Delayed symptomatic cerebral vasospasm following vestibular schwannoma resection: illustrative case

Abstract

Background: Symptomatic cerebral vasospasm following posterior fossa extraaxial tumor resection is a rare phenomenon, with only 13 cases previously reported in the literature. The condition appears similar to vasospasm following supratentorial tumor resection, intraaxial posterior fossa tumor resection, and aneurysmal subarachnoid hemorrhage (aSAH). The majority of patients were not evaluated for vasospasm prior to symptom onset, leading to a delay in diagnosis.

Observations: The authors present their experience in a 56-year-old female who developed delayed cerebral vasospasm after excision of a solid-cystic vestibular schwannoma. Routine postoperative brain computed tomography showed evidence of subarachnoid hemorrhage in the basal cisterns. She was discharged on the 9th postoperative day. On the 11th day after tumor excision, she developed left hemiparesis, dysarthria, and dysphagia and was readmitted. Angiography confirmed bilateral diffuse cerebral vasospasm. The patient responded to standard hyperdynamic therapy used for vasospasm secondary to aSAH.

Lessons: Symptomatic distant cerebral vasospasm after posterior fossa extraaxial tumor excision is a rare but challenging complication with a very high morbidity rate in reported cases. A high index of suspicion is required for early diagnosis and prompt management for a favorable outcome.

Keywords: cerebral vasospasm; complication; extraaxial tumor; posterior fossa; vestibular schwannoma.

FIG. 1

Preoperative axial T2-weighted (A) and postcontrast (B) MRI showing heterogeneously enhancing, 4.2 × 4.6 × 3.5–cm, right cerebellopontine angle and internal auditory canal mass lesion with a fluid-fluid level seen in its posterior part, suggestive of a solid-cystic giant right vestibular schwannoma.

FIG. 2

A: Postcontrast axial CT image showing near-complete excision of the tumor. B and C: Axial CT images showing SAH in the perimesencephalic and interpeduncular cisterns and the bilateral sylvian fissures.

FIG. 3

A: Diffusion-weighted MRI showing an acute nonhemorrhagic right frontal (MCA territory) infarct. B: Magnetic resonance angiography of the brain showing the attenuation of flow in the right MCA mainly in the superior segment (white arrows), proximal M1 segment of the left MCA (white arrow with black border), and terminal portion of the basilar artery (black arrow with white border). C and D: Brain CT scans on postoperative day 27 showing the complete disappearance of the previously seen SAH in the basal cisterns and in the bilateral sylvian fissures.

FIG. 4

Axial T2-weighted (A) and postcontrast (B) MRI showing a small residual tumor in the right intracanalicular and cerebellopontine cistern. Axial diffusion-weighted image (C) showing resolution of the right frontal infarct.