Anomic primary progressive aphasia with kanji-predominant dyslexia and dysgraphia

Reading and writing impairments in primary progressive aphasia (PPA) have received relatively limited attention both globally and in the Japanese context. Although several Japanese patients with anomic aphasia and kanji-predominant dysgraphia have been reported, kanji-predominant dyslexia at a relatively early stage has not been described. We report a case of anomic PPA presenting with kanji-predominant dyslexia and dysgraphia. A 69-year-old right-handed woman first noted word-finding difficulty at age 67 and subsequently developed reading difficulty. Examination revealed anomic aphasia with kanji-predominant dyslexia and dysgraphia. Reading errors occurred mainly with kanji irregular words. Kana word reading and writing were preserved, with reduced performance only in kana non-word reading. Reading sentences consisting of mixed kanji and kana revealed deficits in oral reading and comprehension. Visuospatial function remained intact. Cerebrospinal fluid biomarkers were compatible with Alzheimer's disease pathology. ¹²³I-iodoamphetamine single-photon emission computed tomography demonstrated hypoperfusion in the left inferior temporal region, most prominently in the middle to posterior fusiform gyrus. In contrast, five control patients with anomia and kanji dysgraphia, but without dyslexia, showed hypoperfusion confined to the left lateral temporal cortex, sparing the fusiform gyrus. These findings indicate that dysfunction of the left fusiform gyrus may contribute to the kanji-predominant dyslexia. Further studies are needed to better characterize script-specific deficits across languages and related brain regions in neurodegenerative language disorders.