title: Spontaneously resolving seronegative autoimmune limbic encephalitis.
abstract: OBJECTIVE
  We describe a patient with seronegative autoimmune limbic encephalitis (SNALE) masquerading as glioma. Brain magnetic resonance imaging (MRI) abnormalities, distinctive pathological findings, and spontaneous remission are highlighted.
  
  
  BACKGROUND
  There are 15 previously reported SNALE cases, 1 with pathology.
  
  
  METHODS
  A 66-year-old man presented with prominent amnestic syndrome, progressive cognitive decline, and refractory complex partial seizures.
  
  
  RESULTS
  Initial brain MRI suggested herpes limbic encephalitis. A 3-week course of intravenous acyclovir was ineffective. Cerebrospinal fluid analysis revealed no pleocytosis. Repeat brain MRI showed a left uncal-hippocampal, contrast-enhancing lesion with mass effect, which was resected. Pathology revealed perivascular and parenchymal mixed lymphocytic inflammatory infiltrates, microglial nodules, neuronophagia, microglial activation, astrocytosis, and lymphocyte emperipolesis within neurons. Thorough searches for infectious pathogens and autoantibodies were negative. Six weeks later, a new enhancing right mesial temporal lesion appeared, with increased seizure activity and further cognitive impairment. Although immune therapy was declined, spontaneous resolution of the new enhancing lesion, with full seizure control and significant cognitive improvement, occurred.
  
  
  CONCLUSIONS
  SNALE may masquerade as glioma. Pathologic changes in our case of SNALE are distinctive. Spontaneous resolution of a focal SNALE lesion may potentially occur without immune therapy.
authors.affiliation: Departments of Neurology, Pathology (Division of Neuropathology), Neurosurgery & Psychiatry, NYU-Comprehensive Epilepsy Center, New York University School of Medicine, New York, NY, USA.
authors.forename: Souhel
authors.initials: S
authors.lastname: Najjar
authors.forename: Daniel
authors.initials: D
authors.lastname: Pearlman
authors.forename: David
authors.initials: D
authors.lastname: Zagzag
authors.forename: Orrin
authors.initials: O
authors.lastname: Devinsky
mesh_terms: D000368:Aged; D001323:Autoantibodies / Q000276:immunology; D001327:Autoimmune Diseases / Q000276:immunology / Q000473:pathology*; D001921:Brain / Q000276:immunology / Q000473:pathology*; D006801:Humans; D020363:Limbic Encephalitis / Q000276:immunology / Q000473:pathology*; D008297:Male; D012075:Remission, Spontaneous
chemical_list: D001323:Autoantibodies