Hypervascular floor of mouth tumor: Rare presentation of oral cavity squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is the most common malignancy affecting the oral cavity and commonly presents as an exophytic lesion with red or white granular ulcerations. Most diagnoses are confirmed by biopsy and clinical features; however, early SCC has been shown to hide within benign appearing lesions, such as vascular tumors, resulting in missed diagnoses and delay in treatment. The following case report will discuss a patient who presented with a mass in the floor of the mouth which appeared as a vascular tumor on exam and imaging. This was originally thought to be benign based on FNA findings however was found to harbor invasive squamous cell carcinoma on final pathology. The goal of this case report is to provide a background on the variable presentations of OSCC, vascular tumors, and uncommon presentations for which specialists should be aware of in their practice.

Morphology and Hemodynamics of Cerebral Arteries and Aneurysms in a Rare Pair of Monozygotic Twins.

In this preliminary study, the underlying pathophysiology mechanisms of cerebral aneurysms (CAs) in monozygotic twins (MTs) were investigated via a rare pair of MTs (twin A and twin B) involving four reconstructed arterial models using preclinical information. First, dimensions and configurated outlines of three-perspective geometries were compared. Adopting an in-vitro validated numerical CA model, hemodynamic characteristics were investigated in the MTs, respectively. Despite expected genetic similarities, morphological comparisons show that configurations of cerebral arteries exhibit significant differences between the twins. The ICA size of twin A is larger than that in twin B (2.23~25.86%), varying with specific locations, attributing to variations during embryological developments and environmental influences. Numerical modeling indicates the MTs have some hemodynamic similarities such as pressure distributions (~13,400 Pa) and their oscillatory shear index (OSI) (0~0.49), but present significant differences in local regions. Specifically, the difference in blood flow rate in the MTs is from 16% to 221%, varying with specifically compared arteries. The maximum time-averaged wall shear stress (53.6 Pa vs. 37.8 Pa) and different local OSI distributions were also observed between the MTs. The findings revealed that morphological variations in MTs could be generated by embryological and environmental factors, further influencing hemodynamic characteristics on CA pathophysiology.

The types of neurological deficits might not justify withholding treatment in patients with low total National Institutes of Health Stroke Scale scores.

BACKGROUND AND PURPOSE: There is controversy regarding the threshold for treating patients with mild strokes. Physicians often withhold acute treatment in these patients if they perceive the symptoms are not going to be disabling. We tested the appropriateness of this practice by analyzing the relationship between specific neurological deficits in the National Institutes of Health Stroke Scale (NIHSS) score and long-term outcome among patients with a low total NIHSS score. METHODS: We performed a secondary analysis on those patients enrolled in the Trial of ORG 10172 in Acute Stroke Treatment that presented within 4.5 hours of symptom onset and had a baseline NIHSS score ≤6 (n=194). We performed multivariate logistic regression analyses using very favorable outcome at 3 months as the outcome variable and each of the individual items of the baseline NIHSS examination and syndromic combinations of NIHSS scores as predictors. The analyses were adjusted for potential confounders with and without adjusting for total NIHSS score. RESULTS: Baseline total NIHSS scores were inversely associated with very favorable outcome at 3 months. No individual NIHSS item, or syndromic combination of NIHSS scores, was independently associated with very favorable outcome in a consistent manner after accounting for confounders and collinearity. CONCLUSIONS: The types of neurological deficits in the baseline NIHSS are not independent predictors of long-term prognosis for patients with mild stroke. These exploratory findings argue against the practice of withholding reperfusion treatment in patients with mild stroke when the types of baseline NIHSS deficits are perceived to be nondisabling.

Lack of international consensus on ethical aspects of acute stroke trials.

Acute stroke trials are becoming increasingly multinational. Working toward a shared ethical standard for acute stroke research necessitates evaluating the degree of consensus among international researchers. We surveyed all 275 coinvestigators and coordinators who participated in the AbESTT II study (evaluating abciximab vs placebo) about their experience with their local institutional review board (IRB) or equivalent, as well as, about their personal beliefs regarding the ethical aspects of acute stroke trials. A total of 90 coinvestigators from 15 different countries responded to our survey. Among the IRBs represented by the responding coinvestigators, only 18% allowed surrogate consent to be obtained over the phone. Although 52% allowed the participation of subjects with aphasia, only 5% allowed the participation of subjects with neglect/hemi-inattention. The National Institutes of Health Stroke Scale score was deemed adequate to establish decisional capacity based on language by 62% of the coinvestigators and 36% of the IRBs. A belief that IRB regulations cause unnecessary delays and fear in relatives/patients was reported by 67% of coinvestigators, and the belief that granting an exemption from informed consent under specific circumstances is appropriate was reported by 41%. There appears to be considerable international diversity in the ethical priorities and informed consent standards among different IRBs and investigators in stroke research. The stroke community should make an attempt to standardize the consent process used in research. Given the critical nature of the time to treatment in stroke care, these standards should be integrated into current frameworks of clinical care and research. The absence of an ethical consensus can become a barrier to advancing stroke treatment internationally.

Numerical studies of hemodynamic alterations in pre- and post-stenting cerebral aneurysms using a multiscale modeling.

The aim of this work was to use a multiscale modeling to study the influence of stent deployment, with generic stents, on flow distributions within the vascular network and the hemodynamic alterations within the cerebral aneurysms pre- and post-stenting. To achieve this goal, two image-based anatomical cerebral aneurysm models were reconstructed along with the respective aneurysms post-stenting models after deploying a 16- or 24-wire stent. The investigation results revealed that the stent may increase the local pressure resistance resulting in flow alterations. The hemodynamic parameters demonstrated stent placement can reduce the intra-aneurysmal pressure, decrease wall shear stress (WSS) at the neck region, and increase blood turnover time for aneurysm case I (sidewall aneurysm). These findings are consistent with the trends of hemodynamic changes reported previously. However, aneurysm case II (bifurcation aneurysm) showed gradually increased intra-aneurysmal pressure and the pressure at the neck region, decreased WSS over the sac surface, and enhanced flow vortices within the aneurysm. When simulating the hemodynamics of pre- and post-stenting aneurysms for a patient using measured flow waveforms, the flow alteration induced by the stent deployment may affect the hemodynamic predictions for the post-stenting aneurysm. Thus, the remeasurement of boundary conditions once the morphology of the aneurysm is deformed is needed in follow-up studies with a focus on aneurysm growth and stent deployment.

An In-Vitro Flow Study Using an Artificial Circle of Willis Model for Validation of an Existing One-Dimensional Numerical Model.

A one-dimensional (1D) numerical model has been previously developed to investigate the hemodynamics of blood flow in the entire human vascular network. In the current work, an experimental study of water-glycerin mixture flow in a 3D-printed silicone model of an anatomically accurate, complete circle of Willis (CoW) was conducted to investigate the flow characteristics in comparison with the simulated results by the 1D numerical model. In the experiment, the transient flow and pressure waveforms were measured at 13 selected segments within the flow network for comparisons. In the 1D simulation, the initial parameters of the vessel network were obtained by a direct measurement of the tubes in the experimental setup. The results verified that the 1D numerical model is able to capture the main features of the experimental pressure and flow waveforms with good reliability. The mean flow rates measurement results agree with the predictions of the 1D model with an overall difference of less than 1%. Further experiment might be needed to validate the 1D model in capturing pressure waveforms.

A multiscale computational modeling for cerebral blood flow with aneurysms and/or stenoses.

A 1-dimensional (1D)-3-dimensional (3D) multiscale model for the human vascular network was proposed by combining a low-fidelity 1D modeling of blood circulation to account for the global hemodynamics with a detailed 3D simulation of a zonal vascular segment. The coupling approach involves a direct exchange of flow and pressure information at interfaces between the 1D and 3D models and thus enables patient-specific morphological models to be inserted into flow network with minimum computational efforts. The proposed method was validated with good agreements against 3 simplified test cases where experimental data and/or full 3D numerical solution were available. The application of the method in aneurysm and stenosis studies indicated that the deformation of the geometry caused by the diseases may change local pressure loss and as a consequence lead to an alteration of flow rate to the vessel segment.