Late relapse of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis: a case report.

Background: Anti-N-methyl-D-aspartate receptor encephalitis is a sporadic autoimmune disorder of the brain that presents in a variety of neuropsychiatric manifestations, including seizures, psychosis, and alterations in behavior. N-methyl-D-aspartate receptor is primarily seen in young females. Although this disease can be treated, it can relapse in rare cases. Relapsing typically occurs within the early years following the initial episode and is exceedingly rare after 5 years.

Case Presentation: In this case study, we report on a 16-year-old Iranian female experiencing a relapse of anti-N-methyl-D-aspartate receptor encephalitis 8 years after her initial diagnosis. She was admitted to the hospital with dysphasia (a speech disorder) and dyslexia (reading and writing impairment). A thorough clinical evaluation revealed the presence of anti-glutamate receptor type N-methyl-D-aspartate receptor antibodies in her serum and cerebrospinal fluid, confirming the diagnosis. Following treatment with immunotherapy and plasmapheresis, she made a complete recovery.

Conclusion: This case of relapsing anti-N-methyl-D-aspartate receptor encephalitis, occurring more than 5 years after the initial episode, is exceptionally rare. This late relapse underscores the importance of long-term follow-up for patients with this condition.