Middle cerebral artery fenestration in patients with cerebral ischemia

Background: We report five cases of middle cerebral artery (MCA) fenestration that might have caused cerebral infarction or ischemia. Case report: Unilateral fenestration of the MCA was observed in five patients with artery-relevant cerebral infarction or ischemia. Enhanced magnetic resonance imaging (MRI) and three-dimensional MR angiography (MRA) were performed in the patients, and a division of the lumen after fenestration was observed using virtual arterial endoscopy. In one patient, MRA and virtual endoscopy showed an obstruction in one limb of the fenestration. The MCA fenestrations were observed in the proximal portion in three cases and the intermediate portion in two cases, and there was no associated aneurysm near or far from the fenestration. Methods: The five patients underwent both contrast-enhanced magnetic resonance imaging (MRI) and 3D MRA. Virtual arterial endoscopy was then performed to visualize the division of the lumen, a landmark of fenestration. Conclusions: The association between cerebral ischemia and MCA fenestration in the five cases suggests that the fenestration disturbing local flow hemodynamics seems to cause cerebral ischemia, even a direct causative relationship should be elucidated further.