Delayed remote cerebellar hemorrhage after unilateral biportal endoscopic lumbar decompression: a case report and literature review

Background Remote cerebellar hemorrhage is a rare but potentially life-threatening complication of spinal surgery and is commonly associated with dural injury and cerebrospinal fluid loss. Intracranial complications after irrigation-assisted spinal endoscopy are poorly recognized, particularly when no dural tear is identified and the initial head computed tomography is unremarkable. Case presentation A 55-year-old man with lumbar spinal stenosis underwent unilateral biportal endoscopic decompression at L4–5. No definite dural tear or cerebrospinal fluid leakage was identified intraoperatively. During emergence from anesthesia, he developed marked agitation, hypertension, and tachycardia, although immediate postoperative head computed tomography (CT) showed no definite abnormality. By postoperative day 1, 550 mL of bloody fluid had drained from the lumbar wound. He subsequently developed hypoxemia, nuchal rigidity, and right-sided weakness. Repeat head CT revealed bilateral cerebellar hemorrhage, subarachnoid hemorrhage, and obstructive hydrocephalus. Emergency external ventricular drainage was performed. With multidisciplinary treatment, neurological function gradually improved. At the 2-month follow-up, right-sided muscle strength was grade 4, and he was able to walk independently. Conclusions Unexplained agitation, hypertension, and tachycardia during emergence from anesthesia after UBE should prompt consideration of an irrigation-related craniospinal pressure disturbance. When these signs are accompanied by unexpectedly high wound drainage, nuchal rigidity, or a new neurological deficit, occult cerebrospinal fluid leakage and delayed intracranial complications—including remote cerebellar hemorrhage, subarachnoid hemorrhage, and hydrocephalus—should be considered. Serial neurological assessment and timely repeat neuroimaging are warranted even when the initial head CT is unremarkable.