Cerebellar Hemorrhage after Posterior Lumbar Decompression and Interbody Fusion Complicated by Dural Tear: A Case Report

Remote cerebellar hemorrhage (RCH) is a rare condition which can complicate after supratentorial surgery. Also RCH was reported less frequently after spinal surgery than that of post-cranial surgery. Recently it has been often reported(Table 1).1, 2, 3) In South Korea, only five articles about spinal surgery - related - RCH were reported by neurosurgeons1, 4) and anesthesiologists. Although the pathophysiology of RCH has not been clarified, all cases of RCH after spinal surgery had history of a leakage of cerebrospinal fluid (CSF) or dural tear during operation.

Table 1
The reported cases of remote cerebellar hemorrhage complicated after lumbar spine surgery

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We experienced a case of RCH after posterior decompression and lumbar interbody fusion (PLIF) at L4-5 level. Dural tear with CSF leakage was repaired. Early diagnosis and management could prevent disastrous outcome. The current case is reported with a review of related literatures.

A 57-year-old women with spinal stenosis complained back pain and radiating pain to both legs. She had a neurological claudication and could bear only about five-minute walking. She had no history of diabetes mellitus, hypertension and anticoagulant therapy. On simple radiogram grade I degenerative spondylolisthesis was found, and on magnetic resonance imaging (MRI) severe spinal stenosis with hypertrophy of ligamentum flavum and facet joint arthropathy at L4-5 level was observed (Fig. 1). She had posterior decompression and lumbar interbody fusion of L4-5 segment(Fig. 2).

Fig. 1
Sagittal view (A) of preoperative MRI shows spondylolisthesis with dural compression at L4-5 level. Axial view (B) shows severe dural compression due to both facet joint and ligamentum flavum hypertrophy.

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Fig. 2
Immediate postoperative AP (A) and Lateral (B) x-rays show posterior decompression and reduced spondylolisthesis after posterior lumbar interbody fusion at L4-5 level.

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During the operation, dura was torn accidently. There was CSF leakage through about 5mm longitudinal dural tear. The tear was sutured with non-absorbable suture. Blood pressure was maintained during surgery. Estimated blood loss was 700cc for which a 320cc packed RBC was transfused. Immediate postoperatively there was no neurological change and vital sign. At postoperative 2 hours, hypotension (blood pressure 80/40 mmHg), headache and nausea developed. Hydration with normal saline 500cc was carried out and a packed RBC was transfused, but hypotension persisted for which dopamine was infused. In spite of normalized blood pressure, headache and nausea aggravated and vomiting developed at postoperative day 1. To look for the cause, brain CT was obtained at postoperative day 1. The brain CT revealed bilateral cerebellar hemorrhages facing the tentorium(Fig. 3A). The hemorrhage pattern was considered to be 'zebra sign' which was produced by linear hyperdensities of bleeding and relatively hypodense cerebellar folia.5) Neurosurgical consultation about the cerebellar hemorrhages was obtained. The total suction drainage reached to 510cc at postoperative day 1, and the drainage was stopped immediately. She maintained fortunately normal neurology and consciousness. Amount of the cerebellar hemorrhage was small. Thus, she was managed conservatively. Normal saline and mannitol were infused intravenously while dopamine infusion was tapered.

Fig. 3
Brain CT of postoperative day 1 (A) shows small amount of hemorrhage (black arrow) in cerebellum. Amount of cerebellar hemorrhage increased (black arrow) at postoperative day 5 (B). Brain CT of postoperative one year (C) shows no residual shadow of hemorrhage.

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At postoperative day 2, headache, nausea and vomiting lessened. Blood pressure became stabilized without dopamine infusion. On follow-up brain CT, taken at postoperative day 5 slightly increased cerebellar hemorrhages was observed. But the patient had normal neurology without headache. On postoperative 2 week follow-up CT, cerebellar hemorrhage was absorbed almost completely(Fig. 3B). Consequently the patient could be discharged without any residual symptoms such as headache, unconsciousness and neurological change. At postoperative 1 year follow-up, she had no sequel of cerebellar hemorrhage(Fig. 3C).

Hemorrhage in the remote region - the cerebellum after spinal surgery is a rare complication which is usually known to have favorable prognosis, and to be the self-limiting one. But sometimes it can be life-threatening and needs the surgery.4, 6, 7, 8) So, early diagnosis and proper treatment are essential, if there are suspicious symptoms suggesting RCH in the patients who have CSF leakage through accidental dural tear during surgery.

Since Chadduck's9) first case report of remote cerebellar hemorrhage in 1981, its cause after supratentorial or spinal surgery had been discussed. As yet, its exact pathophysiology has not been clarified, but most of authors thought that RCH was probably venous in origin and caused by perioperative massive CSF leakage, based on the fact that there was CSF leakage through surgical dural tear in all cases of RCH after spinal surgery. In current case, dural tear also complicated during posterior decompression at L4-5. But there was no massive CSF leakage during operation and torn dura was repaired immediately. Postoperative drained fluid was not transparent, rather bloody. So velocity of CSF leakage was thought to be more important factor for RCH than leaked amount of spinal fluid in this case.

The most common clinical symptoms of RCH were headache and unclear consciousness. In the current case, headache and hypotension which couldn't be controlled by hydration and transfusion, and those were the main postoperative clinical features. She had no consciousness change. Postoperative arterial hypertension was reported to be a possible risk factor for RCH.3, 4) But in the current case, postoperative continuous hypotension could be a contributing factor for RCH. It is assumed that continuous hypotension accompanied with CSF leakage could cause intracranial hypotension resulting in downward cerebellar displacement or "sagging".

A study reported the prevalence of asymptomatic RCH was 0.8% in the patient who underwent supratentorial craniotomies.10) Incidence of asymptomatic RCH after spinal surgery may be also higher than that of the suggested one by previous reports. That is the reason why asymptomatic cerebellar hemorrhages are unlikely to be detected. Yoich et al6) emphasized that early diagnosis is particularly important for the treatment of RCH following spinal surgery. In their report patient with severe headache and nausea without neurological change after T9-10 laminectomy with unintentional dural tear underwent second operation for torn dural repair without brain CT or MRI. The patient's consciousness gradually deteriorated and transferred to their institution at second postoperative day 2. Subsequently the patient underwent cranial decompression. So even though headache was the only symptom, brain CT or MRI should be taken in the patient who had CSF leakage or dural tear during spinal surgery. In the case in whom headache could not be controlled by analgesics, and also even in whom the only symptom without diminished consciousness brain CT should be taken.

In all previous reports, neurological symptoms developed at least ten hours after surgery.3, 8) In patient with conscious change, cranial surgery had been needed for RCH. But in the current case, headache developed at postoperative 2 hours without conscious change. By brain CT RCH could be diagnosed earlier. When tentative diagnosis of RCH is made, suction drain should be stopped quickly and the patient should be treated early to prevent aggravation of RCH.

The surgeon must always pay attention that RCH can complicate in the patient who has CSF leakage through dura tear during spinal surgery, even though the amount of CSF leakage is small. It is particularly important to detect RCH early even when the patient had only headache before consciousness change develop.