Unidirectional olfactory hallucination associated with ipsilateral unruptured intracranial aneurysm

Purpose: We describe a patient with complex partial seizure with unidirecti onal olfactory aura associated with ipsilateral unruptured aneurysm. Methods and Results: The patient felt a sweet pleasant smell coming from be hind her light side every time before the attack. Cranial magnetic resonanc e imaging (MRI) and three-dimensional computed tomography (CT) angiography revealed a large aneurysm at the bifurcation of the right middle cerebral a rtery and compression of the right orbitofrontal cortex. Small spikes were recorded from the right orbitofrontal and superior temporal gyri and from t he uncus by the cortical electrodes during clipping of the aneurysm. Conclusions: The orbitofrontal cortex may have a function related to the ip silateral directional olfactory sensation.