Relationship between vasospasm, cerebral perfusion, and delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

Vasospasm after aneurysmal subarachnoid hemorrhage (SAH) is thought to cause ischemia. To evaluate the contribution of vasospasm to delayed cerebral ischemia (DCI), we investigated the effect of vasospasm on cerebral perfusion and the relationship of vasospasm with DCI. We studied 37 consecutive SAH patients with CT angiography (CTA) and CT perfusion (CTP) on admission and within 14 days after admission or at time of clinical deterioration. CTP values (cerebral blood volume, cerebral blood flow (CBF) and mean transit time), degree of vasospasm on CTA, and occurrence of DCI were recorded. Vasospasm was categorized as follows: no spasm (0-25% decrease in vessel diameter), moderate spasm (25-50% decrease), and severe spasm (> 50% decrease). The correspondence of the flow territory of the most spastic vessel with the least perfused region was evaluated, and differences in perfusion values and occurrence of DCI between degrees of vasospasm were calculated with 95% confidence intervals (95% CI). Fourteen patients had no vasospasm, 16 were moderate, and seven were severe. In 65% of patients with spasm, the flow territory of the most spastic vessel corresponded with the least perfused region. There was significant CBF (milliliters per 100 g per minute) difference (-21.3; 95% CI, -37 a dagger"aEuro parts per thousand a'5.3) between flow territories of severe and no vasospasm. Four of seven patients with severe, six of 16 with moderate, and three of 14 patients with no vasospasm had DCI. Vasospasm decreases cerebral perfusion, but corresponds with the least perfused region in only two thirds of our patients. Furthermore, almost half of patients with severe vasospasm do not have DCI. Thus, although severe vasospasm can decrease perfusion, it may not result in DCI

An experimental study on the effects of a simulation game on students’ clinical cognitive skills and motivation

textabstractSimulation games are becoming increasingly popular in education, but more insight in their critical design features is needed. This study investigated the effects of fidelity of open patient cases in adjunct to an instructional e-module on students’ cognitive skills and motivation. We set up a three-group randomized post-test-only design: a control group working on an e-module; a cases group, combining the e-module with low-fidelity text-based patient cases, and a game group, combining the e-module with a high-fidelity simulation game with the same cases. Participants completed questionnaires on cognitive load and motivation. After a 4-week study period, blinded assessors rated students’ cognitive emergency care skills in two mannequin-based scenarios. In total 61 students participated and were assessed; 16 control group students, 20 cases students and 25 game students. Learning time was 2 h longer for the cases and game groups than for the control group. Acquired cognitive skills did not differ between groups. The game group experienced higher intrinsic and germane cognitive load than the cases group (p = 0.03 and 0.01) and felt more engaged (p < 0.001). Students did not profit from working on open cases (in adjunct to an e-module), which nonetheless challenged them to study longer. The e-module appeared to be very effective, while the high-fidelity game, although engaging, probably distracted students and impeded learning. Medical educators designing motivating and effective skills training for novices should align case complexity and fidelity with students’ proficiency level. The relation between case-fidelity, motivation and skills development is an important field for further study

Prognostic imaging variables for recurrent laryngeal and hypopharyngeal carcinoma treated with primary chemoradiotherapy: A systematic and meta-analysis

Background: In this systematic review, we aim to identify prognostic imaging variables of recurrent laryngeal or hypopharyngeal carcinoma after chemoradiotherapy. Methods: A systematic search was performed in PubMed and EMBASE (1990–2020). The crude data and effect estimates were extracted for each imaging variable. The level of evidence of each variable was assessed and pooled risk ratios (RRs) were calculated. Results: Twenty-two articles were included in this review, 17 on computed tomography (CT) and 5 on magnetic resonance imaging (MRI) variables. We found strong evidence for the prognostic value of tumor volume at various cut-off points (pooled RRs ranging from 2.09 to 3.03). Anterior commissure involvement (pooled RR 2.19), posterior commissure involvement (pooled RR 2.44), subglottic extension (pooled RR 2.25), and arytenoid cartilage extension (pooled RR 2.10) were also strong prognostic factors. Conclusion: Pretreatment tumor volume and involvement of several subsites are prognostic factors for recurrent laryngeal or hypopharyngeal carcinoma after chemoradiotherapy

Association of Ischemic Core Imaging Biomarkers With Post-Thrombectomy Clinical Outcomes in the MR CLEAN Registry

Background: A considerable proportion of acute ischemic stroke patients treated with endovascular thrombectomy (EVT) are dead or severely disabled at 3 months despite successful reperfusion. Ischemic core imaging biomarkers may help to identify patients who are more likely to have a poor outcome after endovascular thrombectomy (EVT) despite successful reperfusion. We studied the association of CT perfusion-(CTP), CT angiography-(CTA), and non-contrast CT-(NCCT) based imaging markers with poor outcome in patients who underwent EVT in daily clinical practice. Methods: We included EVT-treated patients (July 2016–November 2017) with an anterior circulation occlusion from the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN) Registry with available baseline CTP, CTA, and NCCT. We used multivariable binary and ordinal logistic regression to analyze the association of CTP ischemic core volume, CTA-Collateral Score (CTA-CS), and Alberta Stroke Program Early CT Score (ASPECTS) with poor outcome (modified Rankin Scale score (mRS) 5-6) and likelihood of having a lower score on the mRS at 90 days. Results: In 201 patients, median core volume was 13 (IQR 5-41) mL. Median ASPECTS was 9 (IQR 8-10). Most patients had grade 2 (83/201; 42%) or grade 3 (28/201; 14%) collaterals. CTP ischemic core volume was associated with poor outcome [aOR per 10 mL 1.02 (95%CI 1.01–1.04)] and lower likelihood of having a lower score on the mRS at 90 days [aOR per 10 mL 0.85 (95% CI 0.78–0.93)]. In multivariable analysis, neither CTA-CS nor ASPECTS were significantly associated with poor outcome or the likelihood of having a lower mRS. Conclusion: In our population of patients treated with EVT in daily clinical practice, CTP ischemic core volume is associated with poor outcome and lower likelihood of shift toward better outcome in contrast to either CTA-CS or ASPECTS

An anomaly detection approach to identify chronic brain infarcts on MRI

The performance of current machine learning methods to detect heterogeneous pathology is limited by the quantity and quality of pathology in medical images. A possible solution is anomaly detection; an approach that can detect all abnormalities by learning how 'normal' tissue looks like. In this work, we propose an anomaly detection method using a neural network architecture for the detection of chronic brain infarcts on brain MR images. The neural network was trained to learn the visual appearance of normal appearing brains of 697 patients. We evaluated its performance on the detection of chronic brain infarcts in 225 patients, which were previously labeled. Our proposed method detected 374 chronic brain infarcts (68% of the total amount of brain infarcts) which represented 97.5% of the total infarct volume. Additionally, 26 new brain infarcts were identified that were originally missed by the radiologist during radiological reading. Our proposed method also detected white matter hyperintensities, anomalous calcifications, and imaging artefacts. This work shows that anomaly detection is a powerful approach for the detection of multiple brain abnormalities, and can potentially be used to improve the radiological workflow efficiency by guiding radiologists to brain anomalies which otherwise remain unnoticed

Spatial correlation between in vivo imaging and immunohistochemical biomarkers: A methodological study

In this study, we present a method that enables voxel-by-voxel comparison of in vivo imaging to immunohistochemistry (IHC) biomarkers. As a proof of concept, we investigated the spatial correlation between dynamic contrast enhanced (DCE-)CT parameters and IHC biomarkers Ki-67 (proliferation), HIF-1α (hypoxia), and CD45 (immune cells). 54 whole-mount tumor slices of 15 laryngeal and hypopharyngeal carcinomas were immunohistochemically stained and digitized. Heatmaps of biomarker positivity were created and registered to DCE-CT parameter maps. The adiabatic approximation to the tissue homogeneity model was used to fit the following DCE parameters: Ktrans (transfer constant), Ve (extravascular and extracellular space), and Vi (intravascular space). Both IHC and DCE maps were downsampled to 4 × 4 × 3 mm[3] voxels. The mean values per tumor were used to calculate the between-subject correlations between parameters. For the within-subject (spatial) correlation, values of all voxels within a tumor were compared using the repeated measures correlation (rrm). No between-subject correlations were found between IHC biomarkers and DCE parameters, whereas we found multiple significant within-subject correlations: Ve and Ki-67 (rrm = -0.17, P <.001), Ve and HIF-1α (rrm = -0.12, P <.001), Ktrans and CD45 (rrm = 0.13, P <.001), Vi and CD45 (rrm = 0.16, P <.001), and Vi and Ki-67 (rrm = 0.08, P =.003). The strongest correlation was found between IHC biomarkers Ki-67 and HIF-1α (rrm = 0.35, P <.001). This study shows the technical feasibility of determining the 3 dimensional spatial correlation between histopathological biomarker heatmaps and in vivo imaging. It also shows that between-subject correlations do not reflect within-subject correlations of parameters

Prophylactic pectoralis major flap to compensate for increased risk of pharyngocutaneous fistula in laryngectomy patients with low skeletal muscle mass (PECTORALIS): study protocol for a randomized controlled trial

BACKGROUND: Total laryngectomy (TL) is a surgical procedure commonly performed on patients with advanced laryngeal or hypopharyngeal carcinoma. One of the most common postoperative complications following TL is the development of a pharyngocutaneous fistula (PCF), characterized by a communication between the neopharynx and the skin. PCF can lead to extended hospital stays, delayed oral feeding, and compromised quality of life. The use of a myofascial pectoralis major flap (PMMF) as an onlay technique during pharyngeal closure has shown potential in reducing PCF rates in high risk patients for development of PCF such as patients undergoing TL after chemoradiation and low skeletal muscle mass (SMM). Its impact on various functional outcomes, such as shoulder and neck function, swallowing function, and voice quality, remains less explored. This study aims to investigate the effectiveness of PMMF in reducing PCF rates in patients with low SMM and its potential consequences on patient well-being. METHODS: This multicenter study adopts a randomized clinical trial (RCT) design and is funded by the Dutch Cancer Society. Eligible patients for TL, aged ≥ 18 years, mentally competent, and proficient in Dutch, will be enrolled. One hundred and twenty eight patients with low SMM will be centrally randomized to receive TL with or without PMMF, while those without low SMM will undergo standard TL. Primary outcome measurement involves assessing PCF rates within 30 days post-TL. Secondary objectives include evaluating quality of life, shoulder and neck function, swallowing function, and voice quality using standardized questionnaires and functional tests. Data will be collected through electronic patient records. DISCUSSION: This study's significance lies in its exploration of the potential benefits of using PMMF as an onlay technique during pharyngeal closure to reduce PCF rates in TL patients with low SMM. By assessing various functional outcomes, the study aims to provide a comprehensive understanding of the impact of PMMF deployment. The anticipated results will contribute valuable insights into optimizing surgical techniques to enhance patient outcomes and inform future treatment strategies for TL patients. TRIAL REGISTRATION: NL8605, registered on 11-05-2020; International Clinical Trials Registry Platform (ICTRP)

Low dose cisplatin weekly versus high dose cisplatin every three weeks in primary chemoradiotherapy in head and neck cancer patients with low skeletal muscle mass: The CISLOW-study protocol

Chemoradiotherapy with cisplatin in a triweekly regimen of 100 mg/m2 body surface area, is used to treat locally advanced head and neck squamous cell carcinoma (HNSCC) with curative intent. Cisplatin dose limiting toxicity (CDLT) occurs often and impedes obtaining the planned cumulative cisplatin dose. A cumulative cisplatin dose of 200 mg/m2 or more is warranted for better survival and locoregional control. Patients with a low skeletal muscle mass (SMM) have a three-fold higher risk of developing CDLT than patients with a normal SMM. SMM can be assessed through measurements on routinely performed diagnostic head and neck CT- or MRI-scans. A weekly regimen of 40 mg/m2 body surface area cisplatin is proposed as a less toxic schedule, which possibly decreases the risk of developing CDLT and enables reaching a higher cumulative cisplatin dose. The aim of this multicenter randomized clinical trial (NL76533.041.21, registered in the Netherlands Trial Register) is to identify whether a regimen of weekly cisplatin increases compliance to the planned chemotherapy scheme in HNSCC patients with low SMM. The primary outcome is the difference in compliance rate, defined as absence of CDLT, between low SMM patients receiving either the weekly or triweekly regimen. Secondary outcomes consist of toxicities, the cumulative cisplatin dose, time to recurrence, incidence of recurrence at two years of follow-up, location of recurrence, 2-year overall, disease free and disease specific survival, quality of life, patient's experiences, and cost-effectiveness

Imaging of intracranial arterial disease: a comparison between MRI and unenhanced CT

BACKGROUND AND PURPOSE: Arterial calcifications on unenhanced CT scans and vessel wall lesions on MRI are often used interchangeably to portray intracranial arterial disease. However, the extent of pathology depicted with each technique is unclear. We investigated the presence and distribution of these two imaging findings in patients with a history of cerebrovascular disease. MATERIALS AND METHODS: We analyzed CT and MRI data from 78 patients admitted for stroke or TIA at our institution. Vessel wall lesions were assessed on 7 T MRI sequences, while arterial calcifications were assessed on CT scans. The number of vessel wall lesions, severity of intracranial internal carotid artery (iICA) calcifications, and overall presence and distribution of the two imaging findings were visually assessed in the intracranial arteries. RESULTS: At least one vessel wall lesion or arterial calcification was assessed in 69 (88%) patients. Only the iICA and vertebral arteries (VA) showed a substantial number of both calcifications and vessel wall lesions. The other vessels showed almost exclusively vessel wall lesions. The number of vessel wall lesions was associated with the severity of iICA calcification ( p  = 0.013). CONCLUSIONS: The number of vessel wall lesions increases with the severity of iICA calcifications. Nonetheless, the distribution of vessel wall lesions on MRI and arterial calcifications on CT shows remarkable differences. These findings support the need for a combined approach to examine intracranial arterial disease