Complications of anticoagulant therapy in patients with known central nervous system lesions.

Spontaneous intracranial hemorrhage in patients receiving anticoagulant therapy is not uncommon. Sometimes this hemorrhage may be the initial presentation of an occult lesion of the central nervous system, such as a tumour, vascular malformation or infarction. Five such cases, one case of hematomyelia and one case of spinal subdural hematoma have been reported in association with proven lesions of the central nervous system in patients on anticoagulant therapy. One other patient is reported who had malignant melanoma with an asymptomatic brain metastasis. Anticoagulant therapy for deep vein thrombosis resulted in a spontaneous intracranial hemorrhage. Patients who have potential central nervous system disease on the basis of previous clinical neurologic events and those known to harbour a malignant tumour should undergo enhanced computerized axial tomography before long-term anticoagulant therapy is begun. Patients with confirmed lesions of the central nervous system are at risk of suffering hemorrhagic complications and should be monitored very closely during anticoagulation. The indications for continuing long-term anticoagulation in these patients should be reviewed frequently.