- BACKGROUND: Giant falcine meningiomas are surgically complex as they are deep in location, concealed by normal brain parenchyma, in close proximity to various neurovascular structures, and frequently involve the falx bilaterally. Although classically accessed using a bifrontal craniotomy and interhemispheric approach, little data exist on alternative operative corridors for these challenging tumors. We evaluated perioperative and long-term outcomes in patients undergoing transcortical resection of giant bilateral falcine meningiomas. - METHODS: From 2013 to 2022, fourteen patients with giant bilateral falcine meningiomas treated via a transcortical approach at our institution were identified. Perioperative and long-term outcomes were evaluated to determine predictors of adverse events. Corticectomy depth was also analyzed to determine if it correlated with increased postoperative seizure rates. - RESULTS: 57.1% of cases were WHO grade 2 meningiomas. Average tumor volume was 77.8 +/- 46.5 cm3 and near/ gross total resection was achieved in 78.6% of patients. No patient developed a venous infarct or had seizures in the 6 months after surgery. Average corticectomy depth was 0.83 +/- 0.71 cm and increasing corticectomy depth did not correlate with higher risk of postoperative seizures (P = 0.44). Increasing extent of tumor resection correlated with lower tumor grade (P = 0.011) and only 1 patient required repeat resection during a median follow -period of 24.9 months. - CONCLUSIONS: The transcortical approach is a safe alternative corridor for accessing giant, falcine meningiomas, and postoperative seizures were not found to correlate with increasing corticectomy depth. Further prospective studies are necessary to determine the best approach to these surgically complex lesions.

OBJECTIVE:As the coronavirus disease 2019 (COVID-19) pandemic spread to the United States in 2020, there was an impetus toward postponing or ceasing nonurgent transsphenoidal pituitary surgeries to prevent the spread of the virus. Some centers encouraged transcranial approaches for patients with declining neurologic function. However, no large-scale data exist evaluating the effects that this situation had on national pituitary practice patterns. METHODS:Pituitary surgeries in the National Inpatient Sample were identified from 2017 to 2020. Surgeries in 2020 were compared with the 3 years previously to determine any differences in demographics, surgical trends/approaches, and perioperative outcomes. RESULTS:In 2020, there was a decline in overall pituitary surgeries (34.2 vs. 36.3%; odds ratio (OR), 0.88; P < 0.001) yet transsphenoidal approaches represented a higher proportion of interventions (69.0 vs. 64.9%; P < 0.001). Neurosurgical complications were higher (51.9 vs. 47.4%; OR, 1.13; P < 0.001) and patients were less likely to be discharged home (86.4 vs. 88.5%; OR, 0.84; P < 0.001). This finding was especially true in April 2020 during the first peak in COVID-19 cases, when transcranial approaches and odds of mortality/complications were highest. CONCLUSIONS:In 2020, transsphenoidal surgery remained the preferred approach for pituitary tumor resection despite initial recommendations against the approach to prevent COVID-19 spread. Pituitary surgeries had a higher risk of periprocedural complications despite accounting for preoperative comorbidities, COVID-19 infection status, and surgical approach, suggesting that an overwhelmed hospital system can negatively influence surgical outcomes in noninfected patients.

As the COVID-19 pandemic spread to the United States in 2020, there was an impetus towards postponing or ceasing non-urgent transsphenoidal pituitary surgeries to prevent spread of the virus. Some centers encouraged transcranial approaches for patients with declining neurologic function. However, no large-scale data exists evaluating the effects this had on national pituitary practice patterns. Pituitary surgeries in the National Inpatient Sample were identified from 2017-2020. Surgeries in 2020 were compared to the three years prior to determine any differences in demographics, surgical trends/approaches and perioperative outcomes. In 2020, there was a decline in overall pituitary surgeries (34.2 vs. 36.3%, odds ratio (OR) 0.88, p<0.001) yet transsphenoidal approaches represented a higher proportion of interventions (69.0 vs. 64.9%, p<0.001). Neurosurgical complications were higher (51.9 vs. 47.4%, OR 1.13, p<0.001) and patients were less likely to be discharged home (86.4 vs. 88.5%, OR 0.84, p<0.001). This was especially true in April 2020 during the first peak in COVID-19 cases when transcranial approaches and odds of mortality/complications were highest. In 2020, transsphenoidal surgery remained the preferred approach for pituitary tumor resection despite initial recommendations against the approach to prevent COVID-19 spread. Pituitary surgeries had a higher risk of periprocedural complications despite accounting for preoperative comorbidities, COVID-19 infection status, and surgical approach, suggesting that an overwhelmed hospital system can negatively influence surgical outcomes in non-infected patients.

BACKGROUND: Current trends in surgical neurooncology show that early discharges are safe and feasible with shorter lengths of stay (LOS) and fewer thromboembolic complications, fewer hospital-acquired infections, reduced costs, and greater patient satisfaction. Traditionally, infra-tentorial tumor resections have been associated with longer LOS and limited data exist evaluating predictors of early discharge in these patients. The objective was to assess patients undergoing posterior fossa craniotomies for tumor resection and identify variables associated with post-operative day 1 (POD1) discharge.METHODS: A retrospective review of posterior fossa craniotomies for tumor resection at our institution was performed from 2011 to 2020. Laser ablations, nontumoral pathologies, and biopsies were excluded. Demographic, clinical, surgical, and postoperative data were collected.RESULTS: One hundred and seventy-three patients were identified and 25 (14.5%) were discharged on POD1. Median length of stay (LOS) was 6 days. The POD1 discharges had significantly better preoperative Karnofsky performance scores (P < 0.001) and modified Rankin scores (P = 0.002) and more frequently presented electively (P = 0.006) and without preoperative neurologic deficits (P = 0.021).No statistically significant difference in 30-day read-missions and rates of PE, UTI, and DVT was found. Univariate logistic regression identified better preoperative functional status, elective admission, and lack of preoperative hydrocephalus as predictors of POD1 discharge, however only the latter remained significant in the multivariable model (P = 0.001).CONCLUSIONS: Discharging patients on POD1 is feasible following posterior fossa tumor resection in a select group of patients. Although we found that the only independent predictor for a longer LOS was preoperative hydrocephalus, larger, prospective studies are needed to confirm these findings.

AbstractBecause of their ease of use, adeno-associated viruses (AAVs) are indispensable tools for much of neuroscience. Yet AAVs have been used relatively little to study the identities and connectivity of peripheral sensory neurons, principally because methods to selectively target peripheral neurons have been limited. The introduction of the AAV-PHP.S capsid with enhanced tropism for peripheral neurons (Chan et al., 2017) offered a solution, which we further elaborate here. Using AAV-PHP.S with GFP or mScarlet fluorescent proteins, we show that the mouse sensory ganglia for cranial nerves V, VII, IX, and X are targeted. Pseudounipolar neurons of both somatic and visceral origin, but not satellite glia, express the reporters. One week after virus injection, ≈66% of geniculate ganglion neurons were transduced. Fluorescent reporters were transported along the central and peripheral axons of these sensory neurons, permitting visualization of terminals at high resolution, and in intact, cleared brain using light sheet microscopy. Further, using a Cre-dependent reporter, we demonstrate by anatomic and functional criteria, that expression is in a cell type-selective manner. Finally, we integrate earlier neuroanatomical and molecular data within vivoCa2+imaging to demonstrate the sensory characteristics of geniculate ganglion auricular neurons, which were previously undocumented. Our analyses suggest that the AAV-PHP.S serotype will be a powerful tool for anatomically and functionally mapping the receptive fields and circuits of the expanding numbers of molecular subtypes of many somatosensory and viscerosensory neurons that continue to be defined via single-cell RNA sequencing.

In mammalian taste buds, Type I cells comprise half of all cells. These are termed “glial-like” based on morphologic and molecular features, but there are limited studies describing their function. We tested whether Type I cells sense chemosensory activation of adjacent chemosensory (i.e., Types II and III) taste bud cells, similar to synaptic glia. Using Gad2;;GCaMP3 mice of both sexes, we confirmed by immunostaining that, within taste buds, GCaMP expression is predominantly in Type I cells (with no Type II and ≈28% Type III cells expressing weakly). In dissociated taste buds, GCaMP+ Type I cells responded to bath-applied ATP (10-100 μm) but not to 5-HT (transmitters released by Type II or III cells, respectively). Type I cells also did not respond to taste stimuli (5 μm cycloheximide, 1 mm denatonium). In lingual slice preparations also, Type I cells responded to bath-applied ATP (10-100 μm). However, when taste buds in the slice were stimulated with bitter tastants (cycloheximide, denatonium, quinine), Type I cells responded robustly. Taste-evoked responses of Type I cells in the slice preparation were significantly reduced by desensitizing purinoceptors or by purinoceptor antagonists (suramin, PPADS), and were essentially eliminated by blocking synaptic ATP release (carbenoxolone) or degrading extracellular ATP (apyrase). Thus, taste-evoked release of afferent ATP from type II chemosensory cells, in addition to exciting gustatory afferent fibers, also activates glial-like Type I taste cells. We speculate that Type I cells sense chemosensory activation and that they participate in synaptic signaling, similarly to glial cells at CNS tripartite synapses. SIGNIFICANCE STATEMENT Most studies of taste buds view the chemosensitive excitable cells that express taste receptors as the sole mediators of taste detection and transmission to the CNS. Type I “glial-like” cells, with their ensheathing morphology, are mostly viewed as responsible for clearing neurotransmitters and as the “glue” holding the taste bud together. In the present study, we demonstrate that, when intact taste buds respond to their natural stimuli, Type I cells sense the activation of the chemosensory cells by detecting the afferent transmitter. Because Type I cells synthesize GABA, a known gliotransmitter, and cognate receptors are present on both presynaptic and postsynaptic elements, Type I cells may participate in GABAergic synaptic transmission in the manner of astrocytes at tripartite synapses.