[Higher Brain Dysfunction Caused by Left Frontal Brain Retraction Injury and Infarction of the Left Genu of the Internal Capsule and Anterior Thalamus: A Case Report of Transient Gerstmann Syndrome Due to Multifocal Lesions].

Abstract

We herein report a case of subarachnoid hemorrhage caused by the rupture of a cerebral aneurysm that was treated by clipping surgery. The patient was a right-handed woman in her 40s who presented with attention disorder and transient Gerstmann syndrome, including left-right disorientation, finger agnosia, acalculia, and agraphia, associated with brain retraction injury in the left inferior frontal gyrus and perforating branch infarction of the horizontal segment of the left anterior cerebral artery. Diffusion tensor tractography was performed to investigate the underlying pathophysiological mechanism of transient Gerstmann syndrome. White matter fibers connecting the frontal lobe to the other lobes such as the left superior longitudinal fasciculus/arcuate fasciculus (SLF/AF), inferior fronto-occipital fasciculus (IFOF), and uncinate fasciculus were compressed by vasogenic and cytotoxic edema without evidence of disconnection. The left thalamic-prefrontal peduncle (TPP), connecting the thalamus and inferior frontal gyrus, was not visualized, whereas left parietal angular-to-supramarginal U-fibers were preserved. These findings suggested that connectional diaschisis involving SLF/AF and IFOF, together with TPP damage, contributed to the development of transient Gerstmann syndrome. Early clinical improvement was expected due to the preservation of multiple association fibers from the frontal lobe to the other lobes without definite disconnection. (Received February 20, 2026; Accepted June 30, 2026; Published October 1, 2026).