Safety of MRI in the localization of implanted intracranial electrodes for refractory epilepsy.

BACKGROUND AND PURPOSE: This is an observational study to evaluate the safety of magnetic resonance imaging (MRI) to localize subdural grids and depth electrodes in patients with refractory epilepsy using a 1.5 Tesla MR scanner. METHODS: We implemented an optimized MRI protocol providing adequate image quality for the assessment of subdural grids and depth electrodes, while minimizing the specific absorption rate (SAR). We reviewed all MRI studies performed in patients with subdural grids and depth electrodes between January 2010 and October 2018. Image quality was graded as acceptable or nonacceptable for the assessment of intracranial device positioning. We reviewed the medical record and any imaging obtained after intracranial implant removal for adverse event or complication occurring during and after the procedure. RESULTS: Ninety-nine patients with refractory epilepsy underwent MRI scans using a magnetization-prepared rapid acquisition of gradient echo sequence and a transmit-receive head coil with depth electrodes and subdural grids in place. Two patients underwent two separate depth electrode implantations for a total of 101 procedures and MRI scans. No clinical adverse events were reported during or immediately after imaging. Image quality was graded as acceptable for 97 MRI scans. Review of follow-up CT and MRI studies after implant removal, available for 70 patients, did not demonstrate unexpected complications in 69 patients. CONCLUSION: In our experience, a low SAR MRI protocol can be used to safely localize intracranial subdural grids and depth electrode in patients with refractory epilepsy.

Supraorbital Craniotomy for Sellar Solitary Fibrous Tumor: Operative Technique and Literature Review.

OBJECTIVE: Solitary fibrous tumors (SFT) are rare, locally aggressive, mesenchymal neoplasms that pose both diagnostic and operative challenges. In this review of the literature, data were collected from all previously described sellar and suprasellar SFTs to date, with special attention paid to presenting symptoms, surgical technique performed, recurrence status, and adjuvant radiotherapy or chemotherapy, among others. METHODS: A review of prior sellar and suprasellar SFTs was performed. Eleven cases of SFTs in the sellar and suprasellar regions were identified. We considered age and sex, along with case-specific information, such as presenting symptoms, surgical approach taken, number of resections, recurrence information, and adjuvant therapy. RESULTS: All cases including ours presented with visual deficits, ranging from blurry vision to complete bilateral visual loss. Endocrine hormonal abnormalities occurred in nearly all patients (90%.) Craniotomy was performed more often than endonasal transsphenoidal resection of tumors, 42% versus 33%, respectively. CONCLUSIONS: SFTs are slow-growing fibroblastic mesenchymal neoplasms that comprise <2% of all intracranial tumors. They are even more infrequently found in the sellar/suprasellar region, with our case being the 12th reported case of such and the first only to use supraorbital craniotomy as a resection strategy. Multimodal therapy consisting of safe gross total resection, radiosurgery, and/or chemotherapy provides the best possible results for these rare and locally aggressive entities.