Venous anomalies and associated lesions.

Developmental venous anomalies (DVAs) of the central nervous system are an exaggeration of the normal venous collector system, not a vascular lesion. They may be associated with many vascular and nonvascular processes with the nervous system including tumors, demyelinating lesions, arteriovenous malformations (AVMs), dural AVMs, cavernous malformations, and vascular lesions of the head, face, and eye. The instigating factors involved are not completely understood. The primary clinical significance of DVAs is that planned or inadvertent occlusion during treatment of associated lesions frequently leads to venous infarction of the surrounding normal brain.