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Remote cerebellar hemorrhage after a neurosurgical procedure: A report of three cases

Remote cerebellar hemorrhage (RCH) is a rare complication of neurosurgical procedures and is characterized by a typical bleeding pattern defined as the “zebra sign.” Only few cases of RCH have been reported in the English literature, and its pathophysiology remains unclear. In this report, we present the cases of three patients with RCH after three different procedures: burr-hole trephination and chronic subdural hematoma evacuation of bilateral cerebral convexity with subsequent subdural drain insertion, lumbar drainage for cerebrospinal fluid divergence for thoracic endovascular aortic repair, and combined bypass surgery for moyamoya disease.


INTRODUCTION
Remote cerebellar hemorrhage (RCH) is a rare postoperative complication that occurs remotely from the site of a neurosurgical procedure. Its incidence is approximately 0.3% following supra-tentorial surgery and is much rarer following spinal surgery. 5)7)10) RCH is usually characterized by a "zebra sign" in approximately 65% of patients and is associated with a good prognosis; otherwise, pure intracerebral hemorrhage indicates a poor prognosis. 9) From 2017 to 2020, we managed three cases of RCH that resulted in poor prognosis after 1) burr-hole trephination and subdural hemorrhage (SDH) evacuation, 2) lumbar drainage for cerebrospinal fluid (CSF) divergence for thoracic endovascular aortic repair, and 3) combined bypass surgery for moyamoya disease (MMD).

Journal of Cerebrovascular and Endovascular Neurosurgery
Volume 24 · Number 3 | September 2022 pneumocephalus with the Mt. Fuji sign was observed. Oxygen administration using a facial oxygen mask was performed to facilitate oxygen absorption.
Nevertheless, his mental status gradually declined from glasgow coma scale (GCS) 13 (E3M6V4) to 9 (E2M5V1). To relieve intracranial pressure (ICP) resulting from increased air volume, air aspiration was performed through a three-way valve of the subdural drain. After the aspiration of a total of 80 cc of air, he spontaneously opened his eyes and recovered with GCS E4M6V3. On the follow-up CT scan, tension pneumocephalus was relieved, but unexpected bilateral RCH appeared (Fig. 1E, 1F). The bleeding did not increase during observation, but the patient developed symptoms associated with cerebellar hemorrhage and did not show improvement. Cerebellar mutism and swallowing difficulty were noted. Moreover, pneumonia and sepsis occurred. Over 4 weeks, the patient was stabilized and transferred to the rehabilitation center. However, recurrent pneumonia occurred after discharge, and the patient eventually expired.

CASE 2
A 70-year-old man was admitted for an elective operation for recently increased chronic type B aortic dissection. He had hypertension, which was effectively controlled using a calcium channel blocker. He also had stage III chronic kidney disease. Brain magnetic resonance imaging (MRI) was performed as a preoperative workup, which showed no significant abnormal findings such as vascular malformation. He had no focal neurologic deficit.
Thoracic endovascular aortic repair (TEVAR) was performed. Lumbar drainage catheter was inserted after general anesthesia to prevent spinal cord ischemia after TEVAR. Data about the amount of intraoperative CSF drainage were not obtained. The operative time was 2 h, and the patient woke up to GCS E3M6Ve and could follow simple commands postoperatively.
On postoperative day 1, the lumbar drainage catheter was removed after confirming that the strength of both

CASE 1
An 87-year-old man presented with the complaint of weakness in both legs since 2 days before presentation. His medical history included head trauma that had occurred a week ago, type 2 diabetes mellitus, and Parkinson's disease. Brain computed tomography (CT) showed bilateral chronic SDH. Burr-hole trephination and SDH evacuation were performed, and a subdural drain was inserted bilaterally (Fig. 1A-D). To reduce the risk of pneumocephalus, rapid catheterization and saline infusion were performed.
However, on the postoperative CT, a large amount of From the night of postoperative day 1, his level of consciousness gradually deteriorated to E1M4V. Brain MRI was performed, which revealed a large amount of bilateral cerebellar hemorrhage compressing the brainstem ( Fig. 2A, 2B). When the patient was re-evaluated after the MRI, no brainstem reflexes were observed. Osmotic therapy was initiated, but the patient did not show any clinical improvement. The patient's family decided not to pursue surgical decompression due to his poor prognosis. Follow-up brain CT showed aggravated hydrocephalus without RCH changes (Fig. 2C, 2D). The patient died 17 days after the onset of RCH.

CASE 3
A 55-year-old woman who presented with transient bilateral limb weakness and motor dysphasia was diagnosed with MMD and admitted for right combined bypass surgery. She also had hyperlipidemia and no focal neurologic deficit. Brain MRI and MR angiography showed typical characteristics of hemodynamically unstable MMD with acute Rt. border-zone infarction.
The patient underwent right combined bypass surgery as scheduled. The surgery was performed in the supine position, and the recipient artery was the angular branch of the right middle cerebral artery. The total operative time was 5 h, and the ischemic time was 59 min. No significant event occurred during surgical procedures. The patient was transferred to the intensive care unit following postoperative CT. Although no specific findings were observed on CT, the patient did not recover from anesthesia for 3 h and her level of consciousness was E1M4V at best. A total of 165 cc of fluid was drained through the sub-galea drainage for 3 h postoperatively. A 2 nd CT was performed to check for any delayed adverse events and RCH was confirmed (Fig. 3).
She gradually recovered from anesthesia to E4M6Ve during close observation, and RCH did not increase on the follow-up CT. However, on the morning of postoperative day 3, stupor (E2M5V1) and grade II left side weakness were noted. Brain MRI revealed an acute infarction of the right frontal lobe. Vigorous hydration and induced hypertension were initiated. The patient gradually recovered her consciousness level to E4M6V2, but left side weakness persisted. She was transferred to the rehabilitation center after 1 month. Unfortunately, no significant change in the patient's status was observed until the 3-year postoperative follow-up.