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Reinterpreting the magnetic resonance signs of hemodynamic impairment in the brains of multiple sclerosis patients from the perspective of a recent discovery of outflow block in the extracranial veins
Author(s) -
Simka Marian,
Zaniewski Maciej
Publication year - 2010
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.22350
Subject(s) - multiple sclerosis , magnetic resonance imaging , medicine , cerebral blood flow , hemodynamics , cerebral veins , susceptibility weighted imaging , perfusion , blood flow , mean transit time , white matter , cardiology , hyperintensity , radiology , perfusion scanning , psychiatry
Multiple sclerosis patients examined with perfusion magnetic resonance (MR) imaging techniques have been found to have patterns of abnormal blood flow. These include prolonged mean transit time, a trend toward decreased cerebral blood flow in the area of plaques, and decreased cerebral blood flow and prolonged mean transit time within normal‐appearing white matter. In‐creased cerebral blood flow and volume and decreased mean transit time (compared with the baseline values before the relapse) were found to precede the development of plaques. In addition, susceptibility‐weighted imaging utilizing deoxyhemoglobin as the contrast has revealed that venous blood in cerebral veins of multiple sclerosis patients is less deoxygenated compared with healthy controls. All these findings were traditionally interpreted as a sign of local flow disturbances mediated by inflammatory and neurodegenerative processes. However, recent findings of significant stenoses in the extracranial veins that drain the brain and spinal cord shed new light on these MR results. With the assumption that a majority, if not all, of multiple sclerosis patients exhibit such extracranial venous obstacles, the perfusion MR images of multiple sclerosis patients should be reinterpreted. Perhaps ongoing MR studies with respect to extracranial venous hemodynamics may decipher some of the unsolved puzzles related to this neurologic disease. © 2010 Wiley‐Liss, Inc.