This patient should be counseled about smoking cessation and provided with smoking cessation aids as appropriate, including nicotine replacement or pharmacologic treatment. She has an unruptured intracranial aneurysm of the left middle cerebral artery. A subarachnoid hemorrhage (SAH) has been ruled out by neuroimaging and lumbar puncture findings. She has no history of a previous SAH, and the aneurysm measures less than 7 mm, both of which indicate a low risk of rupture. The major risk factors for cerebral aneurysms and their rupture are hypertension and tobacco use. Her hypertension is well controlled by the amlodipine. Smoking cessation is indicated to prevent further aneurysmal expansion and rupture.

Neither aneurysmal clipping nor endovascular coiling is necessary because the aneurysm is less than 12 mm and located in the anterior circulation, which suggests a low risk of rupture (0.05% annually). The surgical morbidity associated with either technique is too great given the low risk of rupture. Repeat neuroimaging on an annual basis can be considered to track any change in the aneurysm's size.

The calcium channel blocker nimodipine has been shown to improve outcomes in SAH and is the standard of care for all patients with aneurysmal SAH. SAH has been ruled out in this patient, whose blood pressure is well controlled by amlodipine. No evidence suggests that switching to nimodipine from amlodipine will prevent aneurysmal expansion or rupture.