observed in 12 nfvPPA and 2 unclassified PPA patients. All patients showed mitigated echolalia. We compared nfvPPA patients with echolalia (echolalia group) to those without echolalia (non‐echolalia group). The median age of the echolalia group was significantly lower than that of the non‐echolalia group, and the echolalia group showed a significantly worse auditory comprehension performance than the non‐echolalia group. In contrast, the performance of repetition tasks was not different between the two groups. The prevalence of imitation behaviour in the echolalia group was significantly higher than that in the non‐echolalia group. The rCBFs in the bilateral pre‐supplementary motor area and bilateral middle cingulate cortex in the echolalia group were significantly lower than those in the non‐echolalia group. Conclusions These findings suggest that echolalia is characteristic of nfvPPA patients with impaired comprehension. Reduced inhibition of the medial frontal cortex with release activity of the anterior perisylvian area account for the emergence of echolalia.

Some patients with primary progressive aphasia (PPA) present with various types of hearing deficits. Research on the auditory function and speech sounds in PPA, including temporal, phonemic, and prosodic processing, revealed impairment in some of these auditory processes. Many patients with PPA who present with impaired word recognition subsequently developed non-fluent variant PPA. Herein, we present a patient with semantic variant PPA (svPPA) who demonstrated impaired verbal word discrimination. Audiological examinations revealed normal auditory brainstem responses and slightly impaired pure-tone perception. By contrast, verbal word discrimination and monosyllable identification were impaired, and temporal auditory acuity deteriorated. Analyses of brain magnetic resonance images revealed a significant decrease in the gray matter volume in bilateral superior temporal areas, predominantly on the left, compared with those of patients with typical svPPA, which appeared to be associated with impaired word recognition in our patient.