THE ROLE OF CEREBROSPINAL FLUID DYNAMICS USING PHASE-CONTRAST MAGNETIC RESONANCE IMAGING IN ASSESSMENT OF MULTIPLE SCLEROSIS ACTIVITY

Background Cerebrospinal fluid (CSF) outflow to intra- and extracranial subarachnoid spaces caused by arterial inflow to the brain predominantly compensates systolic increases in cerebral blood volume. Phase-contrast magnetic resonance imaging is a new tool for noninvasive assessment of CSF displacement by measuring CSF peak velocity (CSFV(Peak)). The authors tested this new tool in an experimental human model of increased intracranial pressure and reduced cerebral capacity by means of continuous positive airway pressure (CPAP) breathing. Methods The authors investigated systolic CSFV(Peak) in the aqueduct of Sylvius in 11 awake, normocapnic (end-tidal carbon dioxide [ET(CO2)] = 40 mmHg) volunteers without CPAP and at two different CPAP levels (6 and 12 cm H2O) by means of electroencephalography-gated phase-contrast magnetic resonance imaging. Results Administration of 6 cm H2O CPAP did not change systolic CSFV(Peak) (-4.9+/-2.8 cm/s vs. control: -5.1+/-2.7 cm/s), whereas 12 cm H2O CPAP significantly reduced systolic CSFV(Peak) (-4.0+/-1.8 cm/s vs. control: -5.1+/-2.7 cm/s; P < 0.05). Conclusions These findings in awake volunteers show that monitoring CSFV(Peak) in the aqueduct of Sylvius is a sensitive method for detecting even minor impairment of cerebral capacity caused by experimentally induced increases in intracranial pressure.

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Aging Effects on Cerebral Blood and Cerebrospinal Fluid Flows

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/sj.jcbfm.9600462 ◽

2007 ◽

Vol 27 (9) ◽

pp. 1563-1572 ◽

Cited By ~ 132

Author(s):

Souraya Stoquart-ElSankari ◽

Olivier Balédent ◽

Catherine Gondry-Jouet ◽

Malek Makki ◽

Olivier Godefroy ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Blood Flow ◽

Cerebrospinal Fluid ◽

Magnetic Resonance ◽

Phase Contrast ◽

The Elderly ◽

Elderly Group ◽

Resonance Imaging ◽

Aging Effects ◽

Contrast Magnetic Resonance

Phase-contrast magnetic resonance imaging (PC-MRI) is a noninvasive reliable technique, which enables quantification of cerebrospinal fluid (CSF) and total cerebral blood flows (tCBF). Although it is used to study hydrodynamic cerebral disorders in the elderly group (hydrocephalus), there is no published evaluation of aging effects on both tCBF and CSF flows, and on their mechanical coupling. Nineteen young (mean age 27 ± 4 years) and 12 elderly (71 ± 9 years) healthy volunteers underwent cerebral MRI using 1.5 T scanner. Phase-contrast magnetic resonance imaging pulse sequence was performed at the aqueductal and cervical levels. Cerebrospinal fluid and blood flow curves were then calculated over the cardiac cycle, to extract the characteristic parameters: mean and peak flows, their latencies, and stroke volumes for CSF (cervical and aqueductal) and vascular flows. Total cerebral blood flow was ( P < 0.01) decreased significantly in the elderly group when compared with the young subjects with a linear correlation with age observed only in the elderly group ( R2 = 0.7; P = 0.05). Arteriovenous delay was preserved with aging. The CSF stroke volumes were significantly reduced in the elderly, at both aqueductal ( P < 0.01) and cervical ( P < 0.05) levels, whereas aqueduct/cervical proportion ( P = 0.9) was preserved. This is the first work to study aging effects on both CSF and vascular cerebral flows. Data showed (1) tCBF decrease, (2) proportional aqueductal and cervical CSF pulsations reduction as a result of arterial loss of pulsatility, and (3) preserved intracerebral compliance with aging. These results should be used as reference values, to help understand the pathophysiology of degenerative dementia and cerebral hydrodynamic disorders as hydrocephalus.

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