Wharen, Robert E.

Abstract BACKGROUND: Patients with pleomorphic xanthoastrocytoma (PXA) routinely undergo multiple procedures to ensure recurrence-free survival and are resultantly at increased risk of experiencing perioperative complications (regional, medical, and/or neurological), a combination of which has not been recorded in previous studies. OBJECTIVE: To determine perioperative outcomes in a cohort of patients (adult and pediatric) with intracranial PXA. METHODS: We retrospectively identified 39 patients who underwent surgery at our institution for intracranial PXA between 1994 and 2011. Demographic factors were recorded along with Karnofsky Performance Status (KPS), complications, and mortality. RESULTS: Mean patient age was 31 years at the most recent surgery. A majority of patients (24; 62%) had multiple surgeries with a mean of 2 operations per patient. Eleven PXAs (28%) were malignant (grade III or IV). Perioperative complications included permanent neurological worsening in 4 patients (10%), regional complications in 4 (10%), and medical complications in 3 (8%). Preoperative KPS was ≥70 in 34 of 38 patients (89%). Long-term postoperative KPS was ≥70 in 36 of 37 patients (97%), suggesting good functional outcomes. There was no perioperative mortality, but 7 patients (18%) died of tumor progression. Patients with malignant PXAs trended toward higher risk of regional complications (3 of 11 patients [27%]; P = .06), received adjuvant therapy more often (10 of 11 patients [91%]; P < .001), had higher mortality from tumor progression (7 of 11 patients [64%]; P < .001), and were significantly larger (mean, 6.05 ± 0.73 cm standard error of the mean; n = 7; P < .01). CONCLUSION: Both pediatric and adult PXAs may be resected with good functional outcomes. Perioperative neurological complications are relatively common, but do not affect long-term functional outcome or mortality. Malignant PXAs are higher risk for perioperative complications and, ultimately, death from tumor progression, despite increased use of adjuvant radiation and chemotherapy.

Background Ischemic stroke is a time-sensitive disease, with improved outcomes associated with decreased time from onset to treatment. It was hypothesised that ambulance-based assessment of the National Institutes of Health Stroke Scale (NIHSS) using a Health Insurance Portability and Accountability Act (HIPAA)–compliant mobile platform immediately prior to arrival is feasible. Methods This is a proof-of-concept feasibility pilot study in two phases. The first phase consisted of an ambulance-equipped HIPAA-compliant video platform for remote NIHSS assessment of a simulated stroke patient. The second phase consisted of remote NIHSS assessment by a hospital-based neurologist of acute stroke patients en route to our facility. Five ambulances were equipped with a 4G/LTE-enabled tablet preloaded with a secure HIPAA-compliant telemedicine application. Secondary outcomes assessed satisfaction of staff with the remote platform. Results Phase one was successful in the assessment of three out of three simulated patients. Phase two was successful in the assessment of 10 out of 11 (91%) cases. One video attempt was unsuccessful because local LTE was turned off on the device. The video signal was dropped transiently due to weather, which delayed NIHSS assessment in one case. Average NIHSS assessment time was 7.6 minutes (range 3–9.8 minutes). Neurologists rated 83% of encounters as ‘satisfied’ to ‘very satisfied’, and the emergency medical service (EMS) rated 90% of encounters as ‘satisfied’ to ‘very satisfied’. The one failed video attempt was associated with ‘poor’ EMS satisfaction. Conclusion This proof-of-concept pilot demonstrates that remote ambulance-based NIHSS assessment is feasible. This model could reduce door-to-needle times by conducting prehospital data collection.

Summary Objective Patients with suspected mesial temporal lobe ( MTL ) epilepsy typically undergo inpatient video–electroencephalography ( EEG ) monitoring with scalp and/or intracranial electrodes for 1 to 2 weeks to localize and lateralize the seizure focus or foci. Chronic ambulatory electrocorticography ( EC oG) in patients with MTL epilepsy may provide additional information about seizure lateralization. This analysis describes data obtained from chronic ambulatory EC oG in patients with suspected bilateral MTL epilepsy in order to assess the time required to determine the seizure lateralization and whether this information could influence treatment decisions. Methods Ambulatory EC oG was reviewed in patients with suspected bilateral MTL epilepsy who were among a larger cohort with intractable epilepsy participating in a randomized controlled trial of responsive neurostimulation. Subjects were implanted with bilateral MTL leads and a cranially implanted neurostimulator programmed to detect abnormal interictal and ictal EC oG activity. EC oG data stored by the neurostimulator were reviewed to determine the lateralization of electrographic seizures and the interval of time until independent bilateral MTL electrographic seizures were recorded. Results Eighty‐two subjects were implanted with bilateral MTL leads and followed for 4.7 years on average (median 4.9 years). Independent bilateral MTL electrographic seizures were recorded in 84%. The average time to record bilateral electrographic seizures in the ambulatory setting was 41.6 days (median 13 days, range 0–376 days). Sixteen percent had only unilateral electrographic seizures after an average of 4.6 years of recording. Significance About one third of the subjects implanted with bilateral MTL electrodes required >1 month of chronic ambulatory EC oG before the first contralateral MTL electrographic seizure was recorded. Some patients with suspected bilateral MTL seizures had only unilateral electrographic seizures. Chronic ambulatory EC oG in patients with suspected bilateral MTL seizures provides data in a naturalistic setting, may complement data from inpatient video‐ EEG monitoring, and can contribute to treatment decisions.

Summary Objective To demonstrate the safety and effectiveness of responsive stimulation at the seizure focus as an adjunctive therapy to reduce the frequency of seizures in adults with medically intractable partial onset seizures arising from one or two seizure foci. Methods Randomized multicenter double‐blinded controlled trial of responsive focal cortical stimulation (RNS System). Subjects with medically intractable partial onset seizures from one or two foci were implanted, and 1 month postimplant were randomized 1:1 to active or sham stimulation. After the fifth postimplant month, all subjects received responsive stimulation in an open label period ( OLP ) to complete 2 years of postimplant follow‐up. Results All 191 subjects were randomized. The percent change in seizures at the end of the blinded period was −37.9% in the active and −17.3% in the sham stimulation group (p = 0.012, Generalized Estimating Equations). The median percent reduction in seizures in the OLP was 44% at 1 year and 53% at 2 years, which represents a progressive and significant improvement with time (p < 0.0001). The serious adverse event rate was not different between subjects receiving active and sham stimulation. Adverse events were consistent with the known risks of an implanted medical device, seizures, and of other epilepsy treatments. There were no adverse effects on neuropsychological function or mood. Significance Responsive stimulation to the seizure focus reduced the frequency of partial‐onset seizures acutely, showed improving seizure reduction over time, was well tolerated, and was acceptably safe. The RNS System provides an additional treatment option for patients with medically intractable partial‐onset seizures.

Object Management of idiopathic normal-pressure hydrocephalus (iNPH) is hard because the diagnosis is difficult and shunt surgery has high complication rates. An important complication is overdrainage, which often can be treated with adjustable–shunt valve manipulations but also may result in the need for subdural hematoma evacuation. The authors evaluated shunt surgery overdrainage complications in iNPH and their relationship to lumbar puncture opening pressure (LPOP). Methods The authors reviewed the charts of 164 consecutive patients with iNPH who underwent shunt surgery at their institution from 2005 to 2011. They noted age, sex, presenting symptoms, symptom duration, hypertension, body mass index (BMI), imaging findings of atrophy, white matter changes, entrapped sulci, LPOP, valve opening pressure (VOP) setting, number of valve adjustments, serious overdrainage (subdural hematoma requiring surgery), radiological overdrainage (subdural hematomas or hygroma seen on postoperative imaging), clinical overdrainage (sustained or postural headache), other complications, and improvements in gait, urine control, and memory. Results Eight patients (5%) developed subdural hematomas requiring surgery. All had an LPOP of greater than 160 mm H2O and an LPOP-VOP of greater than 40 mm H2O. Radiological overdrainage was more common in those with an LPOP of greater than 160 mm H2O than in those with an LPOP of less than 160 mm H2O (38% vs 21%, respectively; p = 0.024). The BMI was also significantly higher in those with an LPOP of greater than 160 mm H2O (median 30.2 vs 27.0, respectively; p = 0.005). Conclusions Serious overdrainage that caused subdural hematomas and also required surgery after shunting was related to LPOP and LPOP-VOP, which in turn were related to BMI. If this can be replicated, individuals with a high LPOP should have their VOP set close to the LPOP, or even higher. In doing this, perhaps overdrainage complications can be reduced.

The case of a patient with intractable temporal lobe seizures and inadvertent unilateral intraventricular depth electrode placement is presented. The resting electroencephalograph (EEG) showed marked amplitude differences between the intraventricular electrode on the left and the parenchymal electrode on the right. All recorded seizures originated on the left side and in spite of its intraventricular location, frequency power spectra during the early ictal phase showed a marked increase in power for all frequency bands in the left depth electrode, exceeding that on the right. Analysis with Brain Electrical Source Analysis (BESA) software demonstrated marked ictal baseline shifts which were initially limited to the left side but changed to the right during clinical secondary generalization. In the immediate postictal state, all, except for infraslow, frequencies were markedly reduced in power. We conclude that intraventricular depth electrode contacts placed adjacent to the hippocampal structure can record interictal and ictal activity for all frequency bands, albeit at reduced amplitudes. Furthermore, infraslow activity can provide supplementary information about the epileptogenic zone.

Iatrogenic spinal arachnoid cysts are rare, but have been described as a complication of spinal injection and lumbar puncture procedures. The authors describe 2 cases of iatrogenic spinal arachnoid cyst formation that occurred after incidental durotomy during lumbar spine surgery. In both cases, postoperative MR imaging revealed compression of the cauda equina by an intradural arachnoid cyst. Intradural exploration and fenestration of the arachnoid cyst was accomplished in each case. This entity should be considered in the differential diagnosis of a patient experiencing symptoms of neurological compression after a lumbar surgery complicated by incidental durotomy.