Serial MRI of limbic encephalitis.
BACKGROUND
The aim of the study was to analyze serial magnetic resonance imaging (MRI) scans in patients with various forms of limbic encephalitis (LE) in order to evaluate whether, and at what time point, MRI findings support the diagnosis of LE.


METHODS
Serial MRI scans (1 day to 15 years after the onset of symptoms) of 20 patients with LE were retrospectively evaluated. Of these 20 patients, 16 had definite LE (histopathological limbic inflammation, n=6; onconeural antibodies, n=5; voltage-gated potassium channel antibodies, n=3; malignant tumors, n=5), and 4 possible LE because they met the clinical criteria but had no typical antibodies or tumors.


RESULTS
Of 13 patients who were studied with MRI within 3 months after the onset of symptoms, 11 had swollen temporomesial structures (unilateral, n=7; bilateral, n=4). After up to 9 months, the swelling had resolved in nine of ten re-evaluated patients. Of seven patients who were initially studied with MRI more than 3 months after disease onset, three had swollen temporomesial structures, one had a hyperintense, normal-sized hippocampus, and three had hyperintense and atrophic temporomesial structures.


CONCLUSIONS
LE starts as an acute disease with uni- or bilateral swollen temporomesial structures that are hyperintense on fluid attenuation inversion recovery and T2-weighted sequences. Swelling and hyperintensity may persist over months to years, but in most cases progressive temporomesial atrophy develops.
Urbach
Horst
H
Department of Radiology, University of Bonn Medical Center, Sigmund Freud Str. 25, 53105 Bonn, Germany. urbach@uni-bonn.de
Soeder
Bettina M
BM
Jeub
Monika
M
Klockgether
Thomas
T
Meyer
Bernhard
B
Bien
Christian G
CG
D000328:Adult; D000368:Aged; D001284:Atrophy / Q000209:etiology / Q000473:pathology; D005260:Female; D006801:Humans; D020363:Limbic Encephalitis / Q000150:complications / Q000473:pathology*; D008032:Limbic System / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013702:Temporal Lobe / Q000473:pathology; D013997:Time Factors