Spontaneous resorption of a convexity arachnoid cyst associated with intracystic hemorrhage and subdural hematoma: A case report.

Background: Intracranial arachnoid cysts (ACs) are developmental anomalies usually filled with cerebrospinal fluid (CSF), rarely resolving throughout life. Here, we present a case of an AC with intracystic hemorrhage and subdural hematoma (SDH) that developed after a minor head injury before gradually disappearing. Neuroimaging demonstrated specific changes from hematoma formation to AC disappearance over time. The mechanisms of this condition are discussed based on imaging data. Case Description: An 18-year-old man was admitted to our hospital with a head injury caused by a traffic accident. On arrival, he was conscious with a mild headache. Computed tomography (CT) revealed no intracranial hemorrhages or skull fractures but an AC was seen in the left convexity. One month later, follow-up CT scans showed an intracystic hemorrhage. Subsequently, an SDH appeared then both the intracystic hemorrhage and SDH gradually shrank, with the AC disappearing spontaneously. The AC was considered to have disappeared, along with the spontaneous SDH resorption. Conclusion: We present a rare case where neuroimaging demonstrated spontaneous resorption of an AC combined with intracystic hemorrhage and SDH over time, which may provide new insights into the nature of adult ACs.

De novo formation of twig-like middle cerebral artery: An illustrative case.

Background: Twig-like middle cerebral artery (T-MCA) is a rare vascular abnormality characterized by the replacement of the M1 segment of the middle cerebral artery (MCA) with a plexiform arterial network of small vessels. T-MCA is generally regarded as an embryological persistence. Conversely, T-MCA may also be a secondary sequela but no reports of cases of de novo formation exist. Here, we report the first case describing possible de novo T-MCA formation. Case Description: A 41-year-old woman was referred to our hospital from a nearby clinic because of transient left hemiparesis. Magnetic resonance (MR) imaging revealed mild stenosis of the bilateral MCAs. The patient then underwent MR imaging follow-ups once a year. MR imaging at the age of 53 showed a right M1 occlusion. Cerebral angiography revealed a right M1 occlusion and formation of a plexiform network consistent with the occlusion site, leading to the diagnosis of de novo T-MCA. Conclusion: This is the first case report describing possible de novo T-MCA formation. Although a detailed laboratory examination did not confirm the etiology, autoimmune disease was suspected to have precipitated this vascular lesion.

Remodeling of venous drainage after the treatment of dural sinus malformation with arteriovenous shunts in a neonate: a case report and literature review.

Dural sinus malformations (DSMs) are rare congenital vascular diseases characterized by a giant venous pouch with or without arteriovenous shunts. We present a neonatal case of DSM that was diagnosed prenatally and treated via endovascular intervention in the early postnatal period. The patient presented with a large DSM involving the torcular Herophilion prenatal magnetic resonance imaging (MRI). Enlargement of the head circumference and respiratory failure rapidly progressed after birth. On the 5th day after birth, the neonate underwent endovascular occlusion via the umbilical artery. The arteriovenous shunt was occluded, and the reflux from the enlarged venous pouch to the dural sinus was decreased. No additional procedure other than ventriculoperitoneal shunting was required. The neonate's development slowly caught up to normal parameters. Follow-up MRI demonstrated the successful development of the venous drainage system. DSMs are characterized by an abnormally dilated dural sinus, which can block the venous return and ultimately increase intracranial pressure and cerebral ischemia. Long-term follow-up indicates that an abnormally developed dural sinus can be reconstructed by appropriate and timely treatment.

Stent-Jack Technique for Ruptured Vertebral Artery Dissecting Aneurysm Involving the Origin of Posterior Inferior Cerebellar Artery.

We herein report a case of a ruptured vertebral artery dissecting aneurysm involving the origin of the posterior inferior cerebellar artery that was treated using the stent-jack technique. After parent artery occlusion of the distal vertebral artery, stenting of the posterior inferior cerebellar artery was performed. Further coiling was needed because distal vertebral artery recanalization occurred due to transformation of the coil mass. The stent-jack technique for a ruptured vertebral artery dissecting aneurysm involving the origin of the posterior inferior cerebellar artery is effective; however, careful attention to recanalization after stenting is needed due to transformation of the coil mass.