Olfactory dysfunction after ipsilateral and contralateral pterional approaches for cerebral aneurysms.

OBJECTIVE: This study investigated olfactory dysfunction after using a contralateral or ipsilateral pterional approach for anterior circulation aneurysms and related risk factors.

METHODS: This study included 189 patients who experienced an aneurysmal subarachnoid hemorrhage and in whom a pterional approach was used, including a contralateral pterional approach (12 patients), a pterional approach for an anterior communicating artery (AComA) aneurysm (70 patients), and an ipsilateral pterional approach for aneurysms of the anterior circulation, excluding the AComA (107 patients). In addition to questionnaires on olfactory function, Sniffin' Sticks tests were performed 12 to 38 months after the operation.

RESULTS: The incidence of olfactory dysfunction was high: 58% (7 of 12) with a contralateral pterional approach, 14% (10 of 70) with a pterional approach for an AComA aneurysm, and 4% (4 of 107) with an ipsilateral pterional approach for aneurysms of the anterior circulation, except for the AComA. In addition, patients 55 years and older had a higher incidence of olfactory dysfunction. Among the 12 patients in whom the contralateral pterional approach was used, 5 (42%) were anosmic and 2 (17%) were hyposmic. The incidence of olfactory dysfunction was also significantly higher at ages 55 years and older. The size and location of the contralateral aneurysm, if small (<1 cm) and located within a 3-cm lateral distance from the midline, were not found to influence the incidence.

CONCLUSION: A higher incidence of olfactory dysfunction was found in those patients in whom a contralateral pterional approach and a pterional approach for an AComA aneurysm were used. Another major risk factor was an age of 55 years and older.