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Background/aims: To review the existing literature on pigmented villonodular synovitis (PVNS) of the temporomandibular joint (TMJ) and report a rare case of PVNS of the TMJ presenting with unilateral hearing loss.Methods: Review of the existing literature and a description of personal experience with PVNS of the TMJ presenting with unilateral hearing loss.Results: Review of the existing literature revealed 76 reported cases of PVNS of the TMJ. The most common presenting symptom was of a slowly enlarging mass or swelling of the preauricular area, with dysfunctional TMJ also frequently reported. All patients underwent surgical excision with some pursuing radiation as adjuvant therapy. Presented Patient: A 46-year-old man presented with several months of unilateral subjective hearing loss and aural fullness. Imaging revealed a mass centered along the superior TMJ with expansion through the squamous temporal bone and extra-axial intracranial extension into the middle cranial fossa. Imaging characteristics and fine-needle aspiration biopsy were consistent with PVNS.Intervention: The patient underwent near-total excision of the mass via frontotemporal craniectomy and lateral temporal bone resection.Follow-up: At the 16-month follow-up there was no evidence of disease recurrence.Conclusion: PVNS of the TMJ represents a rare entity that can present with a variety of symptoms including unilateral hearing loss. [ABSTRACT FROM AUTHOR]

Decompressive hemicraniectomy (DHC) is performed to relieve life-threatening intracranial pressure elevations. After swelling abates, a cranioplasty is performed for mechanical integrity and cosmesis. Cranioplasty is costly with high complication rates. Prior attempts to obviate second-stage cranioplasty have been unsuccessful. The Adjustable Cranial Plate (ACP) is designed for implantation during DHC to afford maximal volumetric expansion with later repositioning without requiring a second major operation. The ACP has a mobile section held by a tripod fixation mechanism. Centrally located gears adjust the implant between the up and down positions. Cadaveric ACP implantation was performed. Virtual DHC and ACP placement were done using imaging data from 94 patients who had previously undergone DHC to corroborate our cadaveric results. Imaging analysis methods were used to calculate volumes of cranial expansion. The ACP implantation and adjustment procedures are feasible in cadaveric testing without wound closure difficulties. Results of the cadaveric study showed total volumetric expansion achieved was 222 cm3. Results of the virtual DHC procedure showed the volume of cranial expansion achieved by removing a standardized bone flap was 132 cm3 (range, 89–171 cm3). Applied to virtual craniectomy patients, the total volume of expansion achieved with the ACP implantation operation was 222 cm3 (range, 181–263 cm3). ACP implantation during DHC is technically feasible. It achieves a volume of cranial expansion that will accommodate that observed following survivable hemicraniectomy operations. Moving the implant from the up to the down position can easily be performed as a simple outpatient or inpatient bedside procedure, thus potentially eliminating second-stage cranioplasty procedures. [ABSTRACT FROM AUTHOR]

Objective: To determine in-hospital costs associated with performing an EEA to anterior skull base pathology and to identify drivers of cost variability for patients undergoing endoscopic anterior skull base surgery. Methods: All endoscopic anterior skull base surgeries performed over a period from January 1st, 2015 to October 24th, 2017 were evaluated. The electronic medical record was reviewed for patient factors, tumor characteristics, and cost variables associated with each hospital stay and univariate analysis was performed using Stata software. Results: An EEA was associated with an average total in-hospital cost of $44 545. Compared to patients undergoing a transsphenoidal approach to pituitary tumor resection, EEA patients incurred higher in-hospital costs across all variables including a total cost increase of $15 921 (95% confidence interval $5720-26 122, P =.002). Univariate analysis of all endoscopic anterior skull base surgery patients showed a cost increase of $30 616 associated with post-operative cerebrospinal fluid (CSF) leak ($10 420-50 811, P =.004), $14 610 with post-operative diabetes insipidus (DI) ($4610-24 609, P =.004), and $11 522 with African-American patients relative to Caucasian patients ($3049-19 995, P =.008). Conclusions: Patients who undergo endoscopic EEA for resection of anterior skull base tumors typically incur greater in-hospital costs than patients undergoing a standard TSA. Post-operative complications such as CSF leak and DI, as well as ethnicity, are significant drivers of cost-variability. [ABSTRACT FROM AUTHOR]

Stars may be tidally disrupted if, in a single orbit, they are scattered too close to a supermassive black hole (SMBH). Tidal disruption events are thought to power luminous but short-lived accretion episodes that can light up otherwise quiescent SMBHs in transient flares. Here we explore a more gradual process of tidal stripping where stars approach the tidal disruption radius by stellar evolution while in an eccentric orbit. After the onset of mass transfer, these stars episodically transfer mass to the SMBH every pericenter passage, giving rise to low-level flares that repeat on the orbital timescale. Giant stars, in particular, will exhibit a runaway response to mass loss and “spoon-feed” material to the black hole for tens to hundreds of orbital periods. In contrast to full tidal disruption events, the duty cycle of this feeding mode is of order unity for black holes Mbh ≳ 107M☼. This mode of quasi-steady SMBH feeding is competitive with indirect SMBH feeding through stellar winds, and spoon-fed giant stars may play a role in determining the quiescent luminosity of local SMBHs. [ABSTRACT FROM AUTHOR]

Background: Novel preventive therapies are needed for postoperative delirium, which especially affects older patients. A mouse model is presented that captures inflammation-associated cortical slow wave activity (SWA) observed in patients, allowing exploration of the mechanistic role of prostaglandin-adenosine signalling.Methods: EEG and cortical cytokine measurements (interleukin 6, monocyte chemoattractant protein-1) were obtained from adult and aged mice. Behaviour, SWA, and functional connectivity were assayed before and after systemic administration of lipopolysaccharide (LPS)+piroxicam (cyclooxygenase inhibitor) or LPS+caffeine (adenosine receptor antagonist). To avoid the confounder of inflammation-driven changes in movement which alter SWA and connectivity, electrophysiological recordings were classified as occurring during quiescence or movement, and propensity score matching was used to match distributions of movement magnitude between baseline and post-LPS administration.Results: LPS produces increases in cortical cytokines and behavioural quiescence. In movement-matched data, LPS produces increases in SWA (likelihood-ratio test: χ2(4)=21.51, P<0.001), but not connectivity (χ2(4)=6.39, P=0.17). Increases in SWA associate with interleukin 6 (P<0.001) and monocyte chemoattractant protein-1 (P=0.001) and are suppressed by piroxicam (P<0.001) and caffeine (P=0.046). Aged animals compared with adult animals show similar LPS-induced SWA during movement, but exaggerated cytokine response and increased SWA during quiescence.Conclusions: Cytokine-SWA correlations during wakefulness are consistent with observations in patients with delirium. Absence of connectivity effects after accounting for movement changes suggests decreased connectivity in patients is a biomarker of hypoactivity. Exaggerated effects in quiescent aged animals are consistent with increased hypoactive delirium in older patients. Prostaglandin-adenosine signalling may link inflammation to neural changes and hence delirium. [ABSTRACT FROM AUTHOR]

Abstract: It has been hypothesized that, in the developing rodent hippocampus, mossy fiber terminals release GABA together with glutamate. Here, we used transgenic glutamic acid decarboxylase-67 (GAD67)-GFP expressing mice and multi-label immunohistochemistry to address whether glutamatergic and GABAergic markers are colocalized. We demonstrate that in the dentate gyrus, interneurons positive for GABA/GAD are sparsely distributed along the edge of the hilus, in a different pattern from that of the densely packed granule cells. Co-staining for synaptophysin and vesicular glutamate transporter1 (VGLUT1) in postnatal day 14 brain sections from both mice and rats showed mossy fiber terminals as a group of large (2–5μm in diameter) VGLUT1-positive excitatory presynaptic terminals in the stratum lucidum of area CA3a/b. Furthermore, co-staining for synaptophysin and vesicular GABA transporter (VGAT) revealed a group of small-sized (∼0.5μm in diameter) inhibitory presynaptic terminals in the same area where identified mossy fiber terminals were present. The two types of terminals appeared to be mutually exclusive, and showed no colocalization. Thus, our results do not support the hypothesis that GABA is released as a neurotransmitter from mossy fiber terminals during development. [Copyright &y& Elsevier]

The Wishbone device is designed to enable surgeons to quickly and accurately localize the cranial midline. It is intended to be of particular use when localizing the burr hole site during posterior ventriculoperitoneal shunt (VPS) surgery. The Wishbone is a simple mechanical device with 2 adjustable caliper arms that reversibly attach to a patient's left and right external auditory canals. The Wishbone's laser localizer illuminates the midline scalp. The Wishbone was used to localize the posterior midline in a pilot series of patients undergoing VPS surgery. Midline localization and ventricular catheter placement accuracy were determined using findings from postoperative computed tomography scans. The Wishbone is a mechanically robust device and proved easy for surgeons to use. Forty patients underwent VPS surgery using the Wishbone to localize the posterior midline. The localization procedure took less than 3 minutes. The average distance separating the Wishbone-localized midline scalp location and the computed tomography−defined anatomical midline was 2.9 mm (95% confidence interval 1.6–4.1 mm). In all cases, the ventricular catheter entered the ipsilateral lateral ventricle. The catheter tips were placed in the ipsilateral (n = 34) or contralateral (n = 5) frontal horn in all but 1 patient. In 1 patient, the catheter tip entered the parenchyma due to a burr hole localization error in the rostrocaudal dimension, unrelated to the Wishbone. We describe a simple, efficient, and cost-effective system for accurately localizing the posterior cranial midline. A larger patient series is required to definitively compare its clinical utility relative to frameless stereotaxis-based midline localization methods. [ABSTRACT FROM AUTHOR]