Abstract A 51-year-old woman developed profound coma complicating subarachnoid hemorrhage after aneurysmal rupture. An external ventricular drain was inserted. FDG PET/CT was performed for prognostication purposes and showed global cortical hypometabolism. This was consistent with the clinical findings of an unresponsive wakefulness syndrome. During the follow-up, ventriculitis was diagnosed. Because of no clinical improvement under focused, high-dose antimicrobial treatment, a second FDG PET/CT was performed. It showed an improved diffuse cortical fixation and an intense intraventricular hyperfixation, suggestive of intraventricular abscess. A third functional imaging, performed to monitor treatment, showed progressive metabolic recovery with especially uptake in frontoparietal areas over time.