Contrecoup Injury-Induced Middle Meningeal Arteriovenous Fistula Detected by Time-of-Flight Magnetic Resonance Angiography and Magnetic Resonance Arterial Spin Labeling: Case Report and Review of the Literature

Background Middle meningeal arteriovenous fistula (MM-AVF) is rare; however, it will sometimes be followed by intracranial hemorrhage or progressive symptoms caused by abnormal shunt flow. Radiological examination and endovascular treatment of this condition have recently advanced; thus, we have described the pathogenesis, clinical features, and appropriate diagnostic and therapeutic management of MM-AVF. We also reviewed the reported data of the past 35 years, including 30 cases of MM-AVF. Case Description We report the case of 24-year-old man who had presented with right tinnitus who had experienced previous head trauma on the opposite side to the tinnitus ear. Time-of-flight magnetic resonance angiography and magnetic resonance arterial spin labeling findings were suggestive of MM-AVF, and catheter angiography confirmed MM-AVF with shunt flow draining into the cavernous sinus. Endovascular transarterial embolization was performed, and the MM-AVF was embolized successfully using detachable coils and n-butyl-2-cyanoacrylate. The tinnitus disappeared completely immediately after the treatment. Conclusions MM-AVF is caused, not only by coup injury, but also by contrecoup injury. Time-of-flight magnetic resonance angiography and magnetic resonance arterial spin labeling are useful for detecting MM-AVF. Endovascular transarterial embolization is an effective and safe treatment.