The paravascular pathway, also known as the “glymphatic” pathway, is a recently described system for waste clearance in the brain. According to this model, cerebrospinal fluid (CSF) enters the paravascular spaces surrounding penetrating arteries of the brain, mixes with interstitial fluid (ISF) and solutes in the parenchyma, and exits along paravascular spaces of draining veins. Studies have shown that metabolic waste products and solutes, including proteins involved in the pathogenesis of neurodegenerative diseases such as amyloid-beta, may be cleared by this pathway. Consequently, a growing body of research has begun to explore the association between glymphatic dysfunction and various disease states. However, significant controversy exists in the literature regarding both the direction of waste clearance as well as the anatomical space in which the waste-fluid mixture is contained. Some studies have found no evidence of interstitial solute clearance along the paravascular space of veins. Rather, they demonstrate a perivascular pathway in which waste is cleared from the brain along an anatomically distinct perivascular space in a direction opposite to that of paravascular flow. Although possible explanations have been offered, none have been able to fully reconcile the discrepancies in the literature, and many questions remain. Given the therapeutic potential that a comprehensive understanding of brain waste clearance pathways might offer, further research and clarification is highly warranted.

1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;48:1139-1146.

No abstract

2 Technical Efficacy Stage: 2 J. MAGN. RESON. IMAGING 2018.

Hypertension is associated with cardiovascular disease, stroke, and a range of other medical sequelae. Accurate blood pressure (BP) readings, which depend on the integrity and calibration of the measuring device, are essential to identifying suboptimal BP. This study describes calibration rates of aneroid BP devices (a) utilized in home healthcare (HHC) and (b) having the needle resting within the zero accuracy indicator. BP devices from one branch of a home care agency were inspected and checked for calibration according to the protocol set forth by the European Society of Hypertension. Of the 125 devices measured, 78.4% were in calibration. Of the 94 devices with the gauge needle resting in the zero accuracy indicator, 11.7% were not in calibration; whereas, 51.6% of the 31 devices with the gauge needle resting outside the zero accuracy indicator were found not in calibration. Twenty-one devices were not checked for calibration due to inflation bulb malfunction, tubing tears, or excessive wear. Furthermore, visual inspection of the needle placement did not confirm a device as being in or out of calibration. Proper maintenance and routine calibration of BP equipment is foundational to assuring accuracy of BP readings obtained by HHC providers.