Cognitive function in adolescence and the risk of early-onset stroke.

BACKGROUND: Stroke is increasingly prevalent at younger ages but the risk factors are uncertain. We examined the association between adolescent cognitive function and early-onset stroke. METHODS: This was a nationwide population-based cohort study of 1 741 345 Israeli adolescents (42% women) who underwent comprehensive cognitive function tests at age 16-20 years, before mandatory military service, during 1987-2012. Cognitive function (range: 1-9) was categorised as low (1-3, corresponding to IQ score below 89), medium (4-7, IQ score range: 89-118), or high (8-9, IQ score above 118). Participant data were linked to the Israeli National Stroke Registry. Cox proportional hazard models were used to estimate risks for the first occurrence of ischaemic stroke during 2014-2018. RESULTS: During 8 689 329 person-years of follow-up, up to a maximum age of 50 years, 908 first stroke events occurred (767 ischaemic and 141 haemorrhagic). Compared with a reference group of people with high cognitive function, body mass index-adjusted and sociodemographic-adjusted HRs (95% CIs) for early-onset stroke were 1.78 (1.33-2.38) in medium and 2.68 (1.96-3.67) in low cognitive function groups. There was evidence of a dose-response relationship (P for trend <0.0001) such that one-unit of lower cognitive function z-score was associated with a 33% increased risk of stroke (1.33; 1.23-1.42). These associations were similar for ischaemic stroke but lower for haemorrhagic stroke; persisted in sensitivity analyses that accounted for diabetes status and hypertension; and were evident before age 40 years. CONCLUSIONS: Alongside adolescent obesity and hypertension, lower cognitive function may be a risk factor for early-onset stroke.

Prevalence and Characteristics of Cervical Ossified Posterior Longitudinal Ligament in the Jewish Population.

BACKGROUND: Numerous studies have demonstrated an association between ethnic identity and the prevalence rate of cervical ossified posterior longitudinal ligament (C-OPLL). To date, its prevalence rate in the Jewish population has not been determined. The aim of this historical prospective study is to evaluate the prevalence and characteristics of C-OPLL in the Jewish population. METHODS: We performed a retrospective evaluation of imaging studies of all adult patients who underwent both cervical computed tomography and magnetic resonance imaging for all clinical indications within a span of 36 months between January 2017 and July 2020 at a single tertiary referral hospital located in central Israel. Identified C-OPLL carriers were interviewed by telephone. All the patients provided informed consent and then were questioned for current symptoms and demographics, including religion, Jewish ethnic identity, birthplace, parental birthplace and ethnic identity, and family history of spinal disorders. RESULTS: Overall, 440 participants were radiographically evaluated. The prevalence of C-OPLL in the Jewish population was 7.5% (33 of 440). The mean age of the C-OPLL carriers was 65.8 years. All the C-OPLL carriers were symptomatic at analysis. The carriers had an increased proportion with a Sephardic Jewish ethnic identity (65.4%), with a significantly high rate of homogeneous parental Jewish identity (92.4%), suggesting a prominent genetic contribution to the development of this condition. CONCLUSIONS: The prevalence of C-OPLL in the Jewish population in central Israel was 7.5%. This rate is significantly higher than that in other previously studied populations. To the best of our knowledge, this is the first study to identify the Jewish population as experiencing an increased prevalence of C-OPLL.

The impact on clinical outcomes after 1 year of implementation of an artificial intelligence solution for the detection of intracranial hemorrhage.

BACKGROUND: To assess the effect of a commercial artificial intelligence (AI) solution implementation in the emergency department on clinical outcomes in a single level 1 trauma center. METHODS: A retrospective cohort study for two time periods-pre-AI (1.1.2017-1.1.2018) and post-AI (1.1.2019-1.1.2020)-in a level 1 trauma center was performed. The ICH algorithm was applied to 587 consecutive patients with a confirmed diagnosis of ICH on head CT upon admission to the emergency department. Study variables included demographics, patient outcomes, and imaging data. Participants admitted to the emergency department during the same time periods for other acute diagnoses (ischemic stroke (IS) and myocardial infarction (MI)) served as control groups. Primary outcomes were 30- and 120-day all-cause mortality. The secondary outcome was morbidity based on Modified Rankin Scale for Neurologic Disability (mRS) at discharge. RESULTS: Five hundred eighty-seven participants (289 pre-AI-age 71 ± 1, 169 men; 298 post-AI-age 69 ± 1, 187 men) with ICH were eligible for the analyzed period. Demographics, comorbidities, Emergency Severity Score, type of ICH, and length of stay were not significantly different between the two time periods. The 30- and 120-day all-cause mortality were significantly reduced in the post-AI group when compared to the pre-AI group (27.7% vs 17.5%; p = 0.004 and 31.8% vs 21.7%; p = 0.017, respectively). Modified Rankin Scale (mRS) at discharge was significantly reduced post-AI implementation (3.2 vs 2.8; p = 0.044). CONCLUSION: The added value of this study emphasizes the introduction of artificial intelligence (AI) computer-aided triage and prioritization software in an emergent care setting that demonstrated a significant reduction in a 30- and 120-day all-cause mortality and morbidity for patients diagnosed with intracranial hemorrhage (ICH). Along with mortality rates, the AI software was associated with a significant reduction in the Modified Ranking Scale (mRs).

MRI-based detection of cervical ossification of the posterior longitudinal ligament using a novel automated machine learning diagnostic tool.

OBJECTIVE: Currently, CT is considered the gold standard for the diagnosis of ossification of the posterior longitudinal ligament (OPLL). The objective of this study was to develop artificial intelligence (AI) software and a validated model for the identification and representation of cervical OPLL (C-OPLL) on MRI, obviating the need for spine CT. METHODS: A retrospective evaluation was performed of consecutive imaging studies of all adult patients who underwent both cervical CT and MRI for any clinical indication within a span of 36 months (between January 2017 and July 2020) in a single tertiary-care referral hospital. C-OPLL was identified by a panel of neurosurgeons and a neuroradiologist. MATLAB software was then used to create an AI tool for the diagnosis of C-OPLL by using a convolutional neural network method to identify features on MR images. A reader study was performed to compare the performance of the AI model to that of the diagnostic panel using standard test performance metrics. Interobserver variability was assessed using Cohen's kappa score. RESULTS: Nine hundred consecutive patients were found to be eligible for radiological evaluation, yielding 65 identified C-OPLL carriers. The AI model, utilizing MR images, was able to accurately segment the vertebral bodies, PLL, and discoligamentous complex, and detect C-OPLL carriers. The AI model identified 5 additional C-OPLL patients who were not initially detected. The performance of the MRI-based AI model resulted in a sensitivity of 85%, specificity of 98%, negative predictive value of 98%, and positive predictive value of 85%. The overall accuracy of the model was 98%, with a kappa score of 0.917. CONCLUSIONS: The novel AI software developed in this study was highly specific for identifying C-OPLL on MRI, without the use of CT. This model may obviate the need for CT scans while maintaining adequate diagnostic accuracy. With further development, this MRI-based AI model has the potential to aid in the diagnosis of various spinal disorders and its automated layers may lay the foundation for MRI-specific diagnostic criteria for C-OPLL.

Adolescent Hypertension Is Associated With Stroke in Young Adulthood: A Nationwide Cohort of 1.9 Million Adolescents.

BACKGROUND: Adult hypertension is a well-established risk factor for stroke in young adults (aged <55 years), and the effects are even more deleterious than at an older age. However, data are limited regarding the association between adolescent hypertension and the risk of stroke in young adulthood. METHODS: A nationwide, retrospective cohort study of adolescents (aged 16-19 years) who were medically evaluated before compulsory military service in Israel during 1985 to 2013. For each candidate for service, hypertension was designated after constructed screening, and the diagnosis was confirmed through a comprehensive workup process. The primary outcome was ischemic and hemorrhagic stroke incidence as registered at the national stroke registry. Cox proportional-hazards models were used. We conducted sensitivity analyses by excluding people with a diabetes diagnosis at adolescence or a new diabetes diagnosis during the follow-up period, analysis of adolescents with overweight, and adolescents with baseline unimpaired health status. RESULTS: The final sample included 1 900 384 adolescents (58% men; median age, 17.3 years). In total, 1474 (0.08%) incidences of stroke (1236 [84%] ischemic) were recorded, at a median age of 43 (interquartile range, 38-47) years. Of these, 18 (0.35%) occurred among the 5221 people with a history of adolescent hypertension. The latter population had a hazard ratio of 2.4 (95% CI, 1.5-3.9) for incident stroke after adjustment for body mass index and baseline sociodemographic factors. Further adjustment for diabetes status yielded a hazard ratio of 2.1 (1.3-3.5). We found similar results when the outcome was ischemic stroke with a hazard ratio of 2.0 (1.2-3.5). Sensitivity analyses for overall stroke, and ischemic stroke only, yielded consistent findings. CONCLUSIONS: Adolescent hypertension is associated with an increased risk of stroke, particularly ischemic stroke, in young adulthood.

Janus Kinase-2 V617F Mutation and Antiphospholipid Syndrome in Cerebral Sinus Venous Thrombosis: Natural History and Retrospective Bicenter Analysis.

Background: Cerebral sinus venous thrombosis (CSVT) is a rare neurovascular entity, usually associated with acquired or genetic hypercoagulable states. In up to 30% of the cases it remains idiopathic. Bone marrow proliferation disorders that are associated with Janus Kinase 2 V617F mutation (JAK-2) are known causes of the systemic and cerebral thrombosis-at times despite normal blood counts-for which hematologic treatment exists. However, JAK-2 prevalence in the CSVT cases is not clear. Methods: In this retrospective analysis, data of 236 patients with CSVT admitted to two tertiary centers between 2010 and 2020 were analyzed, with emphasis on laboratory and imaging data and clinical and interventional outcomes. Results: A total of 236 patients were included in the analysis. The patients' median age was 42 years and the average age was 44 years (±19 years), with 59% female patients. JAK-2 positivity rate was 18% (among 77 patients tested for the mutation). Patients with normal blood counts on presentation comprised 36% of the JAK-2 positive cases. Other hypercoagulability states were also investigated, with the antiphospholipid syndrome (APLA) showing the highest prevalence (11%) followed by other etiologies including oral contraceptive use, Factor V Leiden, prothrombin mutation, and malignancy. Selected JAK-2, APLA, and prothrombin mutation cases showed a more severe clinical course. Conclusion: JAK-2 mutation is underdiagnosed and its screening may be warranted in the cases of idiopathic CSVT, even despite normal blood counts, to allow disease-modifying treatment and blood cell count monitoring. JAK-2, APLA, and prothrombin mutation may be associated with a more complicated clinical course.

In-thrombus thrombin secretion: a new diagnostic marker of atrial fibrillation in cryptogenic stroke.

Endovascularly retrieved clots may be a potential resource for diagnosing stroke etiology. This method may influence secondary prevention treatment. We measure thrombin activity eluted by serially washing clots. We concluded that an assay measuring the change in thrombin in clots retrieved during acute stroke endovascular thrombectomy procedures may serve as a diagnostic marker of the origin of the clot. The suggested mechanism for these differences may be the clot location before its retrieval, with high blood flow causing thrombin washout in atherosclerotic clots, in contrast to atrium appendage low blood flow retaining high thrombin levels.

3.0 Tesla normative diffusivity in 3rd trimester fetal brain.

PURPOSE: Apparent diffusion coefficient (ADC) values in the developing fetus provide valuable information on the diagnosis and prognosis of prenatal brain pathologies. Normative ADC data has been previously established in 1.5 T MR scanners but lacking in 3.0 T scanners. Our objective was to measure ADC values in various brain areas in a cohort of normal singleton fetuses scanned in a 3.0 T MR scanner. METHODS: DWI (diffusion-weighted imaging) was performed in 47 singleton fetuses with normal or questionably abnormal results on sonography followed by normal structural MR imaging. ADC values were measured in cerebral lobes (frontal, parietal, temporal lobes), basal ganglia, and pons. Regression analysis was used to examine gestational age-related changes in regional ADC. RESULTS: Median gestational age was 30.1 weeks (range, 26-34 weeks). There was a significant effect of region on ADC values, whereby ADC values were highest in cerebral lobes (parietal > frontal > temporal lobes), compared with basal ganglia. The lowest values were found in the pons. On regression analysis, there was a decrease in ADC values in basal ganglia and pons with increasing gestational age. ADC values in frontal, parietal, and temporal lobes were stable in our cohort. CONCLUSION: Regional brain ADC values in 3.0 T scanners are comparable with previously reported values in 1.5 T scanners, with similar changes over gestational age. Using 3.0 T scanners is increasing worldwide. For fetal imaging, establishing normal ADC values is critical as DWI enables a sensitive and quantitative technique to evaluate normal and abnormal brain development.

CT Perfusion collateral index in assessment of collaterals in acute ischemic stroke with delayed presentation: Comparison to single phase CTA.

BACKGROUND & PURPOSE: Perfusion collateral index (PCI) has been recently defined as a promising measure of collateral status. We sought to compare collateral status assessed via CT-PCI in comparison to single-phase CTA and their relationship to outcome measures including final infarction volume, final recanalization status and functional outcome in ELVO patients. METHODS: ELVO patients with anterior circulation large vessel occlusion who had baseline CTA and CT perfusion and underwent endovascular treatment were included. Collateral status was assessed on CTA. PCI from CT perfusion was calculated in each patient and an optimal threshold to separate good vs insufficient collaterals was identified using DSA as reference. The collateral status determined by CTA and PCI were assessed against 3 measured outcomes: 1) final infarction volume; 2) final recanalization status defined by TICI scores; 3) functional outcome measured by 90-day mRS. RESULTS: A total of 53 patients met inclusion criteria. Excellent recanalization defined by TICI ≥2C was achieved in 36 (68%) patients and 23 patients (43%) had good functional outcome (mRS ≤2). While having good collaterals on both CTA and CTP-PCI was associated with significantly (p<0.05) smaller final infarction volume, only good collaterals status determined by CTP-PCI was associated with achieving excellent recanalization (p = 0.001) and good functional outcome (p = 0.003). CONCLUSION: CTP-based PCI outperforms CTA collateral scores in determination of excellent recanalization and good functional outcome and may be a promising imaging marker of collateral status in patients with delayed presentation of AIS.

Remote ischemic preconditioning improves tissue oxygenation in a porcine model of controlled hemorrhage without fluid resuscitation.

Remote ischemic preconditioning (RIPC) involves deliberate, brief interruptions of blood flow to increase the tolerance of distant critical organs to ischemia. This study tests the effects of limb RIPC in a porcine model of controlled hemorrhage without replacement therapy simulating an extreme field situation of delayed evacuation to definitive care. Twenty-eight pigs (47 ± 6 kg) were assigned to: (1) control, no procedure (n = 7); (2) HS = hemorrhagic shock (n = 13); and (3) RIPC + HS = remote ischemic preconditioning followed by hemorrhage (n = 8). The animals were observed for 7 h after bleeding without fluid replacement. Survival rate between animals of the RIPC + HS group and those of the HS group were similar (HS, 6 of 13[46%]-vs-RIPC + HS, 4 of 8[50%], p = 0.86 by Chi-square). Animals of the RIPC + HS group had faster recovery of mean arterial pressure and developed higher heart rates without complications. They also had less decrease in pH and bicarbonate, and the increase in lactate began later. Global oxygen delivery was higher, and tissue oxygen extraction ratio lower, in RIPC + HS animals. These improvements after RIPC in hemodynamic and metabolic status provide essential substrates for improved cellular response after hemorrhage and reduction of the likelihood of potentially catastrophic consequences of the accompanying ischemia.

Body Mass Index in 1.9 Million Adolescents and Stroke in Young Adulthood.

Background and Purpose: There is a continuous rise in the prevalence of adolescent obesity and incidence of stroke among young adults in many Western countries, but the association between them is unclear. Methods: A nationwide population-based study of 1 900 384 Israeli adolescents (58% men; mean age, 17.3 years) who were evaluated before mandatory military service during 1985 and 2013. Body mass index was classified according to the US Center for Disease Control and Prevention percentiles. Primary outcome was a first stroke event as recorded by the Israeli National Stroke Registry between 2014 and 2018. Cox proportional hazard models were applied. Results: There were 1088 first stroke events (921 ischemic and 167 hemorrhagic; mean diagnosis age, 41.0 years). Adolescent body mass index was significantly associated with a graded increase in the risk for any stroke, ischemic stroke, but less so with hemorrhagic stroke. The hazard ratios for the first ischemic stroke event were 1.4 (95% CI, 1.2­1.6), 2.0 (95% CI, 1.6­2.4), and 3.4 (95% CI, 2.7­4.3) for the 50th to 84th percentile, overweight and obese groups, respectively, after adjustment for sex, age, and sociodemographic confounders with the 5th to 49th body mass index percentile group as the reference. The respective hazard ratios after further adjustment for diabetes status were 1.3 (1.1­1.5), 1.6 (1.3­2.0), and 2.4 (1.9­3.1). Results persisted when the cohort was divided by diabetes status and when ischemic stroke before age 30 was the outcome. Conclusions: High adolescent body mass index was associated with ischemic stroke in young adults with or without diabetes. The rising prevalence of adolescent obesity may increase the future burden of stroke in young adults.

Surgical Management of Failed Endovascular Treatment for Spinal Dural Arteriovenous Fistulas.

BACKGROUND: Spinal dural arteriovenous fistulas (SDAVFs) are rare vascular malformations. Digital subtraction angiography is the modality of choice to demonstrate the malformation before endovascular embolization or open surgical repair. Angiographically occult SDAVFs have been previously reported. Surgical considerations in SDAVFs with misleading angiography findings have not yet been assessed. METHODS: A retrospective evaluation of charts and imaging files of patients operated on for SDAVF in 2018-2019 at a single institution was performed. All patients were referred to surgery following failure of endovascular embolization or owing to clinical and radiographic deterioration in the presence of an angiographically occult lesion. Cases were comprehensively reviewed and evaluated for surgical considerations in these lesions. RESULTS: This case series included 4 cases. Two patients underwent embolization before surgical repair but continued to deteriorate neurologically, and 2 patients had a failed embolization attempt owing to a torturous vascular network. In all 4 patients, exploration was successful, yielding either improvement or stabilization of neurological status. Indocyanine green injection for microscopically integrated fluorescent angiography contributed to the identification of the supplying vessels and confirmed the SDAVF closure. CONCLUSIONS: SDAVFs should be treated promptly after diagnosis. In cases with high suspicion for SDAVF with occult or misleading angiography findings, spinal exploration should be pursued with no delay. Indocyanine green-assisted microscopic angiography may contribute to exploratory spine surgery for SDAVF closure.

In-thrombus thrombin secretion: a new diagnostic marker of atrial fibrillation in cryptogenic stroke.

BACKGROUND: Endovascularly retrieved clots are a potential resource for diagnosing stroke etiology, which may influence secondary prevention treatment. In this study we measured thrombin activity eluted by serially washing clots. METHODS: Clots were retrieved from 68 patients with acute ischemic stroke, freshly frozen and classified by standard criteria into proven atrial fibrillation (AF, 18 patients), atherosclerotic origin (AS, 15 patients), cryptogenic stroke (Cr, 17 patients) and other known causes (18 patients). Thawed clot samples were washed by transferring them into 1 mL buffer in seven hourly cycles and a fluorescent substrate assay was used to measure secreted thrombin activity. The clots were also examined histologically. Artificial fibrin and red blood cell-rich clots were similarly assayed for wash-eluted thrombin activity as an external control. RESULTS: Thrombin activity eluted from clots of AF origin decreased significantly with time in contrast to steady levels eluted from AS origin thrombi (P<0.0001 by repeated measures ANOVA). The Cr stroke group was indistinguishable from the AF group and differed statistically from the AS group (P=0.017 by repeated measures ANOVA). In artificial clots we found a biphasic activity pattern, with initially decreasing levels of eluted thrombin (AF pattern) and then, with continuing washes, steady eluted thrombin levels (AS pattern). CONCLUSIONS: An assay measuring the change in thrombin in clots retrieved during acute stroke endovascular thrombectomy procedures may serve as a diagnostic marker of the origin of the clot. The suggested mechanism for these differences may be the clot location before its retrieval, with high blood flow causing thrombin washout in atherosclerotic clots, in contrast to atrium appendage low blood flow retaining high thrombin levels.

Early Maladaptive Cardiovascular Responses are Associated with Mortality in a Porcine Model of Hemorrhagic Shock.

BACKGROUND: Hemorrhage is a leading cause of death on the battlefield. Current methods for predicting hemodynamic deterioration during hemorrhage are of limited accuracy and practicality. During a study of the effects of remote ischemic preconditioning in pigs that underwent hemorrhage, we noticed arrhythmias among all pigs that died before the end of the experiment but not among surviving pigs. The present study was designed to identify and characterize the early maladaptive hemodynamic responses (tachycardia in the presence of hypotension without a corresponding increase in cardiac index or mean arterial blood pressure) and their predictive power for early mortality in this experimental model. METHODS: Controlled hemorrhagic shock was induced in 16 pigs. Hemodynamic parameters were monitored continuously for 7 h following bleeding. Changes in cardiovascular and laboratory parameters were analyzed and compared between those that had arrhythmia and those that did not. RESULTS: All animals had similar changes in parameters until the end of the bleeding phase. Six animals developed arrhythmias and died early, while 10 had no arrhythmias and survived longer than 6 h or until euthanasia. Unlike survivors, those that died did not compensate for cardiac output (CO), diastolic blood pressure (DBP), and stroke volume (SV). Oxygen delivery (DO2) and mixed venous saturation (SvO2) remained low in animals that had arrhythmia, while achieving certain measures of recuperation in animals that did not. Serum lactate increased earlier and continued to rise in all animals that developed arrhythmias. No significant differences in hemoglobin concentrations were observed between groups. CONCLUSIONS: Despite similar initial changes in variables, we found that low CO, DBP, SV, DO2, SvO2, and high lactate are predictive of death in this animal model. The results of this experimental study suggest that maladaptive responses across a range of cardiovascular parameters that begin early after hemorrhage may be predictive of impending death, particularly in situations where early resuscitative treatment may be delayed.

Styloid Process Elongation on Cervical Spine Computed Tomography is Associated with the Enthesopathy-Related Diseases of Ankylosing Spondylitis and Diffuse Idiopathic Skeletal Hyperostosis.

BACKGROUND: Enthesopathy may lead to calcification of the stylohyoid ligament and can cause elongation of the styloid process (SP). OBJECTIVES: To evaluate whether SP elongation is associated with two common enthesitis-related diseases: ankylosing spondylitis (AS) and diffuse idiopathic skeletal hyperostosis (DISH). METHODS: Cervical spine computed tomography (CT) examinations of patients with DISH (n=64, Resnick criteria), AS (n=24, New York criteria) and a controls (no radiological signs of DISH or AS, n=54) were retrospectively evaluated. The DISH group was further divided into patients with and without cervical DISH. The length of right and left SP was measured independently by two readers on coronal and sagittal curved reformats. The average right and left styloid length and average length per person were compared among the groups. RESULTS: Demographic characteristics were similar between the DISH and control groups (average age 68.2 ± 15.7, 69.2 ± 12.7 years, male:female ratio 48:16 and 35:19, respectively, P > 0.05), whereas age was significantly lower (average age: 53 ± 15 years, P < 0.0001) in the AS group, which was also composed mainly of men. The AS and DISH groups had significantly longer SP compared to controls (AS 37.9 ± 9.6 mm, DISH 34.4 ± 9 mm, control 30.3 ± 10.1 mm, P < 0.05). There was no correlation between age and SP length. Inter-reader reliability of SP measurements was excellent in all groups (ICC = 0.998, P < 0.0001). CONCLUSIONS: SP elongation is associated with both AS and DISH substantiating the enthesopathy-related pathophysiology of this finding.

Discrepancy in fetal head biometry between ultrasound and MRI in suspected microcephalic fetuses.

Background Microcephaly is one of the most common fetal structural abnormalities, and prenatal microcephaly is considered a group I malformation of cortical development diagnosed according to ultrasound (US) skull measurements. Purpose To evaluate the agreement between fetal head US and magnetic resonance imaging (MRI) biometric measurements of suspected microcephalic fetuses. Material and Methods This institutional review board-approved retrospective study with waived informed consent included 180 pregnant women and was conducted at our medical center from March 2011 to April 2013. Biparietal diameter (BPD) and occipitofrontal diameter (OFD) results of fetal head US normograms were compared to normograms for MRI. We used Pearson and Spearman rho non-parametric correlation coefficients to assess the association between two quantitative variables, paired t-test for paired quantitative variables, and McNemar test for paired qualitative variables. Results The average BPD but not the average OFD percentiles in fetal head US differed significantly from the MRI results ( P < 0.0001). When looking at the accepted microcephaly threshold, both BPD and OFD percentiles differed significantly from MRI ( P < 0.0001 and P < 0.004, respectively). There was no correlation between US-measured skull biometry and MRI-measured brain biometry. Estimated cerebrospinal fluid volumes were significantly lower in the study group compared to 120 fetuses with normal findings in prenatal head US and MRI. Also, we have created a MRI-based normogram of fetal head circumference and gestational age. Conclusion The diagnosis of microcephaly by US alone may be insufficient and ideally should be validated by MRI before a final diagnosis is established.

The approximated cardiovascular reserve index complies with haemorrhage related hemodynamic deterioration pattern: A swine exsanguination model.

BACKGROUND: To estimate the cardiovascular reserve we formulated the Cardiovascular Reserve Index (CVRI) based on physiological measurements. The aim of this study was to evaluate the pattern of CVRI in haemorrhage-related haemodynamic deterioration in an animal model simulating combat injury. METHODS: Data were collected retrospectively from a research database of swine exsanguination model in which serial physiological measurements were made under anesthesia in 12 swine of haemorrhagic injury and 5 controls. We calculated the approximated CVRI (CVRIA). The course of haemodynamic deterioration was defined according to the cumulative blood loss until shock. The ability of heart rate (HR), mean arterial blood pressure (MABP), stroke volume (SV), cardiac output (CO) and systemic vascular resistance (SVR) and the CVRIA to predict haemodynamic deterioration was evaluated according to three criteria: strength of association with the course of haemodynamic deterioration (r2 > 0.5); threshold for haemodynamic deterioration detection; and range at which the parameter remained consistently monotonous course of deterioration. RESULTS: Three parameters met the first criterion for prediction of haemodynamic deterioration: HR (r2 = 0.59), SV (r2 = 0.57) and CVRIA (r2 = 0.66). Results were negative for MABP (r2 = 0.27), CO (r2 = 0.33) and SVR (r2 = 0.02). The detection threshold of the CVRIA was 200-300 ml blood loss whereas HR, SV and CO showed a delay in detection, MABP and CVRI exhibited a wide indicative range toward shock. CONCLUSIONS: The CVRIA met preset criteria of a potential predictor of haemorrhage-related haemodynamic deterioration. Prospective studies are required to evaluate use of the CVRI in combat medicine. LEVEL OF EVIDENCE: Level III.

Body-Mass Index in 2.3 Million Adolescents and Cardiovascular Death in Adulthood.

BACKGROUND: In light of the worldwide increase in childhood obesity, we examined the association between body-mass index (BMI) in late adolescence and death from cardiovascular causes in adulthood. METHODS: We grouped data on BMI, as measured from 1967 through 2010 in 2.3 million Israeli adolescents (mean age, 17.3±0.4 years), according to age- and sex-specific percentiles from the U.S. Centers for Disease Control and Prevention. Primary outcomes were the number of deaths attributed to coronary heart disease, stroke, sudden death from an unknown cause, or a combination of all three categories (total cardiovascular causes) by mid-2011. Cox proportional-hazards models were used. RESULTS: During 42,297,007 person-years of follow-up, 2918 of 32,127 deaths (9.1%) were from cardiovascular causes, including 1497 from coronary heart disease, 528 from stroke, and 893 from sudden death. On multivariable analysis, there was a graded increase in the risk of death from cardiovascular causes and all causes that started among participants in the group that was in the 50th to 74th percentiles of BMI (i.e., within the accepted normal range). Hazard ratios in the obese group (≥95th percentile for BMI), as compared with the reference group in the 5th to 24th percentiles, were 4.9 (95% confidence interval [CI], 3.9 to 6.1) for death from coronary heart disease, 2.6 (95% CI, 1.7 to 4.1) for death from stroke, 2.1 (95% CI, 1.5 to 2.9) for sudden death, and 3.5 (95% CI, 2.9 to 4.1) for death from total cardiovascular causes, after adjustment for sex, age, birth year, sociodemographic characteristics, and height. Hazard ratios for death from cardiovascular causes in the same percentile groups increased from 2.0 (95% CI, 1.1 to 3.9) during follow-up for 0 to 10 years to 4.1 (95% CI, 3.1 to 5.4) during follow-up for 30 to 40 years; during both periods, hazard ratios were consistently high for death from coronary heart disease. Findings persisted in extensive sensitivity analyses. CONCLUSIONS: A BMI in the 50th to 74th percentiles, within the accepted normal range, during adolescence was associated with increased cardiovascular and all-cause mortality during 40 years of follow-up. Overweight and obesity were strongly associated with increased cardiovascular mortality in adulthood. (Funded by the Environment and Health Fund.).

Old Challenges and New Perspectives on Developing Military Physicians: The First 4 Years of the New Israeli Model.

Military medicine comprises a set of unique characteristics that differentiate it from other medical specialties. Faced with challenges in recruiting, educating, and training military physicians, the Israel Defense Forces Medical Corps redefined the paradigm for educating military physicians by establishing the Army Program for Excellence in medicine (APEX). This program created a military medical track at the Hebrew University-Hadassah School of Medicine in Jerusalem. All military track students attend a single medical school, which allows for a more focused and efficient program. The students study, dorm, and train together, forming a strong social network. They also receive significant financial, logistical, academic, and educational support. Finally, the program provides a full curriculum in military medical studies, composed of academic courses given for credits and an integrated training schedule designed to build and improve physical and mental fitness for the military environment. In this article, we provide an overview of APEX, including the admissions process and a descriptive analysis of the student body, and present our comprehensive approach to teaching academic military medicine. To the best of our knowledge, APEX represents one of the few fully integrated undergraduate longitudinal military medical education programs, allowing us to educate military physicians "from day one."