A 75-year-old man was admitted because of a sudden onset of a right lateral homonymous hemianopia. He had an 11-year history of a slowly worsening hyposmia. The results of serial otorhinological evaluations had always been normal, and there was no history of skull trauma.
On admission, the patient's neurological examination showed a right lateral superior homonymous quadrantanopia and confirmed a bilateral anosmia (olfactometry). Two days later, a computed tomographic scan (Figure 1) revealed an ischemic lesion in the left inferior calcarine region and showed a big frontal interemispheric hyperdense mass measuring 45 × 35 × 45 mm, with an anteroposterior largest diameter. The lesion was peripherally calcificated and provoked an important straddle of ventricular frontal horns, posteriorly pressing against the terminal plate, anterosuperiorly touching the falx cerebri, and inferiorly leaning against the cribriform plate of the ethmoid bone. Cerebral magnetic resonance imaging (Figure 2) followed by magnetic resonance angiography (Figure 3) disclosed a completely patent giant saccular aneurysm of the anterior communicating artery (ACA) and clearly showed the close relationship with the ethmoid plate and the third ventricle and a dislocation of corpus callosum. Cerebral angiography and partial resection of the aneurysm were suggested to the patient, but he refused both. After 8 months, the results of his clinical examination and cerebral magnetic imaging were unchanged.
Manconi M, Paolino E, Casetta I, Granieri E. Anosmia in a Giant Anterior Communicating Artery Aneurysm. Arch Neurol. 2001;58(9):1474-1475. doi:10.1001/archneur.58.9.1474