A 45-year-old man was admitted for a progressively worsening headache over 2 weeks. He denied history of recent head trauma or anticoagulation and antiplatelet medication. General and neurologic examinations were not remarkable on admission. Routine laboratory investigations including coagulation profiles and platelet function were within normal limits. Head computed tomography (CT) on admission revealed an isodense CSDH on the right hemisphere with mild midline shift (Fig. a). A CT angiography (CTA) was performed to rule out any intracranial vascular malformation. A DAVF was noticed at the transverse sinus with dilated cortical venous drainage (Fig. b). So, a digital subtraction angiography (DSA) of the external carotid artery and DAVF embolization was planned.\nNo anomaly was noticed during selective angiography of the internal carotid and vertebral arteries and the left external carotid artery. Selective angiography of the right external carotid artery showed that the DAVF was located at the transverse sinus and fed by posterior branch of the middle meningeal artery (MMA), the occipital artery, and the posterior meningeal artery and drained to the occipital cortical veins with venous ectasia (Fig. a-b). The DAVF was classified as type IV according to the Cognard classification. The embolization was performed via the MMA. The Headway duo catheter was used and accessed to the DAVF, and Onyx was injected until the shunt disappeared (Fig. c-d). The patient experienced an uneventful recovery. His CSDH gradually resolved in 1 month (Fig. ). No neurologic deficit was noticed.\nA PubMed search of published studies written in English and Chinese was conducted on June 30th, 2017. The following key words were used in relevant combinations: dural arteriovenous fistula, dural arteriovenous malformation, subdural hematoma, subdural haematoma, subdural hemorrhage, and subdural haemorrhage. The reference lists of the identified articles were also manually searched for additional studies. Studies of which full text could not be obtained or those without sufficient individualized description of the isolated SDH cases mixed in larger case series were excluded.\nFinally, 13 articles containing 14 patients were identified [–]. In all 15 patients (9 females, 60%) including 1 case in our institution were included for the final interpretation (Table ). The inflicted patients were aged from 27 to 82 years (55.5 ± 8.6).Of note, 12 (80%) of the 15 patients were aged between 40 and 60 years of age, and 8 (53.3%) patients were between 50 and 60 years. Sides of the DAVF or SDH were obtained in 13 patients with 9 (69.2%) located at the left side and 4 at the right side. The intracranial locations of DAVF were anterior fossa (2), middle fossa (2), frontal region (2), parietal region (3), temporal region (2), and occipital region (2). The types of SDH were CSDH (7/15), acute SDH (ASDH) (7/15), and undefined SDH (1/15). Of the 12 patients feeding artery could be identified, MMA was the commonest feeding artery (8/12, 66.7%). Multiple feeding arteries were identified in 3 (25%) patients. The causes of DAVF were only defined in 3 patients (2 iatrogenic and 1 traumatic), with the rest undefined or not mentioned. Cognard classifications (Table ) of the DAVF were reported or deduced from the reports in 12 patients, with type I, type III, and type IV in 7, 2, and 3 patients respectively. The treatment strategies included hematoma evacuation (2/15), CSDH drainage and DAVF embolization (5/15), craniotomy and DAVF resection (3/15), DAVF embolization and hematoma evacuation (1/15), DAVF embolization (2/15), and not applicable or not mentioned (2/15). Of the 12 patients with direct description of outcome, 7 (58.3%) patients were neurological intact, 3 (25%) patients with neurological deficits, and 2 (16.7%) died.
A 77-year-old male with a recent syncope-related fall and closed head injury presented with gradually worsening isolated right upper extremity monoparesis. The fall occurred 1 month before presentation. On examination, the patient demonstrated 4/5 strength in his right upper extremity, with no additional neurologic deficits. Noncontrast head CT demonstrated bilateral mixed density convexity subdural hematomas [22 mm on the left and 14 mm on the right; and ]. The patient underwent a left craniotomy for evacuation of the larger hematoma, in conjunction with bilateral MMA embolization as primary treatment for the right convexity subdural hematoma in addition to limiting potential recurrence along the left convexity. Intraprocedural digital subtraction angiogram revealed two Cognard Grade III DAVFs, one arising from the parietal branch of the right MMA draining into an occipital cortical vein, and the second arising from the temporal branch of the left MMA draining into the vein of Labbe [-]. Given the presence of cortical venous reflux and associated risk of future intracranial hemorrhage, treatment of the fistulae was indicated. This was approached in two staged procedures. Following an uncomplicated left MMA embolization (frontoparietal branch), the incidental findings were discussed with the patient and he underwent a second stage embolization for the DAVF on a later date. During the second stage, a more prolonged infusion of liquid embolic was employed to ensure penetration into the recipient cortical venous outflow, resulting in nonopacification of the aforementioned fistulae. The postoperative course was complicated by seizures which resolved with uptitration in antiepileptic medications. At 6-month follow-up, there was complete resolution of the patient’s presenting symptoms and surveillance CT demonstrated no residual SDH.