title: Susceptibility-weighted imaging in parenchymal neurosyphilis: identification of a new MRI finding.
abstract: BACKGROUND
  General paresis (GP) is a late form of parenchymal neurosyphilis causing dementia and neuropsychiatric disorders. The diagnosis is often difficult since the clinical signs are protean. So far, neuroimaging has played a minor role as radiological findings are not specific.
  
  
  METHODS
  We studied three immunocompetent patients, admitted to hospital for cognitive impairment. The diagnosis of neurosyphilis was formulated on the basis of serological texts and cerebrospinal fluid analysis. The patients underwent a 3 T MR examination including susceptibility-weighted imaging (SWI) sequence before and after the initiation of penicillin therapy.
  
  
  RESULTS
  In all patients, SWI revealed cortical hypointensity, mostly distributed in frontal and temporal lobes. In drug-naive patients, the hypointensity extended over the whole cortical thickness, from the cortical/subcortical junction to the pial surface. After starting the penicillin therapy, the cortical hypointensity partially reversed, involving only the deep cortical layers.
  
  
  CONCLUSIONS
  The MRI pattern at SWI observed in patients with GP was not reported in other infectious or inflammatory disease of the central nervous system, thus we suggest it could be a peculiar radiological finding of the disease. On the basis of previous pathological data, we hypothesise that cortical SWI hypointensity could be expression of iron deposits within activated microglia.
authors.affiliation: Unit of Neuroradiology, AOUP, Santa Chiara Hospital, Pisa, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Pesaresi
authors.affiliation: Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, Pisa, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Sabato
authors.affiliation: Unit of Infectious Diseases, AOUP, Santa Chiara Hospital, Pisa, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Doria
authors.affiliation: Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, Pisa, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Desideri
authors.affiliation: Unit of Neurology, AOUP, Santa Chiara Hospital, Pisa, Italy.
authors.forename: Melania
authors.initials: M
authors.lastname: Guida
authors.affiliation: Unit of Neurology, AOUP, Santa Chiara Hospital, Pisa, Italy.
authors.forename: Filippo Sean
authors.initials: FS
authors.lastname: Giorgi
authors.affiliation: Unit of Neuroradiology, AOUP, Santa Chiara Hospital, Pisa, Italy Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, Pisa, Italy.
authors.forename: Mirco
authors.initials: M
authors.lastname: Cosottini
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D059906:Neuroimaging / Q000379:methods*; D009494:Neurosyphilis / Q000175:diagnosis* / Q000473:pathology*; D011859:Radiography