Vagal schwannoma of the cerebello-medullary cistern presenting with hoarseness and intractable tinnitus: a rare case of intra-operative bradycardia and cardiac asystole

Abstract

Schwannomas arising from the lower cranial nerves (IX-XI) are rare, constituting only 3% of all intracranial schwannomas unassociated with neurofibromatosis. A great majority of these tumours present as jugular foramen lesions and less commonly they occur along the extracranial course of these nerves. An intracisternal location is extremely rare. We report a case of vagal schwannoma purely in the cerebello-medullary cistern causing distortion of the medulla oblongata. Total microsurgical excision of this tumor, arising from one of the rootlets of the vagus nerve, was achieved with preservation of the 9th, 10th and 11th cranial nerves.The intraoperative course was complicated by two episodes of complete cardiac asystole, each lasting for 4s, and six episodes of severe bradycardia. The patient was relieved of his intractable tinnitus but continued to have a hoarse voice due to an ipsilateral partial vocal cord palsy.