Objective: To provide an overview of retractions of research papers contributed by authors from the Arab region. Method: Papers in which the first author was affiliated to an Arabian country were selected from the Retraction Watch database covering the period 1 January 1998 to 31 December 2018. The retrieved records were divided into nine categories based on the reasons for retraction. Results: The search yielded 322 retractions, and the most frequent reason for retraction was plagiarism (34.5%). The median time from publication to retraction was 14 (25%-75% percentile 5-30) months. The number of papers retracted each year as well as the number of papers published in a given year but subsequently retracted increased steadily over the 21 years. The proportion of retracted papers to the total number of published papers (0.17%) was higher than the global proportion and was the highest for Algeria (1%) and the lowest for Lebanon (0.03%). Of the countries within the Arab region, 12 out of 14 countries showed either plagiarism or duplication as the most common reason for retraction; however, the countries differed in terms of the number of retractions and the time from publishing to retraction. Conclusion: Plagiarism was the most common cause of retraction in the Arab countries. The increase in the number of papers retracted each year was probably because searches now extend farther in the past, whereas the increase in the number of papers published in a given year but subsequently retracted can be attributed to the overall increase in the number of papers published.

A prospective study comparing ultrasonography and angiography for the diagnosis of chronic cerebrospinal venous insufficiency Objectives: This study was aimed at testing the diagnostic accuracy of current sonographic criteria of chronic cerebrospinal venous insufficiency (CCSVI). In addition, we tried to identify alternative sonographic parameters associated with impaired outflow in the internal jugular veins.Method: Firstly, the findings of Doppler sonography were compared with the results of reference test: catheter venography. There were assessed 116 internal jugular veins and vertebral veins in 58 patients with associated multiple sclerosis. We evaluated our findings in the context of current sonographic criteria, proposed by Zamboni, and new criteria: by expert panel of the International Society for Neurovascular Disease (ISNVD). Secondly, we assessed 41 different sonographic variables, also those not mentioned in the current criteria (such as flow direction, peak flow velocity, cross-sectional area and diameter of the vein) in 115 patients. These parameters were also compared with venographic findings.Results: We found that although sonographic patterns suggesting outflow abnormalities were very common in multiple sclerosis patients: e.g. at least one positive Zamboni's criterion was found in 92.2% of the assessed veins, their diagnostic accuracy was limited. For example, positive and negative predictive values of one positive Zamboni's criteria were 79.4% and 33.3%, and of at least two positive criteria: 81.8% and 21.7%. Accuracy of ISNVD criteria was not much better. Multivariate regression analysis of 41 sonographic parameters revealed some variables that were associated with increased prevalence of venographic abnormalities: no flow detected in all three segments of internal jugular vein in upright position, peak flow velocity in the upper and middle segments in upright position less than 24 cm/second, and in lower segment less than 88 cm/second, peak flow velocity in the upper segment in supine position less than 24 cm/second, and cross-sectional area of the upper segment in the supine position less than 8 mm 2 . However, even using these parameters we were unable to create a reliable set of criteria. Of note, many variables used by the current CCSVI sonographic protocols were not proven to be associated with increased prevalence of venographic pathology, for example: reduced or bidirectional flow in the vertebral veins.Conclusions: Our research is showing a clear gap in the understanding of haemodynamics in this particular venous territory. Consequently, more research is needed to improve diagnostic accuracy of Doppler sonography for the diagnosis of CCSVI. It is also possible that in this territory catheter venography is a tarnished 'gold standard' and that some abnormalities (e.g. compression of the vein by adjacent muscles) show only on sonography. Perhaps, a multimodal approach is required to evaluate these veins properly. Role of duplex ultrasound in chronic cerebrospinal venous insufficiency: a ...

Depression in chronic venous disease: an often neglected area