Autoimmune encephalitis: the first observational study from Iran

Background Even within the most populous countries in the Middle East, such as Iran, autoimmune encephalitis cases have been rarely reported. Objective We aimed to describe the demographic, clinical, and paraclinical characteristics of Iranian patients with autoimmune encephalitis positive for anti-neuronal autoantibodies. Methods This cross-sectional study included all patients diagnosed with autoimmune encephalitis and referred to our hospital, in Isfahan, Iran, from March 2016 to May 2020. Patients’ demographic, clinical, laboratory, radiological, and electroencephalographic features were obtained from their medical records. Results We identified a total of 39 (21 females, 53.8%) patients with autoimmune encephalitis (mean age = 34.9 ± 12.8 years). The most commonly detected antibody was anti-NMDAR ( n = 26, 66.7%), followed by anti-GABA B R ( n = 8, 20.5%), anti-Zic4 ( n = 4, 10.3%), and anti-GAD65 ( n = 1, 2.6%) antibodies, in descending order of frequency. Two anti-NMDAR-positive patients had a history of systemic lupus erythematosus (SLE), and four had a prior history of herpes simplex encephalitis. Clinical presentations in patients positive for anti-Zic4 antibodies included cognitive decline ( n = 4, 100%), seizures ( n = 3, 75%), parkinsonism ( n = 1, 25%), and stiff-person syndrome ( n = 1, 25%). Conclusion This was the first case series of Iranian patients with autoimmune encephalitis with some interesting observations, including SLE-associated anti-NMDAR encephalitis, as well as an unusual concurrence of anti-Zic4 antibody positivity and cognitive problems, seizures, parkinsonism, and stiff-person syndrome.