Connectivity changes underlying recovery from pure alexia: a Korean single-case study.

Abstract

Pure alexia (PA) is an isolated reading impairment following brain damage, yet the mechanisms underlying reading recovery remain unclear. We present a Korean patient with PA following a posterior cerebral artery infarction who showed severe impairment in Hangul reading despite preserved writing and spoken language, with substantial recovery of sentence-level reading within six months. Structural and functional connectivity were investigated using diffusion tensor tractography (DTT) and functional connectivity (FC) analyses. DTT revealed degeneration of affected white matter tracts, including the forceps major, inferior longitudinal fasciculus and inferior fronto-occipital fasciculus. Interhemispheric FC was significantly lower than that of healthy controls (HCs) across perilesional regions. In contrast, FC between the left angular gyrus and perilesional regions differed significantly from HCs at specific follow-up time points during behavioral recovery. These findings suggest that functional reorganization of distributed reading networks may support behavioral recovery despite persistent structural disconnection.