Predicting hemorrhagic transformation in posterior circulation stroke patients not treated with reperfusion therapies.

INTRODUCTION: Posterior Circulation (PC) stroke represents one-fifth of all ischemic strokes, with peculiar physiological characteristics. Hemorrhagic Transformation (HT) is a dreaded complication among stroke patients. Many predictive scores of this complication have been proposed, but none is designed specifically for PC stroke patients - therefore, patients who are not eligible for reperfusion therapies (RT) represent about 80% of hospitalized cases. We propose a scoring system to assess the HT risk in PC stroke patients not submitted to RT. METHODS: We retrospectively evaluated data of patients diagnosed with PC stroke not treated with RT from 5 Comprehensive Stroke Centers (four in Brazil, 1 in the US) from 2015 to 2018. All patients underwent CT scan or MRI at admission and a follow-up neuroimaging within seven days. Independent variables identified in a logistic regression analysis were used to produce a predictive grading score. RESULTS: We included 952 patients in the final analysis. The overall incidence of HT was 8.7%. Male gender (1 point), NIH Stroke Scale at admission ≥ 5 points (1), blood glucose at admission ≥ 160 mg/dL (1), and cardioembolism (2) were independently associated with HT. The AUC of the grading score (0 to 5 points) was 0.713 (95% CI 0.65-0.78). Subjects with a score ≥ 3 points had an OR of 4.8 (95% CI 2.9-7.9, p < 0.001) for HT. CONCLUSIONS: Our score has good accuracy in identifying patients at higher risk of HT. This score may be useful for evaluating secondary prevention and stratifying patients in the context of even clinical trials.

Predicting hemorrhagic transformation in patients not submitted to reperfusion therapies.

BACKGROUND: Well studied in patients with ischemic stroke after reperfusion therapies (RT), hemorrhagic transformation (HT) is also common in patients not treated with RT and can lead to disability even in initially asymptomatic cases. The best predictors of HT in patients not treated with RT are not well established. Therefore, we aimed to identify predictors of HT in patients not submitted to RT and create a user-friendly predictive score (PROpHET). MATERIAL AND METHODS: Patients admitted to a Comprehensive Stroke Center from 2015 to 2017 were prospectively evaluated and randomly selected to the derivation cohort. A multivariable logistic regression modeling was built to produce a predictive grading score for HT. The external validation was assessed using datasets from 7 Comprehensive Stroke Centers using the area under the receiver operating characteristic curve (AUROC). RESULTS: In the derivation group, 448 patients were included in the final analysis. The validation group included 2,683 patients. The score derived from significant predictors of HT in the multivariate logistic regression analysis was male sex (1 point), ASPECTS ≤ 7 (2 points), presence of leukoaraiosis (1 point), hyperdense cerebral middle artery sign (1 point), glycemia at admission ≥180 mg/dL (1 point), cardioembolism (1 point) and lacunar syndrome (-3 points) as a protective factor. The grading score ranges from -3 to 7. A Score ≥3 had 78.2% sensitivity and 75% specificity, and AUROC of 0.82 for all cases of HT. In the validation cohort, our score had an AUROC of 0.83. CONCLUSIONS: The PROpHET is a simple, quick, cost-free, and easy-to-perform tool that allows risk stratification of HT in patients not submitted to RT. A cost-free computerized version of our score is available online with a user-friendly interface.

Morphometric Study of the Internal Globus Pallidus Using the Robert, Barnard, and Brown Staining Method.

BACKGROUND: The globus pallidus internus (Gpi) is a major target in functional neurosurgery. Anatomical studies are crucial for correct planning and good surgical outcomes in this region. The present study described the anatomical coordinates of the Gpi and its relationship with other brain structures and compared the findings with those from previous anatomical studies. METHODS: We obtained 35 coronal and 5 horizontal brain specimens from the Department of Anatomy and stained them using the Robert, Barnard, and Brown technique. After excluding defective samples, 60 nuclei were analyzed by assessing their distances to the anatomical references and the trajectories to these nuclei. RESULTS: The barycenter of the Gpi was identified at the level of the mammillary bodies and 1 cm above the intercommissural plane. Thereafter, the distances to other structures were found. The mean ± standard deviation distance was 15.62 ± 2.66 mm to the wall of the third ventricle and 17.02 ± 2.69 mm to its midline, 4.74 ± 1.12 mm to the optic tract, 2.51 ± 0.8 mm and 13.56 ± 2 mm to the internal and external capsule, and 21.3 ± 2.44 mm to the insular cortex. The cortical point of entry should be located 22.03 ± 4.34 mm to 48.74 ± 4.44 mm from the midline. CONCLUSION: The Gpi has less variability in distance to closer anatomical references, such as the optic tract and internal capsule. Distant locations showed a more inhomogeneous pattern. Anatomical studies such as ours are important for the development of new therapeutic approaches and can be used as a basis for new research involving volumetric and specific group analyses.