Clinical Significance of Delirium With Catatonic Signs in Patients With Neurological Disorders.

OBJECTIVE: According to DSM-5, catatonia and delirium are mutually exclusive clinical syndromes. The investigators explored the co-occurrence of delirium and catatonia (i.e., catatonic delirium) and the clinical significance of this syndrome with a sample of neurological patients. METHODS: This prospective study with consecutive sampling included patients diagnosed with delirium at the National Institute of Neurology and Neurosurgery of Mexico. DSM-5 criteria for delirium, the Confusion Assessment Method, and the Delirium Rating Scale-Revised-98 were used to select and characterize patients. Catatonia was assessed using the Bush-Francis Catatonia Rating Scale and DSM-5 diagnostic criteria. Logistic regression analysis was performed to identify etiological factors associated with catatonic delirium. RESULTS: A total of 264 patients with delirium were included, 61 (23%) of whom fulfilled the criteria for catatonia and delirium simultaneously. Brain tumors, subarachnoid hemorrhage, acute hydrocephalus, and ischemic stroke were associated with delirium without catatonic signs. Catatonic delirium was observed among patients with encephalitis, epilepsy, brain neoplasms, and brain tuberculosis. After multivariate analysis, the association between catatonic delirium and encephalitis (both viral and anti-N-methyl-d-aspartate receptor [NMDAR]) was confirmed. CONCLUSIONS: Delirium is a common complication of neurological diseases, and it can coexist with catatonia. The recognition of catatonic delirium has clinical significance in terms of etiology, as it was significantly associated with viral and anti-NMDAR encephalitis.

[Neuropsychiatric aspects of anti-NMDA receptor encephalitis]. / Aspectos neuropsiquiátricos de la encefalitis por anticuerpos contra el receptor NMDA.

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is a potentially lethal clinical entity that belongs to the group of antibody-mediated encephalitis against synaptic proteins. It shows IgG antibodies against the NR1 subunit of the NMDA receptor (NMDA-R), which have been associated with psychiatric and neurological symptoms that develop in stages in the course of the disease. The predominance of neuropsychiatric symptoms in the early stages of the disease results in an increased number of patients that search for psychiatric evaluation as their first contact with the health system. For this reason, it is vital for physicians to recognize this entity as an important differential diagnosis in their clinical practice because, despite the severity of this condition, more than 75 % of patients achieve a substantial recovery with appropriate and timely treatment. We present a review of the literature on this disease, with special emphasis on the neuropsychiatric aspects.

La encefalitis por anticuerpos contra el receptor anti-N-metil-D-aspartato (NMDA) es una entidad clínica potencialmente letal perteneciente al grupo de las encefalitis mediadas por anticuerpos contra proteínas sinápticas. En esta se demuestran anticuerpos IgG contra el receptor de NMDA (NMDAr), asociados con síntomas psiquiátricos y neurológicos que se desarrollan por estadios en el curso de la enfermedad. El predominio de síntomas neuropsiquiátricos en las etapas tempranas provoca que un elevado porcentaje de pacientes busquen evaluación psiquiátrica como un primer contacto con el sistema de salud. Por esta razón, es vital que los médicos reconozcan esta entidad como un diagnóstico diferencial importante en la práctica clínica, puesto que, a pesar de la gravedad de esta condición, más de 75 % de los pacientes logra una recuperación sustancial con un tratamiento adecuado y oportuno. Presentamos una revisión de la literatura sobre esta enfermedad, con especial énfasis en los aspectos neuropsiquiátricos.

[Autoinmune psychosis]. / Psicosis autoinmune.

With the advent of the description of autoimmune encephalitis by different neuronal cell-surface antibodies (anti-NMDAr, among others) and that psychosis may be the only manifestation without neurological symptoms (epilepsy, movement disorders, autonomic dysfunction, altered state of consciousness) in 6.5 % of patients, the term "autoimmune psychosis" has become remarkably interesting among researchers. In 2020, an international consensus for the description and diagnostic approach of autoimmune psychosis was created. Through this consensus, by taking different criteria into account, the definition of autoimmune psychosis was proposed at different degrees of certainty (possible, probable, and defined). The purpose of these criteria is to underpin the autoimmune origin in patients who present psychosis with atypical characteristics, thus justifying the realization of laboratory studies and complementary clinical tests (lumbar puncture, electroencephalogram, and magnetic resonance imaging of the brain); in addition, these criteria are applied in patients with psychosis without neurological symptoms that do not fully meet the criteria of autoimmune encephalitis. As in autoimmune encephalitis, the early initiation of immunotherapy has a direct impact on the functional prognosis of patients, so an early initiation of treatment must be considered in clinical scenarios of probable or definite autoimmune psychosis.

Con el advenimiento de la descripción de las encefalitis autoinmunes por diferentes anticuerpos neuronales de superficie (anti-NMDAr, entre otros) y que la psicosis puede ser la única manifestación sin síntomas neurológicos (epilepsia, alteraciones del movimiento, disautonomías, alteración del despierto) en 6.5 % de los pacientes, el término psicosis autoinmune ha retomado gran interés entre los investigadores. En 2020 se creó un consenso internacional para la descripción del término "psicosis autoinmune" y su abordaje diagnóstico. A través de este consenso, considerando diferentes criterios, se propone la definición de psicosis autoinmune en diferentes grados de certeza (posible, probable y definida). La finalidad de estos criterios es sustentar el origen autoinmune en pacientes que presenta psicosis con características atípicas, justificando así la realización de estudios de laboratorio y gabinete complementarios (punción lumbar, electroencefalograma, imagen de resonancia magnética de encéfalo); además, estos criterios se aplican a pacientes con psicosis sin síntomas neurológicos que no cumplen completamente con los criterios de encefalitis autoinmune. El inicio temprano de la inmunoterapia impacta directamente en el pronóstico funcional de los pacientes; se debe considerar el inicio temprano de tratamiento en cuadros clínicos de psicosis autoinmune probable o definida.

Neuropsychiatry of Susac syndrome: A case report.

Susac syndrome is a rare clinical condition, possibly mediated by an autoimmune process; the classic triad is composed of retinopathy, decreased hearing acuity and neuropsychiatric symptoms (encephalopathy). There are few cases reported with neuropsychiatric symptoms as the main manifestation. We present a case of Susac syndrome in a 34-year-old female with a predominance of neuropsychiatric symptoms, characterised by partial Klüver-Bucy syndrome, apathy syndrome, pathological laughter and crying, and cognitive dysfunction predominantly affecting attention, which showed a qualitative improvement with the use of immunological therapy. This case report highlights the importance of neuropsychiatric manifestations as clinical presentation in patients with neurological conditions.

Neuropsiquiatría del síndrome de Susac: a propósito de un caso / Neuropsychiatry of Susac Syndrome: a Case Report

RESUMEN El síndrome de Susac es una entidad clínica poco frecuente, posiblemente mediada por un proceso autoinmune; la tríada clásica se compone de retinopatía, disminución en la agudeza auditiva y síntomas neuropsiquiátricos (encefalopatía). Hay pocos casos descritos con sintomatología neuropsiquiátrica como la sintomatología principal. Presentamos un caso de síndrome de Susac, que corresponde a una mujer de 34 arios, con predominio de sintomatologia neuropsiquiátrica, caracterizada por un síndrome de Klüver-Bucy parcial, un síndrome apático, risa y llanto patológico y alteraciones cognitivas de predominio atencional; dichos síntomas mejoraron cualitativamente con el uso de terapia inmunológica. Este caso revela la importancia de las manifestaciones neuropsiquiátricas como presentación clínica en pacientes con entidades neurológicas.

ABSTRACT Susac syndrome is a rare clinical condition, possibly mediated by an autoimmune process; the classic triad is composed of retinopathy, decreased hearing acuity and neuropsychiatric symptoms (encephalopathy). There are few cases reported with neuropsychiatric symptoms as the main manifestation. We present a case of Susac syndrome in a 34-year-old female with a predominance of neuropsychiatric symptoms, characterised by partial Klüver-Bucy syndrome, apathy syndrome, pathological laughter and crying, and cognitive dysfunction predominantly affecting attention, which showed a qualitative improvement with the use of immunological therapy. This case report highlights the importance of neuropsychiatric manifestations as clinical presentation in patients with neurological conditions.

Neuropsychiatry of Susac Syndrome: a Case Report. / Neuropsiquiatría del síndrome de Susac: a propósito de un caso.

Susac syndrome is a rare clinical condition, possibly mediated by an autoimmune process; the classic triad is composed of retinopathy, decreased hearing acuity and neuropsychiatric symptoms (encephalopathy). There are few cases reported with neuropsychiatric symptoms as the main manifestation. We present a case of Susac syndrome in a 34-year-old female with a predominance of neuropsychiatric symptoms, characterised by partial Klüver-Bucy syndrome, apathy syndrome, pathological laughter and crying, and cognitive dysfunction predominantly affecting attention, which showed a qualitative improvement with the use of immunological therapy. This case report highlights the importance of neuropsychiatric manifestations as clinical presentation in patients with neurological conditions.

Delirious mania as a frequent and recognizable neuropsychiatric syndrome in patients with anti-NMDAR encephalitis.

BACKGROUND: Previous case reports showed that delirious mania could be one of the many neuropsychiatric presentations of Anti-N-methyl-d-aspartate receptor encephalitis (ANMDARE). OBJECTIVE: To evaluate the frequency of delirious mania and its associated factors in ANMDARE. METHOD: A prospective study, including all patients with ANMDARE admitted to the National Institute of Neurology and Neurosurgery of Mexico, from January 2014 to April 2019. The diagnosis of delirious mania was established when diagnostic criteria for mania and delirium were fulfilled simultaneously. RESULTS: 79 patients with definitive ANMDARE were included. Delirious mania was identified in 20 (25.3%) of these patients. Catatonia, psychomotor agitation, disinhibition, impulsivity, and grandiose delusions were significantly associated with delirious mania. Also, a lower frequency of EEG abnormalities, absence of extreme delta brush, and a shorter hospital stay was observed in these patients. CONCLUSION: Delirious mania proved to be a frequent neuropsychiatric presentation of ANMDARE, and its presence should warn the physician about the possibility of this diagnosis. It was mainly associated with higher rates of catatonia, psychomotor agitation, disinhibition, and psychotic symptoms. The lack of recognition of delirious mania as a neuropsychiatric presentation in ANMDARE may be a source of diagnostic and therapeutic errors, as most physicians associate this with bipolar disorder.

Longitudinal atrophy characterization of cortical and subcortical gray matter in Huntington's disease patients.

Huntington's disease (HD) is an inherited neurodegenerative disease with clinical manifestations that involve motor, cognitive and psychiatric deficits. Cross-sectional magnetic resonance imaging (MRI) studies have described the main cortical and subcortical macrostructural atrophy of HD. However, longitudinal studies characterizing progressive atrophy are lacking. This study aimed to describe the cortical and subcortical gray matter atrophy using complementary volumetric and surface-based MRI analyses in a cohort of seventeen early HD patients in a cross-sectional and longitudinal analysis and to correlate the longitudinal volumetric atrophy with the functional decline using several clinical measures. A group of seventeen healthy individuals was included as controls. After obtaining structural MRIs, volumetric analyses were performed in 36 cortical and 7 subcortical regions of interest per hemisphere and surface-based analyses were performed in the whole cortex, caudate, putamen and thalamus. Cross-sectional cortical surface-based and volumetric analyses showed significant decreases in frontoparietal and temporo-occipital cortices, while subcortical volumetric analysis showed significant decreases in all subcortical structures except the hippocampus. The longitudinal surface-based analysis showed widespread cortical thinning with volumetric decreases in the superior frontal lobe, while a subcortical volumetric decrease occurred in the caudate, putamen and thalamus with shape deformation on the anterior, medial and dorsal side. Functional capacity and motor status decline correlated with caudate progressive atrophy, while cognitive decline correlated with left superior frontal and right paracentral progressive atrophy. These results provide new insights into progressive volumetric and surface-based morphometric atrophy of gray matter in HD.

Characterisation and outcome of neuropsychiatric symptoms in patients with anti-NMDAR encephalitis.

BACKGROUND: Encephalitis due to anti-N-methyl-D-aspartate receptor antibodies (ANMDARE) is the most frequent immune-mediated encephalitis. It is distinguished by the subacute onset of neuropsychiatric symptoms. OBJECTIVE: To evaluate the characteristic neuropsychiatric symptoms and their outcome in patients diagnosed with ANMDARE. METHODS: This was a prospective, longitudinal study in patients with a diagnostic suspicion of ANMDARE that presented to the National Institute of Neurology from March 2018 to February 2019. A comparative analysis of two groups (positive N-methyl-D-aspartate receptor [NMDAR] vs. negative NMDAR antibodies in cerebrospinal fluid [CSF]) was done on admission and at discharge. Neuropsychiatric systematic assessments included the Neuropsychiatric Inventory Questionnaire, the Bush Francis Catatonia Rating Scale, the Confusion Assessment Method Severity, the Montreal Cognitive Assessment, and the Overt Agitation Severity Scale. RESULTS: 24 individuals were analysed: 14 had positive NMDAR antibodies, and 10 had negative NMDAR antibodies in CSF. On admission, agitation/aggression, euphoria/exaltation, and disinhibition were more common in patients with positive antibodies. Excited catatonia and delirium were diagnosed more frequently in patients with positive antibodies. At discharge, there was an important decrease in neuropsychiatric symptoms, but substantial cognitive impairment remained. The mean hospitalisation length was 41.71 (SD 39.33) days for patients with definitive ANMDARE (p 0.259). CONCLUSIONS: Neuropsychiatric symptoms profile in ANMDARE was associated with the early onset of euphoria/exaltation and disinhibition, accompanied by marked psychomotor agitation. When ANMDARE was suspected, the presence of excited-type catatonia and delirium showed a tendency to predict definitive ANMDARE. At discharged, most patients recovered from catatonia, delirium, and psychosis, but marked cognitive symptoms, anxiety, and depression persisted at discharge.

FDG-PET in Cotard syndrome before and after treatment: can functional brain imaging support a two-factor hypothesis of nihilistic delusions?

Introduction: Cotard syndrome is a neuropsychiatric entity recognised by the presence of nihilistic delusions. Although different models have been proposed for the development of monothematic delusions, including Cotard syndrome, functional neuroanatomical models are lacking.Methods: A case report of a 19-year old male with autoimmune encephalitis and Cotard syndrome, in whom Positron Emission Tomography (18F-FDG-PET) scans were performed before and after successful treatment with electroconvulsive therapy (ECT), is presented. Literature review on brain imaging is provided to discuss a functional neuroanatomical model of Cotard syndrome, in accordance with the two-factor theory of delusions.Results: The patient's 18F-FDG-PET showed marked insular and prefrontal metabolic abnormalities. Except for insular hypometabolism, metabolic abnormalities improved after ECT. Previously reported structural neuroimaging studies in Cotard syndrome showed a predominance of right hemisphere lesions, in which frontal lobes were more frequently involved, followed by parietal and temporal lesions. Functional neuroimaging studies reported abnormalities in frontoparietal circuits as well as midline structures included in the "default mode network".Conclusions: Abnormalities in the functioning of the insular cortex and the prefrontal cortex could be related to the development of nihilistic delusions when a two-factor theory of delusions is considered.

Theory of mind impairment in Huntington's disease patients and their relatives.

Huntington disease (HD) is an autosomal dominant genetic disorder characterized by movement disorders, cognitive impairment, and psychiatric symptoms. Relatives of HD patients experience a great burden as the latter suffer from altered social conduct and deterioration of interpersonal relationships. Theory of mind (ToM) is the ability to attribute mental states (to oneself and others). Deficits in ToM are thought to have a role in the changes in empathy and interpersonal difficulties that HD patients face. METHODS We conducted a cross sectional study to compare ToM task scores of patients with mild to moderate HD, their relatives (spouse or at-risk first-degree relative with a negative gene test) and controls.Individuals with dementia or depression were excluded. The ToM test battery included Spanish versions of the Reading Mind in the Eyes Test (RMET), Happé's Strange Stories (Social and Physical Stories subtests) and the Hinting Task. RESULTS The series comprised 12 HD patients, 12 relatives and 12 controls. The HD patients showed lower affective ToM scores than controls (RMET 19 [3.5] vs 23.9 [2.7], p = 0.016). Cognitive ToM tasks scores were lower in HD patients than controls as well (Happé's Social Stories 9 [2.6] vs 13 [1.9], p = 0.001; the Hinting Task 13.6 [3.4] vs 17.5 [4.0], p = 0.009). In the Hinting Task, HD relatives had lower scores in than controls (13 [3.2] vs 17.5 [4.0], p = 0.009) and similar scores to controls in the rest of the battery. CONCLUSION The HD patients with mild to moderate disease severity and their relatives show ToM deficits.

Are We Missing Subtle Forms of Anti-N-Methyl-D-Aspartate Encephalitis With the Current Diagnostic Approach? A Case Report.

Encephalitis related to antibodies against the N-methyl-D-aspartate receptor (NMDAr) is a recently described clinical entity in which IgG autoantibodies against the NR1 subunit of the NMDAr lead to the appearance of complex neuropsychiatric symptoms. As psychiatric symptoms predominate in early stages, anti-NMDAr encephalitis is frequently mistaken as a primary psychiatric disorder which delays treatment and has serious consequences for patients. This report presents the case of a 24-year-old woman with a subacute onset of psychotic and catatonic symptoms in whom current diagnostic criteria for probable anti-NMDAr encephalitis were not fulfilled. On the basis of the red flags that have been proposed to raise suspicion of anti-NMDAr encephalitis, a study of fluorodeoxyglucose positron emission tomography was requested and demonstrated bilateral occipital hypometabolism consistent with clinical suspicion of anti-NMDAr encephalitis. Once the appropriate treatment was established, the patient recovered completely. This case supports the need to maintain clinical suspicion of anti-NMDAr encephalitis, even when conventional diagnostic tests have been normal. Psychiatrists should be familiar with this entity to promote timely diagnosis and prompt treatment.

Theory of mind impairment in Huntington's disease patients and their relatives / Déficits en teoría de la mente en pacientes con enfermedad de Huntington y sus familiares

ABSTRACT Huntington disease (HD) is an autosomal dominant genetic disorder characterized by movement disorders, cognitive impairment, and psychiatric symptoms. Relatives of HD patients experience a great burden as the latter suffer from altered social conduct and deterioration of interpersonal relationships. Theory of mind (ToM) is the ability to attribute mental states (to oneself and others). Deficits in ToM are thought to have a role in the changes in empathy and interpersonal difficulties that HD patients face. Methods: We conducted a cross sectional study to compare ToM task scores of patients with mild to moderate HD, their relatives (spouse or at-risk first-degree relative with a negative gene test) and controls.Individuals with dementia or depression were excluded. The ToM test battery included Spanish versions of the Reading Mind in the Eyes Test (RMET), Happé's Strange Stories (Social and Physical Stories subtests) and the Hinting Task. Results: The series comprised 12 HD patients, 12 relatives and 12 controls. The HD patients showed lower affective ToM scores than controls (RMET 19 [3.5] vs 23.9 [2.7], p = 0.016). Cognitive ToM tasks scores were lower in HD patients than controls as well (Happé's Social Stories 9 [2.6] vs 13 [1.9], p = 0.001; the Hinting Task 13.6 [3.4] vs 17.5 [4.0], p = 0.009). In the Hinting Task, HD relatives had lower scores in than controls (13 [3.2] vs 17.5 [4.0], p = 0.009) and similar scores to controls in the rest of the battery. Conclusion: The HD patients with mild to moderate disease severity and their relatives show ToM deficits.

RESUMEN La enfermedad de Huntington (EH) es una enfermedad genética autosómica dominante caracterizada por trastornos del movimiento, deterioro cognitivo y síntomas psiquiátricos. Los familiares de las personas con EH experimentan gran carga dado que los pacientes sufren de conducta social alterada y deterioro de relaciones interpersonales. La Teoría de la mente (ToM) consiste en la habilidad para atribuir estados mentales (a uno mismo o a otros). Se piensa que déficits en ToM tienen un rol en los cambios en empatia y en las dificultades interpersonales que los pacientes con EH enfrentan. Métodos: Condujimos un estudio transversal para comparar el desempeño en puntajes de tareas de ToM en pacientes con EH leve a moderada, sus familiares (pareja o familiar en riesgo con prueba genética negativa) y controles sanos. Se excluyó a sujetos con demencia o depresión. La batería de pruebas de ToM incluyó versiones en español de la prueba de lectura de la mente en los ojos (RMET), Historias Extrañas de Happé (subpruebas Social y Física) y Hinting Task. Resultados: La serie consistió de 12 pacientes con EH, 12 familiares y 12 controles. Los pacientes con EH mostraron puntajes menores de tareas de ToM afectiva que los controles (RMET 19 [3.5] vs 23.9 [2.7], p = 0.016). Los puntajes de tareas de ToM cognitiva fueron inferiores a los controles en los pacientes con EH (Historias Sociales de Happé 9 [2.6] vs 13 [1.9], p = 0.001; Hinting task 13.6 [3.4] vs 175 [4.0], p = 0.009). En la Hinting task los familiares de pacientes con EH mostraron puntajes inferiores que los de los controles (13 [3.2] vs 175 [4.0], p = 0.009) y puntajes similares a aquellos de los controles en el resto de la batería. Conclusión: Los pacientes con EH con enfermedad leve a moderada y sus familiares muestran déficits en tareas de ToM.

Banderas rojas para sospechar encefalitis anti-NMDAr en un primer episodio psicótico: reporte de dos casos / Red flags for suspecting anti-NMDAr encephalitis in a first psychotic episode: report of two cases

RESUMEN La encefalitis asociada a anticuerpos contra el receptor de N-metil-D-Aspartato (NMDAr) es una entidad clínica recientemente descrita con un número creciente de casos reporta dos. Los síntomas psiquiátricos en etapas tempranas de la enfermedad conforman un reto diagnóstico para el médico tratante. Presentamos dos casos clínicos: el caso clínico 1, un hombre de 26 arios y el caso clínico 2, un joven de 18 arios, ambos abordados como primer episodio de psicosis y hospitalizados en instituciones psiquiátricas. Posteriormente, ambos casos fueron diagnosticados como encefalitis anti-NMDAr. La alta prevalencia de síntomas psiquiátricos en la encefalis anti-NMDAr demanda a los médicos psiquiatras y neurólogos a tener un alto índice de sospecha en presencia de síntomas atípicos en pacientes evaluados por primer episodio de psicosis.

ABSTRACT Anti-N-methyl-D-Aspartate receptor (NMDAr) encephalitis is a recently described clinical entity with an increasing number of reported cases. Psychiatric symptoms in the early stages of the disease constitute a diagnostic challenge for the treating physician. We present two clinical cases: clinical case 1, a 26-year-old man, and clinical case 2, an 18-year-old man; both presented with a first episode of psychosis and were hospitalized as psychiatric disorders. Subsequently, both cases were diagnosed as anti-NMDAr encephalitis. The high prevalence of psychiatric symptoms in anti-NMDAr encephalitis forces psychiatrists and neurologists to have a high degree of suspicion in the presence of atypical symptoms in patients evaluated for the first episode of psychosis.

Catatonia in patients with anti-NMDA receptor encephalitis.

AIM: There is a lack of studies related to the frequency, phenomenology, and associated features of catatonic syndrome in patients with anti-NMDA receptor encephalitis (ANMDARE). This study aimed to measure the frequency of catatonia in this condition and to delineate its particular symptoms. METHODS: A prospective study was done with all inpatients who fulfilled the criteria of definite ANMDARE admitted to the National Institute of Neurology and Neurosurgery of Mexico from January 2014 to September 2018. The Bush-Francis Catatonia Rating Scale and Braünig Catatonia Rating Scale were administered at admission. RESULTS: Fifty-eight patients were included and catatonia was diagnosed in 41 of these patients (70.6%). Immobility, staring, mutism, and posturing were the most frequent catatonic signs. Catatonia was associated with delirium, hallucinations, psychomotor agitation, generalized electroencephalography dysfunction, and previous use of antipsychotics. Mortality was present in 10% of the total sample; it was associated with status epilepticus, and was less frequent in the catatonia group. After immunotherapy, all cases showed a complete recovery from catatonic signs. CONCLUSION: This systematic assessment of catatonic syndrome shows that it is a frequent feature in patients with ANMDARE as part of a clinical pattern that includes delirium, psychomotor agitation, and hallucinations. The lack of recognition of this pattern may be a source of diagnostic and therapeutic errors, as most physicians associate catatonia with schizophrenia and affective disorders.

Red flags for suspecting anti-NMDAr encephalitis in a first psychotic episode: report of two cases. / Banderas rojas para sospechar encefalitis anti-NMDAr en un primer episodio psicótico: reporte de dos casos.

Anti-N-methyl-D-Aspartate receptor (NMDAr) encephalitis is a recently described clinical entity with an increasing number of reported cases. Psychiatric symptoms in the early stages of the disease constitute a diagnostic challenge for the treating physician. We present two clinical cases: clinical case 1, a 26-year-old man, and clinical case 2, an 18-year-old man; both presented with a first episode of psychosis and were hospitalized as psychiatric disorders. Subsequently, both cases were diagnosed as anti-NMDAr encephalitis. The high prevalence of psychiatric symptoms in anti-NMDAr encephalitis forces psychiatrists and neurologists to have a high degree of suspicion in the presence of atypical symptoms in patients evaluated for the first episode of psychosis.