title: Cerebral glucose hypometabolism in Tick-Borne Encephalitis, a pilot study in 10 Patients.
abstract: BACKGROUND
  Tick borne encephalitis (TBE) is an acute meningoencephalitis with or without myelitis caused by an RNA virus from the flavivirus family transmitted by Ixodes spp ticks. The neurotropic TBE virus infects preferentially large neurons in basal ganglia, anterior horns, medulla oblongata, Purkinje cells and thalamus. Brain metabolic changes related to radiologic and clinical findings have not been described so far.
  
  
  METHODS
  Here we describe the clinical course of 10 consecutive TBE patients with outcome assessment at discharge and after 12 month using a modified Rankin Scale. Patients underwent cerebral MRI after confirmation of diagnosis and before discharge.18F-FDG PET/CT scans were performed within day 5 to day 14 after TBE diagnosis. Extended analysis of coagulation parameters by thrombelastometry (ROTEM® InTEM, ExTEM, FibTEM) was performed every other day after confirmation of TBE diagnosis up to day 10 after hospital admission or discharge.
  
  
  RESULTS
  All patients presented with a meningoencephalitic course of disease. Cerebral MRI scans showed unspecific findings at predilection areas in 3 patients.18F-FDG PET/CT showed increased glucose utilization in one patient and decreased18F-FDG uptake in seven patients. Changes in coagulation measured by standard parameters and thrombelastometry were not found in any of the patients.
  
  
  CONCLUSIONS
  Glucose hypometabolism was present in 7 out of 10 TBE patients reflecting neuronal dysfunction in predilection areas of TBE virus infiltration responsible for development of clinical signs and symptoms.
authors.affiliation: Department of Neurology, Neurological Intensive Care Unit, Innsbruck Medical University, Innsbruck, Austria. Electronic address: anelia.dietmann@gmail.com.
authors.forename: Anelia
authors.initials: A
authors.lastname: Dietmann
authors.affiliation: Department of Nuclear Medicine, Innsbruck Medical University, Innsbruck, Austria; Department of Radiology, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Daniel
authors.initials: D
authors.lastname: Putzer
authors.affiliation: Department of Neurology, Neurological Intensive Care Unit, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Ronny
authors.initials: R
authors.lastname: Beer
authors.affiliation: Department of Neurology, Neurological Intensive Care Unit, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Raimund
authors.initials: R
authors.lastname: Helbok
authors.affiliation: Department of Neurology, Neurological Intensive Care Unit, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Bettina
authors.initials: B
authors.lastname: Pfausler
authors.affiliation: Diagnostic Nuklear Imaging Centre, Universiti Putra Malaysia Serdang, Selangor, Malaysia.
authors.forename: Abdul Jalil
authors.initials: AJ
authors.lastname: Nordin
authors.affiliation: Department of Nuclear Medicine, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Irene
authors.initials: I
authors.lastname: Virgolini
authors.affiliation: Department of Neuroradiology, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Astrid E
authors.initials: AE
authors.lastname: Grams
authors.affiliation: Department of Neurology, Neurological Intensive Care Unit, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Erich
authors.initials: E
authors.lastname: Schmutzhard
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000821:virology; D004669:Encephalitis Viruses, Tick-Borne / Q000502:physiology*; D004675:Encephalitis, Tick-Borne / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000821:virology; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000032:analysis; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D018884:Ixodes / Q000821:virology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D000072078:Positron Emission Tomography Computed Tomography; D011446:Prospective Studies; D013916:Thrombelastography; D055815:Young Adult
chemical_list: D019788:Fluorodeoxyglucose F18; D005947:Glucose
keywords: FDG-PET; glucose metabolism; neuroinfection; tick borne encephalitis