Remote contralateral intraparenchymal hemorrhage after overdrainage of a chronic subdural hematoma

Chronic subdural hematoma (cSDH) is frequently seen by neurosurgeons. Treatment often includes evacuation of the subdural hematoma (SDH) through one or two burr holes and placement of a drain in the subdural space to further evacuate subdural fluid and prevent reaccumulation of blood during the immediate postoperative period. Complications associated with this type of drainage include fluid and blood reaccumulation, tension pneumocephalus, seizures and subdural empyema.

The author presents a case in which aggressive CSF overdrainage most likely led to acute severe intracranial hypotension, causing the collapse of the contralateral bridging veins and ultimately resulting in venous insufficiency and hemorrhagic infarction. The remote intracerebral hemorrhages were suspected to be due to CSF overdrainage through the subdural drain, so the drain was immediately removed. After drain removal, the patient's neurologic status improved and his hemiplegia disappeared within 4h. A follow-up head CT scan 1 month later revealed resolution of his subdural fluid collection and right-sided intraparenchymal hemorrhages. He returned to work 1 month later in good condition.

Although many authors have examined factors affecting the success of cSDH drainage procedures, there are few reports about the risks of overdrainage and little information available about drainage volume. This report links excessive cSDH drainage of with a remote contralateral intraparenchymal hemorrhage, a complication that has been noted only twice previously, and neither report suggested the mechanism for occurrence of the hemorrhage, or specified the amount of drainage.

Subdural drainage should be carefully monitored to avoid overdrainage.