Anti-N-methyl-d-aspartate receptor encephalitis in a patient with a 7-year history of being diagnosed as schizophrenia: complexities in diagnosis and treatment

Abstract

Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis is a form of autoimmune encephalitis associated with antibodies against the NR1 subunits of NMDARs. Although new-onset acute prominent psychotic syndromes in patients with NMDAR encephalitis have been well documented, there is a lack of case studies on differential diagnosis and treatment of anti-NMDAR encephalitis after a long-term diagnostic history of functional psychotic disorders. The present study reports an unusual case of anti-NMDAR encephalitis. The patient had been diagnosed with schizophrenia 7 years earlier, and was currently hospitalized for acute-onset psychiatric symptoms. The diagnosis became unclear when the initial psychosis was confounded with considerations of other neurotoxicities (such as neuroleptic malignant syndrome). Finally, identification of specific immunoglobulin G NR1 autoantibodies in the cerebrospinal fluid and greater effectiveness of immunotherapy over antipsychotics alone (which has been well documented in anti-NMDAR encephalitis) indicated the diagnosis of anti-NMDAR encephalitis in this case. Based on the available evidence, however, the relationship between the newly diagnosed anti-NMDAR encephalitis and the seemingly clear, long-term history of schizophrenia in the preceding 7 years is uncertain. This case report illustrates that psychiatrists should consider anti-NMDAR encephalitis and order tests for specific immunoglobulin G NR1 autoantibodies in patients presenting with disorientation, disturbance of consciousness, cognitive deficit, dyskinesia, autonomic disturbance, or rapid deterioration, even with a seemingly clear history of a psychiatric disorder and no specific findings on routine neuroimaging, electroencephalography, or cerebrospinal fluid tests in the early stage of the illness.

Case report of anti-N-methyl-D-aspartate receptor encephalitis in a middle-aged woman with a long history of major depressive disorder

“…A 33-year-old woman with anti-NMDAR encephalitis also demonstrated normal EEG [ 8 ]. The previous studies indicated that non-specific findings have been described in EEG [ 10 , 16 ]. So, diagnosis of anti-NMDAR encephalitis remains a challenge according to single laboratory study.…”

“…Most patients initially seek help from a psychiatrist, but the disorder is difficult to recognize because psychosis is evident but acute-onset psychiatric episodes are typically absent. Schizophrenia has been reported in several patients who later turned out to have encephalitis [ 10 ]. To our knowledge, only one case has been reported in which the disorder was detected in a patient (16-year-old girl) previously diagnosed with severe depression [ 11 ].…”

A patient with a long history of relapsing psychosis and mania presenting with anti-NMDA receptor encephalitis ten years after first episode

“…To our knowledge, this is the second comprehensive description of a patient with long-term diagnosis of mania and multiple relapses of psychiatric symptoms, in which the last episode was diagnosed as anti-NMDAR encephalitis. 1 This case is important for several reasons. Firstly, diagnosis was delayed because neuropsychiatric symptoms were attributed to a previously existing, long-standing psychiatric disorder.…”

Anti-N-Methyl-D-aspartate Receptor Encephalitis: A Severe, Potentially Reversible Autoimmune Encephalitis

“…The clinical manifestations are variable and sometimes easily misdiagnosed with viral encephalitis [ 39 ], psychosis [ 41 – 43 ], epilepsy, or other diseases, such as Hashimoto's encephalopathy [ 44 ] and Rasmussen syndrome [ 45 ]. Thus, it is a challenge to the psychiatrists, neurologists, and emergency physicians, as well as gynecologists and oncologists because of the association with teratoma or other tumors.…”