Meyer, Fredric B.

Object Microsurgical resection of supratentorial cavernomas associated with intractable epilepsy is performed frequently. Despite its common occurrence, little is known about patient perceptions of microsurgical resection for cavernomas. This survey study was performed to investigate patient perceived outcome after surgery for cavernomas associated with intractable epilepsy. Methods The authors' surgical database was searched for cavernoma resection performed between 1971 and July of 2006. Of the initial 173 patients identified, 102 met criteria for medically intractable seizures. These 102 patients were then mailed a survey to determine follow-up and patient satisfaction. Thirty-nine surveys were returned as undeliverable, and 30 (48%) of the remaining 63 patients responded. Results The average age at surgery for patients responding to this survey was 40 ± 16 years compared with 35 ± 15 years for all 102 patients. At prolonged follow-up, 87% of patients reported being seizure-free. Of those with seizures, 2 (7%) reported being nearly seizure-free (rare disabling seizures), 2 (7%) believed they had a worthwhile improvement in seizure frequency, and no patient (0%) in this series believed they did not have a worthwhile improvement in seizure frequency. Ninety percent of responders stated they definitely, and 10% probably, would have surgery again. No patient responded that they probably or definitely would not have epilepsy surgery. Mean clinical follow-up was 36 ± 8 months and survey follow-up was 97 ± 13 months for these 30 patients. Use of the mail-in survey increased follow-up length 2.7 times longer compared with clinical follow-up. Conclusions It is clear from this select group of survey responders that patients undergoing surgery for cavernomas associated with medically intractable epilepsy are happy they underwent surgery (100%) and had excellent surgical outcomes (87% seizure-free) at prolonged follow-up of 97 ± 13 months. These survey results support that microsurgical resection for cavernomas is highly effective and significantly improves these patients' quality of life.

Background and Purpose— The purpose of this study was to determine and compare the rate of stroke, myocardial infarction, and death in patients undergoing early and late carotid endarterectomy (CEA) after a symptomatic event and in asymptomatic patients. Methods— We conducted a retrospective analysis of all CEAs performed in the Department of Neurosurgery between January 2004 and May 2009. Patients were divided into 3 groups: Group 1, asymptomatic patients; Group 2, symptomatic patients operated on >2 weeks after their transient ischemic attack or stroke; and Group 3, symptomatic patients operated on ≤2 weeks of their transient ischemic attack or stroke. Primary outcomes were any myocardial infarction, stroke, or death occurring within 30 days postoperatively. The secondary end point was transient ischemic attack within 30 days postoperatively. Results— Five hundred thirty-two CEAs were performed on 507 patients during the study period. Thirty-day follow-up was available for 500 patients with 525 CEAs. Groups 1, 2, and 3 consisted of 278, 105, and 142 CEAs, respectively. In total, 12 patients had primary outcomes. In Group 1, 5 patients had primary outcomes of stroke, myocardial infarction, or death (1.8%); in Group 2, 1 patient had primary outcomes (1.0%); and in Group 3, 6 patients had primary outcomes (4.2%). There was no significant difference in the rate of primary outcomes among the 3 groups ( P =0.17) or when Groups 2 and 3 were compared ( P =0.24). Conclusions— Although the perioperative risk of transient ischemic attacks, stroke, death, and myocardial infarction is slightly higher in symptomatic patients operated on early, CEA can be done with an acceptable risk in properly selected symptomatic patients within 2 weeks of their transient ischemic attack or stroke.

Object Second-generation antiepileptic drugs (AEDs) are increasingly used in the care of patients with glioma. There is little data on how this practice compares with the use of traditional AEDs in this population. This noninferiority analysis compares seizure outcomes and side effects in patients with glioma treated with phenytoin and levetiracetam monotherapy. Methods The authors retrospectively reviewed the records of 500 consecutive patients with glioma who were treated in clinical trials from 2001 to 2008 at 3 Mayo Clinic campuses. To be eligible for the study, these patients had to have had at least 1 clinical seizure and to have undergone follow-up for at least 6 months. Seizure outcomes, defined by the occurrence of a second seizure, time to second seizure, and seizure frequency, along with AED side effects, were compared between cohorts treated with phenytoin or levetiracetam Results Seventy-six patients were identified, 25 treated with phenytoin and 51 with levetiracetam. Sixty-four percent of the patients had a Grade 4 astrocytoma. There was no difference in seizure outcome between the phenytoin and levetiracetam groups when comparing time to second seizure (p = 0.584), second seizure rates (p = 0.561), and average seizures per month (p = 0.776). When adjusting for age, sex, type of seizure, type of glioma, and dosage using univariate and multivariate models, there were no differences between the treatment groups and none of these covariates were statistically significant for explaining the second seizure rates between treatment groups (all p values > 0.05). The incidence of side effects in the levetiracetam group was 6% versus 20% in the phenytoin group (p = 0.106). Additionally, 36% of the patients in the phenytoin group had dose adjustments unrelated to breakthrough seizures compared with only 10% in the levetiracetam group (p = 0.010) Conclusions In this study, patients with glioma treated with levetiracetam and phenytoin had similar seizure control. Patients treated with levetiracetam experienced fewer side effects and required fewer nonseizure-related dose adjustments than patients treated with phenytoin. Levetiracetam is a safe, effective, and preferred alternative for seizure management in patients with glioma.

Object Obesity as a consequence of management of pediatric craniopharyngioma is a well-described phenomenon related to the degree of hypothalamic involvement. However, weight change and obesity have not been analyzed in adult patients. Therefore, the purpose of this study was 1) to evaluate the pattern of postoperative weight gain related to preoperative body mass index (BMI), 2) determine if postoperative weight gain is an issue in adult patients, and 3) develop an objective MR imaging grading system to predict risk of postoperative weight gain and obesity in adults treated for craniopharyngioma. Methods The authors retrospectively screened 296 patients with known craniopharyngioma for the following inclusion criteria: pathologically confirmed craniopharyngioma, index surgery at the authors' institution, and operative weight and height recorded with at least 3 months of follow-up including body weight measurement. Patients aged 18 years or younger were excluded, yielding 28 cases for analysis. Cases of craniopharyngiomas were compared with age- and sex-matched controls (pituitary adenoma patients) to evaluate the pattern and significance of perioperative weight changes. Results Mean age was 46 ± 17 years at surgery, and 64% of the patients were male. Complete resection was achieved in 71% of cases. There was no correlation of preoperative BMI and postoperative weight gain testing in a linear model. Sixty-one percent and 46% of patients had postoperative weight gains greater than 4 and 9%, respectively. Comparing craniopharyngioma patients (cases) to age- and sex-matched controls, the preoperative BMIs were similar (p = 0.93) between cases (mean 28.9 [95% CI 30.9–26.9]) and controls (mean 29.3 [95% CI 31.9–26.7]). However, there was a trend to a greater mean postoperative weight change (percentage) in cases (10.1%) than in controls (5.6%) (p = 0.24). Hypothalamic T2 signal change and irregular contrast enhancement correlated and predicted higher-grade hypothalamic involvement. Furthermore, they can be used to objectively grade hypothalamic involvement as the authors propose. Progressive hypothalamic involvement correlated with larger postoperative weight gains (p = 0.022); however, hypothalamic involvement did not correlate with preoperative BMI (p = 0.5). Conclusions Postoperative weight gain in adult patients undergoing surgery for craniopharyngioma is a significant problem and correlates with hypothalamic involvement, as it does in pediatric patients. Finally, objective MR imaging criteria can be used to predict risk of postoperative weight gain and aid in grading of hypothalamic involvement.

Object Intracranial monitoring for temporal lobe seizure localization to differentiate neocortical from mesial temporal onset seizures requires both neocortical subdural grids and hippocampal depth electrode implantation. There are 2 basic techniques for hippocampal depth electrode implantation. This first technique uses a stereotactically guided 8-contact depth electrode directed along the long axis of the hippocampus to the amygdala via an occipital bur hole. The second technique involves direct placement of 2 or 3 4-contact depth electrodes perpendicular to the temporal lobe through the middle temporal gyrus and overlying subdural grid. The purpose of this study was to determine whether one technique was superior to the other by examining monitoring success and complications. Methods Between 1997 and 2005, 41 patients underwent invasive seizure monitoring with both temporal subdural grids and depth electrodes placed in 2 ways. Patients in Group A underwent the first technique, and patients in Group B underwent the second technique. Results Group A consisted of 26 patients and Group B 15 patients. There were no statistically significant differences between Groups A and B regarding demographics, monitoring duration, seizure localization, or outcome (Engel classification). There was a statistically significant difference at the point in time at which these techniques were used: Group A represented more patients earlier in the series than Group B (p < 0.05). The complication rate attributable to the grids and depth electrodes was 0% in each group. It was more likely that the depth electrodes were placed through the grid if there was a prior resection and the patient was undergoing a new evaluation (p < 0.05). Furthermore, Group A procedures took significantly longer than Group B procedures. Conclusions In this patient series, there was no difference in efficacy of monitoring, complications, or outcome between hippocampal depth electrodes placed laterally through temporal grids or using an occipital bur hole stereotactic approach. Placement of the depth electrodes perpendicularly through the grids and middle temporal gyrus is technically more practical because multiple head positions and redraping are unnecessary, resulting in shorter operative times with comparable results.

Object A review of the literature has revealed scant data related to neurosurgical treatment of gravid patients. The authors reviewed their experience with the neurosurgical treatment of pregnant women to better characterize the optimal management strategies for intracranial pathological entities in this population. Methods Between July 1969 and July 2005, 34 patients with documented pregnancy and concomitant intracranial pathological entities were treated at the authors' institution. The average age of the gravid patients at presentation was 27 ± 6 years. Twelve patients harbored vascular and 14 patients harbored neoplastic lesions. Four gravid patients suffered from traumatic intracranial hemorrhage, 2 had primary intracerebral hemorrhage, and 2 had hydrocephalus. The medical records of these patients were reviewed to assess the outcome for the mothers and fetuses. Results Nineteen pregnant patients (56%) underwent a neurosurgical procedure after induction of general anesthesia. Of these, 14 (74%) underwent craniotomies for clipping/resection of their lesion, 2 (10%) underwent stereotactic biopsies, and 3 (16%) underwent CSF shunting procedures. Three patients (9%) delivered by cesarean section followed by their neurosurgical procedure, and 5 (15%) underwent therapeutic abortion preoperatively to allow for radiation therapy early in their pregnancy (4 of these patients underwent surgery prior to their therapeutic abortion). Eleven patients (32%) were treated nonoperatively while pregnant, and 3 of these received their treatment after delivery. There was no operative maternal mortality or permanent morbidity. The fetuses did not suffer from any complications related to the mother's neurosurgical procedure. Conclusions Based on the authors' experience and a review of the literature, surgery for intracranial lesions in pregnant patients is generally well tolerated by both mother and fetus. Preoperative delivery by cesarean section of term or near-term babies is reasonable. Some patients treated conservatively may deteriorate and require an operation.

Object Cavernous hemangiomas associated with epilepsy present an interesting surgical dilemma in terms of whether one should perform a pure lesionectomy or tailored resection, especially in the temporal lobe given the potential for cognitive damage. This decision is often guided by electrocorticography (ECoG), despite the lack of data regarding its value in cavernoma surgery. The purpose of the present study was several-fold: first, to determine the epilepsy outcome following resection of cavernomas in all brain regions; second, to evaluate the usefulness of ECoG in guiding surgical decision making; and third, to determine the optimum surgical approach for temporal lobe cavernomas. Methods The authors identified from their surgical database 173 patients who had undergone resection of cavernomas. One hundred two of these patients presented with epilepsy, and 61 harbored temporal lobe cavernomas. Preoperatively, all patients were initially evaluated by an epileptologist. The mean follow-up was 37 months. Results Regardless of the cavernoma location, surgery resulted in an excellent seizure control rate: Engel Class I outcome in 88% of patients at 2 years postoperatively. Of 61 patients with temporal lobe cavernomas, the mesial structures were involved in 35. Among the patients with temporal lobe cavernomas, those who underwent ECoG typically had a more extensive parenchymal resection rather than a lesionectomy (p < 0.0001). The use of ECoG in cases of temporal lobe cavernomas resulted in a superior seizure-free outcome: 79% (29 patients) versus 91% (23 patients) of patients at 6 months postresection, 77% (22 patients) versus 90% (20 patients) at 1 year, and 79% (14 patients) versus 83% (18 patients) at 2 years without ECoG versus with ECoG, respectively. Conclusions The surgical removal of cavernomas most often leads to an excellent epilepsy outcome. In cases of temporal lobe cavernomas, the more extensive the ECoG-guided resection, the better the seizure outcome. In addition to upholding the concept of kindling, the data in this study support the use of ECoG in temporal lobe cavernoma surgery in patients presenting with epilepsy.

Biologically malignant pilocytic astrocytomas are rare. Precise morphologic criteria permitting their identification and clinically meaningful distinction from more ordinary pilocytic astrocytomas have not been developed. The histologic grading schemes applied to fibrillary astrocytomas—ones based on nuclear atypia, increased cellularity, mitotic activity, endothelial proliferation, and necrosis—are thought not to correlate with prognosis in pilocytic astrocytomas. Nonetheless, these features were systematically sought in 107 cerebellar pilocytic astrocytomas, four of which were histologically malignant. The clinical, morphologic, and flow cytometric features of these cases were studied. The incidence of histologic malignancy occurring spontaneously in otherwise typical pilocytic astrocytomas was 0.9%; that occurring after radiation was 1.8%. The four histologically malignant tumors occurred in two males and two females, ages 6 to 18 years. All showed increased mitotic activity (three to five mitoses per high-power microscopic field [250×]). Endothelial proliferation and necrosis were present in three and two cases each. DNA ploidy analysis showed the spontaneously occurring malignant-appearing tumors to be aneuploid, whereas both previously radiated tumors were tetraploid; 5% to 11% of cells were in S phase. The appearance of histologic malignancy in pilocytic astrocytoma is rare and less reliably correlated with prognosis than in patients with fibrillary astrocytomas. Essential features of such tumors include a high mitotic index and perhaps a high percentage of cells in S phase. (J Child Neurol 1994;9:301-310).