MRI study of cerebral blood flow and CSF flow dynamics in an upright posture: the effect of posture on the intracranial compliance and pressure

Alperin, Noam; Hushek, Stephen G.; Lee, S. H.; Sivaramakrishnan, Anusha; Lichtor, Terry

doi:10.1007/3-211-32318-x_38

Cited by 102 publications

(71 citation statements)

References 5 publications

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“…First, because CSF is highly conductive, minute shifts in CSF concentration can cause substantial alterations in EEG signals (Ramon et al, 2006;Ramon et al, 2004;Wendel et al, 2008). Using upright and recumbent MRI scanners, findings demonstrated that intracranial CSF concentration decreased when sitting up compared with lying down (Alperin et al, 2005). Thus, CSF scattering may influence the propagation and recording of high frequency cortical activity (Rice et al, 2013).…”

Section: Discussionmentioning

confidence: 99%

Posture alters human resting-state

Thibault

Lifshitz

Jones

et al. 2014

Cortex

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Neuroimaging is ubiquitous; however, neuroimagers seldom investigate the putative impact of posture on brain activity. Whereas participants in most psychological experiments sit upright, many prominent neuroimaging techniques (e.g., functional magnetic resonance imaging (fMRI)) require participants to lie supine. Such postural discrepancies may hold important implications for brain function in general and for fMRI in particular. We directly investigated the effect of posture on spontaneous brain dynamics by recording scalp electrical activity in four orthostatic conditions (lying supine, inclined at 45°, sitting upright, and standing erect). Here we show that upright versus supine posture increases widespread high-frequency oscillatory activity.Our electroencephalographic findings highlight the importance of posture as a determinant in neuroimaging. When generalizing supine imaging results to ecological human cognition, therefore, cognitive neuroscientists would benefit from considering the influence of posture on brain dynamics.

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Section: Discussionmentioning

confidence: 99%

Posture alters human resting-state

Thibault

Lifshitz

Jones

et al. 2014

Cortex

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“…Although initially described as accessory, the secondary venous pathways, namely epidural vein, vertebral vein, and deep cervical vein, are now recognized to represent a significant fraction of the venous cranial drainage, depending on posture (sitting or standing position, in which the jugular veins collapse) or on intrathoracic pressure. [24][25][26] Moreover, a previous PC-MRI study performed on HC has demonstrated that the role of secondary venous pathways may be physiologically variable, independently of posture-related factors. 8 These heterogeneous venous flow patterns observed in MS patients as well as in HC renders difficult to assess 'venous obstructions,' as distinguishing between physiologic side dominance, secondary venous drainage preponderance, or venous obstruction may be challenging in subjects with flow asymmetry.…”

Section: Venous Flowsmentioning

confidence: 99%

Concomitant Analysis of Arterial, Venous, and CSF Flows using Phase-Contrast MRI: A Quantitative Comparison Between MS Patients and Healthy Controls

ElSankari

Balédent

Pesch

et al. 2013

J Cereb Blood Flow Metab

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Venous dysfunction has recently been hypothesized to contribute to the pathophysiology of multiple sclerosis (MS). 2D phasecontrast (PC) magnetic resonance imaging (MRI) is a non-invasive and innocuous technique enabling reliable quantification of cerebrospinal fluid (CSF) and blood flows in the same imaging session. We compared PC-MRI measurements of CSF, arterial and venous flows in MS patients to those from a normative cohort of healthy controls (HC). Nineteen MS patients underwent a standardized MR protocol for cerebral examination on a 3T system including Fast cine PC-MRI sequences with peripheral gating in four acquisition planes. Quantitative data were processed using a homemade software to extract CSF and blood flow regions of interest, animate flows, and calculate cervical and intracranial vascular flow curves during the cardiac cycle (CC). Results were compared with values obtained in 21 HC using multivariate analysis. Venous flow patterns were comparable in both groups without signs of reflux. Arterial flows (P ¼ 0.02) and cervical CSF dynamic oscillations (P ¼ 0.01) were decreased in MS patients. No significant differences in venous cerebral and cervical outflows were observed between groups, thereby contradicting the recently proposed theory of venous insufficiency. Unexpected decrease in arterial perfusion in MS patients warrants further correlation to volumetric measurements of the brain.

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“…Reports on positional venous MR angiography are scarce, 9,10 because only a few dedicated MR imaging scanners are available. The magnetic field of positional MR imaging scanners is typically lower compared with conventional MR imaging scanners; hence the possibility of performing MR angiography is reduced.…”

Section: Technical Features Of Positional Mr Venographymentioning

confidence: 99%

“…9,10 The presented methods, however, do not allow investigating strictures, since they either lack the possibility to acquire 3D datasets or do not cover the entire cervical region.…”

mentioning

confidence: 99%