[Venous anomalies of the brain. The clinical significance of the so-called venous angioma].

In contrast to angiography, MRI not only allows the diagnosis of DVA (developmental venous anomaly, so-called venous angioma), but also shows up cavernomas and other angiographically occult vascular malformations. It also differentiates between DVAs and occult true malformations. This has completely changed the pathological assessment of DVAs. In a retrospective study on 31 patients with angiographically proven DVAs neighbouring cavernoma was a frequent finding (15 patients, 48% group I). Symptoms caused by cavernoma were present in 6 (40%) of these 15 patients. The following associations were also found: cerebral arterial aneurysm (2), spinal arterio-venous dural fistula (1), dermal haemangioma (1), Klippel-Trénauny syndrome (1). Only 16 (52%) of the 31 cases with DVA were free of associated cavernoma (group II). Only 3 (19%) of these patients with a solitary DVA were symptomatic. In our series we have seen no case of bleeding from a DVA. A DVA is a vascular anomaly characterized, like other anomalies, by reduced resistance and limited capacity for regulation and adaptation. In rare cases this can result in haemodynamic disturbances, thrombosis and ischaemia. Wall rupture with bleeding does not occur in DVA. It must be assumed that bleeding reported in patients with DVAs before the availability of MRI resulted from an associated true vascular malformation in most cases.