Dejana Stanisavljevic

Long-Term Prognosis of Vascular Hemiballismus

Background and Purpose— The aim of this study was to prospectively evaluate the long-term prognosis of hemiballismus due to first-ever ischemic strokes. Methods— A cohort of 27 patients with hemiballismus due to first-ever ischemic strokes was followed for a mean period of 30 months (range, 5 days to 150 months). Results— During the follow-up period there were 11 deaths (44%). The survival rate was 85% (95% CI, 71% to 99%) at 6 months, 81% (95% CI, 65% to 97%) at 15 months, 51% (95% CI, 24% to 78%) at 36 months, and only 32% (95% CI, 4% to 60%) at 150 months. The survival rate free from recurrent stroke was 96% (95% CI, 87% to 100%) at 6 months, 91% (95% CI, 79% to 100%) at 12 months, 80% (95% CI, 61% to 99%) at 24 months, and 27% (95% CI, 0% to 71%) at 150 months. Conclusions— The long-term prognosis of patients with vascular hemiballismus is similar to that of other stroke patients, ie, it follows the etiologic pattern of hemiballismus.

Diffusion-weighted MRI versus transient elastography in quantification of liver fibrosis in patients with chronic cholestatic liver diseases

PURPOSE To evaluate the diagnostic value of diffusion-weighted magnetic resonance imaging (DWMRI) and transient elastography (TE) in quantification of liver fibrosis in patients with chronic cholestatic liver diseases. MATERIALS AND METHODS Forty-five patients underwent DWMRI, TE, and liver biopsy for staging of liver fibrosis. Apparent diffusion coefficient (ADC) was calculated for six locations in the liver for combination of five diffusion sensitivity values b=0, 50, 200, 400 and 800 s/mm(2). A receiver operating characteristic (ROC) analysis was performed to determine the diagnostic performance of DWMRI and TE. Segmental ADC variations were evaluated by means of coefficient of variation. RESULTS The mean ADCs (× 10(-3)mm(2)/s; b=0-800 s/mm(2)) were significantly different at stage F1 versus F ≥ 2 (p<0.05) and F2 versus F4. However, no significant difference was found between F2 and F3. For prediction of F ≥ 2 and F ≥ 3 areas under the ROC curves were 0.868 and 0.906 for DWMRI, and 0.966 and 0.960 for TE, respectively. The sensitivity and specificity were 90.9% and 89.3% for F ≥ 2 (ADC ≤ 1.65), and 92.3% and 92.1% for F ≥ 3 (ADC ≤ 1.63). Segmental ADC variation was lowest for F4 (CV=9.54 ± 6.3%). CONCLUSION DWMRI and TE could be used for assessment of liver fibrosis with TE having higher diagnostic accuracy and DWMRI providing insight into liver fibrosis distribution.

MR imaging of primary sclerosing cholangitis: additional value of diffusion-weighted imaging and ADC measurement.

Background Primary sclerosing cholangitis (PSC) is a cholestatic liver disease with chronic inflammation and progressive destruction of biliary tree. Magnetic resonance (MR) examination with diffusion-weighted imaging (DWI) allows analysis of morphological liver parenchymal changes and non-invasive assessment of liver fibrosis. Moreover, MR cholangiopancreatography (MRCP), as a part of standard MR protocol, provides insight into bile duct irregularities. Purpose To evaluate MR and MRCP findings in patients with primary sclerosing cholangitis and to determine the value of DWI in the assessment of liver fibrosis. Material and Methods The following MR findings were reviewed in 38 patients: abnormalities in liver parenchyma signal intensity, changes in liver morphology, lymphadenopathy, signs of portal hypertension, and irregularities of intra- and extrahepatic bile ducts. Apparent diffusion coefficient (ADC) was calculated for six locations in the liver for b = 800 s/mm2. Results T2-weighted hyperintensity was seen as peripheral wedge-shaped areas in 42.1% and as periportal edema in 28.9% of patients. Increased enhancement of liver parenchyma on arterial-phase imaging was observed in six (15.8%) patients. Caudate lobe hypertrophy was present in 10 (26.3%), while spherical liver shape was noted in 7.9% of patients. Liver cirrhosis was seen in 34.2% of patients; the most common pattern was micronodular cirrhosis (61.5%). Other findings included lymphadenopathy (28.9%), signs of portal hypertension (36.7%), and bile duct irregularities (78.9%). The mean ADCs (×10-3mm2/s) were significantly different at stage I vs. stages III and IV, and stage II vs. stage IV. No significant difference was found between stages II and III. For prediction of stage ≥II and stage ≥III, areas under receiver-operating characteristic curves were 0.891 and 0.887, respectively. Conclusion MR with MRCP is a necessary diagnostic procedure for diagnosis of PSC and evaluation of disease severity. Moreover, DWI could be used in continuation with standard MR sequences for the evaluation of liver fibrosis stage and distribution.

Improving Education in Medical Statistics: Implementing a Blended Learning Model in the Existing Curriculum

Background Although recent studies report on the benefits of blended learning in improving medical student education, there is still no empirical evidence on the relative effectiveness of blended over traditional learning approaches in medical statistics. We implemented blended along with on-site (i.e. face-to-face) learning to further assess the potential value of web-based learning in medical statistics. Methods This was a prospective study conducted with third year medical undergraduate students attending the Faculty of Medicine, University of Belgrade, who passed (440 of 545) the final exam of the obligatory introductory statistics course during 2013–14. Student statistics achievements were stratified based on the two methods of education delivery: blended learning and on-site learning. Blended learning included a combination of face-to-face and distance learning methodologies integrated into a single course. Results Mean exam scores for the blended learning student group were higher than for the on-site student group for both final statistics score (89.36±6.60 vs. 86.06±8.48; p = 0.001) and knowledge test score (7.88±1.30 vs. 7.51±1.36; p = 0.023) with a medium effect size. There were no differences in sex or study duration between the groups. Current grade point average (GPA) was higher in the blended group. In a multivariable regression model, current GPA and knowledge test scores were associated with the final statistics score after adjusting for study duration and learning modality (p<0.001). Conclusion This study provides empirical evidence to support educator decisions to implement different learning environments for teaching medical statistics to undergraduate medical students. Blended and on-site training formats led to similar knowledge acquisition; however, students with higher GPA preferred the technology assisted learning format. Implementation of blended learning approaches can be considered an attractive, cost-effective, and efficient alternative to traditional classroom training in medical statistics.

The influence of the metabolic syndrome on atrial fibrillation occurrence and outcome after coronary bypass surgery: a 3-year follow-up study.

BACKGROUND We sought to investigate the influence of the metabolic syndrome (MS) on new-onset postoperative atrial fibrillation (POAF), and occurrence of major adverse cardiovascular and cerebrovascular events (MACCE) in a period of 3 years after isolated coronary artery bypass grafting (CABG) surgery. METHODOLOGY The study included 460 patients who underwent the first CABG operation without baseline atrial fibrillation. The MS was defined by the presence of three or more Adult Treatment Panel (ATP)-American Heart Association (AHA)- National Heart, Lung, and Blood (NHLB) Institute criteria. POAF was diagnosed by continuous electrocardiographic monitoring during the first 48 to 72 hours after CABG. All the patients were followed up for at least 3 years after surgery. RESULTS The MS and its criteria were significantly associated with POAF and MACCE occurrence in the 3-year period after isolated CABG surgery. Among the MS risk factors, hypertension, abdominal obesity, and the increased fasting glucose level were independently associated with both POAF and MACCE onset in the observed patients. Individuals with four or five MS criteria have similar risk of POAF or MACCE as individuals with three MS criteria. In the 3-year period of follow-up, the MS was proven to be associated with MACCE occurrence, independently of hypertension, diabetes, and obesity defined by body mass index. CONCLUSIONS The MS and its criteria significantly increased risk of POAF and MACCE in a 3-year period. The MS, irrespective of hypertension, diabetes, and obesity, was associated with POAF and MACCE in the patients who underwent CABG.

Assessing attitudes towards statistics among medical students: psychometric properties of the Serbian version of the Survey of Attitudes Towards Statistics (SATS).

Background Medical statistics has become important and relevant for future doctors, enabling them to practice evidence based medicine. Recent studies report that students’ attitudes towards statistics play an important role in their statistics achievements. The aim of the study was to test the psychometric properties of the Serbian version of the Survey of Attitudes Towards Statistics (SATS) in order to acquire a valid instrument to measure attitudes inside the Serbian educational context. Methods The validation study was performed on a cohort of 417 medical students who were enrolled in an obligatory introductory statistics course. The SATS adaptation was based on an internationally accepted methodology for translation and cultural adaptation. Psychometric properties of the Serbian version of the SATS were analyzed through the examination of factorial structure and internal consistency. Results Most medical students held positive attitudes towards statistics. The average total SATS score was above neutral (4.3±0.8), and varied from 1.9 to 6.2. Confirmatory factor analysis validated the six-factor structure of the questionnaire (Affect, Cognitive Competence, Value, Difficulty, Interest and Effort). Values for fit indices TLI (0.940) and CFI (0.961) were above the cut-off of ≥0.90. The RMSEA value of 0.064 (0.051–0.078) was below the suggested value of ≤0.08. Cronbach’s alpha of the entire scale was 0.90, indicating scale reliability. In a multivariate regression model, self-rating of ability in mathematics and current grade point average were significantly associated with the total SATS score after adjusting for age and gender. Conclusion Present study provided the evidence for the appropriate metric properties of the Serbian version of SATS. Confirmatory factor analysis validated the six-factor structure of the scale. The SATS might be reliable and a valid instrument for identifying medical students’ attitudes towards statistics in the Serbian educational context.

Prognostic factors for therapy-related acute myeloid leukaemia (t-AML) - A single centre experience

Prognostic parameters for treatment outcome in 42 consecutive patients with t-AML diagnosed and treated in a single centre between 2000-2010 (mean age: 56.07 years, range: 23-84; 30 females) were evaluated retrospectively/prospectively. Antecedent malignancy occurred in 37 patients (88.15%): 28 solid cancers (breast, n=14), nine haematological. History of previous chemotherapy (CT), radiotherapy (RT) alone and combined CT/RT was present in 42.9%, 6.19% and 30.1% patients, respectively. Primary disease was active in 11 patients (six relapsed or metastatic cancers; five autoimmune diseases). Myelodysplastic syndrome preceded t-AML in 29% of patients. Median latency period from prior CT/RT was 54.62 months (range: 6-243). Median WBC count was 27.23 × 10⁹/L, platelet count 62.29 × 10⁹/L, haemoglobin level 87.83 g/L, peripheral blood and bone marrow blast percentage 30.7% and 66.7% respectively, serum LDH 1216 U/L. Aberrant expression of B or T lymphoid markers was registered in seven out of 39 and six out of 39 patients, respectively. Aberrant karyotype was detected in 24 out of 33 (72.7%) of eligible patients: favourable: 15.2%, intermediate: 42.4% and unfavourable: 42.4%. Eastern Cooperative Oncology Group (ECOG) performance status greater or equal to 2 and Haematopoietic Cell Transplantation Specific Comorbidity Index (HCT-CI) greater or equal to 3 exhibited 83.3% and 76.2% patients, respectively. Intensive induction CT for t-AML was administered in 24 patients. The median follow-up and the median overall survival (OS) for the whole cohort were 2 months and 5.94 months (range: 0.5-34), respectively. In 10 patients (23.8%) achieving complete remission (CR), median disease free survival (DFS) was 11.8 months (range: 4-32). Only CD19 expression, pretreatment karyotype, ECOG PS, HCT-CI and activity of primary disease had impact on OS (P<0.05).

The possible benefit from total tumour resection in primary diffuse large B-cell lymphoma of central nervous system – a one-decade single-centre experience

Background and methods. The aim of the study was to evaluate retrospectively clinical course of 27 patients with primary central nervous system lymphoma (PCNSL) diagnosed and treated by different surgical approaches. Initial therapy-diagnostic approach included surgery with total tumour reduction (TTR) performed in 12 patients (44.4%), while partial reduction and biopsy were performed in 8 (29.7%) and 7 (25.9%) patients, respectively. All patients were treated with chemotherapy based on high-dose methotrexate (HD-MTX) with/without whole-brain radiotherapy (WBRT). Results. The median overall survival (OS) and event-free survival were 37 and 31 months, respectively, with overall response rate of 74%. The patients who underwent an open surgery with TTR had significantly longer OS (median not reached), comparing with partial tumour reduction or biopsy only (Log-Rank χ2 6.08, p = 0.014) when median OS was 23 months. In patients with performance status according to Eastern Cooperative Oncology Group (ECOG PS) ≥ 3, OS was 23 months, contrary to ECOG PS 1–2 when median was not reached. The International Extranodal Lymphoma Study Group score (low, intermediate and high) also influenced OS between three risk groups (Log-Rank χ2 12.5, p = 0.002). Conclusion. The treatment of PCNSL still remains doubtful, however possible benefit from the TTR followed with HD-MTX with/without WBRT should be reconsidered.

Left atrial phasic function and heart rate variability in asymptomatic diabetic patients

AbstractAimsWe evaluated left atrial (LA) phasic function and heart rate variability (HRV) in asymptomatic diabetic patients, and the relationship between HRV indices and LA phasic function assessed by volumes and speckle tracking imaging. MethodThis cross-sectional study included 55 asymptomatic patients with type 2 diabetes and 50 healthy controls without cardiovascular risk factors. All study subjects underwent laboratory analyses, complete two-dimensional echocardiography examination (2DE) and 24-h Holter monitoring.ResultsMaximum, minimum LA and pre-A LA volumes and volume indexes are significantly higher in diabetic patients. Total and passive LA emptying fractions (EF), representing the LA reservoir and conduit function, are significantly lower in diabetic subjects. Active LA EF, the parameter of the LA booster pump function, is compensatory increased in diabetic patients. Similar results were obtained by 2DE strain analysis. Cardiac autonomic function, assessed by HRV, is significantly deteriorated in diabetic patients. Time and frequency-domain HRV measures are significantly lower in diabetic subjects than in controls. HbA1c, LV mass index and HRV are associated with total LA EF and longitudinal LA strain independently of age, body mass index and LV diastolic function in the whole study population.ConclusionsLA phasic function and cardiac autonomic nervous system assessed by HRV are impacted by diabetes. HbA1c and HRV are independently associated with LA reservoir function evaluated by volumetric and strain methods in the whole study population. This study emphasizes the importance of determination of LA function and HRV as important markers of preclinical cardiac damage and autonomic function impairment in diabetic patients.

Meta-analysis of the changes in correlations between depression instruments used in longitudinal studies.

BACKGROUND Correlations between instruments measuring the same construct reflect their concurrent validity. Little is known about changes in correlations between such instruments employed in studies with repeated assessment. The aim of this meta-analysis was to examine the changes in correlations between depression instruments in the course of longitudinal studies. METHODS A literature search was conducted using MEDLINE and PsycINFO for the period from 1960 to 2013. The total number of collected articles was 3723, of which 61 were included. Three meta-analyses were performed for the changes in correlations between each pair of the three depression scales: Hamilton Rating Scale for Depression (HAMD), Montgomery-Asberg Depression Rating Scale (MADRS) and Beck Depression Inventory (BDI). The effect size in these meta-analyses was obtained by the z-transformation of correlation coefficients. RESULTS Correlations between depression scales increased over time in 52 studies. Significant changes in correlation coefficients were found for correlations between HAMD and BDI (p<0.001) and for correlations between HAMD and MADRS (p<0.001). An increase in correlations between the scales was associated with a decrease in depression scores and increase in their variability. LIMITATIONS Univariable and multivariable meta-regression models were not obtained in all three meta-analyses because of the lack of data. CONCLUSIONS A finding that correlations between depression instruments tended to increase over time has significant implications for assessment of the concurrent validity of these instruments. In longitudinal designs it is important to estimate correlations between depression scales over time because different thresholds for scale correlations indicate acceptable concurrent validity at different times.