Spontaneous subdural hematoma concomitant with subarachnoid hemorrhage and intracerebral hemorrhage due to ruptured brain arteriovenous malformation treated with curative embolization

INTRODUCTION: An arteriovenous malformation (AVM) consists of a tangled cluster of dilated blood vessels forming anomalous communication between arterial and venous systems without capillary bridging. The most likely manifestations of a ruptured AVM are intracerebral hemorrhage (ICH), subarachnoid hemorrhage (SAH), or intraventricular hemorrhage (IVH). Subdural hematoma (SDH) is exceptional in cases of ruptured brain arteriovenous malformation (BAVM). CASE REPORT: A 30-year-old female was referred to the Emergency Room with a major complaint of sudden thunderclap headache 1 day before admission. The patient also complained of double vision and left ptosis that lasted for 1 day. There was no other complaint or history of hypertension, diabetes, or trauma. Non-contrast head computed tomography (CT) showed ICH-SAH-SDH on the left side of the brain which was not typical of a hypertensive pattern. The secondary ICH has a score of 6, indicating that 100% of the bleeding might be caused by underlying vascular malformation. Furthermore, cerebral angiography showed cortical plexiform BAVM on the left occipital lobe, and the patient underwent curative embolization. DISCUSSION: Spontaneous SDH is very rare, and there are some hypotheses about the reasons for its occurrence. First, brain movement stretches the arachnoid layer that adheres to the AVM, resulting in direct bleeding into subdural space. Second, high-flow pia-arachnoid ruptured blood might extravasate into subdural space. Finally, the ruptured cortical artery that connects the cortex and dura layer (bridging artery) might also cause SDH. Some scoring systems are useful in BAVM, and this study selected endovascular embolization for the patient. CONCLUSION: Brain AVM rupture usually causes ICH, SAH, or IVH. Clinicians must be more aware of spontaneous SDH because it might be caused by a vascular malformation, although it is rare.