Abstract Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis, a subtype of autoimmune encephalitis, presents with a rapid onset of psychiatric and neurological symptoms. Findings include cerebrospinal fluid (CSF) with lymphocytosis or oligoclonal bands, an electroencephalograph with slow waves, and often a normal MRI of the brain. Diagnosis is confirmed by a positive IgG antibody against the NMDA receptor in the CSF. Forty-five percent and twenty-five percent of all patients have concurrent teratoma and Herpes Simplex encephalitis, respectively. Treatment includes high-dose steroids, intravenous immunoglobulin (IVIG), plasma exchange (PLEX), rituximab, and tumor resection. We present a case of delayed diagnosis of anti-NMDAR encephalitis. With an appropriate standard of treatment, as well as early initiation of rituximab, she had an unexpectedly rapid recovery. A 21-year-old Hispanic female with a history of recent diagnosis of seizure disorder and peripheral neuropathy presented with aggressive behavior, mutism, and altered mentation. Ischemic, hemorrhagic, metabolic, infectious, and epileptic etiologies were ruled out. A diagnosis of primary psychiatric disorder was made, and she was discharged on second-generation antipsychotics. However, the patient shortly returned to the hospital for uncontrolled seizures and catatonia. After two weeks of no clinical improvement with antipsychotic and antiepileptic medication, autoimmune encephalitis workups were initiated, which confirmed the diagnosis of anti-NMDAR encephalitis with a positive anti-NMDA receptor antibody in the cerebrospinal fluid. This delay in diagnosis was due to an overfocus on the separation of her neurological and psychiatric symptoms. Once both symptoms were seen as one cohesive etiology, she was started on high-dose steroids, IVIG, and PLEX, but with only slight improvement. The first dose of rituximab was administered shortly after the onset of initial treatment. Significant clinical improvement was noted two weeks after the second dose. She presented to the outpatient clinic four weeks after discharge, with a surprising improvement in her independent function, communication, and behavior. Anti-NMDAR encephalitis typically presents with neurological and psychiatric symptoms with a variable timeline. Delayed treatment of anti-NMDAR encephalitis often results in significant residual deficits in daily functioning. Although rare, clinicians should consider autoimmune encephalitis in the differential when psychiatric and neurological symptoms coexist. Once other causes have been ruled out, it is crucial to initiate treatment early, while simultaneously ruling out teratoma and HSV encephalitis. In cases of delayed diagnosis, consideration should be given to the early initiation of rituximab. As seen in our patient, aggressive management of delayed diagnosis of anti-NMDAR encephalitis can drastically improve both short-term and long-term function. This abstract is funded by: none
Yin et al. (Fri,) studied this question.