Gompel, Jamie J. Van

Abstract BACKGROUND Subdural grids and strip electrodes provide wide coverage of the cerebral cortex, precise delineation of the extent of the seizure onset zone, and improved spatial sampling to perform functional mapping for eloquent cortex. OBJECTIVE To describe a novel device that allows for a minimally invasive approach to implantation of subdural grid and strip electrodes. METHODS A skull mounted device was created to allow for implantation of subdural electrodes through a keyhole craniotomy with direct visualization using the aid of a flexible neurovideoscope. The initial studies in preparation for grid development performed on cadaveric skulls were analyzed to determine the size of craniotomy required for deployment, maximal distance of strip electrode deployment from center of craniotomy, and visual inspection of the cortex was performed for any underlying damage. RESULTS The device allowed for the placement of subdural electrodes through a 40-mm craniotomy. Subdural electrodes were deployed in multiple directions to a distance of a 70-mm radius from the center of the craniotomy. There was no visual damage to the underlying cortex after the procedures were completed. CONCLUSION Large craniotomies are typically desired to provide direct visualization of the implantation of subdural electrodes, but can increase the risk of subdural hemorrhages and infections. This study describes a novel minimally invasive endoscopically assisted device for the implantation of subdural strip electrodes under direct visualization. With this device, we are able to limit the size of the craniotomy, avoid incision through the temporalis muscle, and implant subdural electrodes with visualization of the cortex.

Background There is no consensus exists regarding which reconstructive approach, if any, should be used after performing transcranial lateral orbital wall resections. Rigid reconstruction is often done to prevent enophthalmos; however, it is not clear if this is a risk with extensive orbital wall resections for transcranial surgery. Objective To assess globe position dynamics in patients that underwent transcranial lateral and superior orbital wall resections without rigid reconstruction to determine if enophthalmos is a significant risk. Methods Preoperative (PO) and postoperative data were retrospectively collected from the electronic medical records of 55 adult patients undergoing lateral and superior orbital wall resections as part of a skull base approach. The globe positions were assessed radiologically at all available time points and used to track relative globe displacements over time. Results An evaluation of PO variables identified a relationship between maximum lesion diameters and globe positions dynamics. The composition of globe position presentations in the population remained relatively stable over time, with only 1 out of 55 patients (1.81%) developing postoperative enophthalmos. An assessment of mean globe displacements revealed improvements in the patients presenting with PO exophthalmos, and stability in the patients presenting with normal PO globe positions. Conclusions Excellent results in long-term postoperative globe position dynamics can be achieved without the use of rigid reconstruction after transcranial lateral and superior orbital wall resections, regardless of the PO globe positioning.

Abstract BACKGROUND AND IMPORTANCE Temporal lobe encephaloceles are increasingly recognized as a potential cause of medically refractory epilepsy and surgical treatment has proven effective. Resection of the encephalocele and associated cortex is often sufficient to provide seizure control. However, it is difficult to determine the extent of adjacent temporal lobe that should be resected. We present a case report and our technique of a tailored inferior temporal pole resection. CLINICAL PRESENTATION A 32-yr-old man with an 11-yr history of medically refractory epilepsy. Prolonged electroencephalography (EEG) revealed frequent left and rare right frontotemporal sharp waves. Numerous seizures were captured with EEG, all of which originated from the left temporal region. Statistical parametric mapping (SPM) subtraction ictal–interictal SPECT coregistered with magnetic resonance imaging (MRI) (SISCOM) demonstrated ictal hyperperfusion in the anterior left temporal lobe. MRI showed 2 encephaloceles in the left anterior temporal lobe with the accompanying bony defects in the floor of the middle cranial fossa apparent on the computed tomography scan. The patient underwent left temporal craniotomy with intraoperative electrocorticography, resection of the encephaloceles, and a tailored inferior temporal lobectomy (IFTL) and repair of the middle fossa defects. At 7 mo follow up he reported seizure-freedom since surgery. CONCLUSION Resection of temporal encephalocele and adjacent cortex is safe and effective procedure for select patients with medically refractory epilepsy. This video demonstrates our technique which provides a more standardized approach to the resection.

Abstract Colloid cysts are typically slow-growing lesions that account for approximately 1% of primary intracranial neoplasms and predominantly exist intraventricularly. These benign lesions typically can exist symptom-free for years and do not require surgical intervention. However, if the location of the colloid cyst is symptomatic, surgical debulking may be indicated. In this intraoperative video, we illustrate the case of an 8 cm, intra/extra-ventricular colloid cyst that appeared as a craniopharyngioma on preoperative imaging, but upon resection via a trans-middle temporal gyrus approach, was found to be very atypically filled with a thick, “tarry” substance, which we hypothesize is due to serial, subacute lesional hemorrhages. After debulking and piecemeal resection of the majority of the mass with ultrasonic aspiration and microsurgical tools, a hard, calcified nodule was left tenaciously adherent to the superior cerebellar artery to prevent damage to this vascular structure.

Objectives Determine the effect of endoscopic skull base surgery (ESBS) on long‐term olfactory outcomes after surgery. Methods An English‐language search was conducted using the Cochrane, MEDLINE, Scopus, and Embase databases from January 2000 to October 2017 for adult patients undergoing ESBS with subjective and objective olfaction outcomes. Two authors independently examined articles to identify those meeting inclusion criteria. Studies examining objective olfactory outcomes after ESBS were included in the meta‐analysis. A random‐effects meta‐analysis of patients undergoing sellar and parasellar ESBS was conducted to compare preoperative and postoperative olfactory outcomes using the University of Pennsylvania Smell Identification Test (UPSIT) and Cross‐Cultural Smell Identification Test (CCSIT). Results Among 339 eligible articles, 29 articles met inclusion criteria. Twenty‐five of these focused on sellar and parasellar tumors. Individual articles not meeting criteria for meta‐analysis were qualitatively reported. Meta‐analysis showed there was no difference in preoperative and postoperative olfactory function after sellar and parasellar ESBS based on the UPSIT (five studies, mean difference [MD] = −1.03; 95% CI: −3.98, 1.93; P = .50) and the CCIST (three studies, MD = −0.77; 95% CI: −3.03, 1.49; P = .50). A pooled overall meta‐analysis revealed similar results (eight studies, effect size = −0.30; 95% CI: −0.79, 0.18; P = .22). However, heterogeneity for all meta‐analyses was high ( I 2 > 95%, P < .01), suggesting significant variation in the included studies. Conclusions Based on published objective olfaction outcomes after sellar and parasellar ESBS, there was no significant difference between preoperative and postoperative olfaction. Further prospective studies using validated objective measures of olfaction are required to improve our understanding on this subject. Level of Evidence 2a Laryngoscope , 129:1998–2007, 2019

Objectives To present a rare case of traumatic facial neuroma involving the geniculate ganglion and review relevant literature. Patient Thirty-year-old man. Intervention Microsurgical resection via combined mastoid-middle fossa approach with great auricular nerve interpositional graft. Main Outcome Measures Patient demographics and pre- and postoperative facial nerve function. Results A 30-year-old man with a reported history of prior Bell's palsy developed progressive complete (House–Brackmann VI) right facial paralysis following blunt trauma. Imaging was strongly suggestive of a geniculate ganglion hemangioma. As the patient had no spontaneous improvement in his poor facial function over the course of 9 months, he underwent resection of the facial nerve lesion with great auricular nerve graft interposition via a combined mastoid-middle fossa approach. Histopathology demonstrated disorganized fascicles, with axonal clustering reminiscent of sprouting/regeneration following trauma. No cellular proliferation or vascular malformation was present. Conclusion Traumatic facial nerve neuromas can occur following temporal bone trauma and can closely mimic primary facial nerve tumors. Akin to the management of geniculate ganglion hemangioma and schwannoma, preoperative facial function largely dictates if and when surgery should be pursued.