Cerebral Sinovenous Thrombosis.
Cranial sinovenous disorders comprise a disparate group of illnesses affecting one or more intracranial venous sinuses and cerebral veins, alone or in combination, due to a variety of causes. As medical knowledge advances, fewer and fewer patients have an "idiopathic" diagnosis, with causes clarified in an ever-increasing number of patients. These not only include the long-known puerperal, marantic, infective, and traumatic causes, but in recent years, also a variety of congenital and acquired coagulation disorders, such as protein S, protein C, and antithrombin III deficiency. Certain sinuses are preferentially involved with certain causative entities; for example, cavernous and lateral sinuses are more frequently occluded in relation to infectious processes, either directly or as a parameningeal focus, whereas the superior sagittal sinus is most often occluded by trauma, tumor, or coagulopathy. The optimal treatment of sinovenous occlusion depends on establishing the cause with alacrity, because delays in diagnosis may lead to life-threatening hyperpyrexia, elevations in intracranial pressure, venous infarctions, seizures, coma, and death. However, because up to a third of patients with nonseptic occlusions may survive untreated, with few residua, controversy persists regarding optimal management. There has been a dearth of randomized, prospective treatment trials in this group of disorders. The little data that exist suggest that rapid control of infection, seizure prophylaxis, and anticoagulation must be achieved early so as to prevent progression of thrombosis and intracranial venous hypertension. In recent years, direct retrograde venous thrombolysis has become increasingly available, and has produced such remarkable results that it is likely soon to become the primary treatment of choice for the nontraumatic or nontumoral occlusions.