Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Long-term surveillance of intracranial pressure (ICP) in neurological/neurosurgical patients during ventilator weaning and early neurorehabilitation currently relies on clinical observation because neuroimaging is rarely readily available. In this prospective study, multimodal neurosonography and pupillometry are evaluated for follow-up monitoring. ⋯ Multimodal neurosonography may be a noninvasive means for long-term ICP assessment, whereas pupillometry may only detect rapid ICP changes during acute neurointensive care. The study also illustrates common pitfalls in neuromonitoring in general, with large numbers of pathological albeit nonsignificant findings. Additional controlled studies should validate the influence of detected subtle changes in ICP on neurological outcome.
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In hepatic encephalopathy (HE), osmotic stressors promoting brain edema result in a compensatory drop in the astrocyte metabolite myo-inositol (mI). Identifying differences between nonalcoholic steatohepatitis (NASH) with and without HE and healthy controls using proton magnetic resonance spectroscopy (MRS) and evaluating hypoalbuminemia and hyperammonemia as osmotic stressors that predict the reduction of mI allow further understanding of mechanisms that promote brain edema in HE. The aim of this study was to assess brain edema in HE using characteristic MRS markers and serum albumin. ⋯ Low mI/tCr and increased Gln/tCr were characteristics of Crhs+HE. Low serum albumin was the strongest predictor of brain osmotic stress indicated by reduced mI/tCr, with no residual independent association seen for brain Gln/tCr concentration. This suggests that hypoalbuminemia in chronic liver disease may promote brain edema in HE.
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Arterial recanalization to restore the blood supply and limit the brain damage is the primary goal in the management of acute ischemic stroke (AIS). Since the publication of pivotal randomized clinical trials in 2015, endovascular thrombectomy has become part of the standard of care in selected cases of AIS from large-vessel occlusions up to 6 hours after the onset of symptoms. However, the association between endovascular reperfusion and improved functional outcome is not strictly time dependent. ⋯ This information is invaluable in identifying patients who are likely to benefit from reperfusion therapies and excluding those who are unlikely to benefit or are at risk of adverse effects. The approach to reperfusion therapies continues to evolve, and imaging is acquiring a greater role in the diagnostic work-up and treatment decisions as shown in recent clinical trials with extended time window. The 2018 American Heart Association/American Stroke Association guidelines reflect a paradigm shift in the management of AIS from "Time is Brain" to "Imaging is Brain." This review discusses the essential role of multimodal imaging developing from recent trials on therapy for AIS.
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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as the name suggests was initially thought to only cause a respiratory illness. However, several reports have been published of patients with ischemic strokes in the setting of coronavirus disease 2019 (COVID-19). The mechanisms of how SARS-CoV-2 results in blood clots and large vessel strokes need to be defined as it has therapeutic implications. ⋯ As the blood-air barrier is breached, varying degrees of collateral damage occur. Although antiviral and immune therapies are studied, the role of blood thinners in the prevention, and management of blood clots in Covid-19 need evaluation. In addition to ventilators and blood thinners, continuous aspiration and clot retrieval devices (approved in Europe, cleared in the United States) or cyclical aspiration devices (approved in Europe) need to be considered for the emergent management of life-threatening clots including PE and large vessel strokes.
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Transvascular water exchange plays a key role in the functional integrity of the blood-brain barrier (BBB). In white matter (WM), a variety of imaging modalities have demonstrated age-related changes in structure and metabolism, but the extent to which water exchange is altered remains unclear. Here, we investigated the cumulative effects of healthy aging on WM capillary water exchange. ⋯ Previous studies have shown that kpo tracks Na+ , K+ -ATPase activity-dependent water exchange at the BBB and likely reflects neurogliovascular unit (NGVU) coupled metabolic activity. The age-related decline in kpo observed here is consistent with compromised NGVU metabolism in older individuals and the dysregulated cellular bioenergetics that accompany normal brain aging.