Epidermoid cysts (ECs) are uncommon pediatric tumors that often occur in the cerebellopontine angle. Although cyst rupture is a recognized complication, the radiographic evolution of an EC following rupture and the resultant parenchymal brainstem edema have not been reported. The authors present the case of a 13-year-old female with a newly diagnosed cerebellopontine angle EC who presented with worsening headaches, photophobia, and emesis. Magnetic resonance imaging demonstrated significant pericystic brainstem edema and mass effect with effacement of the fourth ventricle. Refractory symptoms prompted repeat imaging, revealing cyst enlargement and dense rim enhancement. Resection of the EC resolved both her symptoms and the brainstem edema. This case documents the radiographic evolution of EC rupture and subsequent clinical course.
Zhe Guan, Todd Hollon, J. Nicole Bentley, and Hugh J. L. Garton
J. Nicole Bentley, Ramón E. Figueroa, and John R. Vender
Cerebral venous thrombosis is an uncommon cause of stroke but remains a challenge for physicians faced with this diagnosis largely due to the variability in presentation. Anticoagulation, typically with intravenous heparin, remains the mainstay of treatment for stable patients and is sufficient in the majority of cases. However, a significant mortality rate exists for cerebral venous thrombosis due to patients who deteriorate or do not adequately respond to initial treatments. It is in these patients that more aggressive interventions must be undertaken. The neurosurgeon is often called on, either acutely for initial evaluation of the stroke or venous hemorrhage or after the failure of initial therapy for clot evacuation, hemicraniectomy, or thrombectomy. A proper workup must include a search for an underlying, correctable cause as well as thorough follow-up with correction of identified risk factors to decrease the risk of recurrent disease.
J. Nicole Bentley, Cindy Chestek, William C. Stacey, and Parag G. Patil
Optogenetics, the use of light to stimulate or inhibit neural circuits via viral transduction of protein channels, has emerged as a possible method of treating epilepsy. By introducing viral vectors carrying algal-derived cation or anion channels, known as opsins, neurons that initiate or propagate seizures may be silenced. To date, studies using this technique have been performed in animal models, and current efforts are moving toward more sophisticated nonhuman primate models. In this paper, the authors present a brief overview of the development of optogenetics and review recent studies investigating optogenetic modification of circuits involved in seizures. Further developments in the field are explored, with an emphasis on how optogenetics may influence future neurosurgical interventions.
Eric W. Franz, J. Nicole Bentley, Patricia P. S. Yee, Kate W. C. Chang, Jennifer Kendall-Thomas, Paul Park, and Lynda J. S. Yang
Patient outcome measures are becoming increasingly important in the evaluation of health care quality and physician performance. Of the many novel measures currently being explored, patient satisfaction and other subjective measures of patient experience are among the most heavily weighted. However, these subjective measures are strongly influenced by a number of factors, including patient demographics, level of understanding of the disorder and its treatment, and patient expectations. In the present study, patients referred to a neurosurgery clinic for degenerative spinal disorders were surveyed to determine their understanding of lumbar spondylosis diagnosis and treatment.
A multiple-choice, 6-question survey was distributed to all patients referred to a general neurosurgical spine clinic at a tertiary care center over a period of 11 months as a quality improvement initiative to assist the provider with individualized patient counseling. The survey consisted of questions designed to assess patient understanding of the role of radiological imaging in the diagnosis and treatment of low-back and leg pain, and patient perception of the indications for surgical compared with conservative management. Demographic data were also collected.
A total of 121 surveys were included in the analysis. More than 50% of the patients indicated that they would undergo spine surgery based on abnormalities found on MRI, even without symptoms; more than 40% of patients indicated the same for plain radiographs. Similarly, a large proportion of patients (33%) believed that back surgery was more effective than physical therapy in the treatment of back pain without leg pain. Nearly one-fifth of the survey group (17%) also believed that back injections were riskier than back surgery. There were no significant differences in survey responses among patients with a previous history of spine surgery compared with those without previous spine surgery.
These results show that a surprisingly high percentage of patients have misconceptions regarding the diagnosis and treatment of lumbar spondylosis, and that these misconceptions persist in patients with a history of spine surgery. Specifically, patients overemphasize the value of radiological studies and have mixed perceptions of the relative risk and effectiveness of surgical intervention compared with more conservative management. These misconceptions have the potential to alter patient expectations and decrease satisfaction, which could negatively impact patient outcomes and subjective valuations of physician performance. While these results are preliminary, they highlight a need for improved communication and patient education during surgical consultation for lumbar spondylosis.
Jacob R. Lepard, Esther Dupépé, Matthew Davis, Jennifer DeWolfe, Bonita Agee, J. Nicole Bentley, and Kristen Riley
Invasive monitoring has long been utilized in the evaluation of patients for epilepsy surgery, providing localizing information to guide resection. Stereoelectroencephalography (SEEG) was introduced at the authors’ level 4 epilepsy surgery program in 2013, with responsive neurostimulation (RNS) becoming available the following year. The authors sought to characterize patient demographics and epilepsy-related variables before and after SEEG introduction to understand whether differences emerged in their patient population. This information will be useful in understanding how SEEG, possibly in conjunction with RNS availability, may have changed practice patterns over time.
This is a retrospective cohort study of consecutive patients who underwent surgery for epilepsy from 2006 to 2018, comprising 7 years before and 5 years after the introduction of SEEG. The authors performed univariate analyses of patient characteristics and outcomes and used generalized estimating equations logistic regression for predictive analysis.
A total of 178 patients were analyzed, with 109 patients in the pre-SEEG cohort and 69 patients in the post-SEEG cohort. In the post-SEEG cohort, more patients underwent invasive monitoring for suspected bilateral seizure onsets (40.6% vs 22.0%, p = 0.01) and extratemporal seizure onsets (68.1% vs 8.3%, p < 0.0001). The post-SEEG cohort had a higher proportion of patients with seizures arising from eloquent cortex (14.5% vs 0.9%, p < 0.001). Twelve patients underwent RNS insertion in the post-SEEG group versus none in the pre-SEEG group. Fewer patients underwent resection in the post-SEEG group (55.1% vs 96.3%, p < 0.0001), but there was no significant difference in rates of seizure freedom between cohorts for those patients having undergone a follow-up resection (53.1% vs 59.8%, p = 0.44).
These findings demonstrate that more patients with suspected bilateral, eloquent, or extratemporal epilepsy underwent invasive monitoring after adoption of SEEG. This shift occurred coincident with the adoption of RNS, both of which likely contributed to increased patient complexity. The authors conclude that their practice now considers invasive monitoring for patients who likely would not previously have been candidates for surgical investigation and subsequent intervention.
Ganne Chaitanya, Andrew K. Romeo, Adeel Ilyas, Auriana Irannejad, Emilia Toth, Galal Elsayed, J. Nicole Bentley, Kristen O. Riley, and Sandipan Pati
Despite numerous imaging studies highlighting the importance of the thalamus in a patient’s surgical prognosis, human electrophysiological studies involving the limbic thalamic nuclei are limited. The objective of this study was to evaluate the safety and accuracy of robot-assisted stereotactic electrode placement in the limbic thalamic nuclei of patients with suspected temporal lobe epilepsy (TLE).
After providing informed consent, 24 adults with drug-resistant, suspected TLE undergoing evaluation with stereoelectroencephalography (SEEG) were enrolled in the prospective study. The trajectory of one electrode planned for clinical sampling of the operculoinsular cortex was modified to extend it to the thalamus, thereby preventing the need for additional electrode placement for research. The anterior nucleus of the thalamus (ANT) (n = 13) and the medial group of thalamic nuclei (MED) (n = 11), including the mediodorsal and centromedian nuclei, were targeted. The postimplantation CT scan was coregistered to the preoperative MR image, and Morel’s thalamic atlas was used to confirm the accuracy of implantation.
Ten (77%) of 13 patients in the ANT group and 10 (91%) of 11 patients in the MED group had electrodes accurately placed in the thalamic nuclei. None of the patients had a thalamic hemorrhage. However, trace asymptomatic hemorrhages at the cortical-level entry site were noted in 20.8% of patients, who did not require additional surgical intervention. SEEG data from all the patients were interpretable and analyzable. The trajectories for the ANT implant differed slightly from those of the MED group at the entry point—i.e., the precentral gyrus in the former and the postcentral gyrus in the latter.
Using judiciously planned robot-assisted SEEG, the authors demonstrate the safety of electrophysiological sampling from various thalamic nuclei for research recordings, presenting a technique that avoids implanting additional depth electrodes or compromising clinical care. With these results, we propose that if patients are fully informed of the risks involved, there are potential benefits of gaining mechanistic insights to seizure genesis, which may help to develop neuromodulation therapies.