Background: MCA has several anomalies, such as accessory MCA, duplicated MCA and twig-like MCA, up to now all these reported anomalies were hypothesized to due to the failure in fusion of the primitive arterial network. No anomaly of over fused MCA has been reported.
Case presentation: A 59- year- old male was hospitalized with a history of paroxysmal slurred speech and left side headache for a week, his blood pressure was 160/80 mmHg and he manifested mild incomplete motor aphasia at the time of admission. The head and neck CTA and DSA all presented a huge and tortuous left MCA, we diagnosed it an anomaly and termed it over-fused MCA. The patient's speech impairment and headache were relieved by controlling his blood pressure.
Conclusions: Such an anomaly of over-fused MCA is reported for the first time, it's not needed to put special intervention on the anomaly of the patient temporarily, but more observation are needed.
Keywords: Anomaly; Case report; Middle cerebral artery; Over-fused MCA.