Transient Ischemic Attack Due to Unruptured Basilar Artery Aneurysm

Area of Science:

• Neurology
• Vascular Neurology
• Neuroimaging

Background:

• Unruptured intracranial aneurysms (UIAs) are typically asymptomatic and rarely cause ischemic events.
• Transient ischemic attacks (TIAs) or strokes from UIAs can occur through parent vessel thrombosis, emboli, or arterial compression.
• The vertebrobasilar system is particularly prone to poor outcomes with fusiform aneurysms.

Observation:

• An elderly male with hypertension presented with transient right-sided weakness and altered sensorium, recovering fully within hours.
• Brain imaging revealed a dilated, tortuous basilar artery suggestive of an aneurysm compressing the brainstem.
• Cerebral angiography confirmed a partially thrombosed fusiform aneurysm of the left vertebral and basilar arteries.

Findings:

• The patient experienced a TIA, likely due to aneurysm-induced brainstem compression, a rare mechanism.
• Multiple lacunar infarcts in the posterior circulation were noted, potentially from emboli originating from the aneurysm's thrombus.
• Given the patient's frailty and aneurysm characteristics, surgical intervention was deemed too risky.

Implications:

• UIAs, particularly in the vertebrobasilar system, should be considered in the differential diagnosis of TIAs in elderly patients.
• Medical management with antiplatelets is a viable and recommended treatment strategy for high-risk surgical candidates.
• Comprehensive vascular imaging is crucial for diagnosing UIAs presenting with ischemic symptoms.