Brusner et al. take on an extremely important issue of diagnostic test evaluation. In this era of changing definition of stroke from clinical to tissue based definition they compare one of the most commonly used diagnostic methods in stroke, positive diffusion weighted image to a reference standard. It is a single center study and neuroradiologists were unblinded which are limitations of this study but it was prospective and included more than 700 patients. It verifies that DWI if positive overwhelming supports the diagnosis of acute ischemic stroke. The likelihood ratio is more than 10 in this case. And if negative, diagnosis of acute ischemic stroke should be questioned.
Given this finding this article is a good read before morning report and or stroke rounds to get the details on positive diffusion imaging.
Malignant emboli on Trans-cranial Doppler during Carotid Stenting predict post procedure DWI lesions. Stroke. 2013
Given that this is a small single arm, single center non randomized study the novel aspect is which part of the CAS procedure carries the largest risk of embolization. Maybe the deployment stage of the procedure can be modified to make sure that this embolization risk is minimized?
Recently, secondary stroke prevention in those with atrial fibrillation has become more exciting with the recent addition of new anticoagulants such as dabigatran, apixaban, and rivaroxaban to the previous mainstay, warfarin. While the focus has been on the differences in pharmacological properties between these medications, economic differences should also be considered.
Harrington et al. from the University of Arizona sought to estimate the cost-effectiveness of stroke prevention in patients with nonvalvular atrial fibrillation, comparing those receiving apixaban 5mg, dabigatran 150mg, and rivaroxaban 20mg with warfarin. Using a Markov decision-analysis model, the group sought to account for not only complications and associated costs of the medication using probability of adverse events from recent studies such as ARISTOTLE, RE-LY, and ROCKET-AF, but life expectancy, willingness-to-pay analysis, measured in quality-adjusted-life-years (QALY). The group found that the QALY estimate for apixaban was the highest, whereas the lowest was for that of warfarin.
This is the first study to compare several of the novel anticoagulants against each other in relation to warfarin. Although this type of study has inherent limitations based on assumptions and variations in data sources, this study is valuable at a time when clinicians are still learning to incorporate these medications into their practice. Until we have better data on such areas as side effects and treatment compliance, this study suggests that the new oral anticoagulants have added economic benefit compared to the time-tested warfarin, providing further incentive to prescribe them.
Taub E, Uswatte G, Mark VW,Morris DM, Barman J, Bowman MH, et al. Method for Enhancing Real-World Use of a More Affected Arm in ChronicStroke: Transfer Package of Constraint-Induced Movement Therapy. Stroke. 2013.
Constraint- Induced Movement therapy (CI) for the upper- extremity has shown benefit in post-stroke and cerebral palsy patients, and has suggested benefit in traumatic brain injury and multiple sclerosis as well. In this study, 40 outpatient who were >1 year out with post-stroke hemiparesis were randomly assigned to four groups that differed in the type of training (shaping vs repetition), and presence/ absence of a set of techniques called the Transfer Package (TP). The TP involves behavioral techniques used to facilitate real-world application of therapeutic gains made in the lab by encouraging self-motivation and reinforcing practice at home of lab-learned skills.
Taub et al. were able to show that using TP resulted in 2.4 times increased spontaneous use of the affected arm regardless of type of training, and these gains persisted beyond 1 year post-treatment. A sub-study also showed that weekly phone contacts for the first month post-treatment bridged half the the gap between groups with and without TP.
This study reiterates the consensus that real-world functional activity is the most important outcome to pursue, and that use of TP facilitates this process. What makes this method attractive is that it does not involve longer therapist time or other expensive resources, but rather a more psychological approach towards the rehabilitation process. This is a good example of how a multidisciplinary effort between physicians, therapists and psychologists is key in achieving good functional outcomes in our post-stroke patients. The fact that four extra phone calls made a positive difference to outcomes goes to show that these patients need a long lasting system of support and encouragement.