Developmental Venous Anomaly: Benign or Not Benign.

Developmental venous anomalies (DVAs), previously called venous angiomas, are the most frequently encountered cerebral vascular malformations. However, DVA is considered to be rather an extreme developmental anatomical variation of medullary veins than true malformation. DVAs are composed of dilated medullary veins converging centripetally into a large collecting venous system that drains into the superficial or deep venous system. Their etiology and mechanism are generally accepted that DVAs result from the focal arrest of the normal parenchymal vein development or occlusion of the medullary veins as a compensatory venous system. DVAs per se are benign and asymptomatic except for under certain unusual conditions. The pathomechanisms of symptomatic DVAs are divided into mechanical, flow-related causes, and idiopathic. However, in cases of DVAs associated with hemorrhage, cavernous malformations (CMs) are most often the cause rather than DVAs themselves. The coexistence of CM and DVA is common. There are some possibilities that DVA affects the formation and clinical course of CM because CM related to DVA is generally located within the drainage territory of DVA and is more aggressive than isolated CM in the literature. Brain parenchymal abnormalities surrounding DVA and cerebral varix have also been reported. These phenomena are considered to be the result of venous hypertension associated with DVAs. With the advance of diagnostic imagings, perfusion study supports this hypothesis demonstrating that some DVAs have venous congestion pattern. Although DVAs should be considered benign and clinically silent, they can have potential venous hypertension and can be vulnerable to hemodynamic changes.

Clinical features of Sturge-Weber syndrome without facial nevus: five novel cases.

Classic Sturge-Weber syndrome (SWS) is characterized by presence of flammeus nevus involving the first sensory branch of trigeminal nerve, ipsilateral leptomeningeal angiomatosis, and choroidal angioma. Sporadic cases of SWS without facial nevus (SWS type III) have been rarely reported. Here we report the clinical and neuroradiological findings of five patients with SWS type III and compare their findings with those described in the literature. This study confirmed that SWS type III should be considered in any child or young adult presenting with seizures or complicated migraine and intracranial unilateral calcification. The diagnosis must be confirmed with contrast-enhanced MRI images of the brain. Surgical therapy should be considered in patients with drug-resistant and persistent epileptic seizures.

[Clinical features and management of cavernous and venous angiomas in the head].

Cerebral cavernous angiomas consist of well-circumscribed collections of thin-walled sinusoidal vascular channels lacking the intervening brain tissue. They are present in 0.4-0.8% of the population, and can occur in a sporadic or familial form. Most common symptoms are seizures, hemorrhage, and focal neurological deficits. The annual bleeding rate of the patient is reported to be 0.25%-20%. High-resolution magnetic resonance imaging (MRI) is a useful diagnostic tool with a high degree of sensitivity and specificity. Microsurgical excision of the lesion is a good treatment choice for cavernous angiomas in the brain, even in the brainstem. Although stereotactic radiosurgery may reduce the incidence of rebleeding and the frequency of seizures, its indication should be carefully investigated because of the relatively high rate of radiation-induced side effects. Less frequently, cavernous angiomas can be located at the extra-axial regions of the head, which include the cavernous sinus, the orbit, and the cranial nerves. Cavernous angiomas in the cavernous sinus pose a neurosurgical challenge due to the high vascularity and involvement of the neurovascular structures, and stereotactic radiosurgery is considered as an additional option. Surgical resection is recommended for symptomatic cavernous angiomas in the orbit; however, the rate of complications after resection is not necessarily low for cavernous angiomas within the apex. Venous angiomas are anomalies of normal venous drainage, which show characteristic appearance of the drainage system in the late phase of angiography (caput medusae). They are found either alone or in combination with other vascular malformations. Conservative treatment is recommended except for patients with a large hematoma or with a coexisting cavernous angioma.

The association of venous developmental anomalies and cavernous malformations: pathophysiological, diagnostic, and surgical considerations.

Developmental venous anomalies (DVAs) are often associated with intracranial cavernous malformations (CMs). The frequency of this association and the observation of de novo CMs located near a known, preexisting DVA raise speculations as to the possible etiopathogenetic relationship between the two. In this article, the authors review the recent literature dealing with the potential etiopathogenetic, prognostic, and therapeutic implications of the association between DVAs and CMs.