Fig 3.

A 45-year-old who man presented with a ruptured aneurysm of the anterior communicating artery. Surgical clipping of the aneurysm was performed the day of onset (patient 4). Neuropsychological examination 3 months after the rupture confirmed amnesia. The imaging anatomy of the basal forebrain is detailed in On-line Fig 2: paramedian sagittal (A), coronal (B), and axial (C) and its next superior section (D), volumetric isotropic turbo spin-echo acquisition of T2WI (T2WI-VISTA) images shows infarcted foci in the midline (light blue arrows) and paramedian parts (dashed light blue arrows) of the anterior commissure along with the pars libera (red arrows) and pars tecta (dashed red arrows, C) of the columns of the fornices. Note that on coronal (B) and axial (C) images, infarcted foci in the bilateral anterior commissure show a characteristic bow-tie-like appearance and are associated with the infarcted foci in the adjoining bilateral pars libera and pars tecta of the column of the fornix. Other than the columns of the fornix and anterior commissure, no other regions are involved in the basal forebrain. The orbitofrontal region and temporal tip on the left were also involved, presumably damaged by the surgical procedure of the aneurysmal clipping (not shown).