title: Supratentorial white matter blurring associated with voltage-gated potassium channel-complex limbic encephalitis.
abstract: BACKGROUND
  Limbic encephalitis (LE) associated with voltage-gated potassium channel-complex antibodies (VGKC-LE) is frequently non-paraneoplastic and associated with marked improvement following corticosteroid therapy. Mesial temporal lobe abnormalities are present in around 80 % of patients. If associated or preceded by faciobrachial dystonic seizures, basal ganglia signal changes may occur. In some patients, blurring of the supratentorial white matter on T2-weighted images (SWMB) may be seen. The purpose of this study was to evaluate the incidence of SWMB and whether it is specific for VGKC-LE.
  
  
  METHODS
  Two experienced neuroradiologists independently evaluated signal abnormalities on FLAIR MRI in 79 patients with LE while unaware on the antibody type.
  
  
  RESULTS
  SWMB was independently assessed as present in 10 of 36 (28 %) compared to 2 (5 %) of 43 non-VGKC patients (p = 0.009). It was not related to the presence of LGI1 or CASPR2 proteins of VGKC antibodies. MRI showed increased temporomesial FLAIR signal in 22 (61 %) VGKC compared to 14 (33 %) non-VGKC patients (p = 0.013), and extratemporomesial structures were affected in one VGKC (3 %) compared to 11 (26 %) non-VGKC patients (p = 0.005).
  
  
  CONCLUSIONS
  SWMB is a newly described MRI sign rather specific for VGKC-LE.
authors: Department of Neuroradiology, University Medical Center Freiburg, Breisacher Str. 64, 79106, Freiburg, Germany. horst.urbach@uniklinik-freiburg.de.
authors: H
authors: H
authors: Urbach
authors: Department of Neurology, University Medical Center Freiburg, Freiburg, Germany.
authors: S
authors: S
authors: Rauer
authors: Department of Neuroradiology, University Medical Center Freiburg, Breisacher Str. 64, 79106, Freiburg, Germany.
authors: I
authors: I
authors: Mader
authors: Department of Neurology, University Medical Center, Bonn, Germany.
authors: S
authors: S
authors: Paus
authors: Department of Epileptology, University Medical Center, Bonn, Germany.
authors: J
authors: J
authors: Wagner
authors: Department of Neurology, University of Cologne, Cologne, Germany.
authors: M P
authors: MP
authors: Malter
authors: Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
authors: H
authors: H
authors: Prüss
authors: Department of Neurology, Ulm University, Ulm, Germany.
authors: J
authors: J
authors: Lewerenz
authors: Department of Neurology, Ulm University, Ulm, Germany.
authors: J
authors: J
authors: Kassubek
authors: Department of Neurology, University Innsbruck, Innsbruck, Austria.
authors: H
authors: H
authors: Hegen
authors: Department of Neurology, University Innsbruck, Innsbruck, Austria.
authors: M
authors: M
authors: Auer
authors: Department of Neurology, University Innsbruck, Innsbruck, Austria.
authors: F
authors: F
authors: Deisenhammer
authors: Department of Neurology, University Medical Center, Hamburg, Germany.
authors: F
authors: F
authors: Ufer
authors: Epilepsy Centre Bethel, Bielefeld-Bethel, Germany.
authors: C G
authors: CG
authors: Bien
authors: Department of Neurology, University Medical Center Freiburg, Freiburg, Germany.
authors: A
authors: A
authors: Baumgartner
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000276:immunology; D054022:Cerebrum / Q000276:immunology / Q000473:pathology*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D020363:Limbic Encephalitis / Q000276:immunology* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D024642:Potassium Channels, Voltage-Gated / Q000276:immunology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D066127:White Matter / Q000276:immunology / Q000473:pathology*; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D024642:Potassium Channels, Voltage-Gated
keywords: Epilepsy; Limbic encephalitis; MRI; VGKC; White matter