Practical utility of clinical prediction rules for suspected acute pulmonary embolism in a large academic institution

INTRODUCTION: In an attempt to standardize clinicians' approach to the determination of pretest probability (PTP) in pulmonary embolism (PE), two simplified scoring models have recently been proposed. We sought to determine the utility of these algorithms in patients with suspected PE in a large, tertiary, academic medical center. METHODS: We performed a retrospective analysis of 295 inpatients and outpatients from our institution who were evaluated for suspected PE. Pretest probability (PTP) was calculated using two previously formulated scoring systems by Wells et al. (Canadian score) and Wicki et al. (Geneva score). Our primary endpoint was the prevalence of PE within each strata of PTP. RESULTS: The prevalence of pulmonary embolism in our cohort was 30%. The prevalence of PE in the low, intermediate and high PTP groups using the Canadian score was 15.3% (95% CI 9.5-23.7%), 34.8% (95% CI 27.9-42.4%), and 47.2% (95% CI 32.0-63.0), respectively. When compared with the low PTP group, the odds ratios of the likelihood of PE was 2.95 (95% CI 1.56-5.59) in the intermediate PTP group and 4.95 (95% CI 2.11-11.64) in the high PTP. The Wicki analysis was divided into "Geneva pure" and "Geneva presumed", where the fractional inspired oxygen concentration was known and presumed to have been sampled on room air, respectively. Neither of the Geneva scores showed statistical significance in the prevalence of PE among the PTP groups. CONCLUSIONS: The Wells' clinical prediction score is easily applied and meaningfully risk stratifies patients with suspected PE. In our population, the Geneva score was less useful.     

Prefrontal-subcortical dissociations underlying inhibitory control revealed by event-related fMRI

Using event-related fMRI, this study investigated the neural dynamics of response inhibition under fluctuating task demands. Fourteen participants performed a GO/NOGO task requiring inhibition of a prepotent motor response to NOGO events that occurred as part of either a Fast or Slow presentation stream of GO stimuli. We compared functional activations associated with correct withholds (Stops) required during the Fast presentation stream of stimuli to Stops required during the Slow presentation stream. A predominantly right hemispheric network was activated across conditions, consistent with previous studies. Furthermore, a functional dissociation of activations between conditions was observed. Slow Stops elicited additional activation in anterior dorsal and polar prefrontal cortex and left inferior parietal cortex. Fast Stops showed additional activation in a network that included right dorsolateral prefrontal cortex, insula and dorsal striatum. These results are discussed in terms of our understanding of the impact of preparation on the distributed network underlying response inhibition and the contribution of subcortical areas, such as the basal ganglia, to executive control processes.     

Oligoclonal bands predict multiple sclerosis in children with optic neuritis

We retrospectively evaluated predictors of conversion to multiple sclerosis (MS) in 357 children with isolated optic neuritis (ON) as a first demyelinating event who had a median follow‐up of 4.0 years. Multiple Cox proportional‐hazards regressions revealed abnormal cranial magnet resonance imaging (cMRI; hazard ratio [HR] = 5.94, 95% confidence interval [CI] = 3.39–10.39, p < 0.001), presence of cerebrospinal fluid immunoglobulin G oligoclonal bands (OCB; HR = 3.69, 95% CI = 2.32–5.86, p < 0.001), and age (HR = 1.08 per year of age, 95% CI = 1.02–1.13, p = 0.003) as independent predictors of conversion, whereas sex and laterality (unilateral vs bilateral) had no influence. Combined cMRI and OCB positivity indicated a 26.84‐fold higher HR for developing MS compared to double negativity (95% CI = 12.26−58.74, p < 0.001). Accordingly, cerebrospinal fluid analysis may supplement cMRI to determine the risk of MS in children with isolated ON. Ann Neurol 2015;77:1076–1082     

Quantitative MRI in Outpatient Childhood Epilepsy

Summary: Purpose: In adult studies, MRI volumetrics is a proven technique in presurgical assessment of epilepsy. Hippocampal volume loss is maximal in the syndrome of mesial temporal lobe epilepsy. We aimed (a) to validate this methodology in a pediatric outpatient epilepsy population (b) to determine the relationship of hippocampal asymmetry (HA) to epileptic syndromes and risk factors. Methods: Two neurologists classified the epileptic syndrome in 79 pediatric outpatients, according to the International Classification of Epilepsies and Epileptic Syndromes (ILAE). Hippocampal volumetrics were performed in all patients. HA was defined according to adult control values. Results: Inter-rater variability on measurement of HA was very small (Correlation of test retest of 0.97 on 17 children <3 years old). The rate of HA was 44/79 (57%). In 21 patients, (27%) potentially epileptogenic lesions (other than HA) were identified (cerebral dysgenesis n = 11). HA was present in 9/15 (60%) of temporal lobe epilepsy and in 15/28 (54%) extratemporal onset epilepsy and 5/11 (46%) of generalized symptomatic epilepsy. Analysis confined to <13 years also showed HA was not specific for epileptic syndrome. There was no significant association of febrile convulsions (13%) with HA or temporal lobe epilepsy. Conclusions: There is a high incidence of HA in childhood epilepsy. HA was not confined to clinically defined temporal lobe epilepsy. The poor correlation of epileptic syndrome to quantitative MRI findings may be due to the inadequacies of epilepsy classification in the younger child, with the clinical semiology providing misleading localizing information. Normative childhood data for hippocampal volumes and symmetry is needed.     

No evidence for association of the dysbindin gene [DTNBP1] with schizophrenia in an Irish population-based study

A recent family-based association study identified a putative association between variants in the dystrobrevin binding protein 1 (dysbindin) gene (DTNBP1) and schizophrenia. This study used a sample of 270 Irish pedigrees multiply affected with schizophrenia. We attempted to replicate these findings in an independent Irish sample of 219 schizophrenia cases and 231 controls. No evidence was found to suggest an association between the DTNBP1 gene and schizophrenia in our sample. Possible reasons for these findings are discussed.