Abstract WP493: Post-Stroke Chinese Pure Alexia: Prominent Shape-Similar Errors and Associated Neuropsychological Profiles

Objective: To describe the characteristics of post-stroke Chinese pure alexia and associated neuropsychological profiles. Methods: All patients with post-stroke pure alexia from the neurology department of our hospital were enrolled from June 2018 to July 2019. Brain MRI was performed to evaluate the stroke radiologically. The Aphasia Battery of Chinese (ABC) was used to evaluate the general language functions. A Chinese individual character reading test including 68 commonly used characters was used to evaluate the ability to read individual Chinese characters. The numbers of correct reading and misreading were recorded, and the error types of misreading were analyzed. MMSE, auditory verbal learning test, cube copying task, clock drawing test, and picture copying tests were performed to evaluate other cognitive impairments. Results: A total of 5 male patients were included, with a median age of 58 years (50-64 years). They all had Chinese pure alexia with intact verbal comprehension and speech and relatively preserved writing skills. The etiologies were all acute infarction involving the left temporo-parietal lobe and splenium of corpus callosum. In the Chinese individual character reading test, the median number of correct reading was 21 (18-44) out of 68 characters, with many shape-similar errors (one character was read as another one with a similar shape but different meaning and pronunciation). The percentage of shape-similar errors among all type errors was 81.5%, 60.0%, 23.7%, 18.5%, and 57.9% respectively, and 43.1% overall, much higher than other type errors. All the patients had obvious impairment in memory and visuospatial function with an exception that one patient had relatively preserved visuospatial ability. Conclusion: Shape-similar error is a remarkable feature of Chinese pure alexia. Chinese pure alexia is associated with impaired visuospatial function, but visuospatial dysfunction is not necessary for the development of Chinese pure alexia.