Neurological Deterioration Following Bilateral Burr-Hole Drainage for Chronic Subdural Hematoma: A Case Report

Abstract

Background: Spontaneous intracranial hypotension (SIH) is a relatively rare but known pathology that results in brain herniation or sagging due to CSF hypovolemia. SIH can commonly be misdiagnosed when occurring with other pathologies including chronic subdural hematoma (CSDH). Neurological decline caused by SIH is rare, but is often rapid and much more severe. Case description: A 69-year-old man was delivered to the emergency department for loss of consciousness and mild left hemiparesis. Brain computed tomography (CT) revealed increased density over basal cisterns suggestive of subarachnoid hemorrhage (SAH), and CSDH. Cerebral angiography showed dural arteriovenous fistula, but there was no apparent cerebral aneurysm. We first performed trans-arterial embolization using n-butyl cyanoacrylate, followed by bilateral hematoma evacuation. A postoperative CT showed that CSDH was evacuated, but the subdural space was filled with free air. A subsequent CT examination revealed mild re-accumulation of CSDH without significant brain compression. On postoperative day 14 the patient became progressively lethargic, for which he was transferred to the intensive care unit. As gadolinium-enhanced magnetic resonance imaging and radionuclide cisternography suggested the leakage of cerebrospinal fluid, an epidural catheter was inserted in the head- down positioned patient and an epidural infusion of saline was given for 3 days. The patient stabilized and regained consciousness over 2 weeks. The patient became neurologically intact with imaging showing almost complete parenchymal expansion and resolution of subdural fluid collection. Conclusion: This is an instructive case because the patient deteriorated after the surgery for CSDH, but it is also a unique case because the deterioration occurred over 14 days. This report emphasizes the possibility that SIH should be taken into consideration when there is an unknown reason for early CSDH recurrence and neurological deterioration.