Multimodal and autoregulation monitoring in the neurointensive care unit

Given the complexity of cerebral pathology in patients with acute brain injury, various neuromonitoring strategies have been developed to better appreciate physiologic relationships and potentially harmful derangements. There is ample evidence that bundling several neuromonitoring devices, termed “multimodal monitoring,” is more beneficial compared to monitoring individual parameters as each may capture different and complementary aspects of cerebral physiology to provide a comprehensive picture that can help guide management. Furthermore, each modality has specific strengths and limitations that depend largely on spatiotemporal characteristics and complexity of the signal acquired. In this review we focus on the common clinical neuromonitoring techniques including intracranial pressure, brain tissue oxygenation, transcranial doppler and near-infrared spectroscopy with a focus on how each modality can also provide useful information about cerebral autoregulation capacity. Finally, we discuss the current evidence in using these modalities to support clinical decision making as well as potential insights into the future of advanced cerebral homeostatic assessments including neurovascular coupling

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

Management of Blood Pressure During and After Recanalization Therapy for Acute Ischemic Stroke.

Ischemic stroke is a common neurologic condition and can lead to significant long term disability and death. Observational studies have demonstrated worse outcomes in patients presenting with the extremes of blood pressure as well as with hemodynamic variability. Despite these associations, optimal hemodynamic management in the immediate period of ischemic stroke remains an unresolved issue, particularly in the modern era of revascularization therapies. While guidelines exist for BP thresholds during and after thrombolytic therapy, there is substantially less data to guide management during mechanical thrombectomy. Ideal blood pressure targets after attempted recanalization depend both on the degree of reperfusion achieved as well as the extent of infarction present. Following complete reperfusion, lower blood pressure targets may be warranted to prevent reperfusion injury and promote penumbra recovery however prospective clinical trials addressing this issue are warranted

Overview of Neurovascular Physiology.

Purpose of reviewNeurophysiology is a complex network of cellular, electrical, and vascular systems which function to maximize neuronal functioning and brain performance. The brain exists in a closed system made up of parenchyma, cerebrospinal fluid, and blood with any increase in volume leading to a corresponding decrease in one of the components. Once these compensatory mechanisms are exhausted, there is a precipitous increase in the intracranial pressure leading to decreases in cerebral perfusion and resulting ischemia. The cerebral vasculature has significant control over the total volume of blood and regional flow throughout the brain via autoregulation. Through this process, blood flow is tightly regulated to prevent fluctuations and is coupled precisely with metabolic demand. Moreover, oxygen delivery and aerobic respiration are essential for proper brain functioning and can become deranged in various disease states leading to cellular injury and death.Recent findingsOngoing trials have provided evidence that in addition to targeted therapy for intracranial pressure monitoring, optimizing brain tissue oxygenation and cerebral autoregulation may lead to improved clinical outcomes. An understanding of neurophysiology is not only essential for treating patients suffering from intracranial injury but also for the development of novel monitoring and therapeutic techniques

Overview of Neurovascular Physiology.

Purpose of reviewNeurophysiology is a complex network of cellular, electrical, and vascular systems which function to maximize neuronal functioning and brain performance. The brain exists in a closed system made up of parenchyma, cerebrospinal fluid, and blood with any increase in volume leading to a corresponding decrease in one of the components. Once these compensatory mechanisms are exhausted, there is a precipitous increase in the intracranial pressure leading to decreases in cerebral perfusion and resulting ischemia. The cerebral vasculature has significant control over the total volume of blood and regional flow throughout the brain via autoregulation. Through this process, blood flow is tightly regulated to prevent fluctuations and is coupled precisely with metabolic demand. Moreover, oxygen delivery and aerobic respiration are essential for proper brain functioning and can become deranged in various disease states leading to cellular injury and death.Recent findingsOngoing trials have provided evidence that in addition to targeted therapy for intracranial pressure monitoring, optimizing brain tissue oxygenation and cerebral autoregulation may lead to improved clinical outcomes. An understanding of neurophysiology is not only essential for treating patients suffering from intracranial injury but also for the development of novel monitoring and therapeutic techniques