Search results for "Data interpretation"
showing 10 items of 195 documents
Treating missing data in a clinical neuropsychological dataset--data imputation.
2001
Missing data frequently reduce the applicability of clinically collected data in research requiring multivariate statistics. In data imputation, missing values are replaced by predicted values obtained from models based on auxiliary information. Our aim was to complete a clinical child neuropsychological data set containing 5.2% of missing observations. This was to be used in research requiring multivariate statistics. We compared four data imputation methods by artificially deleting some data. A real-donor imputation method which preserved the parameter estimates and which predicted the observed values with acceptable accuracy was used to complete the data set. In addressing the lack of st…
Validating the DemTect with 18-Fluoro-2-Deoxy-Glucose Positron Emission Tomography as a Sensitive Neuropsychological Screening Test for Early Alzheim…
2005
<i>Objectives:</i> The first study to validate the diagnostic value of the DemTect, a short neuropsychological screening test for dementia (8–10 min), using 18-fluoro-2-deoxy-glucose positron emission tomography (FDG-PET) in patients of a memory clinic. <i>Methods:</i> DemTect results were compared to the clinical diagnosis and to FDG-PET as a reference method for the early in vivo detection of Alzheimer’s disease (AD). <i>Results:</i> 38 patients (age 65.2 ± 9.8 years, 16 men, 22 women) were investigated using clinical standard examination, FDG-PET, and cranial magnetic resonance imaging. According to NINCDS-ADRDA and Petersen’s criteria, 18 patients had…
Stroke care organization overcomes the deleterious ‘weekend effect’ on 1-month stroke mortality: a population-based study
2013
Background and purpose Suffering a stroke during the weekend is associated with a poorer prognosis. The impact of implementing a dedicated stroke care network in Dijon, France, in 2003 on 30-day mortality in strokes/transient ischaemic attacks (TIA) occurring during weekends/bank holidays was evaluated. Methods All cases of stroke and TIA from 1985 to 2010 were identified from a population-based registry, using multiple overlapping sources of information. Demographics and clinical data were recorded. Cox regression models were used to evaluate associations between day of onset (weekdays versus weekends/bank holidays) and 30-day all-cause mortality. Data were stratified according to time per…
The role of pregnenolone sulphate in spatial orientation-acquisition and retention: An interplay between cognitive potentiation and mood regulation
2013
Abstract Neurosteroids can alter neuronal excitability interacting with specific neurotransmitter receptors, thus affecting several functions such as cognition and emotionality. In this study, we investigated, in adult male rats, the effects of the acute administration of pregnenolone-sulfate (PREGS) (10 mg/Kg, s. c.) on cognitive processes using the Can test, a non aversive spatial/visual task which allows the assessment of spatial information-acquisition during the baseline training, and of memory retention in the longitudinal study. Furthermore, on the basis of PREGS pharmacological profile, the modulation of depressive-like behaviour was also evaluated in the forced swim test (FST). Our…
Spectrum of collateral findings in multislice CT coronary angiography.
2007
Purpose. The aim of the study was to investigate the prevalence of the noncardiac collateral findings during multislice computed tomography coronary angiography (MSCT-CA). Materials and methods. Six hundred and seventy patients undergoing MSCT-CA with 16-slice and 64-slice CT scanners for suspected atherosclerotic disease of the coronary arteries were retrospectively reviewed. All data sets obtained with a large field of view (FOV) were analysed by two radiologists using standard mediastinal and lung window settings. Collateral findings were divided according to clinical importance into nonsignificant, remarkable and compulsory to be investigated. Results. Eighty-five percent of patients re…
Cortical networks of procedural learning: Evidence from cerebellar damage
2007
The lateral cerebellum plays a critical role in procedural learning that goes beyond the strict motor control functions attributed to it. Patients with cerebellar damage show marked impairment in the acquisition of procedures, as revealed by their performance on the serial reaction time task (SRTT). Here we present the case of a patient affected by ischemic damage involving the left cerebellum who showed a selective deficit in procedural learning while performing the SRTT with the left hand. The deficit recovered when the cortical excitability of an extensive network involving both cerebellar hemispheres and the dorsolateral prefrontal cortex (DLPFC) was decreased by low-frequency repetitiv…
Impact of intravascular enhancement, heart rate, and calcium score on diagnostic accuracy in multislice computed tomography coronary angiography.
2005
PURPOSE: To assess the effect of intravascular enhancement, heart rate, and calcium score on diagnostic accuracy in the detection of significant coronary artery stenosis using 16-row multislice computed tomography (MSCT). MATERIALS AND METHODS: One hundred patients (88 males; 59+/-11 years) with suspected coronary artery disease who had undergone conventional coronary angiography (CA) and MSCT-CA were retrospectively enrolled for the study. Patients underwent a MSCT-CA, with the following protocol: collimation 16x0.75 mm, gantry rotation time 420 ms, feed/rotation 2.8 mm, kV 120, mAs 400-500. The protocol for contrast material administration was 100 ml of Iodixanol 320 mgI/ml at 4 ml/s and …
Comment on ‘Estimating average annual per cent change in trend analysis’ by Clegg LX, Hankey BF, Tiwari R, Feuer EJ, Edwards BK, Statistics in Medici…
2010
Trends in incidence or mortality rates over a specified time interval are usually described by the conventional annual per cent change (cAPC), under the assumption of a constant rate of change. When this assumption does not hold over the entire time interval, the trend may be characterized using the annual per cent changes from segmented analysis (sAPCs). This approach assumes that the change in rates is constant over each time partition defined by the transition points, but varies among different time partitions. Different groups (e.g. racial subgroups), however, may have different transition points and thus different time partitions over which they have constant rates of change, making co…
Tuberculosis of the central nervous system in children: 32 years survey.
2005
Aim. In order to study the impact of clinical and diagnostic parameters on the clinical outcome of children with central nervous system tuberculosis (CNS-TB), we retrospectively reviewed all cases of CNS-TB diagnosed over a 32-year period at the Children's Hospital of Palermo, Italy. Methods. Data were collected with regard to the clinical, laboratory and demographic characteristics of patients, as well as the results of radiological investigations and data on clinical outcome. In relation to the date of introduction of new diagnostic methods (indirect as well direct) and to the change of treatment periods, the authors compared the clinical outcome of patients admitted prior and after 1984.…
Coupling between simultaneously recorded BOLD response and neuronal activity in the rat somatosensory cortex
2007
Abstract Understanding the link between the hemodynamic response and the underlying neuronal activity is important for interpreting functional magnetic resonance (fMRI) signals in human and animal studies. Simultaneous electrophysiological and functional imaging measurements provide a knowledge of information processing and communication in the brain with high spatial and temporal resolution. In this study, a range of neural and blood oxygenation level-dependent (BOLD) responses were elicited in the rat somatosensory cortex by changing the type of anesthesia (urethane or alpha-chloralose) and the electrical forepaw stimulus frequency (1–15 Hz). Duration of the stimulus was 30 s. Electrical …