TIA triage in emergency department using acute MRI (TIA-TEAM): a feasibility and safety study.

BACKGROUND: Positive diffusion weighted imaging (DWI) on MRI is associated with increased recurrent stroke risk in TIA patients. Acute MRI aids in TIA risk stratification and diagnosis. AIM: To evaluate the feasibility and safety of TIA triage directly from the emergency department (ED) with acute MRI and neurological consultation. METHODS: Consecutive ED TIA patients assessed by a neurologist underwent acute MRI/MRA of head/neck per protocol and were hospitalized if positive DWI, symptomatic vessel stenosis, or per clinical judgment. Stroke neurologist adjudicated the final TIA diagnosis as definite, possible, or not a cerebrovascular event. Stroke recurrence rates were calculated at 7, 90, 365 days and compared with predicted stroke rates derived from historical DWI and ABCD(2) score data. RESULTS: One hundred twenty-nine enrolled patients had a mean age of 69 years (± 17) and median ABCD(2) score of 3 (interquartile range [IQR] 3-4). During triage, 112 (87%) patients underwent acute MRI after a median of 16 h (IQR 10-23) from symptom onset. No patients experienced a recurrent event before imaging. Twenty-four (21%) had positive DWI and 8 (7%) had symptomatic vessel stenosis. Of the total cohort, 83 (64%) were discharged and 46 (36%) were hospitalized. By one-year follow-up, one patient in each group had experienced a stroke. Of 92 patients with MRI and index cerebrovascular event, recurrent stroke rates were 1.1% at 7 and 90 days. These were similar to predicted recurrence rates. CONCLUSION: TIA triage in the ED using a protocol with neurological consultation and acute MRI is feasible and safe. The majority of patients were discharged without hospitalization and rates of recurrent stroke were not higher than predicted.

Radiological examinations of transient ischemic attack.

Neuroimaging is critical in the evaluation of patients with TIA. CT and MRI are the two available options for imaging. Head CT is more widely available and commonly used. Diffusion MRI is the recommended modality to image an ischemic lesion. The presence of a diffusion lesion in a patient with transient neurological symptoms is an indicator of a high risk of recurrent stroke. Perfusion imaging with perfusion MRI or CT perfusion may improve the detection of ischemic lesions. Noninvasive vessel imaging may detect a symptomatic vessel lesion associated with an increased risk of stroke.

Diagnostic Yield of Extended Cardiac Patch Monitoring in Patients with Stroke or TIA.

BACKGROUND: It is important to evaluate patients with transient ischemic attack (TIA) or stroke for atrial fibrillation (AF) because the detection of AF changes the recommended anti-thrombotic regimen from treatment with an antiplatelet agent to oral anticoagulation. This study describes the diagnostic yield of a patch-based, single-use, and water-resistant 14-day continuous cardiac rhythm monitor (ZIO Patch) in patients with stroke or TIA. METHODS: We obtained data from the manufacturer and servicer of the ZIO Patch (iRhythm Technologies). Patients who were monitored between January 2012 and June 2013 and whose indication for monitoring was TIA or stroke were included. The duration of monitoring, the number and type of arrhythmias, and the time to first arrhythmia were documented. RESULTS: One thousand one hundred seventy-one monitoring reports were analyzed. The mean monitor wear time was 10.9 days and the median wear time was 13.0 days (interquartile range 7.2-14.0). The median analyzable time relative to the total wear time was 98.7% (IQR 96.0-99.5%). AF was present in 5.0% of all reports. The mean duration before the first episode of paroxysmal AF (PAF) was 1.5 days and the median duration was 0.4 days. 14.3% of first PAF episodes occurred after 48 h. The mean PAF burden was 12.7% of the total monitoring duration. CONCLUSION: Excellent quality of the recordings and very good patient compliance coupled with a substantial proportion of AF detection beyond the first 48 h of monitoring suggest that the cardiac patch is superior to conventional 48-h Holter monitors for AF detection in patients with stroke or TIA.

Transient global amnesia associated with a unilateral infarction of the fornix: case report and review of the literature.

Stroke is an extremely uncommon cause of transient global amnesia (TGA). Unilateral lesions of the fornix rarely cause amnesia and have not previously been reported to be associated with the distinctive amnesic picture of TGA. We describe the case of a 60-year-old woman who presented with acute onset, recent retrograde, and anterograde amnesia characteristic of TGA. Serial magnetic resonance imaging showed a persistent focal infarction of the body and left column of the fornix, without acute lesions in the hippocampus or other structures. Amnesia resolved in 6 h. Infarction of the fornix should thus be included in the differential diagnosis of TGA, as it changes the management of this otherwise self-limited syndrome.

Education research: changing practice. Residents' adoption of the atraumatic lumbar puncture needle.

BACKGROUND: The atraumatic needle is recommended over the cutting needle to prevent complications related to lumbar puncture and to reduce costs to the health care system. However, very few practicing neurologists use the atraumatic needle, which in turn limits the teaching of its use to neurology residents. Despite this, neurology residents may be able to adopt the atraumatic needle for lumbar punctures. METHODS: Residents at one neurology residency program were given didactic sessions regarding the atraumatic needle and the opportunity to practice using a lumbar puncture simulator. After the first time a resident performed a lumbar puncture with the atraumatic needle, he or she was asked to complete an electronic survey. RESULTS: The reported mean number of lumbar punctures performed using the cutting needle prior to the study was 25. Eleven residents (92%) who used the atraumatic needle said they would use it again for future lumbar punctures. The most common reasons cited for wanting to continue to use the atraumatic needle were to prevent post-lumbar puncture headaches, to choose the cost-effective option, and to stay up-to-date with changes in practice. CONCLUSION: Neurology residents can successfully adopt the atraumatic needle as standard of care for lumbar punctures.

Cost comparison between the atraumatic and cutting lumbar puncture needles.

OBJECTIVE: The aim of this study was to determine which type of spinal needle is preferred from a cost perspective, taking into account costs of the spinal needle and treatment of postlumbar puncture headache. METHODS: A decision-analytic model was created to determine the cost of diagnostic lumbar punctures using atraumatic and cutting needles. We assumed a health care system perspective and based the analysis on the treatment of a patient facing event probabilities derived from prior studies. The economic outcome measure was the difference in estimated costs between the 2 needles. One-way and probabilistic sensitivity analyses tested the robustness of the model. RESULTS: Lumbar puncture performed with the atraumatic needle is associated with an average cost savings of $26.07 per patient. Average total health care costs are $166.08 with the atraumatic needle, compared to $192.15 with the cutting needle. There is 94% certainty that the atraumatic needle is cost-saving compared to the cutting needle based on probabilistic sensitivity analysis. Use of the atraumatic needle over the cutting needle by neurologists alone may result in $10.4 million in cost savings to the US health care system per year. CONCLUSION: The atraumatic spinal needle is associated with an overall cost savings to the US health care system. The balance of costs and benefits favors the use of the atraumatic needle over the cutting needle for diagnostic lumbar puncture.

Cost-effectiveness of tissue-type plasminogen activator in the 3- to 4.5-hour time window for acute ischemic stroke.

BACKGROUND AND PURPOSE: The aim of this study was to determine the cost-effectiveness of tissue-type plasminogen activator (tPA) treatment in the 3- to 4.5-hour time window after ischemic stroke. METHODS: Decision-analytic and Markov state-transition models were created to determine the cost-effectiveness of treatment of ischemic stroke patients with intravenous tPA administered in the 3- to 4.5-hour time window compared with medical therapy without tPA. Health benefits were measured in quality-adjusted life-years (QALYs). The economic outcome measure of the model was the difference in estimated healthcare costs between the 2 treatment alternatives. The incremental cost-effectiveness ratio was calculated by dividing the cost difference by the difference in QALYs. One-way sensitivity and probabilistic analyses were performed to test the robustness of the model. RESULTS: The administration of tPA compared with standard medical therapy resulted in a lifetime gain of 0.28 QALYs for an additional cost of $6050, yielding an incremental cost-effectiveness ratio of $21 978 per QALY. One-way sensitivity analyses demonstrated that the incremental cost-effectiveness ratio was most sensitive to the cost of hospitalization for patients who received tPA. Based on probabilistic analysis, there is an 88% probability that tPA is the preferred treatment at a willingness-to-pay threshold of $50 000 per QALY. CONCLUSIONS: The balance of costs and benefits favors treatment with intravenous tPA in the 3- to 4.5-hour time window. This supports, from a societal perspective, the use of tPA therapy in this treatment time window for acute ischemic stroke.

Role of diffusion and perfusion MRI in selecting patients for reperfusion therapies.

After onset of ischemic stroke, potentially viable tissue at risk (ischemic penumbra) may be salvageable. Currently, intravenous alteplase is approved for up to 4.5 hours after symptom onset of acute ischemic stroke. Increasing this time window may allow many more patients to be treated. The ability to use MRI to help define the irreversibly damaged brain (infarct core) and the reversible ischemic penumbra shows great promise for stroke treatment. Recent advances in penumbral imaging technology may enable a phase III trial of an intravenous thrombolytic to be performed beyond 4.5 hours using techniques to select patients with penumbral tissue.

Angiopoietin-1 induces neurite outgrowth of PC12 cells in a Tie2-independent, beta1-integrin-dependent manner.

Overexpression of angiopoietin (Ang) 1 in the brain results in increased vascularization and altered neuronal dendrite configuration. We hypothesized that Ang1 acts directly on neurons inducing neurite outgrowth. We stimulated PC12 cells with Ang1 and observed outgrowth levels comparable to nerve growth factor (NGF). Western blotting and RT-PCR demonstrated the absence of the Ang1 receptor, Tie2 and the presence of beta1-integrin. Downstream of beta1-integrin, Ang1 stimulation led to a approximately 2.6 fold increase in focal adhesion kinase (FAK) phosphorylation and no change in the activation of mitogen-activated protein kinase (MAPK) nor c-Jun N-terminal kinase (JNK). Conversely, NGF stimulation had no effect on FAK phosphorylation but led to a approximately 3.1 and approximately 2 fold increase in phosphorylation of MAPK and JNK. Ang1, but not NGF-mediated outgrowth was attenuated following functional inhibition of beta1-integrin and FAK, and Wortmannin inhibited neurite outgrowth mediated by both. Our results suggest that Ang1 induces neurite outgrowth in PC12 cells in a Tie2-independent, beta1-integrin-FAK-PI3K-Akt-dependent manner and that NGF and Ang1 mediate neurite outgrowth via two independent signaling mechanisms.