Foundations in Neurological Surgery

Continuously searching for ways to improve resident education, Dr. Ashwini Sharan has begun a series of classes for residents. Each class is a one-day session focused on a specific set of techniques that the resident will need competency in. Using a traditional class format means that each resident is not only drilled on specific skills, but also gets to learn from his fellow students - and future colleagues- by observing them perform the same tasks. The Congress of Neurological Surgeons conference has similar workshops where practicing neurosurgeons can get familiarity with new tools. These classes are intended to ensure that residents enter the OR with a solid foundation of basic skills. The first class was conducted with support from Stryker, a medical technology firm which is interested in staging similar courses at universities around the countr

Auras in patients with temporal lobe epilepsy and mesial temporal sclerosis.

We investigated auras in patients with drug-resistant temporal lobe epilepsy (TLE) and mesial temporal sclerosis (MTS). We also investigated the clinical differences between patients with MTS and abdominal auras and those with MTS and non-mesial temporal auras. All patients with drug-resistant TLE and unilateral MTS who underwent epilepsy surgery at Jefferson Comprehensive Epilepsy Center from 1986 through 2014 were evaluated. Patients with good postoperative seizure outcome were investigated. One hundred forty-nine patients (71 males and 78 females) were studied. Thirty-one patients (20.8%) reported no auras, while 29 patients (19.5%) reported abdominal aura, and 30 patients (20.1%) reported non-mesial temporal auras; 16 patients (10.7%) had sensory auras, 11 patients (7.4%) had auditory auras, and five patients (3.4%) reported visual auras. A history of preoperative tonic-clonic seizures was strongly associated with non-mesial temporal auras (odds ratio 3.8; 95% CI: 1.15-12.98; p=0.02). About one-fifth of patients who had MTS in their MRI and responded well to surgery reported auras that are historically associated with non-mesial temporal structures. However, the presence of presumed non-mesial temporal auras in a patient with MTS may herald a more widespread epileptogenic zone

Patient historical risk factors associated with seizure outcome after surgery for drug-resistant nonlesional temporal lobe epilepsy.

OBJECTIVE: To investigate the possible influence of risk factors on seizure outcome after surgery for drug-resistant nonlesional temporal lobe epilepsy (TLE). METHODS: This retrospective study recruited patients with drug-resistant nonlesional TLE who underwent epilepsy surgery at Jefferson Comprehensive Epilepsy Center and were followed for a minimum of one year. Patients had been prospectively registered in a database from 1991 through 2014. Postsurgical outcome was classified into two groups; seizure free or relapsed. The possible risk factors influencing long-term seizure outcome after surgery were investigated. RESULTS: Ninety-five patients (42 males and 53 females) were studied. Fifty-four (56.8%) patients were seizure free. Only a history of febrile seizure in childhood affected the risk of post-operative seizure recurrence (odds ratio 0.22; 95% CI: 0.06-0.83; p = 0.02). Gender, race, family history of epilepsy, history of status epilepticus, duration of disease before surgery, aura symptoms, intelligence quotient, and seizure type or frequency were not predictors of outcome. CONCLUSION: Many patients with drug-resistant nonlesional TLE responded favorably to surgery. The only factor predictive of seizure outcome after surgery was a history of febrile seizure in childhood. It is critical to distinguish among different types of TLE when assessing outcome after surgery

Historical Risk Factors Associated with Seizure Outcome After Surgery for Drug-Resistant Mesial Temporal Lobe Epilepsy.

OBJECTIVE: To investigate the possible influence of risk factors on seizure outcome after surgery for drug-resistant temporal lobe epilepsy (TLE) and mesial temporal sclerosis (MTS). METHODS: This retrospective study recruited patients with drug-resistant MTS-TLE who underwent epilepsy surgery at Jefferson Comprehensive Epilepsy Center and were followed for a minimum of 1 year. Patients had been prospectively registered in a database from 1986 through 2014. After surgery outcome was classified into 2 groups: seizure-free or relapsed. The possible risk factors influencing long-term outcome after surgery were investigated. RESULTS: A total of 275 patients with MTS-TLE were studied. Two thirds of the patients had Engel\u27s class 1 outcome and 48.4% of the patients had sustained seizure freedom, with no seizures since surgery. Patients with a history of tonic-clonic seizures in the year preceding surgery were more likely to experience seizure recurrence (odds ratio, 2.4; 95% confidence interval 1.19-4.80; P = 0.01). Gender, race, family history of epilepsy, history of febrile seizure, history of status epilepticus, duration of disease before surgery, intelligence quotient, and seizure frequency were not predictors of outcome. CONCLUSIONS: Many patients with drug-resistant MTS-TLE respond favorably to surgery. It is critical to distinguish among different types and etiologies of TLE when predicting outcome after surgery

Occipital nerve stimulator systems: Review of complications and surgical techniques

Introduction: Stimulation of the occipital nerves is becoming more widely accepted in the treatment of occipital neuritis and migraine disorders. Objective: Presently, equipment available for spinal cord stimulation is adapted for insertion into the subcutaneous space over the occipital nerves. Many technical factors need to be reassessed to optimize the therapy. Methods: We performed a retrospective review of patients implanted from 2003 to 2007 at a single center. We aimed to analyze the rate of surgical complications related to implantation technique. A total of 28 patients were present for analysis. Patients were followed up to 60 months with a mean follow-up of 21 months. Results: There is a 32% revision rate for electrode migration or displacement, 3.6% removal rate for infection, and a 21% removal rate for lack of efficacy. Although not well studied secondary to small patient populations, this was consistent with a review of the literature which demonstrated a 10-60% revision rate. Other factors such as anchoring strategy, strain relief, and battery location were all considered in the analysis and will be presented. A major determination was that use of a second incision with an additional strain relief loop had only a 10% revision rate of the lead while those without this additional strain relief loop had a 62.5% revision rate. Conclusion: Many technical factors need to be addressed for optimization of occipital nerve stimulation

Evaluating the Migration Rates in Percutaneous Spinal Cord Stimulation Trials

Introduction: Spinal cord stimulation (SCS) provides symptom reduction in patients with chronic low back pain. The most common complication in SCS is percutaneous lead migration from initial placement site. It is our goal to determine whether using skin anchors during trial implantation reduces SCS trial lead migration rates compared to historical controls. Methods: 197 patients who underwent SCS trial placement at Thomas Jefferson University Hospital between 2015 and 2018 were considered for this study. Complete data including device impedance measurements and pre and post trial x-rays was collected on 12 historical control patients and 19 patients with leads secured using an anchor. Results: The mean degree of lead migration was not statistically significantly different between the anchor group and control group in the right lead (0.71 mm (95% CI -6.24, 7.66, p=0.84) and the left lead (-0.85 mm (95% CI -7.70, 6.00, p=0.80). Additionally, there was no statistical difference in device impedance from the first day of the trial to the trial removal date between the anchor group and control group (-47.35 Ohms (95% CI -181.48, 86.78, p=0.47). Discussion: There was no significant reduction in lead migration or device impedance measurement in patients who underwent trial SCS with leads secured with an anchor compared to historical controls. This raises the question of whether the anchoring technique successfully reduces lead migration and emphasizes the importance of obtaining pre and post trial x-rays to evaluate lead migration

Presurgical thalamic hubness predicts surgical outcome in temporal lobe epilepsy.

OBJECTIVE: To characterize the presurgical brain functional architecture presented in patients with temporal lobe epilepsy (TLE) using graph theoretical measures of resting-state fMRI data and to test its association with surgical outcome. METHODS: Fifty-six unilateral patients with TLE, who subsequently underwent anterior temporal lobectomy and were classified as obtaining a seizure-free (Engel class I, n = 35) vs not seizure-free (Engel classes II-IV, n = 21) outcome at 1 year after surgery, and 28 matched healthy controls were enrolled. On the basis of their presurgical resting-state functional connectivity, network properties, including nodal hubness (importance of a node to the network; degree, betweenness, and eigenvector centralities) and integration (global efficiency), were estimated and compared across our experimental groups. Cross-validations with support vector machine (SVM) were used to examine whether selective nodal hubness exceeded standard clinical characteristics in outcome prediction. RESULTS: Compared to the seizure-free patients and healthy controls, the not seizure-free patients displayed a specific increase in nodal hubness (degree and eigenvector centralities) involving both the ipsilateral and contralateral thalami, contributed by an increase in the number of connections to regions distributed mostly in the contralateral hemisphere. Simulating removal of thalamus reduced network integration more dramatically in not seizure-free patients. Lastly, SVM models built on these thalamic hubness measures produced 76% prediction accuracy, while models built with standard clinical variables yielded only 58% accuracy (both were cross-validated). CONCLUSIONS: A thalamic network associated with seizure recurrence may already be established presurgically. Thalamic hubness can serve as a potential biomarker of surgical outcome, outperforming the clinical characteristics commonly used in epilepsy surgery centers

Cervical Intramedullary Ganglioma

A 48 year male presented to the ER with severe headaches which were episodic in nature and which had been present for several weeks. Patient had a history of traumatic head injury (TBI) several years prior. Otherwise, he was in good health with no significant past medical or surgical history. On physical exam, patient was oriented x 3 with an intact cranial nerve exam. He had significant upper and lower extremity spasticity with mild hand intrinsic weakness. His motor exam was otherwise unremarkable. His gait was very spastic. He had sustained lower extremity clonus, upgoing toes, and increased tone in the upper and lower extremities. His sensation was intact to light touch, pinprick, proprioception and temperature

Type of preoperative aura may predict postsurgical outcome in patients with temporal lobe epilepsy and mesial temporal sclerosis.

PURPOSE: As the initial symptoms of epileptic seizures, many types of auras have significant localizing or lateralizing value. In this study, we hypothesized that the type of aura may predict postsurgical outcome in patients with medically refractory temporal lobe epilepsy (TLE) and mesial temporal sclerosis (MTS). METHODS: In this retrospective study, all patients with a clinical diagnosis of medically refractory TLE due to unilateral mesial temporal sclerosis who underwent epilepsy surgery at the Jefferson Comprehensive Epilepsy Center were recruited. Patients were prospectively registered in a database from 1986 through 2014. Postsurgical outcome was classified into two groups: seizure freedom or relapse. Outcome was compared between seven groups of patients according to their preoperative auras. RESULTS: Two hundred thirty-seven patients were studied. The chance of becoming free of seizures after surgery in patients with abdominal aura was 65.1%, while in other patients, this was 43.3% (P=0.01). In two-by-two comparisons, no other significant differences were observed. CONCLUSION: Patients with medically refractory TLE-MTS who reported abdominal auras preceding their seizures fared better postoperatively with regard to seizure control compared with those who did not report auras, which may indicate bitemporal dysfunction, and to patients with other auras, which may indicate a widespread epileptogenic zone in the latter group of patients

Characterizing the timeline of drug resistant epilepsy surgery.

Introduction: Although early detection and surgery are crucial for positive outcomes in individuals with drug-resistant epilepsy (DRE), a minority of qualifying patients receive it in the US. This retrospective study investigates why some DRE patients who undergo complete pre-surgical assessment end up not receiving surgery. Methods: We analyzed 211 EPIC charts from all of Jefferson Comprehensive Epilepsy Center\u27s patients who underwent DRE surgical evaluation from 2017 through 2019. To that end, we characterized the DRE surgery timeline and collected data on age, onset of seizures and drug resistance, surgery dates, surgical modalities, and notes that elucidated the reasoning behind surgical decisions. We analyzed the data by comparing the surgery completion rates and breaking them down by surgery modality and decision reason. Results: Of the 211 patients, 130(61.6%) received surgery, and 81(38.4%) did not. The two most frequent reasons for patients not receiving surgery were the patient\u27s loss of interest in surgery (34.6%) and the need for further antiepileptic drug trials (14.8%) to confirm DRE status. Within the non-interested group, 13(46.4%) patients were thought to benefit from resection or ablation, and 10(35.7%) from phase 2 invasive monitoring. Discussion: The biggest reason for patients not receiving life-improving DRE surgery is the individual\u27s lack of interest in the procedure even after full evaluation and planning. We hope this information gets us a step closer to targeting the low DRE surgical rates and helps physicians better guide their patients through the surgery process, delivering earlier surgeries, and improving outcomes