Anti-NMDA receptor encephalitis in Japan: long-term outcome without tumor removal

Serum cystatin C and anti-N-methyl-D-aspartate receptor encephalitis

BACKGROUND

Cystatin C (CysC) is associated with many neurodegenerative disorders and autoimmune diseases, but its relationship with anti-N-Methyl-D-aspartate receptor (anti-NMDAR) encephalitis is unknown.

METHODS

Serum levels of CysC were determined in 66 patients with anti-NMDAR encephalitis and 115 healthy controls. Of the 66 patients, 30 had a follow-up evaluation at 3 months after admission. Association of CysC with anti-NMDAR encephalitis and its clinical parameters were evaluated in the patients.

RESULTS

The serum levels of CysC were significantly lower in patients with anti-NMDAR encephalitis than in controls (0.70 ± 0.13 vs 0.83 ± 0.17 mg/mL, P < .001). Disease severity and disease duration were significantly associated with CysC levels. Furthermore, a follow-up evaluation revealed that after treatment anti-NMDAR encephalitis patients had significantly increased serum CysC levels (P < .001) and significantly decreased modified Rankin Scale (mRS) scores (P < .001) compared with before treatment. In addition, a significant negative correlation was observed between the change in CysC levels and the change in mRS scores (r = -.700, P < .001).

CONCLUSION

Our results show that the serum levels of CysC are associated with anti-NMDAR encephalitis and its clinical parameters and that the changes in CysC levels correlate with therapeutic effect. Therefore, our findings provide new insights into the association between serum CysC and anti-NMDAR encephalitis.

Evoked potential studies for predicting functional recovery in a case of acute necrotizing encephalopathy

Normal‐appearing evoked potentials during the acute stage of the disease despite persistent coma may predict subsequent functional recovery of the brain in a pediatric case of acute necrotizing encephalopathy, indicating that evoked potential studies are useful for predicting functional outcome of the brain.

[A case of limbic encephalitis associated with Sjögren's syndrome mimicking anti N-methyl D-aspartate receptor encephalitis]

A 25-year-old woman in her 37 weeks and 5 days pregnant presented with abnormal behavior and memory impairment following a high fever. Her manifestations were diagnosed as limbic encephalitis, and she delivered a baby by Cesarean section. In the operation, bilateral ovarian tumors were found and resected, though they were revealed as non-teratoma afterward. After operation, she became agitated, and started to present oral dyskinesia, intractable systemic myoclonus, central hypoventilation, and autonomic manifestations such as labile blood pressure, but her symptoms responded well to immunotherapy. Her clinical course was typical for anti-N-methyl D-aspartate (NMDA) receptor encephalitis, but anti-NMDA receptor antibody was not detected in her serum and CSF. On the other hand, anti SS-A antibody was positive in her serum, and the lip biopsy findings confirmed Sjögren's syndrome (SjS). Only several cases of SjS-associated limbic encephalitis have been reported, but none of them mimicked anti-NMDA receptor encephalitis. This patient indicates that SjS should be considered even in a case of limbic encephalitis with a typical clinical spectrum of anti-NMDAR encephalitis.

Resistance to eye opening in patients with disorders of consciousness

INTRODUCTION

Resistance to eye opening (REO) is a commonly encountered phenomenon in clinical practice. We aim to investigate whether REO is a sign of consciousness or a reflex in severely brain-injured patients.

METHODS

We recorded REO in chronic patients with disorders of consciousness during a multimodal diagnostic assessment. REO evaluations were performed daily in each patient and clinical diagnosis of unresponsive wakefulness syndrome (UWS), minimally conscious state with (MCS+) or without (MCS-) preserved language processing was made using the Coma Recovery Scale-Revised (CRS-R).

RESULTS

Out of 150 consecutive patients, 79 patients fit inclusion criteria. REO was seen in 19 patients (24.1%). At the group level, there was a significant relationship between the presence of REO and the level of consciousness. We also observed a difference in the repeatability of REO between patients in UWS, MCS- and MCS+. Out of 23 patients in UWS, six showed REO, in whom five showed atypical brain patterns activation.

CONCLUSION

Our findings suggest a voluntary basis for REO and stress the need for multiple serial assessments of REO in these patients, especially since most patients show fluctuating levels of consciousness.

Fulminant course in a patient with anti-N-methyl-D-aspartate receptor encephalitis with bilateral ovarian teratomas: A case report and literature review

RATIONALE

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is an autoimmune disorder that can be controlled and reversed by immunotherapy. The presentation of NMDA receptor encephalitis varies, but NMDA receptor encephalitis is seldom reported in patients with both bilateral teratomas and preexisting brain injury.

PATIENT CONCERNS

A 28-year-old female with a history of traumatic intracranial hemorrhage presented acute psychosis, seizure, involuntary movement, and conscious disturbance with a fulminant course. Anti-NMDA receptor antibody was identified in both serum and cerebrospinal fluid, confirming the diagnosis of anti-NMDA receptor encephalitis. Bilateral teratomas were also identified during tumor survey. DIAGNOSES:: anti-N-methyl-D-aspartate receptor encephalitis.

INTERVENTIONS

Tumor resection and immunotherapy were performed early during the course.

OUTCOMES

The patient responded well to tumor resection and immunotherapy. Compared with other reports in the literature, her symptoms rapidly improved without further relapse.

LESSONS

This case report demonstrates that bilateral teratomas may be related to high anybody titers and that the preexisting head injury may be responsible for lowering the threshold of neurological deficits. Early diagnosis and therapy are crucial for a good prognosis in such patients.

Clinical and pathogenic significance of IgG, IgA, and IgM antibodies against the NMDA receptor

OBJECTIVE

To determine the frequency and clinical relevance of immunoglobulin (Ig)G, IgA, and IgM N-methyl-d-aspartate receptor (NMDAR) antibodies in several diseases, and whether the IgG antibodies occur in disorders other than anti-NMDAR encephalitis.

METHODS

Evaluation of IgG, IgA, and IgM NMDAR antibodies in serum of 300 patients with anti-NMDAR encephalitis, stroke, dementia, schizophrenia, or seronegative autoimmune encephalitis. Antibodies and their effect on cultured neurons were examined with cell-based assays and brain and live neuronal immunostaining. Retrospective analysis of the clinical diagnoses of a cohort of 1,147 patients with IgG NMDAR antibodies identified since 2005.

RESULTS

Among the 300 patients studied, IgG NMDAR antibodies were only identified in those with anti-NMDAR encephalitis and all reacted with brain and live neurons. By cell-based assay, IgA or IgM antibodies were detected in 22 of 300 patients (7%) with different diseases, but only 10 (3%) reacted with brain and 7 (2%) with live neurons. In cultured neurons, IgG but not IgA or IgM antibodies caused a decrease of synaptic and extrasynaptic NMDAR. Among the cohort of 1,147 patients with IgG NMDAR antibodies, 1,015 (88.5%) had anti-NMDAR encephalitis, 45 (3.9%) a limited form of the disease, 41 (3.6%) autoimmune post-herpes simplex encephalitis, 37 (3.2%) overlapping syndromes (anti-NMDAR encephalitis and demyelinating disease), and 9 (0.8%) atypical encephalitic syndromes; none had schizophrenia.

CONCLUSIONS

IgG NMDAR antibodies are highly specific for anti-NMDAR encephalitis and cause a decrease of the levels of NMDAR. In contrast, IgA or IgM antibodies occur infrequently and nonspecifically in other diseases and do not alter the receptor levels.

Ketamine independently modulated power and phase-coupling of theta oscillations in Sp4 hypomorphic mice

Reduced expression of Sp4, the murine homolog of human SP4, a risk gene of multiple psychiatric disorders, led to N-methyl-D-aspartate (NMDA) hypofunction in mice, producing behavioral phenotypes reminiscent of schizophrenia, including hypersensitivity to ketamine. As accumulating evidence on molecular mechanisms and behavioral phenotypes established Sp4 hypomorphism as a promising animal model, systems-level neural circuit mechanisms of Sp4 hypomorphism, especially network dynamics underlying cognitive functions, remain poorly understood. We attempted to close this gap in knowledge in the present study by recording multi-channel epidural electroencephalogram (EEG) from awake behaving wildtype and Sp4 hypomorphic mice. We characterized cortical theta-band power and phase-coupling phenotypes, a known neural circuit substrate underlying cognitive functions, and further studied the effects of a subanesthetic dosage of ketamine on theta abnormalities unique to Sp4 hypomorphism. Sp4 hypomorphic mice had markedly elevated theta power localized frontally and parietally, a more pronounced theta phase progression along the neuraxis, and a stronger frontal-parietal theta coupling. Acute subanesthetic ketamine did not affect theta power in wildtype animals but significantly reduced it in Sp4 hypomorphic mice, nearly completely neutralizing their excessive frontal/parietal theta power. Ketamine did not significantly alter cortical theta phase progression in either wildtype or Sp4 hypomorphic animals, but significantly strengthened cortical theta phase-coupling in wildtype, but not in Sp4 hypomorphic animals. Our results suggested that the resting-state phenotypes of cortical theta oscillations unique to Sp4 hypomorphic mice closely mimicked a schizophrenic endophenotype. Further, ketamine independently modulated Sp4 hypomorphic anomalies in theta power and phase-coupling, suggesting separate underlying neural circuit mechanisms.

Management of Refractory Orofacial Dyskinesia Caused by Anti-N-methyl-d-aspartate Receptor Encephalitis Using Botulinum Toxin

The use of botulinum neurotoxin serotype A (BoNT-A) injections for the treatment of orofacial dyskinesia secondary to anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis is rarely reported. Here, we report a case of an urgent, successful management of severe orofacial dyskinesia in an 8-year-old girl with anti-NMDAR encephalitis using BoNT-A injection. The patient presented with de novo unilateral paroxysmal movement disorder progressing to generalized dystonia and repetitive orofacial dyskinesia. Diagnosis was confirmed by the presence of NMDAR antibodies in serum and cerebrospinal fluid. The orofacial dyskinesia worsened despite the aggressive use of first-line immunotherapy and second-line immunotherapy (rituximab), and resulted in a potentially fatal self-inflicted oral injury. We urgently attempted symptomatic management using BoNT-A injections in the masseter, and induced muscle paralysis using vecuronium. The patient’s severe orofacial dyskinesia was controlled. We observed the effects of the BoNT-A injections and a tapering off of the effects of vecuronium 10 days after the treatment. The movement disorder had improved significantly 4 weeks after the first administration of rituximab. The injection of BoNT-A into the masseter may be an effective treatment for medically refractory orofacial dyskinesia in pediatric patients with anti-NMDAR encephalitis. We propose that the use of BoNT-A injections should be considered early to avoid self-inflicted oral injury due to severe refractory orofacial dyskinesia in patients with anti-NMDAR encephalitis.

Anti-N-methyl-D-aspartate receptor encephalitis associated with acute Toxoplasma gondii infection: A case report

RATIONALE

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis has been recognized as the most frequent autoimmune encephalitis in children. Several infectious agents have been implicated in anti-NMDA encephalitis.

PATIENT CONCERNS

A previously healthy immunocompetent 9-year-old girl first presented with seizures, headaches and vomiting. Cerebrospinal fluid and brain magnetic resonance imaging were normal. After one week onset, the patient gradually developed unexplained personality and behavior changes, accompanied by fever and seizures again. Repeated CSF analysis revealed a slightly lymphocytic predominant pleocytosis and positive anti-NMDAR antibody. A variety of pathogenic examinations were negative, except for positive toxoplasma IgM and IgG.

DIAGNOSES

The patient was diagnoses for anti-NMDA encephalitis associated with acute acquired toxoplasma gondii infection.

INTERVENTIONS

The patient received 10 days azithromycin for treatment of acquired toxoplasma infection. The parents refuse immunotherapy because substantial recovery from clinical symptoms.

OUTCOMES

The patient was substantially recovered with residual mild agitation after therapy for acquired toxoplasma gondii infection. Two months later, the patient was completely devoid of symptoms, and the levels of serum IgM and IgG of toxoplasma gondii were decreased.

LESSONS

Acquired toxoplasma gondii infection may trigger anti-NMDAR encephalitis in children, which has not been reported previously. Clinicians should assess the possibility of toxoplasma gondii infection when evaluating a patient with anti-NMDA encephalitis.

Failure to improve after ovarian resection could be a marker of recurrent ovarian teratoma in anti-NMDAR encephalitis: a case report

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a type of autoimmune encephalitis that can be paraneoplastic and usually responds to tumor resection and immunotherapy. More than 75% of patients with anti-NMDAR encephalitis fully recover or have only mild sequelae, whereas the remainder experience severe disability. It remains unknown why certain cases have refractory clinical disease courses. We report a case of anti-NMDAR encephalitis with bilateral ovarian teratomas who was refractory to tumor resection and early initiation of immunotherapy. During intensive care, immunohistochemical analyses of her cerebrospinal fluid showed persistently high reactivity of NMDAR antibody over time. Six months after the operation, pelvic computed tomography detected a recurrent ovarian teratoma. After total enucleation of the bilateral ovaries, with significant pathological findings of bilateral mature cystic teratomas, her clinical condition improved rapidly, paralleled by a decrease in anti-NMDAR reactivity. This case illustrates the need to keep considering why extensive treatment fails to influence the disease when we encounter patients with refractory anti-NMDAR encephalitis. Failure to improve after ovarian resection could be a marker of recurrent ovarian teratoma in anti-NMDAR encephalitis.

Anti-NMDA-Receptor Encephalitis: From Bench to Clinic

NMDAR encephalitis is a common cause of autoimmune encephalitis, predominantly affecting young adults. Current data supports the idea that autoantibodies targeting NMDARs are responsible for disease pathogenesis. While these autoantibodies occur in the setting of underlying malignancy in approximately half of all patients, initiating factors for the autoimmune response in the remainder of patients are unclear. While there is increasing evidence supporting viral triggers such as herpes simplex encephalitis, this association and the mechanism of action have not yet been fully described. Although the majority of patients achieve good outcomes, those without an underlying tumor consistently show worse outcomes, prolonged recovery, and more frequent relapses. The cloning of patient-specific autoantibodies from affected individuals has raised important questions as to disease pathophysiology and clinical heterogeneity. Further advances in our understanding of this disease and underlying triggers are necessary to develop treatments which improve outcomes in patients presenting in the absence of tumors.

Teratoma-associated anti-NMDAR encephalitis: Two cases report and literature review

OBJECTIVE

This study aimed to discuss the pathogenesis, clinical manifestation, diagnosis, and treatment of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis.

CASE REPORT

The diagnosis and treatment of 2 cases with teratoma-associated anti-NMDAR encephalitis were summarized and the clinical data of patients reported by domestic and international studies were reviewed in this study. The 2 cases were both adolescent females who showed mental abnormalities as their main clinical manifestation. The patients were positive for anti-NMDAR antibody in their serum and cerebrospinal fluid, and gynecologic ultrasound detected ovarian teratoma. After diagnosis, the patients underwent teratoma resection, followed by pulse therapy of hormones and gamma globulin. Chemotherapy was performed to prevent tumor recurrence, and patients were in a stable condition.

CONCLUSIONS

Teratoma-associated anti-NMDAR encephalitis is commonly seen in young women. The clinical manifestation of this disease is nonspecific, and the patients mainly have fever, psychosis, and seizure. Tumor resection and immune therapy are effective treatment strategies, and standardized chemotherapy should also be performed to prevent recurrence.

Encephalitis associated with antibodies against the NMDA receptor

The encephalitis associated with antibodies against the N-methyl-D-aspartate receptor (NMDAR) is characterized by the presence of antibodies against the GluN1 subunit of this receptor, resulting in symptoms that are similar to those observed in models of genetic or pharmacologic reduction of NMDARs. Patients are usually young adults, predominantly women, and children who develop, in a sequential manner, rapidly progressive symptoms including psychosis, abnormal movements, autonomic dysfunction, and coma. Epileptic seizures are variable and can occur throughout the course of the disease. The disease is often mistaken as viral encephalitis, primary psychiatric disorders, drug abuse, or neuroleptic malignant syndrome. About 50% of young women have an ovarian teratoma; in young girls and men the presence of a tumour is infrequent. In some patients, the disease is triggered by herpes simplex encephalitis. The recognition of anti-NMDAR encephalitis is important because, despite its severity, most patients respond to immunotherapy.

Resection of melanocytic nevi as a potential treatment of anti-NMDAR encephalitis patients without tumor: report of three cases

The most common underlying tumor associated with anti-N-methyl D-aspartate-receptor (NMDAR) encephalitis is ovarian teratoma. Resection of the underlying tumor may decrease exposure of autoantigen and make for faster response of immunotherapy and less relapse frequency. Similar to teratoma, expression of NMDAR in human epidermal melanocytes was suspected recently. The dense melanocytes in melanocytic nevus may serve as potential autoantigens and are prone to increase relapse frequency in the tumor-negative patients. Three patients with confirmed diagnosis of anti-NMDAR encephalitis were described here. They shared common features that the screening tests for an ovarian teratoma or other tumors were all negative, while they were found to have prominent melanocytic nevi on the skin and resection of the nevi likely played a positive effect on their persistent recovery. This is a report on treatment of anti-NMDAR encephalitis patients without underlying tumor through resection of melanocytic nevi. More clinical and experimental investigations are needed to prove its validity.

Anti-NMDA Receptor Encephalitis: Clinical Features and Basic Mechanisms

In slightly more than 10 years, anti-NMDA receptor (NMDAR) encephalitis has changed from a rare paraneoplastic syndrome to the most common cause of nonviral encephalitis. It presents fulminantly with progressive psychosis, seizures, and autonomic dysfunction, leading to death if untreated. However, rapid recognition and treatment can lead to survival and a return to baseline levels of functioning in many patients. While initially associated with ovarian teratomas, it is now associated with other tumors and can reflect a postviral event. The antibodies to the NMDAR made in this syndrome are pathogenic and are directed at the extracellular domain of the GluN1 subunit. Such antibodies lead to internalization of NMDARs in model systems, leading to a physiological state characterized by NMDAR hypofunction. Analogous disorders, characterized by antibodies to other synaptic receptors, present with neurological and psychiatric dysfunction and also appear to reflect antibody-induced internalization of receptors. However, this simple pathophysiology may be too simplistic to reflect the complexity of events in anti-NMDAR encephalitis. Future scientific investigations may allow a more complete understanding of this disorder and improve treatment of anti-NMDAR encephalitis.

Dystonic Seizures and Intense Hyperperfusion of the Basal Ganglia in a Patient with Anti-N-Methyl-D-Aspartate Receptor Encephalitis

This report describes a rare case presenting with dystonic seizures due to anti-N-methyl-D-aspartate (NMDA) receptor encephalitis. The patient was an 18-year-old woman with repeated right-dominant dystonic seizures even under sedation. Single-photon emission computed tomography (SPECT) showed intense hyperperfusion of the caudate nuclei, putamen, globus pallidus, thalamus, and insula on the left side, suggesting encephalitis. Antibodies against NMDA receptors were detected in the sera and cerebrospinal fluids. Immune-mediated treatments were administered. Three months later, the dystonic seizures disappeared. We diagnosed her with anti-NMDA receptor encephalitis. SPECT suggested that the main region of encephalitis was the basal ganglia. Therefore, we propose that the patient's dystonic seizures may originate from the insula and be generated by intense hyperactivity of the basal ganglia.

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

BACKGROUND

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune disease involving antibodies against the NR1 subunits of NMDARs. The disease shows variable clinical presentation, and involves new-onset acute psychotic symptoms, making it difficult to differentiate from major depressive disorder with psychotic symptoms. Potential associations between this autoimmune disorder and onset or progression of major depressive disorder remains unclear.

CASE PRESENTATION

We present a rare case of a patient who had both major depressive disorder and anti-NMDAR encephalitis and in whom the encephalitis initially went undetected. The patient had been suffering from depressive disorder for more than 6 years without any treatment, when she was hospitalized for new-onset psychotic symptoms. She was initially diagnosed only with major depressive disorder with psychotic symptoms, but antipsychotics did not alleviate symptoms and the patient's psychiatric course began to fluctuate rapidly. Anti-NR1 IgG autoantibodies were detected in cerebrospinal fluid, and the combination of immunotherapy and antipsychotics proved more effective than antipsychotics alone. The patient was then also diagnosed with anti-NMDAR encephalitis.

CONCLUSIONS

Our case suggests that clinicians should consider anti-NMDAR encephalitis when a patient with depressive disorder shows sudden fluctuations in psychiatric symptoms. It also highlights the need for research into possible relationships between anti-NMDAR encephalitis and major depressive disorder.

Treatment strategies for autoimmune encephalitis

Autoimmune encephalitis is one of the most rapidly growing research topics in neurology. Along with discoveries of novel antibodies associated with the disease, clinical experience and outcomes with diverse immunotherapeutic agents in the treatment of autoimmune encephalitis are accumulating. Retrospective observations indicate that early aggressive treatment is associated with better functional outcomes and fewer relapses. Immune response to first-line immunotherapeutic agents (corticosteroids, intravenous immunoglobulin, plasma exchange, and immunoadsorption) is fair, but approximately half or more of patients are administered second-line immunotherapy (rituximab and cyclophosphamide). A small but significant proportion of patients are refractory to all first- and second-line therapies and require further treatment. Although several investigations have shown promising alternatives, the low absolute number of patients involved necessitates more evidence to establish further treatment strategies. In this review, the agents used for first- and second-line immunotherapy are discussed and recent attempts at finding new treatment options are introduced.

Arterial spin labeling perfusion imaging demonstrates cerebral hyperperfusion in anti-NMDAR encephalitis

Anti-N-methyl-d-aspartate receptor encephalitis is an increasingly recognized autoimmune disorder that results in substantial morbidity, prolonged hospital stays, and even death. The diagnosis is often delayed or unrecognized entirely as a result of absent or only subtle initial magnetic resonance imaging findings and a nonspecific clinical syndrome. The discovery of early imaging findings in this disease may help clinicians to more aggressively treat this autoimmune encephalitis and to potentially lessen morbidity and mortality. We report a novel case of anti-N-methyl-d-aspartate receptor encephalitis characterized by early evidence of increased cerebral perfusion on arterial spin labeling perfusion imaging, a finding that preceded laboratory diagnosis and conventional magnetic resonance imaging abnormalities. Further investigation is needed to firmly establish the pathologic basis of this finding.

Case report: anaesthetic management of radical gastrectomy for gastric cancer associated with anti-N-methyl-D-aspartate receptor encephalitis

BACKGROUND

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a rare neurological disorder that is caused by the production of antibodies against NMDARs. As many anaesthetic drugs interact with NMDARs and may worsen the disease and because the disease poses risks, such as cardiovascular events, hyperthermia and respiratory insufficiency, while under anaesthesia, administering anaesthesia to patients with this disorder is clinically challenging.

CASE PRESENTATION

A 55-year-old man with gastric cancer associated with anti-NMDAR encephalitis who was diagnosed 8 months prior was admitted to Peking University Cancer Hospital for tumour resection. Before surgery, the patient's symptoms had been successfully controlled via aggressive immunotherapy. Radical gastrectomy was performed under general anaesthesia induced with remifentanil, propofol, and cisatracurium and maintained with sevoflurane and remifentanil. The patient had a favourable recovery without any adverse symptoms or post-operative complications.

CONCLUSIONS

Adequate preparation for surgery is essential for the anaesthetic management of patients with anti-NMDAR encephalitis. These rare patients may benefit from general anaesthesia induced using remifentanil, propofol and cisatracurium and maintained using sevoflurane and remifentanil. Additionally, the use of NMDA antagonists, such as ketamine, nitrous oxide and tramadol, should be avoided.

Extended Clinical Spectrum of Anti-N-Methyl-d-Aspartate Receptor Encephalitis in Children: A Case Series

OBJECTIVE

There is a wide spectrum of clinical manifestations in children with anti-N-methyl-d-aspartate (NMDA) receptor antibody encephalitis from two different health care settings.

METHODS

We describe our experience with 13 patients (median age, 7 years; range, 5 months to 19 years) presenting to tertiary referral centers in India and the United States.

RESULTS

Initial manifestations were neurological (seizures or movement disorders) in eight patients, and psychiatric (e.g., emotional lability and hallucination) in five patients. Symptoms during the clinical course included seizures in ten patients, movement disorders (dyskinesia and choreiform movements) in 11 patients, and behavioral changes (aggressiveness and insomnia) in ten patients. Concomitant infections (herpes simplex virus 1, tuberculous meningitis, and influenza A) were present in three patients. Analysis of the cerebrospinal fluid in all except two cases preceded by infection (herpes simplex virus encephalitis and tuberculous meningitis) was unremarkable. Treatment included intravenous immunoglobulin/methylprednisolone (11 patients), rituximab (eight patients), plasmapheresis (two patients), and cyclophosphamide (two patients). Six patients recovered completely. Two patients had mild residual neurological deficits, whereas four had severe residual neurological deficits. Two patients had profound autonomic instability, which was the cause of death for one of them. Two patients relapsed at two and six months after the initial recovery.

CONCLUSIONS

We describe the differences and similarities of clinical presentation, test results, and response to treatment of children with anti-N-methyl-d-aspartate receptor encephalitis from India and the United States. Included is a description of one of the youngest patients with anti-N-methyl-d-aspartate receptor encephalitis (five months) and the first patient to be reported in association with tuberculous meningitis.

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

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is potentially lethal, but it is also a treatable autoimmune disorder characterized by prominent psychiatric and neurologic symptoms. It is often accompanied with teratoma or other neoplasm, especially in female patients. Anti-NMDAR antibodies in cerebrospinal fluid (CSF) and serum are characteristic features of the disease, thereby suggesting a pathogenic role in the disease. Here, we summarize recent studies that have clearly documented that both clinical manifestations and the antibodies may contribute to early diagnosis and multidisciplinary care. The clinical course of the disorder is reversible and the relapse could occur in some patients. Anti-NMDAR encephalitis coexisting with demyelinating disorders makes the diagnosis more complex; thus, clinicians should be aware of the overlapping diseases.

Association of Progressive Cerebellar Atrophy With Long-term Outcome in Patients With Anti-N-Methyl-d-Aspartate Receptor Encephalitis

IMPORTANCE

Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis is an immune-mediated disorder that occurs with IgG antibodies against the GluN1 subunit of NMDAR. Some patients develop reversible diffuse cerebral atrophy (DCA), but the long-term clinical significance of progressive brain and cerebellar atrophy is unknown.

OBJECTIVE

To report the long-term clinical implications of DCA and cerebellar atrophy in anti-NMDAR encephalitis.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective observational study and long-term imaging investigation was conducted in the Department of Neurology at Kitasato University. Fifteen patients with anti-NMDAR encephalitis admitted to Kitasato University Hospital between January 1, 1999, and December 31, 2014, were included; data analysis was conducted between July 15, 2015, and January 18, 2016.

EXPOSURES

Neurologic examination, immunotherapy, and magnetic resonance imaging (MRI) studies were performed.

MAIN OUTCOMES AND MEASURES

Long-term MRI changes in association with disease severity, serious complications (eg, pulmonary embolism, septic shock, and rhabdomyolysis), treatment, and outcome.

RESULTS

The clinical outcome of 15 patients (median age, 21 years, [range, 14-46 years]; 10 [67%] female) was evaluated after a median follow-up of 68 months (range, 10-179 months). Thirteen patients (87%) received first-line immunotherapy (intravenous high-dose methylprednisolone, intravenous immunoglobulin, and plasma exchange alone or combined), and 4 individuals (27%) also received cyclophosphamide; 2 patients (13%) did not receive immunotherapy. In 5 patients (33%), ovarian teratoma was found and removed. Serious complications developed in 4 patients (27%). Follow-up MRI revealed DCA in 5 patients (33%) that, in 2 individuals (13%), was associated with progressive cerebellar atrophy. Long-term outcome was good in 13 patients (87%) and poor in the other 2 individuals (13%). Although cerebellar atrophy was associated with poor long-term outcome (2 of 2 vs 0 of 13 patients; P = .01), other features, such as DCA without cerebellar atrophy, serious complications, ventilatory support, or prolonged hospitalization, were not associated with a poor outcome. Five patients with DCA had longer hospitalizations (11.1 vs 2.4 months; P = .002), required ventilatory support more frequently (5 of 5 vs 4 of 10 patients; P = .04), and developed more serious complications (4 of 5 vs 0 of 10 patients; P = .004) compared with those without DCA. Although DCA was reversible, cerebellar atrophy was irreversible.

CONCLUSIONS AND RELEVANCE

In anti-NMDAR encephalitis, DCA can be reversible and does not imply a poor clinical outcome. In contrast, cerebellar atrophy was irreversible and associated with a poor outcome. This observation deserves further study to confirm progressive cerebellar atrophy as a prognostic marker of poor outcome.

[Autoimmune encephalitis associated to antibodies against the N-methyl-D-aspartate receptor: Report of two cases]

Anti-N-methyl-D-aspartate receptor encephalitis is a neurological syndrome that is more common in young women and is often associated with ovarian teratoma. It is characterized by acute general unspecific symptoms that evolve to neurological deterioration, psychosis and seizures. In its more advanced stage it is associated with abnormal movements and dysautonomia.We report two cases in women of 23 and 12 years of age. Given its low incidence, we present the clinical exercise that led to their diagnoses and the treatment options employed.

A severe anti-NMDA-receptor encephalitis case with extensive cortical and white matter changes, cerebral atrophy and communicating hydrocephalus

A 21-year-old woman presented with a viral prodrome, abnormal behaviours, confusion and short-term memory loss, followed by status epilepticus that later evolved to orofacial dyskinesias, autonomic dysfunctions and hypoventilation requiring prolonged ventilator support and ICU admission. Cerebrospinal fluid (CSF) and serum analysis confirmed the presence of anti-NMDAR autoantibodies. A left salpingoopherectomy was performed on day 35 of admission revealing an immature ovarian teratoma. Following surgical and two courses of intravenous immunoglobulin therapy, her response remained poor. Initial brain magnetic resonance imaging (MRI) during the acute stage showed enlarged left hippocampus. Further MRI follow-up 13 weeks after admission showed unusual findings of extensive cortical and white matter changes, generalised cerebral atrophy, dilated ventricles and possible transependymal CSF seepage of communicating hydrocephalus. A ventriculo-peritoneal shunt was performed subsequently and she was discharged 6 months after admission without significant change in her clinical status. Follow-up 4 months later showed some improvement but patient remained severely disabled.

Clinical characteristics, treatments, and outcomes of patients with anti-N-methyl-d-aspartate receptor encephalitis: A systematic review of reported cases

Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis is a recently recognized autoimmune disorder which is responsive to immunotherapy. However, the outcomes of different immunotherapies have not been defined and there have been few studies that carried out a comparison among them. To provide an overview of the clinical characteristics, treatments, and outcomes of anti-NMDAR encephalitis, we systematically reviewed the literature in the PubMed, Medline, Embase, Cochrane Library, BioMedical Literature Database (CBM), China National Knowledge Infrastructure (CNKI), and Wan-fang databases. Eighty-three studies with a total of 432 patients were included. The median age was 22years. Two hundred ninety-three (68%) patients were female, 87 (21%) of 412 patients had a tumor, including 68 (78%) patients with ovarian teratoma. Pediatric patients had a higher ratio of seizures to psychiatric symptoms as the initial manifestation (p=0.0012), a lower proportion with a tumor (p<0.0001) and CSF pleocytosis (p=0.0163), and a better outcome (p=0.0064) than adults. Patients who died had a higher proportion of CSF pleocytosis than the patients who survived (p=0.0021). There were no significant differences among three first-line immunotherapy used alone (p=0.9172) or among combinations of every two of them (p=0.3059). With regard to the use of corticosteroid and IVIG, there were no significant differences between the outcomes of early combined treatment and sequential treatment (p=0.7277), or between using corticosteroid first and IVIG first (p=0.5422). Our findings suggest that the clinical characteristics and outcomes for pediatric patients were different from adult patients, and no significant differences were found among different immunotherapies.

Diagnostic Value of 18F-FDG PET/CT Versus MRI in the Setting of Antibody-Specific Autoimmune Encephalitis

Diagnosis of autoimmune encephalitis presents some challenges in the clinical setting because of varied clinical presentations and delay in obtaining antibody panel results. We examined the role of neuroimaging in the setting of autoimmune encephalitides, comparing the utility of ¹⁸F-FDG PET/CT versus conventional brain imaging with MRI. Methods: A retrospective study was performed assessing the positivity rate of MRI versus ¹⁸F-FDG PET/CT during the initial workup of 23 patients proven to have antibody-positive autoimmune encephalitis. ¹⁸F-FDG PET/CT studies were analyzed both qualitatively and semiquantitatively. Areas of cortical lobar hypo (hyper)-metabolism in the cerebrum that were 2 SDx from the mean were recorded as abnormal. Results: On visual inspection, all patients were identified as having an abnormal pattern of ¹⁸F-FDG uptake. In semiquantitative analysis, at least 1 region of interest with metabolic change was identified in 22 of 23 (95.6%) patients using a discriminating z score of 2. Overall, ¹⁸F-FDG PET/CT was more often abnormal during the diagnostic period than MRI (10/23, 43% of patients). The predominant finding on brain ¹⁸F-FDG PET/CT imaging was lobar hypometabolism, being observed in 21 of 23 (91.3%) patients. Hypometabolism was most commonly observed in the parietal lobe followed by the occipital lobe. An entire subset of antibody-positive patients, anti-N-methyl-d-aspartate receptor (5 patients), had normal MRI results and abnormal ¹⁸F-FDG PET/CT findings whereas the other subsets demonstrated a greater heterogeneity. Conclusion: Brain ¹⁸F-FDG PET/CT may play a significant role in the initial evaluation of patients with clinically suspected antibody-mediated autoimmune encephalitis. Given that it is more often abnormal when compared with MRI in the acute setting, this molecular imaging technique may be better positioned as an early biomarker of disease so that treatment may be initiated earlier, resulting in improved patient outcomes.

Autoimmune epilepsy

Seizures are a common manifestation of autoimmune limbic encephalitis and multifocal paraneoplastic disorders. Accumulating evidence supports an autoimmune basis for seizures in the absence of syndromic manifestations of encephalitis. The autoimmune epilepsies are immunologically mediated disorders in which recurrent seizures are a primary and persistent clinical feature. When other etiologies have been excluded, an autoimmune etiology is suggested in a patient with epilepsy upon detection of neural autoantibodies and/or the presence of inflammatory changes on cerebrospinal fluid (CSF) or magnetic resonance imaging. In such patients, immunotherapy may be highly effective, depending on the particular autoimmune epilepsy syndrome present. In this chapter, several autoimmune epilepsy syndromes are discussed. First, epilepsies secondary to other primary autoimmune disorders will be discussed, and then those associated with antibodies that are likely to be pathogenic, such as voltage-gated potassium channel-complex and N-methyl-d-aspartate receptor, gamma-aminobutyric acid A and B receptor antibodies. For each syndrome, the typical clinical, imaging, electroencephaloram, CSF, and serologic features, and pathophysiology and treatment are described. Finally, suggested guidelines for the recognition, evaluation, and treatment of autoimmune epilepsy syndromes are provided.

First reported cases of anti-NMDA receptor encephalitis in Vietnamese adolescents and adults

Introduction

Anti-NMDA receptor encephalitis is increasingly recognised as an important differential diagnosis in patients with encephalitis of unknown aetiology. We report the first case series of patients diagnosed in Vietnam.

Methods

Samples of CSF from patients with presumed encephalitis but negative microbiological investigations, who exhibited dyskinesia, autonomic instability or psychosis were tested for antibodies against the NR1 subunit of the glutamate (type-NMDA) receptor using an indirect immunofluorescence assay.

Results

Of 99 patients admitted with all-cause encephalitis over an 18 month period, 9.1% (n = 9 patients, 5 female, median age 28 years) had confirmed NMDAR encephalitis. All patients were admitted from one mental health hospital, and the incidence may therefore be an underestimate. Common features included reduction in speech (n = 9), catatonia (n = 9), convulsions (n = 7), dyskinesia (n = 9), rigidity (n = 9) and autonomic dysfunction (n = 7). Aside from a modest lymphocytic pleocytosis, routine CSF analysis was usually normal. No female patient had ovarian teratoma detected by abdominal ultrasound. Most patients were treated with high dose corticosteroids, and one patient received intravenous immunoglobulin. The median duration of hospitalization was 75 days and no patient died during admission.

Conclusions

Anti-NMDA receptor encephalitis is an important differential diagnosis to consider for patients presenting with acute onset psychiatric symptoms, who develop ensuing seizures, movement or autonomic disorder in Vietnam. A stronger evidence base for management and access to second line immunotherapy agents may help to reduce morbidity from this disease.

•

Anti-NMDA encephalitis is an important differential for unexplained encephalitis.

•

For the first time we have confirmed the diagnosis in adolescents and adults in Vietnam.

•

Psychiatric symptoms are followed by movement/autonomic disorder and convulsions.

•

Treatment is usually with high dose corticosteroids.

•

A robust evidence base is required to support clinical management algorithms.

Synaptic and Neuronal Autoantibody-Associated Psychiatric Syndromes: Controversies and Hypotheses

Autoimmune encephalitis (AE) mediated by antibodies against synaptic and neuronal surface targets frequently presents with a psychiatric syndrome. In these patients, removal of autoantibodies treats the disease and outcomes are closely linked to early intervention. The discovery of these autoantibodies in isolated psychiatric syndromes has raised the possibility that these patients may derive similar benefits from immunotherapy, a potentially transformational approach to the treatment of mental illness. Although open-label case series suggest impressive therapeutic outcomes, the pathological relevance of these autoantibodies outside of canonical presentations is debated. The advent of diagnostic criteria for AE attempts to facilitate its prompt identification but risks prematurely neglecting the potential scientific and clinical significance of isolated syndromes that do not satisfy these criteria. Here, we propose using a syndrome-level taxonomy that has occasional, but not necessary, overlap with AE: synaptic and neuronal autoantibody-associated psychiatric syndromes or "SNAps". This will prevent confusion with AE and act heuristically to promote active investigation into this rare example of psychopathology defined on a molecular level. We suggest that this concept would have application in other autoantibody-associated syndromes including seizure, cognitive, and movement disorders, in which similar issues arise. We review putative direct and indirect mechanisms and outline experimentally testable hypotheses that would help to determine prospectively in whom autoantibody detection is relevant, and as important, in whom it is not. We summarize a pragmatic approach to autoantibody testing and management in severe mental illness in order to promptly diagnose AE and advocate a research-orientated experimental medicine paradigm for SNAps, where there is greater equipoise. We conclude that SNAps remains a nascent area of clinical neuroscience with great potential and in ongoing need of psychiatry-led basic and clinical research.

Clinical Characteristics and Follow-up of South Indian Children with Autoimmune Encephalopathy

OBJECTIVE

To describe the clinical characteristics of a cohort of south Indian children with probable autoimmune encephalopathy from a tertiary care academic hospital and to compare this data with the existing literature.

METHODS

Patients with encephalopathy plus one or more of neuropsychiatric symptoms, seizures, movement disorder or cognitive dysfunction were identified. Common infectious causes were excluded. Clinical characteristics, investigations, management and outcome were analyzed.

RESULTS

Thirteen patients were included in the study; 12 were females (92.3 %) and mean age was 9.6 y. Most common presentation was behavior change (13 patients) followed by seizures (11 patients). Three patients showed lymphocytic pleocytosis in CSF and one patient had oligoclonal bands. Initial MRI was normal in all patients except in one. Most common EEG abnormality was mild background slowing. Only one child had ovarian tumor. S.NMDA receptor antibody was positive in 10 patients (83 %), and all of them received immunotherapy. Six out of 13 children were followed up for more than 1 y (mean - 21 mo). Recurrence was noted in 4 out of 6 patients (66 %). On last follow-up, good recovery was seen in 2 children (33 %), moderate disability in 3 (50 %) and severe disability in 1 (16 %).

CONCLUSIONS

The clinical characteristics and outcome of one of the largest single center cohort of Indian children with autoimmune encephalopathy is reported. Autoimmune encephalopathy should be considered as a differential diagnosis in the acute and subacute encephalopathies of childhood and treating pediatrician should be aware of this entity.

Spontaneous recovery of memory functions in an untreated case of anti NMDAR encephalitis - a reason to maintain hope

OBJECTIVE

Anti N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an autoimmune disorder that was only fully discovered recently and neuropsychological outcome data remains sparse. We present the case of BA, a 19-year-old male, which illustrates the cognitive outcome in an untreated case over a time period of over 2½ years.

METHOD

We conducted three cognitive assessments, including tests of memory and executive functioning, over this time period and considered the evidence for reliable change in memory function using the Wechsler Advanced Clinical Solutions (ACS) serial assessment package.

RESULTS

Our findings revealed mild memory problems 6 months post-discharge with, at best, static and potentially declining memory functioning at follow-up assessment 12 months post-discharge. However, the results of testing at 30 months post-discharge revealed significant improvements in immediate and delayed memory index performances.

CONCLUSIONS

Our report of a case of anti-NMDAR encephalitis provides evidence for spontaneous improvements in memory functioning occurring more than 2 years after initial assessment and also demonstrates both the utility and potential limitations of the ACS serial assessment software when used in a relatively typical clinical assessment situation.

Successful treatment of anti-NMDA receptor encephalitis with a prompt ovarian tumour removal and prolonged course of plasmapheresis: A case report

Anti-N-methyl-d-aspartate-receptor (NMDAR) encephalitis is an uncommon autoimmune disorder with a wide spectrum of neuropsychiatric symptoms. There is a great requirement to emphasize the importance of a multidisciplinary team approach in the process of diagnosis and treatment of the potentially fatal condition, including psychiatrists, neurologists, gynaecologists and intensivists. Physicians must be aware that psychiatric and neurological disorders, which are typical features for NMDAR encephalitis in young women with ovarian tumours, may progress into status epilepticus and respiratory insufficiency. This disease can only be successfully treated with prompt surgical intervention and an early implementation of a wide array of immunosuppressive therapies. Optimal timing of initiation of therapeutic plasma exchange, as well as duration of treatment necessary to achieve desirable outcomes in patients with NMDAR remains unknown. The present case report aims to raise awareness about the importance of early implementation of this potentially life-saving therapy and continuing the treatment courses until full subsidence of symptoms.

[Anesthesia in anti-N-methyl-d-aspartate receptor encephalitis - is general anesthesia a requisite? A case report]

Anti-N-methyl-d-aspartate receptor encephalitis is a recently described neurological disorder and an increasingly recognized cause of psychosis, movement disorders and autonomic dysfunction. We report 20-year-old Chinese female who presented with generalized tonic-clonic seizures, recent memory loss, visual hallucinations and abnormal behavior. Anti-N-methyl-d-aspartate receptor encephalitis was diagnosed and a computed tomography scan of abdomen reviewed a left adnexal tumor. We describe the first such case report of a patient with anti-N-methyl-d-aspartate receptor encephalitis who was given a bilateral transversus abdominis plane block as the sole anesthetic for removal of ovarian tumor. We also discuss the anesthetic issues associated with anti-N-methyl-d-aspartate receptor encephalitis. As discovery of tumor and its removal is the focus of initial treatment in this group of patients, anesthetists will encounter more such cases in the near future.

Anti-N-methyl-D-aspartate receptor encephalitis: a common cause of encephalitis in the intensive care unit

Anti-N-methyl-D-aspartate receptor encephalitis (anti-NMDAR encephalitis) is the most common type of immune-mediated encephalitis. This study aimed to assess the incidence and mortality of anti-NMDAR encephalitis in intensive care unit (ICU) to evaluate the clinical manifestations, laboratory findings, managements and outcomes, and to compare these characteristics with patients with non-anti-NMDAR encephalitis admitted to ICU. Patients admitted to the neurological ICU with suspected encephalitis were included between January 1, 2012 and July 31, 2015. Cerebrospinal fluid (CSF) of enrolled patients was screened for anti-NMDAR antibodies using a cell-based assay. 72 critically ill patients with encephalitis of uncertain etiology were investigated, and 16 patients were positive for anti-NMDAR antibodies in CSF. Compared to patients with non-anti-NMDAR encephalitis, patients with anti-NMDAR encephalitis were younger, more likely to present with the psychiatric symptoms, dyskinesia, and autonomic dysfunction, and had longer ICU stays. The abnormal movements were so difficult to control that complicated the management. The outcome was favorable in ten patients 1 year after the disease onset, and the mortality was as high as 25 % overall. The incidence of anti-NMDAR encephalitis is high among critically ill patients with encephalitis of uncertain etiology. Controlling dyskinesia proved to be a challenge. Persistent dysautonomias were additional difficult to manage confounders. Same points being highlighted in this study may aid clinicians in the management of patients with anti-NMDAR encephalitis in intensive care practice.

Anti-NMDA receptor encephalitis presenting as an acute psychotic episode misdiagnosed as dissociative disorder: a case report

Background

In 2005, “anti-N-methyl-d-aspartate (NMDA) receptor encephalitis,” a syndrome with prominent psychiatric symptoms, memory loss, decrease in level of consciousness, and central hypoventilation, was described in young women with ovarian teratomas and antibodies against an antigen highly expressed in the hippocampus. This report highlights the growing need for increased awareness among psychiatrists and other relevant medical professionals about this under-diagnosed disorder, which should be considered in differential diagnoses.

Case presentation

A 19-year-old female with no psychiatric history presented to a district general hospital with acute psychosis, emotional lability, memory deficit, fluctuating behavioral changes such as wandering and babbling, and seizure. She was admitted to the hospital with a provisional diagnosis of dissociative disorder. Soon after admission, she developed aspiration pneumonia and was intubated for mechanical ventilation. She was transferred to our hospital for further assessment and admitted to the intensive care unit for ventilation. Laboratory test results were unremarkable, but her EEG showed non-specific slowing with no epileptiform activity, and brain computed tomography (CT) and MRI also showed no remarkable findings. Cerebrospinal fluid (CSF) analysis showed an elevated white blood cell count (15 cells/hpf; 70 % lymphocytes), and blood serum and CSF samples tested positive for NMDA receptor antibodies. Abdominal contrast-enhanced CT revealed an ovarian teratoma, which was subsequently removed laparoscopically. Postoperative immunotherapy (steroids, intravenous immunoglobulin, and plasmapheresis) led to gradual improvement. On day 25 of hospitalization, neuropsychological assessment demonstrated that overall, she had returned to her premorbid level of functioning. Her condition substantially improved over several months of cognitive rehabilitation, and she was eventually discharged on day 75.

Conclusions

Anti-NMDA receptor encephalitis, a form of autoimmune encephalitis, is commonly associated with tumors and often misdiagnosed. Diagnosis can be confirmed by detecting NMDA receptor antibodies in the patient’s serum or CSF. Management can be achieved with immunosuppressive therapy and tumor resection.

First-episode psychosis in a 15 year-old female with clinical presentation of anti-NMDA receptor encephalitis: a case report and review of the literature

Background

Anti-NMDA receptor encephalitis is an autoimmune disease that was identified in 2007, and manifests in a stepwise manner with psychiatric, neurological and autonomic symptoms. The disease is caused by autoantibodies against NMDA receptors. It can have a paraneoplastic origin, mainly secondary to ovarian teratomas, but it can also be unrelated to the tumor. This disease can affect both sexes and all ages.

Case presentation

Here, we present a case of a 15 year-old female adolescent with first-episode psychosis with anti-NMDA receptor encephalitis not related to tumor, which manifested with delusion, hallucinations, panic attacks, agitation, and neurological symptoms, and later with autonomic instability. She was treated with immunotherapy and psychiatric medication resulting in improvement of her main psychiatric and neurological symptoms.

Conclusion

Our main objective in presenting this case is to alert clinicians to this challenging and recent disease that has a clinical presentation that might resemble a functional psychiatric condition and can be underdiagnosed in the context of child and adolescent psychiatry.

[Subacute anti-N-methyl-D-aspartate receptor encephalitis. A serie of 13 paediatric cases]

INTRODUCTION

Subacute anti-NMDA receptor encephalitis was recognised in 2007 as a clinical entity, and was first described in young women with ovarian teratoma. The first paediatric series unrelated with tumours was reported in 2009.

OBJECTIVE

To present the clinical features, treatment, and prognosis of 13 patients with anti-NMDA receptor encephalitis in Chile.

PATIENTS AND METHOD

A description is presented of 13 children, 9 males, aged between 1 and 16 years, diagnosed between 2009 and 2016 in 7 hospitals. All patients were evaluated with cerebral magnetic resonance and electroencephalogram. Cytochemical, oligoclonal bands and virus studies (PCR and antibodies) were performed in cerebrospinal fluid. All patients were evaluated in search of anti NMDA receptor in serum and cerebrospinal fluid. Tumor imaging studies were performed in all children.

RESULTS

All children began the disease with psychiatric symptoms, and 11/13 had seizures. All of them subsequently presented with psychomotor agitation, dystonia, and bucolingual dyskinesias, with 11/13 loss of language and 6/13 autonomic disorders. All of them (13/13) had positive anti-NMDA receptor antibodies. CSF was normal in 12/13 children, positive oligoclonal bands in 6/10 patients, normal brain resonance in 13/13 children, EEG changes in 11/13 children, and abnormal SPECT in 6/6 children. A methylprednisolone bolus of 30mg/kg was given for 3-5 days to 12/13 children, and 6 received immunoglobulin 2g/kg. The large majority (12/13) of children recovered 1-4 months after disease onset. One child had a recurrence one year later, and recovered quickly.

CONCLUSIONS

Subacute encephalitis due to NMDA anti-receptor antibodies should be suspected in children with psychiatric disorders and abnormal movements. Functional studies, such as EEG and SPECT are valuable diagnostic support. Early detection of this encephalitis leads to a faster recovery of patients.