Pathophysiologic mechanisms in the development of age-related whitematter changes of the brain
F. Fazekas
Bok Engelsk 1998
| Utgitt | 1998
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|---|---|
| Omfang | Side 2- 5
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| Opplysninger | Magnetic resonance imaging (MRI) has dramatically enhanced ourcapability of detecting age-related changes of the brain even beforethey become clinically apparent. Among those are preferentiallyalterations of the white matter in periventricular, deep andsubcortical locations which display high signal intensity on bothproton density- and T-2-weighted images. Correlative histopathologicfindings show hyperintense periventricular capping of the frontalhorns to reflect predominantly a specific anatomic situationcharacterized by loosely arranged fine-fiber tracts with low myelinand high extracellular fluid content. A smooth halo ofperiventricular hyperintensity has been linked to disruption of theependymal lining with subependymal gliosis and concomitant loss ofmyelin. In contrast, punctate, early confluent and confluenthyperintensities in the deep and subcortical white matter as well asirregular periventricular hyperintensity appear to be of vascularorigin. Punctate lesions tend to correspond to a perivascularreduction in myelin content with atrophy of the neuropil and seem toconstitute a negligeable extent of tissue damage from lowpermeability through thickened arteriolar walls. Early confluent andconfluent hyperintensities, however, indicate more extensive ischemicdamage consistent with advanced microangiopathy.
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| Emner |
