- Hyperintensities
Hyperitensities refer to areas of high intensity on particular types of
magnetic resonance imaging scans of thehuman brain . These small regions of high intensity are observed on T2 images within cerebralwhite matter or subcortical gray matter. They are usually seen in normal aging but also in a number of neurological and psychiatric illnesses. For example deep white matter hyperintensites are 2.5 - 3 times for likely to occur inbipolar disorder andmajor depressive disorder than control subjects. [Kempton, M.J., Geddes, J.R, Ettinger, U. et. al. (2008). " [http://archpsyc.ama-assn.org/cgi/content/short/65/9/1017 Meta-analysis, Database, and Meta-regression of 98 Structural Imaging Studies in Bipolar Disorder] ," "Archives of General Psychiatry", 65:1017–1032 see also MRI database at [http://www.bipolardatabase.org www.bipolardatabase.org] .] [Videbech, P (1997). " [http://www3.interscience.wiley.com/journal/119945126/abstract MRI findings in patients with affective disorder: a meta-analysis] ," "Acta Psychiatrica Scandinavica", 96:157–168.]Hyperintensities are commonly divided into 3 types depending on the region of the brain where they are found. Deep white matter hyperintensites occur deep within white matter, periventricular white matter hyperintensities occur adjacent to the
lateral ventricles and subcortical hyperintensities occur in thebasal ganglia .Postmortem studies combined with MRI suggest that hyperintensities are dilated perivascular spaces, or demyelination caused by reduced local blood flow. [Thomas, A.J., Perry, R., Barber, R., Kalaria, R.N., O’Brien, J.T. (2002). " [http://www3.interscience.wiley.com/journal/120778635/abstract Pathologies and pathological mechanisms for white matter hyperintensities in depression] ," "Ann N Y Acad Sci.", 977:333–339.]
ee also
*
Hypertensive leukoencephalopathy
*Virchow-Robin spaces
*Subcortical ischemic depression References
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