OBJECTIVEEndoscopic skull base surgery (ESBS) is a relatively recent addition to the neurosurgical armamentarium. As with many new approaches, there has been significant controversy regarding its ...value compared with more traditional approaches to ventral skull base pathology. Although early enthusiasm for new approaches that appear less invasive is usually high, these new techniques require rigorous study to ensure that widespread implementation is in the best interest of patients.METHODSThe authors compared surgical results for ESBS with transcranial surgery (TCS) for several different pathologies over two different time periods (prior to 2012 and 2012-2017) to see how results have evolved over time. Pathologies examined were craniopharyngioma, anterior skull base meningioma, esthesioneuroblastoma, chordoma, and chondrosarcoma.RESULTSESBS offers clear advantages over TCS for most craniopharyngiomas and chordomas. For well-selected cases of planum sphenoidale and tuberculum sellae meningiomas, ESBS has similar rates of resection with higher rates of visual improvement, and more recent results with lower CSF leaks make the complication rates similar between the two approaches. TCS offers a higher rate of resection with fewer complications for olfactory groove meningiomas. ESBS is preferred for lower-grade esthesioneuroblastomas, but higher-grade tumors often still require a craniofacial approach. There are few data on chondrosarcomas, but early results show that ESBS appears to offer clear advantages for minimizing morbidity with similar rates of resection, as long as surgeons are familiar with more complex inferolateral approaches.CONCLUSIONSESBS is maturing into a well-established approach that is clearly in the patients' best interest when applied by experienced surgeons for appropriate pathology. Ongoing critical reevaluation of outcomes is essential for ensuring optimal results.
Observed rapid seizure spread through large brain areas seems at odds with the classical view that seizures arise from small foci. Using an acute animal model, Liou et al. demonstrate that seizure ...propagation can proceed via two topologically distinct patterns that both depend on the same breakdown of inhibition.
Abstract
Focal seizure propagation is classically thought to be spatially contiguous. However, distribution of seizures through a large-scale epileptic network has been theorized. Here, we used a multielectrode array, wide field calcium imaging, and two-photon calcium imaging to study focal seizure propagation pathways in an acute rodent neocortical 4-aminopyridine model. Although ictal neuronal bursts did not propagate beyond a 2-3-mm region, they were associated with hemisphere-wide field potential fluctuations and parvalbumin-positive interneuron activity outside the seizure focus. While bicuculline surface application enhanced contiguous seizure propagation, focal bicuculline microinjection at sites distant to the 4-aminopyridine focus resulted in epileptic network formation with maximal activity at the two foci. Our study suggests that both classical and epileptic network propagation can arise from localized inhibition defects, and that the network appearance can arise in the context of normal brain structure without requirement for pathological connectivity changes between sites.
Objective To assess long-term efficacy of the gasket seal, a method for watertight closure of the cranial base using autologous fascia lata held in place by a rigid buttress, in a large case series. ...Methods A prospectively acquired database of all endonasal endoscopic surgeries performed over a 5-year period at Weill Cornell Medical College starting in September 2005 was reviewed. Results The gasket seal was used in 46 consecutive patients. Mean age was 53 years (range 7–83 years). All patients had extensive intracranial disease with a significant intraoperative cerebrospinal fluid (CSF) leak. Pathology included craniopharyngioma (39.1%), meningioma (23.9%), and pituitary adenoma (17.4%). After a mean follow-up of 28 months (range 3–63 months), two (4.3%) patients had a postoperative CSF leak. Excluding the patients with adenomas, the CSF leak rate was 5.2% (2 of 38 patients). One leak was controlled with reoperation, and the other was stopped with a lumbar drain (LD). The significance of pathology, type of approach, exposure of the ventricular system, use of fat graft, use of nasoseptal (NS) flap, and use of lumbar drain (LD) was examined, and none of these were significant predictors of postoperative CSF leak. Conclusions Gasket seal closure is a reliable long-term effective method for achieving watertight closure of the cranial base. It can be used in association with an intracranial fat graft, NS flap, LD, and tissue sealants. In this series, none of these other factors were significant predictors of postoperative CSF leak.
Despite the substantial impact of cavernous sinus invasion (CSI) in pituitary adenoma surgery, its radiologic determination has been inconsistent and variable, and the role of endonasal endoscopic ...surgery has been unclear. This is a systematic review and pooled data meta-analysis of the literature to ascertain the best radiologic criteria for CSI and verify the efficacy and safety of an endonasal endoscopic approach.
We searched the MEDLINE database (1993–2015) to identify studies on radiologic criteria for CSI and endonasal surgery. Using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, the studies included were reviewed for CSI criteria, gross total resection (GTR), endocrine remission, cranial nerve deficits, carotid injury, and other complications.
The prevalence of CSI was 43% radiographically compared with 18% intraoperatively (P < 0.001). The radiologic criteria of inferolateral venous compartment obliteration and Knosp 3–4 had the highest correlation with intraoperative CSI and the lowest correlation with GTR. Microscopy had significantly overestimated intraoperative CSI compared with endoscopy (P < 0.001) for each Knosp grade. Endoscopy had significantly higher GTR than did microscopy particularly for Knosp 3–4 (47% vs. 21%; P = 0.001). Carotid injury and cranial nerve deficits occurred in 0.9% and 5%, respectively, with endoscopy. Among endoscopic series with CSI, GTR% showed significant correlation with number of patients in the series (P ≤ 0.01) but no correlation with complications, indicating the relative safety of endonasal endoscopy in experienced hands for removing tumors with CSI.
Knosp 3–4 remains the best objective indicator of CSI. Microscopy tends to overestimate intraoperative CSI compared with endoscopy. Among pituitary adenomas with CSI, GTR in endoscopic series is higher than microscopy and improves with experience without significant additional morbidity.
Abstract Parvalbumin-expressing, fast spiking interneurons have high-energy demands, which make them particularly susceptible to energy impairment. Recent evidence suggests a link between ...mitochondrial dysfunction in fast spiking cortical interneurons and neuropsychiatric disorders. However, the effect of mitochondrial dysfunction restricted to parvalbumin interneurons has not been directly addressed in vivo. To investigate the consequences of mitochondrial dysfunction in parvalbumin interneurons in vivo, we generated conditional knockout mice with a progressive decline in oxidative phosphorylation by deleting cox10 gene selectively in parvalbumin neurons (PV-Cox10 CKO). Cox10 ablation results in defective assembly of cytochrome oxidase, the terminal enzyme of the electron transfer chain, and leads to mitochondrial bioenergetic dysfunction. PV-Cox10 CKO mice showed a progressive loss of cytochrome oxidase in cortical parvalbumin interneurons. Cytochrome oxidase protein levels were significantly reduced starting at postnatal day 60, and this was not associated with a change in parvalbumin interneuron density. Analyses of intrinsic electrophysiological properties in layer 5 primary somatosensory cortex revealed that parvalbumin interneurons could not sustain their typical high frequency firing, and their overall excitability was enhanced. An increase in both excitatory and inhibitory input onto parvalbumin interneurons was observed in PV-Cox10 CKO mice, resulting in a disinhibited network with an imbalance of excitation/inhibition. Investigation of network oscillations in PV-Cox10 CKO mice, using local field potential recordings in anesthetized mice, revealed significantly increased gamma and theta frequency oscillation power in both medial prefrontal cortex and hippocampus. PV-Cox10 CKO mice did not exhibit muscle strength or gross motor activity deficits in the time frame of the experiments, but displayed impaired sensory gating and sociability. Taken together, these data reveal that mitochondrial dysfunction in parvalbumin interneurons can alter their intrinsic physiology and network connectivity, resulting in behavioral alterations similar to those observed in neuropsychiatric disorders, such as schizophrenia and autism.
Purpose/introduction
Craniopharyngiomas are locally-aggressive tumors arising along the hypothalamic-pituitary axis. Treatment is nuanced as a result of their proximity and adherence to vital ...neurovascular structures and responsiveness to surgery, radiation and, in some cases, chemotherapy.
Methods
We reviewed the literature discussing the current state of knowledge regarding craniopharyngioma biology and therapy.
Results
Recent advances in endoscopic endonasal surgery (EEA) have made surgery a safer and more effective option. While cure may be achieved with gross total resection (GTR), when felt to be too risky, a subtotal resection followed by radiation is often a more prudent strategy, particularly in children with hypothalamic invasion. Data on long-term outcome are mostly derived from older studies in which a craniotomy, rather than EEA, was performed. Long-term EEA outcome studies are lacking. Enhanced knowledge of the biological basis of papillary CPs has led to novel medical treatments for
BRAF
v
600E
variants that appear to be effective.
Conclusion
Endoscopic technology has improved surgical results for craniopharyngiomas and expanded the indications for the transsphenoidal approach. The goal of CP surgery goal is maximal safe resection to achieve cure, but subtotal resection and radiation may be equally effective. Early diagnosis of specific variants will facilitate enrollment in promising medical trials.
The Simpson Grade was introduced in the era of limited resources, outdated techniques, and rudimentary surgical and imaging technologies. With the advent of modern techniques including pre- and ...post-operative imaging, microsurgical and endoscopic techniques, advanced histopathology and molecular analysis and adjuvant radiotherapy, the utility of the Simpson Grade scale for prognostication of recurrence after meningioma resection has become less useful. While the extent of resection remains an important factor in reducing recurrence, a subjective naked-eye criteria to Grade extent of resection cannot be generalized to all meningiomas regardless of their location or biology. Achieving the highest Simpson Grade resection should not always be the goal of surgery. It is prudent to take advantage of all the tools in the neurosurgeons’ armamentarium to aim for maximal safe resection of meningiomas. The primary goal of this study was to review the literature highlighting the Simpson Grade and its association with recurrence in modern meningioma practice. A PubMed search was conducted using terms “Simpson”, “Grade”, “meningioma”, “recurrence”, “gross total resection”, “extent of resection” “human”. A separate search using the terms “intraoperative imaging”, “intraoperative MRI” and “meningioma” were conducted. All studies reporting prognostic value of Simpson Grades were retrospective in nature. Simpson Grade I, II and III can be defined as gross total resection and were associated with lower recurrence compared to Simpson Grade IV or subtotal resection. The volume of residual tumor, a factor not considered in the Simpson Grade, is also a useful predictor of recurrence. Subtotal resection followed by stereotactic radiosurgery has similar recurrence-free survival as gross total resection. In current modern meningioma surgery, the Simpson Grade is no longer relevant and should be replaced with a grading scale that relies on post-operative MRI imaging that assess GTR versus STR and then divides STR into > or <4−5 cm3, in combination with modern molecular-based techniques for recurrence risk stratification.
Findings in animal models demonstrate that activity within hierarchically early sensory cortical regions can be modulated by cross-sensory inputs through resetting of the phase of ongoing intrinsic ...neural oscillations. Here, subdural recordings evaluated whether phase resetting by auditory inputs would impact multisensory integration processes in human visual cortex. Results clearly showed auditory-driven phase reset in visual cortices and, in some cases, frank auditory event-related potentials (ERP) were also observed over these regions. Further, when audiovisual bisensory stimuli were presented, this led to robust multisensory integration effects which were observed in both the ERP and in measures of phase concentration. These results extend findings from animal models to human visual cortices, and highlight the impact of cross-sensory phase resetting by a non-primary stimulus on multisensory integration in ostensibly unisensory cortices.
•Auditory driven phase reset occurs over visual cortices.•This can lead to an auditory evoked potential.•Multisensory interactions occur extensively in visual cortices.•In visual regions, auditory phase resetting interacts with evoked visual activity.
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