Intracochlear hemorrhage after gamma knife radiosurgery

Purpose: To describe an acute complication after gamma knife stereotactic radiosurgery (GKRS) for vestibular schwannoma (VS) in a neurofibromatosis type 2 (NF2) patient. Study Design: Case report. Setting: Tertiary care center. Patient: A 20-year-old man, who had bilateral VS and was having right-sided profound deafness, underwent GKRS for a 2-cm left-sided VS in an attempt to preserve his only hearing ear. He received a margin dose of 13 Gy to the 50% isodose line. Twenty-four hours after treatment, he presented with spinning vertigo, left-sided dead ear, and ipsilateral mild facial paralysis (House-Brackmann grade 3). Results: Magnetic resonance imaging demonstrated an intracochlear hemorrhage at the level of the basal turn of the left cochlea. Hearing did not recover, and the patient had to resort to lip reading. The facial paralysis regressed completely after 3 months. Conclusion: Many cases of hemorrhage caused by GKRS have previously been reported, but all were related to meningiomas or brain metastases. Because the patient had no coagulation defect, sign of trauma, or any history of infection, the hemorrhage might have been caused by a direct thermal effect on the endothelial cells or to an immediate tumoral swelling, inducing an increase in intravascular outflow resistance and leading to venous obliteration. To our knowledge, this is the first report of acute intracochlear hemorrhage after GKRS for VS.