Diffusion-weighted MR imaging in hypertensive encephalopathy: clues to pathogenesis.
Year: 1998
Type: article
Study design: Case Report
Abstract: PURPOSE: Hypertensive encephalopathy, a complex of cerebral disorders, including headache, seizures, visual disturbances, and other neurologic manifestations, is associated with a variety of conditions in which blood pressure rises acutely. It has been ascribed to either exuberant vasospasm with ischemia/infarction or breakthrough of autoregulation with interstitial edema. Diffusion-weighted MR imaging may be used to determine whether the edema in hypertensive encephalopathy is cytotoxic or vasogenic in origin. METHODS: Diffusion-weighted imaging was performed using the double line scan diffusion imaging technique on a 1.5-T MR system. Seven patients with hypertensive encephalopathy were imaged within 1 day of the onset of their symptoms. Apparent diffusion coefficient maps as well as low and high b-factor images were acquired. The two-tailed paired Student's t-test was used to compare the apparent diffusion coefficients in edematous brain regions with those of normal white matter. RESULTS: In all cases the apparent diffusion coefficient maps of the patients with hypertensive encephalopathy showed increased signal in regions corresponding to increased T2 signal on standard T2-weighted (low b-factor) images. Quantitative apparent diffusion coefficients in regions of abnormal T2 signal were 1.36 +/- 0.14 microm2/ms, compared with 0.80 +/- 0.05 microm2/ms in normal white matter. Diffusion-weighted (high b-factor) T2-weighted images did not show abnormal signal. CONCLUSION: Diffusion-weighted MR imaging shows that the edema in hypertensive encephalopathy is of vasogenic origin and does not represent ischemia or infarction. This finding may have therapeutic implications.
Source: PubMed Central
Authors: R B Schwartz, R V Mulkern, H Gudbjartsson, F Jolesz
Institution: Brigham and Women's Hospital
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2116842997
