The Molecular Basis of Cerebrovascular Malformations.

Four categories of cerebrovascular lesions have been identified: telangiectasias, venous malformations, arteri-ovenous malformations, and cavernous malformations. Telangiectasias are vascular lesions composed of small vessels separated by normal brain tissue. Small (0.3-1.0 cm) and rarely symptomatic, telangiectasias are usually identified as an incidental finding upon autopsy. Venous malformations, also usually benign, appear to be a normal variant of veins separated by normal brain tissue. With no definitive arterial input, venous malformations rarely cause hemorrhage or seizures. [ABSTRACT FROM AUTHOR]