Localization of Angiopoietin-1 and Tie2 Immunoreactivity in Rodent Ependyma and Adjacent Blood Vessels Suggests Functional Relationships

Angiopoietin-1 (Angpt1; previously Ang-1) participates in vascular maintenance and remodeling. In the current study, we investigated the distribution of Angpt1 protein in rat brain. We detected Angpt1 immunoreactivity (IR) in cerebral blood vessels, cuboidal ependyma, and tanycytes, which are specialized hypothalamic bipolar ependymal cells. We also evaluated patterns of IR of endothelium-specific receptor tyrosine kinase 2 (Tie2, the receptor for Angpt1). Tie2 IR was present in Angpt1-immunoreactive cuboidal ependyma in a membranous pattern, suggesting an autocrine or paracrine role for Angpt1–Tie2. Tie2 IR was also associated with peri-ependymal blood vessels, some of which were contacted by tips of Angpt1-immunoreactive tanycyte processes, implying a potential functional ligand−receptor interaction mediating communication between the cerebrospinal fluid and vascular compartments. Because we previously found that cerebral Angpt1 expression was modulated by 17β-estradiol (E2), and because some tanycyte functions are modulated by E2, we tested the hypothesis that E2 affects ependymal and tanycyte Angpt1 expression in vivo. No gross E2 effect on the ependymal pattern of Angpt1 IR or cerebral Angpt1 protein content was observed. (J Histochem Cytochem 58:53–60, 2010

The State of Neurocritical Care Fellowship Training and Attitudes toward Accreditation and Certification: A Survey of Neurocritical Care Fellowship Program Directors

Neurocritical care as a recognized and distinct subspecialty of critical care has grown remarkably since its inception in the 1980s. As of 2016, there were 61 fellowship training programs accredited by the United Council for Neurologic Subspecialties (UCNS) in the United States and more than 1,000 UCNS-certified neurointensivists from diverse medical backgrounds. In late 2015, the Program Accreditation, Physician Certification, and Fellowship Training (PACT) Committee of the Neurocritical Care Society (NCS) was convened to promote and support excellence in the training and certification of neurointensivists. One of the first tasks of the committee was to survey neurocritical care fellowship training program directors to ascertain the current state of fellowship training and attitudes regarding transition to Accreditation Council for Graduate Medical Education (ACGME) accreditation of training programs and American Board of Medical Specialties (ABMS) certification of physicians. First, the survey revealed significant heterogeneities in the manner of neurocritical care training and a lack of consistency in requirements for fellow procedural competency. Second, although a majority of the 33 respondents indicated that a move toward ACGME accreditation/ABMS certification would facilitate further growth and mainstreaming of training in neurocritical care, many programs do not currently meet administrative requirements and do not receive the level of institutional support that would be needed for such a transition. In summary, the results revealed that there is an opportunity for future harmonization of training standards and that a transition to ACGME accreditation/ABMS certification is preferred. While the results reflect the opinions of more than half of the survey respondents, they represent only a small sample of neurointensivists

Applications and advantages of power motion-mode Doppler in acute posterior circulation cerebral ischemia

Background and Purpose - Evaluation of posterior circulation with single-gate transcranial Doppler (TCD) is technically challenging and yields lower accuracy parameters in comparison to anterior circulation vessels. Transcranial power motion-mode Doppler (PMD-TCD), in addition to spectral information, simultaneously displays in real-time flow signal intensity and direction over 6 cm of intracranial space. We aimed to evaluate the diagnostic accuracy of PMD-TCD against angiography in detection of acute posterior circulation stenoocclusive disease. Methods - Consecutive patients presenting to the emergency room with symptoms of acute (< 24 hours) cerebral ischemia underwent emergent neurovascular evaluation with PMD-TCD and angiography (computed tomographic angiography, magnetic resonance angiography, or digital subtraction angiography). Previously published diagnostic criteria were prospectively applied for PMD-TCD interpretation independent of angiographic findings. Results - A total of 213 patients (119 men; mean age 65 +/- 16 years; ischemic stroke 71%, transient ischemic attack 29%) underwent emergent neurovascular assessment. Compared with angiography, PMD-TCD showed 17 true-positive, 8 false-negative, 6 false-positive, and 182 true-negative studies in posterior circulation vessels (sensitivity 73% [55% to 91%], specificity 96% [93% to 99%], positive predictive value 68% [50% to 86%], negative predictive value 95% [92% to 98%], accuracy 93% [90% to 96%]). In 14 patients (82% of true-positive cases), PMD display showed diagnostic flow signatures complementary to the information provided by the spectral display: reverberating or alternating flow, distal basilar artery flow reversal, high-resistance flow, emboli tracks and, bruit flow signatures. Conclusions - PMD-TCD yields a satisfactory agreement with urgent brain angiography in the evaluation of patients with acute posterior circulation cerebral ischemia. PMD display can depict flow signatures that are complimentary to and can increase confidence in standard single-gate TCD spectral findings

Mechanical Thrombectomy for Patients with In-Hospital Ischemic Stroke: A Case-Control Study

Background and Aim: Patients with in-hospital acute ischemic stroke (AIS) have, in general, worse outcomes compared to those presenting from the community, partly attributed to the numerous contraindications to intravenous thrombolysis. We aimed to identify and analyze a group of patients with in-hospital AIS who remain suitable candidates for acute endovascular therapies. Methods: A retrospective 6-year data analysis was conducted in patients evaluated through the in-hospital stroke alert protocol in a single tertiary care university hospital to identify those with in-hospital AIS due to acute intracranial large vessel occlusion (ILVO). Feasibility and safety of mechanical thrombectomy for in-hospital AIS was assessed in a case-control study comparing inpatients to those presenting from the community. Results: From 1460 in-hospital stroke alert activations, 11% had a final diagnosis of AIS (n = 167). One hundred and two patients with in-hospital AIS had emergent intracranial vessel imaging and were included in our cohort. Acute ILVO was identified in 27 patients within this cohort. Patients were younger in the ILVO group and had more severe neurologic deficit on presentation. Compared to a matched (1:2) control group of patients presenting from the community, inpatients who underwent mechanical thrombectomy achieved equivalent technical success, safety, and clinical outcomes. Conclusions: The incidence of acute ILVO in patients with in-hospital AIS who underwent emergent vessel imaging is similar to the reported incidence of ILVO in patients presenting with community-onset AIS. Among patients with in-hospital AIS secondary to ILVO, mechanical thrombectomy is a feasible and safe therapy associated with favorable outcomes