Cycloid psychosis as a psychiatric expression of anti-NMDAR encephalitis. A systematic review of case reports accomplished with the authors' cooperation.

OBJECTIVE: We reviewed the psychotic symptoms of anti-NMDA receptor encephalitis (NMDARE) to differentiate its presentation from those found in a primary psychiatric disorder. We hypothesized that the cycloid psychosis (CP) phenotype would be a frequent clinical presentation in the psychiatric phase of NMDARE. METHOD: A systematic literature review in PubMed of all case reports published on NMDARE was performed from database inception to March 2020. We included all cases where psychotic symptoms were reported and whose diagnoses were confirmed by the presence of anti-NMDAR antibodies in the cerebrospinal fluid (CSF). An email including a short test (CP phenotype, Perris and Brockington's criteria) was sent to all case report authors asking them to describe the psychotic symptoms. RESULTS: We identified 335 case reports fulfilling our criteria, and the authors of 200 replied. Our analyses were based exclusively on those answers and data extracted from the articles. Median patient age was 25 years (+-11.4), 81% were female, and 39% had an ovarian teratoma. A complete CP phenotype was identified in 175 patients (87%). These were acute psychotic episodes with a sudden onset and a fluctuating clinical pattern mostly characterized by confusion (97%), delusions (75%), hallucinations (69%), motility disturbances (87%), and mood oscillations (80%). CONCLUSION: The complete CP phenotype was frequently the expression of psychotic symptoms in NMDARE. We suggest that patients with a first psychotic episode who initially exhibit the CP phenotype should undergo CSF analysis to determine whether antibodies against neuronal cell surface or synaptic receptors are present to rule out a possible diagnosis of autoimmune encephalitis.

Encefalitis antirreceptor de NMDA. Diagnóstico y tratamiento precoz en pacientes con sintomatología psicótica aguda-subaguda / Anti-NMDA receptor encephalitis. Early diagnosis and treatment in patients with acute-subacute psychotic symptoms

Introducción. La encefalitis por anticuerpos antirreceptor de NMDA es una entidad aguda y grave, cuya rápida identificación y tratamiento puede comportar recuperaciones sin secuelas. Es más prevalente en mujeres jóvenes y a menudo está asociada a un tumor subyacente. Los síntomas iniciales son habitualmente psiquiátricos y en días o semanas adquieren el perfil neurológico característico. Casos clínicos. Tres mujeres, de 17, 23 y 35 años, que ingresaron en el Servicio de Psiquiatría con clínica psicótica aguda. La mala respuesta a los antipsicóticos, las fluctuaciones del nivel de conciencia, la disautonomía y las crisis epilépticas fueron los síntomas que despertaron la sospecha clínica. El líquido cefalorraquídeo mostró leve pleocitosis y positividad para los anticuerpos antirreceptor de NMDA en todas las pacientes. Sólo una mostró alteraciones en la resonancia magnética cerebral, y dos, el patrón electroencefalográfico extreme delta brush. En todas se diagnosticó un teratoma ovárico, que fue resecado antes del mes. Dos se recuperaron sin secuelas y la tercera, a los seis meses del alta, presenta secuelas cognitivas. Conclusiones. Los casos descritos comenzaron con clínica psicótica aguda. La evolución psiquiátrica atípica y la clínica neurológica alertaron de la posibilidad de una encefalitis. El reconocimiento de la enfermedad y la coordinación entre servicios es fundamental para un diagnóstico y tratamiento precoz. El análisis sistemático de líquido cefalorraquídeo en pacientes con un primer episodio psicótico agudo-subagudo contribuiría a adelantar el diagnóstico. En mujeres jóvenes hay que buscar siempre un teratoma ovárico u otro tumor asociado

Introduction. Encephalitis due to anti-NMDA receptor antibodies is an acute and severe condition, which, if identified and treated quickly, can entail recovery without any sequelae. It is more prevalent in young females and is often associated with an underlying tumour. The initial symptoms are usually of a psychiatric nature, and in a matter of days or weeks take on a characteristic neurological profile. Case reports. We report the cases of three women, 17, 23 and 35 years of age, who were admitted to Psychiatry with acute psychotic clinical features. The poor response to antipsychotics, the fluctuations in the level of consciousness, dysautonomia and epileptic seizures were the symptoms that led to the clinical suspicion. The cerebrospinal fluid revealed slight pleocytosis and gave positive for anti-NMDA receptor antibodies in all cases. Only one patient displayed alterations in the magnetic resonance brain scan, and in two cases there was an extreme delta brush electroencephalographic pattern. All three women were diagnosed with an ovarian teratoma which was resectioned within a month. Two of the patients recovered without any sequelae, and the third presents cognitive sequelae six months after being discharged. Conclusions. The cases described began with an acute psychotic clinical picture. The atypical psychiatric progression and the neurological symptoms indicated the possible presence of encephalitis. Recognition of the disease and coordination among the different services is essential for early diagnosis and treatment. The systematic analysis of cerebrospinal fluid in patients with a first acute-subacute psychotic episode would help to reach a diagnosis sooner. In young women, a search must always be carried out for an ovarian teratoma or other associated tumour

Considerations of psychotic symptomatology in anti-NMDA encephalitis: Similarity to cycloid psychosis.

Most patients with anti-NMDA receptor (NMDAR) encephalitis present with acute psychosis which is difficult to differentiate from psychotic episodes related to a primarily psychiatric disease. A precise description of the psychiatric phenotype of this disease would greatly facilitate the early diagnosis of these patients. We provide here a detailed description of three of these patients and the similarity of the clinical features with cycloid psychosis. All three patients met Perris and Brockington's criteria for cycloid psychosis in the initial phase of the autoimmune process, including among other an acute and polysymptomatic onset, polymorphous psychotic symptomatology, mood swings, and changes in psychomotricity. In addition, none of the patients had experienced an extended psychiatric prodromal phase. External stress factors preceded symptom onset in the three patients, who also showed common base personality traits and intolerance to a range of antipsychotic treatments. Complementary studies disclosed that the three patients had ovarian teratoma as well as abnormal EEG, and CSF antibodies against NMDAR. Patients with anti-NMDAR encephalitis may present with clinical features that resemble cycloid psychosis. In addition, our patients did not have prodromal history of psychiatric symptoms and showed intolerance to antipsychotic medication, which all should raise concern for anti-NMDAR encephalitis, prompting CSF antibody testing.