title: Autoimmune causes of encephalitis syndrome in Thailand: prospective study of 103 patients.
abstract: BACKGROUND
  Data on encephalitis in Thailand have not been completely described. Etiologies remain largely unknown. We prospectively analyzed 103 Thai patients from 27 provinces for the causes of encephalitis using clinical, microbiological and neuroimaging indices; caseswithout a diagnosis were evaluated for autoimmune causes of encephalitis.
  
  
  METHODS
  Patients with encephalitis and/or myelitis were prospectively studied between October 2010 and August 2012. Cases associated with bacterial, rickettsial and mycobacterial diseases were excluded. Herpes viruses 1-6 and enteroviruses infection was diagnosed using PCR evaluation of CSF; dengue and JE viruses infection, by serology. The serum of test-negative patients was evaluated for the presence of autoantibodies.
  
  
  RESULTS
  103 patients were recruited. Fifty-three patients (52%) had no etiologies identified. Twenty-five patients (24%) were associated with infections. Immune encephalitis was found in 25 (24%); neuropsychiatric lupus erythematosus (4), demyelinating diseases (3), Behcet's disease (1) and the remaining had antibodies to NMDAR (5), ANNA-2 (6), Yo (2), AMPA (1), GABA (1), VGKC (1) and NMDA coexisting with ANNA-2 (1). Presenting symptoms in the autoimmune group included behavioral changes in 6/25 (versus 12/25 in infectious and 13/53 in unknown group) and as psychosis in 6/25 (versus 0/25 infectious and 2/53 unknown). Seizures were found in 6/25 autoimmune, 4/25 infectious and 19/53 unknown group. Two patients with anti-ANNA-2 and one anti-Yo had temporal lobe involvement by magnetic resonance imaging. Two immune encephalitis patients with antibodies to NMDAR and ANNA-2 had ovarian tumors.
  
  
  CONCLUSIONS
  Autoantibody-associated encephalitis should be considered in the differential diagnosis and management algorithm regardless of clinical and neuroimaging features.
authors.affiliation: Neuroscience Centre for Research and Development, Division of Neurology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand. abhinbhen@gmail.com.
authors.forename: Abhinbhen
authors.initials: A
authors.lastname: Saraya
authors.forename: Aekkapol
authors.initials: A
authors.lastname: Mahavihakanont
authors.forename: Shanop
authors.initials: S
authors.lastname: Shuangshoti
authors.forename: Nuntaporn
authors.initials: N
authors.lastname: Sittidetboripat
authors.forename: Tayard
authors.initials: T
authors.lastname: Deesudchit
authors.forename: Michael
authors.initials: M
authors.lastname: Callahan
authors.forename: Supaporn
authors.initials: S
authors.lastname: Wacharapluesadee
authors.forename: Henry
authors.initials: H
authors.lastname: Wilde
authors.forename: Thiravat
authors.initials: T
authors.lastname: Hemachudha
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood*; D001927:Brain Diseases / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D004660:Encephalitis / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D050031:Hashimoto Disease / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013785:Thailand / Q000453:epidemiology; D055815:Young Adult
chemical_list: D001323:Autoantibodies