The preservation and reconstruction of cerebral veins and sinuses.

Although cerebral veins and venous sinuses are very important to the neurosurgeon, they have received adequate attention only recently. The consequences of cerebral venous occlusion are well known. When the venous outflow is compromised due to a lack of adequate collateral circulation, venous infarction follows, with swelling, haemorrhage and neuronal death. The clinical consequences will depend upon the region of involvement of the brain and the site of the infarcted tissue. The symptoms may include seizures, hemiplegia, aphasia, coma and death. Similarly, the consequences of cerebral venous sinus occlusion depend upon the availability of collateral circulation. When such collaterals are not available, papilledema and visual loss and a pseudotumour cerebri syndrome are observed in milder cases, whereas, severe diffuse brain swelling, coma and death may be observed in severe cases. Acute venous or venous sinus occlusion is potentially very dangerous, whereas slow and chronic venous or venous sinus occlusion is better tolerated. Even in such patients, some neurological manifestations may follow, when the collaterals are poor.