Developmental venous anomalies and brainstem cavernous malformations: a proposed physiological mechanism for haemorrhage.

The incidental diagnosis of both developmental venous anomalies (DVAs) and cavernous malformations (CMs) in the central nervous system is increasing with improved imaging techniques. While classically silent diseases, these cerebrovascular pathologies can follow an aggressive course, particularly when present in the brainstem. In the last decade, substantial research has focussed on KRIT1-mediated tight junction gene expression and their role in CM development. However, our understanding of the physiologic conditions precipitating symptomatic CM development or CM haemorrhage with and without concomitant DVAs, remains lacking. The only established risk factor for CM haemorrhage is a previous history of haemorrhage, and literature currently reports trauma as the only precipitant for symptomatic events. While plausible, this occurs in a minority, with many patients experiencing occult events. This manuscript presents a hypothesis for symptomatic CM events by first discussing the anatomical pathways for intracranial venous outflow via the internal jugular veins (IJV) and vertebral venous plexus (VVP), then exploring the role of venous flow diversion away from the IJVs under physiologic stress during dynamic postural shift. The resultant increase in intracranial venous pressure can exacerbate normal and pre-existing structural DVA pathologies, with repeated exposure causing symptomatic or CM-inducing events. This pathophysiological model is considered in the context of the role of the autonomic nervous system (ANS) in postural intracranial venous outflow diversion, and how this may increase the risk of DVA or CM events. It is hoped that this hypothesis invokes further investigation into precipitants for DVA or CM events and their sequela and, also, furthers the current knowledge on pathophysiological development of DVAs and CMs.

Formation During Lifetime of Arteriovenous Shunt in Developmental Venous Anomaly That Caused Intracerebral Hemorrhage.

BACKGROUND: Developmental venous anomaly (DVA) or venous angioma is a common anomaly of cerebral veins that is found incidentally in the majority of cases. There are few cases of arteriovenous shunting in DVA associated with a more malignant course of the disease. Whether these DVAs with shunts are of congenital pathology or lifetime formations is unclear. CASE DESCRIPTION: We report a case of lifetime arteriovenous shunt formation in DVA that caused intracerebral hemorrhage in a child. The patient underwent 2 sequential direct surgeries: an emergency evacuation of the intracerebral hematoma and a scheduled excision of the DVA with arteriovenous shunting. CONCLUSIONS: Arteriovenous shunting in DVA may develop during a lifetime and cause intracerebral hemorrhages. This case showed that localization of DVA with arteriovenous shunting in a noneloquent area enables its complete microsurgical excision with favorable functional outcomes.

[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.

Cerebral developmental venous anomalies: current concepts.

Cerebral developmental venous anomalies are the most frequently encountered cerebral vascular malformation, and as such, are frequently reported as fortuitous findings in computed tomography (CT) and magnetic resonance imaging (MRI) studies. Developmental venous anomalies (DVAs) are generally considered extreme anatomical variations of the cerebral vasculature, and follow a benign clinical course in the vast majority of cases. Here we review current concepts on DVAs with the aim of helping clinicians understand this complex entity. Morphological characteristics that are necessary to conceptualize DVAs are discussed in depth. Images modalities used in diagnosing DVAs are reviewed, including new MRI or CT techniques. Clinical presentation, association with other vascular malformations and cerebral parenchymal abnormalities, and possible physiopathological processes leading to associated imaging or clinical findings are discussed. Atypical forms of DVAs are also reviewed and their clinical significance discussed. Finally, recommendations as to how to manage asymptomatic or symptomatic patients with a DVA are advanced.

Pathomechanisms of symptomatic developmental venous anomalies.

BACKGROUND AND PURPOSE: Although it is generally accepted that developmental venous anomalies (DVAs) are benign vascular malformations, over the past years, we have seen patients with symptomatic DVAs. Therefore, we performed a retrospective study and a literature study to review how, when, and why DVAs can become clinically significant. METHODS: Charts and angiographic films of 17 patients with DVAs whose 18 vascular symptoms could be attributed to a DVA were selected from a neurovascular databank of our hospital. MRI had to be available to rule out any other associated disease. In the literature, 51 cases of well-documented symptomatic DVAs were found. Pathomechanisms were divided into mechanical and flow-related causes. RESULTS: Mechanical (obstructive or compressive) pathomechanisms accounted for 14 of 69 symptomatic patients resulting in hydrocephalus or nerve compression syndromes. Flow-related pathomechanisms (49 of 69 patients) could be subdivided into complications resulting from an increase of flow into the DVA (owing to an arteriovenous shunt using the DVA as the drainage route; n=19) or a decrease of outflow (n=26) or a remote shunt with increased venous pressure (n=4) leading to symptoms of venous congestion. In 6 cases, no specific pathomechanisms were detected. CONCLUSIONS: Although DVAs should be considered benign, under rare circumstances, they can be symptomatic. DVAs, as extreme variations of normal venous drainage, may represent a more fragile venous drainage system that can be more easily affected by in- and outflow alterations. The integrity of the DVA needs to be preserved irrespective of the treatment that should be tailored to the specific pathomechanism.

Decreased cortical excitability due to a large venous angioma.

This study reports on a patient with episodes of right hand paralysis and complete sensory loss, considered to be functional because of a glove-like distribution of the sensory deficit, normal motor and sensory nerve conduction studies of median and ulnar nerve as well as normal median nerve somatosensory evoked potentials. Transcranial magnetic stimulation indicated increased threshold of the left hemisphere. Neuroimaging studies revealed a large venous angioma in the left frontal lobe.

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.

Successful ECT in a patient with intracranial venous angioma.

The 1990 American Psychiatric Association (APA) Task Force report on electroconvulsive therapy (ECT) suggests that there is an increased risk of complications in patients with intracranial vascular masses. There have been only a few published reports on the use of ECT in these patients. In this case report, an additional case is described that used ECT in the treatment of major depression in a 72-year-old patient with a venous angioma involving the left cerebellum. Brain imaging studies, neurosurgery, cardiology, and orthopedic consultations were obtained prior to ECT. Blood pressure was monitored closely throughout the course of ECT. Prior to each ECT, antihypertensive medication was given in addition to other pretreatment medications. Consistent with previously published reports, the patient did not experience any neurological deterioration or adverse effects. A brief review of the literature on the use of ECT in patients with venous angioma and other intracranial vascular masses is presented.

Third ventricle cavernoma associated with venous angioma. Case report and review of the literature.

A case of third ventricle cavernous angioma associated with venous angioma is reported. By a transventricular approach, the cavernoma was totally removed with successful preservation of the venous malformation. After review of the literature, the clinical characteristics and the surgical approach to third ventricle cavernous angioma are discussed; the importance of preservation of associated venous angioma is also underlined.