Partial Rhombencephalosynapsis.

Clinical history - A 4-year-old boy, born prematurely at 29 weeks (twin pregnancy), with periventricular leukomalacia and epilepsy underwent brain MRI. Neurological examination showed severe developmental retardation with axial hypotonia, spastic tetraparesis and convergent strabismus. Imaging findings - Cranial MRI revealed typical aspects of partial rhombencephalosynapsis with vermian hypoplasia, midline fusion of the cerebellar hemispheres and transversely oriented folia and fissures. There was also mild dilatation and dysmorphism of the ventricular system, the septum pellucidum was absent, the hippocampi were malrotated and had vertical orientation and additional finding of associated periventricular cystic leukomalacia. Discussion - Rhombencephalosynapsis (RS) is a rare congenital defect of the cerebellum classically characterised by vermian agenesis or hypogenesis, fusion of the hemispheres, and closely apposed or fused dentate nuclei. It is now considered to result from an absence of division of the cerebellar hemispheres, following an insult between the 28th and 44th day of gestation (i.e., before the formation of the vermis). Other features have also been described such as fusion of the thalami and cerebral peduncles, malrotated hippocampi, corpus callosum agenesis, hypoplastic chiasm, absence of the septum pellucidum, ventriculomegaly, agenesis of the posterior lobe of the pituitary and cortical malformations. Musculoskeletal, cardiovascular, urinary tract, and respiratory abnormalities have been reported. Typical symptoms consist of swallowing difficulties, delayed motor acquisitions, muscular hypotonia, spastic quadriparesis, cerebellar signs including dysarthria, gait ataxia, abnormal eye movements, and seizures and hydrocephalus. The major MRI signs consist of fused cerebellar hemispheres, with absent or hypoplastic vermis, narrow diamond-shaped fourth ventricle and fused dentate nuclei. In a minority of cases, partial RS has been identified by MRI, demonstrating the presence of the nodulus and the anterior vermis and absence of part of the posterior vermis with only partial fusion of the hemispheres in the inferior part. Other cerebellar malformations involving vermian agenesis or hypoplasia include the Dandy–Walker continuum, Joubert syndrome, tectocerebellar dysraphy or pontocerebellar hypoplasias, and are now easily distinguished from RS by both brain MRI and morphology.

Validation of Two US Risk Scores for Percutaneous Coronary Intervention in a Single-Center Portuguese Population of Patients with Acute Coronary Syndrome

INTRODUCTION: New scores have been developed and validated in the US for in-hospital mortality risk stratification in patients undergoing coronary angioplasty: the National Cardiovascular Data Registry (NCDR) risk score and the Mayo Clinic Risk Score (MCRS). We sought to validate these scores in a European population with acute coronary syndrome (ACS) and to compare their predictive accuracy with that of the GRACE risk score. METHODS: In a single-center ACS registry of patients undergoing coronary angioplasty, we used the area under the receiver operating characteristic curve (AUC), a graphical representation of observed vs. expected mortality, and net reclassification improvement (NRI)/integrated discrimination improvement (IDI) analysis to compare the scores. RESULTS: A total of 2148 consecutive patients were included, mean age 63 years (SD 13), 74% male and 71% with ST-segment elevation ACS. In-hospital mortality was 4.5%. The GRACE score showed the best AUC (0.94, 95% CI 0.91-0.96) compared with NCDR (0.87, 95% CI 0.83-0.91, p=0.0003) and MCRS (0.85, 95% CI 0.81-0.90, p=0.0003). In model calibration analysis, GRACE showed the best predictive power. With GRACE, patients were more often correctly classified than with MCRS (NRI 78.7, 95% CI 59.6-97.7; IDI 0.136, 95% CI 0.073-0.199) or NCDR (NRI 79.2, 95% CI 60.2-98.2; IDI 0.148, 95% CI 0.087-0.209). CONCLUSION: The NCDR and Mayo Clinic risk scores are useful for risk stratification of in-hospital mortality in a European population of patients with ACS undergoing coronary angioplasty. However, the GRACE score is still to be preferred.