Transcutaneous Vagus Nerve Stimulation (tVNS) for Treatment of Drug-Resistant Epilepsy: A Randomized, Double-Blind Clinical Trial (cMPsE02).

Background: Various brain stimulation techniques are in use to treat epilepsy. These methods usually require surgical implantation procedures. Transcutaneous vagus nerve stimulation (tVNS) is a non-invasive technique to stimulate the left auricular branch of the vagus nerve at the ear conch.

Convection-enhanced delivery of therapeutics for brain disease, and its optimization.

Convection-enhanced delivery (CED) is the continuous injection under positive pressure of a fluid containing a therapeutic agent. This technique was proposed and introduced by researchers from the US National Institutes of Health (NIH) by the early 1990s to deliver drugs that would otherwise not cross the blood-brain barrier into the parenchyma and that would be too large to diffuse effectively over the required distances were they simply deposited into the tissue. Despite the many years that have elapsed, this technique remains experimental because of both the absence of approved drugs for intraparenchymal delivery and the difficulty of guaranteed delivery to delineated regions of the brain.

Susceptibility-sensitive magnetic resonance imaging detects human myocardium supplied by a stenotic coronary artery without a contrast agent.

Objectives: Evaluation of the severity of a coronary artery stenosis is of paramount importance for therapy. A relevant stenosis provokes post-stenotic microvascular dilation with capillary recruitment. This autoregulatory response was investigated in the present study by use of susceptibility-sensitive magnetic resonance imaging (MRI) without contrast agents.

The relationship between the BOLD-induced T(2) and T(2)(*): a theoretical approach for the vasculature of myocardium.

Recently the blood oxygenation level-dependent (BOLD)-related T(2)* of myocardium was derived as an analytical function of intracapillary blood volume, blood oxygenation, and nuclear spin diffusion. The basis of this approach was to approximate the diffusion-induced field fluctuations a nuclear spin is subjected to by strong collision dynamics, i.e.

BOLD-MRI in ten patients with coronary artery disease: evidence for imaging of capillary recruitment in myocardium supplied by the stenotic artery.

Changes of myocardial oxygenation can be studied by measurements of the apparent transverse relaxation time T2*, which is correlated with the oxygenation state of hemoglobin. In this study, ten patients with coronary artery disease (CAD) underwent blood oxygenation level dependent (BOLD) T2* measurements using a segmented gradient echo pulse sequence with ten echoes. T2* measurements were performed in a single short-axis slice of the heart at rest and under pharmacological stress with dipyridamole (DIP), which increases myocardial blood flow.

Changes in myocardial oxygenation and perfusion under pharmacological stress with dipyridamole: assessment using T*2 and T1 measurements.

The aim of this pilot-study was to evaluate changes in myocardial oxygenation and perfusion under pharmacological stress with dipyridamole (DIP) by means of MRI. Twenty healthy volunteers were examined using a multi-echo gradient-echo sequence. The differential myocardial signal response due to the blood oxygen level dependent (BOLD) effect was studied under variable conditions of myocardial oxygen supply caused by the vasodilator DIP.

Theory of the BOLD effect in the capillary region: an analytical approach for the determination of T2 in the capillary network of myocardium.

This article presents an analytical approach for the quantification of the blood oxygen level dependent (BOLD) effect in the capillary region. The capillary geometry of myocardium is considered. The relaxation rate R*2 is determined as a function of the capillary radius Rc, the intracapillary volume fraction RBV, and the diffusion coefficient D.