Resolution of diminished olfactory sensation after treatment of bilateral ophthalmic segment aneurysms with flow diversion: Case report

Background and importance: Olfactory tract dysfunction due to an unruptured intracranial aneurysm is rare. We present a case in which a patient with impaired olfaction related to bilateral internal carotid artery aneurysms experienced subjective and quantitative objective improvement of olfactory sensation after treatment of ophthalmic segment aneurysms with flow diversion. Clinical presentation: A 44-year-old woman presented with hyposmia and bilateral ophthalmic segment internal carotid artery aneurysms. The symptom of hyposmia, worsening over a period of several months, was suspected to be due to mass effect from bilateral unruptured ophthalmic segment aneurysms pressing on the olfactory tracts. Each aneurysm was treated with a Pipeline embolization device (PED). Follow-up angiography at 5 months showed occlusion of both aneurysms. The patient experienced subjective improvement in olfaction and complete objective resolution of her hyposmia as measured by the validated University of Pennsylvania Smell Identification Test (UPSIT). Conclusion: Intracranial aneurysms causing dysfunction of olfactory sensation due to mass effect upon the olfactory tract can be successfully treated with flow diversion. Flow diversion should be considered as one of the treatment options for patients with cranial nerve dysfunction due to unruptured intracranial aneurysms.