Journal of neurosurgery
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Journal of neurosurgery · Dec 2013
Case ReportsImmediate neurological deterioration after gamma knife radiosurgery for acoustic neuroma: case report.
The authors describe acute deterioration in facial and acoustic neuropathies following radiosurgery for acoustic neuromas. In May 1995, a 26-year-old man, who had no evidence of neurofibromatosis Type 2, was treated with gamma knife radiosurgery (GKS; maximum dose 20 Gy and margin dose 14 Gy) for a right-sided intracanalicular acoustic tumor. Two days after the treatment, he developed headache, vomiting, right-sided facial weakness, tinnitus, and right hearing loss. ⋯ The tumor has been unchanged in size for 5 years, and facial nerve function has also been maintained at Grade 2 with unchanged deafness. This is the first detailed report of immediate facial neuropathy after GKS for acoustic neuroma and MR imaging revealing early possibly toxic changes. Potential explanations for this phenomenon are presented.
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Journal of neurosurgery · Dec 2013
Gamma Knife radiosurgery for larger-volume vestibular schwannomas: clinical article.
Stereotactic radiosurgery (SRS) is an important management option for patients with small- and medium-sized vestibular schwannomas. To assess the potential role of SRS in larger tumors, the authors reviewed their recent experience. ⋯ Although microsurgical resection remains the primary management choice in patients with low comorbidities, most vestibular schwannomas with a maximum diameter less than 4 cm and without significant mass effect can be managed satisfactorily with Gamma Knife radiosurgery.
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Journal of neurosurgery · Dec 2013
Case ReportsAcute neurological complications following gamma knife surgery for vestibular schwannoma: case report.
The authors describe an acute facial and acoustic neuropathy following gamma knife surgery (GKS) for vestibular schwannoma (VS). This 39-year-old woman presenting with tinnitus underwent GKS for a small right-sided intracanalicular VS, receiving a maximal dose of 26 Gy and a tumor margin dose of 13 Gy to the 50% isodose line. Thirty-six hours following treatment she presented with nausea, vomiting, vertigo, diminished hearing, and a House-Brackmann Grade III facial palsy. ⋯ This is the first detailed report of acute facial and vestibulocochlear neurotoxicity following GKS for VS that improved with time. In addition, MR imaging findings were indicative of early neurotoxic changes. A review of possible risk factors and explanations of causative mechanisms is provided.
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Journal of neurosurgery · Dec 2013
Radiation exposure of normal temporal bone structures during stereotactically guided gamma knife surgery for vestibular schwannomas.
The dosimetry of radiation exposure of healthy inner, middle, and external ear structures that leads to hearing loss, tinnitus, facial weakness, dizziness, vertigo, and imbalance after gamma knife surgery (GKS) for vestibular schwannomas (VSs) is unknown. The authors quantified the dose of radiation received by these structures after GKS for VS to assess the likelihood that these doses contributed to postradiosurgery complications. ⋯ Doses delivered to middle and external ear structures are unlikely to contribute to post-GKS complications, but unexpectedly high doses may be delivered to sensitive areas of the intratemporal facial nerve and inner ear. Unintentional delivery of high doses to the stria vascularis, the sensory neuroepithelium of the inner ear organs and/or their ganglia, may play a role in the development of post-GKS tinnitus, hearing loss, dizziness, vertigo, and imbalance. Minimizing treatment complications post-GKS for VS requires precise dose planning conformality with the three-dimensional surface of the tumor.
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Journal of neurosurgery · Dec 2013
Outpatient gamma knife surgery for vestibular schwannoma: definition of the therapeutic profile based on a 10-year experience.
The purpose of the study was to define the therapeutic profile of outpatient gamma knife surgery (GKS) for vestibular schwannoma (VS) by using sequential tumor volumetry to quantify changes following treatment. ⋯ Outpatient GKS is feasible, effective, and safe. Its therapeutic profile compares favorably with that of microsurgery.