MRI and Diffusion MRI in nonparaneoplastic limbic encephalitis

This paper reports an 65-year-old woman with nonparaneoplastic limbic encephalitis. On MRI and diffusion MRI, diffuse and symmetrical, bilateral high-signal lesions were evident in the medial temporal lobes. The affected areas were hyperintense on b = 1000 s/mm(2) (heavily diffusion-weighted or true diffusion) images, a pattern similar to cytotoxic edema. However, apparent diffusion coefficient (ADC) values read directly from corresponding ADC maps at each temporal lobe were within normal limits: 0.96 and 0.97 x 10(-3) mm(2)/s, respectively, excluding cytotoxic edema, The changes were shown to be resolved on a 9-month follow-up MRI. (C) 2002 Elsevier Science Ltd. All rights reserved.