Serum NfL associated with anti-NMDA receptor encephalitis

Neurological Sciences - Neurofilament light chains (NfL) have been reported as potential markers for neuronal-axonal injury in neuroinflammatory diseases. In the current study, we describe serum...     

Pitfalls in clinical diagnosis of anti-NMDA receptor encephalitis

Objectives

To report pitfalls in the clinical diagnosis of anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis.

Methods

We retrospectively reviewed the clinical information of 221 patients with clinically suspected autoimmune neurological disorders who underwent testing for autoantibodies against neuronal cell-surface antigens between January 1, 2007 and September 10, 2017. Forty-one patients met the diagnostic criteria for probable anti-NMDAR encephalitis (probable criteria), but one was excluded because neither serum nor CSF was examined at the active stage. Thus, in 220 patients, sensitivity and specificity of the probable criteria were assessed.

Results

NMDAR-antibodies were detected in 34 of 40 patients (85%) with the probable criteria; however, 2 of the 6 antibody-negative patients had ovarian teratoma. The median age at onset was higher in antibody-negative patients than those with antibodies (49 vs. 27 years, p = 0.015). The age at onset was associated with the probability of antibody detection (p = 0.014); the probability was less than 50% in patients aged 50 years or older. NMDAR-antibodies were also detected in 5 of 180 patients who did not fulfill the probable criteria; these patients presented with isolated epileptic syndrome (n = 2), atypical demyelinating syndrome (n = 2; one with aquaporin 4 antibodies), and autoimmune post-herpes simplex encephalitis (post-HSE) (n = 1). Sensitivity and specificity of the probable criteria was 87.2 and 96.7%, respectively.

Conclusion

The probable criteria are valid, but the diversity of clinical phenotype should be taken into account in diagnosing anti-NMDAR encephalitis particularly in patients aged 50 years or older, or with isolated epileptic syndrome, atypical demyelinating syndrome, or post-HSE.

     

20例抗N-甲基-D-天冬氨酸受体脑炎患者临床特点分析

目的回顾性分析总结20例抗N-甲基-D-天冬氨酸受体(NMDAR)脑炎患者的临床特点,增强对抗NMDAR脑炎的认识。方法对90例临床疑似脑炎患者的血清和脑脊液进行抗NMDAR-IgG检测,分析确诊为抗NMDAR脑炎的20例患者的临床表现、实验室检查、治疗及预后。结果抗NMDAR脑炎患者男女比例为6:14,中位年龄24岁,首发症状及主要精神症状多有不同。20例抗NMDAR脑炎患者中有12例患者血清和脑脊液中抗NMDAR-IgG抗体均阳性,其他8例仅在血清或脑脊液中检测到抗NMDAR-IgG抗体。5例盆腔检查异常,其中1例病理确诊为成熟囊性畸胎瘤。6例患者脑电图异常,7例头颅MRI异常。除1例患者未接受免疫治疗死亡外,其余患者接受免疫治疗后症状均有不同程度的缓解,其中3例未伴畸胎瘤的患者用二线免疫治疗后复检血清和脑脊液中抗NMDAR-IgG抗体水平下降。结论抗NMDAR脑炎患者中年轻女性发病率较高。二线免疫治疗可能对不伴有畸胎瘤患者的疗效更好。CSF中的抗NMDAR-IgG抗体的阳性率高于血清,同时检测血清和脑脊液中抗NMDAR抗体可以提高疾病的诊断效率。     

视神经脊髓炎合并抗N-甲基-D-天冬氨酸受体脑炎1例

目的 探讨视神经脊髓炎合并抗N-甲基-D-天冬氨酸(NMDA)受体脑炎的临床特征。方法 报道本院收治的1例视神经脊髓炎合并抗N-甲基-D-天冬氨酸受体脑炎的临床特点及诊治经过,并结合文献分析该病的特征。结果 患者为21岁女性,表现为腹泻后急性起病的下肢麻木无力、昏睡、视物模糊; MRI示双侧基底节、海马、桥臂、齿状回、延髓背侧多发异常信号,同时伴有颈髓多发条片状长T₂异常信号。脑脊液NMDA受体抗体阳性,血清和脑脊液水通道蛋白4(AQP4)抗体阳性,合并心动过缓并发症,筛查未发现肿瘤; 经激素冲击、丙种球蛋白及免疫抑制剂治疗后症状逐渐好转至痊愈。结论 视神经脊髓炎合并抗N-甲基-D-天冬氨酸受体脑炎可以在感染后起病,症状和影像学主要表现为两种疾病的叠加,可出现心动过缓并发症,早期积极行免疫治疗效果较好。     

Aberrant multimodal brain networks in patients with anti-NMDA receptor encephalitis

AimsTo explore large‐scale brain network alterations and examine their clinical and neuropsychological relevance in patients with anti‐N‐methyl‐D‐aspartate receptor (NMDAR) encephalitis.MethodsTwenty‐four patients with anti‐NMDAR encephalitis and 26 matched healthy controls (HCs) were enrolled in our study. Based on the multimodal MRI dataset, individual morphological, structural, and functional brain networks were constructed and compared between the two groups at multiple levels. The associations with clinical/neuropsychological variables and the discriminant ability of significant alterations were further studied.ResultsMultimodal network analysis revealed that anti‐NMDAR encephalitis mainly affected morphological and structural networks, but subtle alterations were observed in functional networks. Intriguingly, decreased network local efficiency was observed for both morphological and structural networks and increased nodal centrality in the lateral orbital gyrus was convergently observed among the three types of networks in the patients. Moreover, the alterations, particularly those from structural networks, accounted largely for cognitive deficits of the patients and could distinguish the diseased individuals from the HCs with excellent performance (area under the curve =0.933).ConclusionsThe current study provides a comprehensive view of characteristic multimodal network dysfunction in anti‐NMDAR encephalitis, which is crucial to establish new diagnostic biomarkers and promising therapeutic targets for the disease.     

Analysis of electroencephalogram characteristics of anti-NMDA receptor encephalitis patients in China

Objective

To explore the characteristics of electroencephalogram (EEG) in patients with anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis.

Suppression of synaptic plasticity by cerebrospinal fluid from anti-NMDA receptor encephalitis patients

The functional effects of cerebrospinal fluid (CSF) from patients with anti-NMDA receptor (NMDAR) encephalitis on the NMDAR-mediated synaptic plasticity were evaluated by using mouse hippocampus slices. Anti-NMDAR antibody detection system was established by immunostaining recombinant NMDAR heteromers expressed in HEK cell culture as well as native NMDARs in cultured hippocampal neurons. Under a complete blind manner for the clinical information, CSF and sera collected from 36 pre-diagnosed patients were tested for anti-NMDAR antibodies. With this test, thirteen patients were diagnosed as anti-NMDAR encephalitis. CSF positive for anti-NMDAR antibodies suppressed induction of long-term potentiation (LTP) at Schaffer collateral-CA1 synapses in mouse hippocampal slices. LTP induction was not suppressed by CSF collected from herpes simplex virus (HSV) encephalitis or non-encephalitis control patients. Antibody absorption with NMDAR-expressing HEK cell culture reversed the suppression of LTP by anti-NMDAR encephalitis patients' CSF, confirming that anti-NMDAR antibodies suppressed LTP. The present experiments firmly support the proposal that the anti-NMDAR encephalitis autoantibody is responsible for cognitive disorders like amnesia accompanying this disease.     

Reversible brain atrophy in anti-NMDA receptor encephalitis: a long-term observational study

The long-term neuroimaging correlates of clinical recovery have not been described in anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis. The aim of the study is to evaluate the long-term outcome of brain atrophy in anti-NMDAR encephalitis. Patients were two women (ages 17 and 33 years) with severe anti-NMDAR encephalitis resulting in decreased level of consciousness, autonomic instability, hypoventilation, and dyskinesias requiring continuous infusion of anesthetic agents for 6–7 months. Brain MRI and cerebral blood flow SPECT obtained at the time of maximal neurological disability were compared with similar studies obtained 5–7 years later. Both patients were hospitalized for 9–14 months and developed frontotemporal atrophy and hypoperfusion 7–12 months after symptom presentation. In both patients, cognitive functions gradually improved over the next 4–5 years. Comparative neuroimaging studies obtained 5–7 years after symptom presentation showed dramatic improvement of the atrophy and frontotemporal hypoperfusion. The severe and protracted deficits and the frontotemporal atrophy that occur in some patients with anti-NMDAR encephalitis are potentially reversible. This suggests that a functional rather than a structural neuronal damage underlies the pathogenesis of this disorder.     

Cytokine/chemokine elevation during the transition phase from HSV encephalitis to autoimmune anti-NMDA receptor encephalitis

A 3-year-old girl suffered from anti-N-methyl-d-aspartate (anti-NMDA) receptor encephalitis after resolution of herpes simplex virus encephalitis (HSE). Methylprednisolone pulse and immunoglobulin therapies showed little effect, but the patient completely recovered after six courses of monthly cyclophosphamide pulse therapy and successive maintenance on mycophenolate mofetil for one year. Anti-NMDA receptor antibody in the cerebrospinal fluid (CSF) was minimally detected during the prodromal febrile period and then was seen to be markedly elevated at the onset of second encephalopathy phase. CSF interleukin (IL)-6, and 10, tumor necrosis factor-α, interferon gamma, C-X-C motif ligands (CXCL)10 and 13, chemokine ligand 2, and migration inhibitory factor showed a second peak during the prodromal period and were reduced at the onset of anti-NMDA receptor encephalitis. These suggest the presence of cytokine/chemokine phase between the initial HSE and the secondary autoimmune encephalitis phases. Treatment strategy during the early stage of this entity should be further explored.     

Novel FDG-PET findings in anti-NMDA receptor encephalitis: a case based report

The clinical manifestation and nuclear imaging findings in a 15-year-old boy with anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis are described in this case report. The previously healthy patient presented with new onset hallucinations, seizure, and within a week, his mental status rapidly deteriorated to nonverbal with oro-lingual-facial dyskinesias. An extensive laboratory work-up for encephalopathy was negative. Repeated brain magnetic resonance imaging (MRI) studies were normal. On day 26 of admission, nuclear imaging using fluorodeoxyglucose positron emission tomography (FDG-PET) showed global hypometobolism with a prominent focally intense hypermetabolic lesion in the right cerebellar cortex. Diagnosis of anti-NMDAR encephalitis was confirmed with quantitative serology. The patient showed clinical signs of improvement after 2 courses of intravenous immunoglobulin therapy over 4 weeks. On day 46, repeat brain FDG-PET showed overall improvement but in contrast to the previous, the right cerebellar cortex showed focal hypometabolism. This is the first reported case of such findings using FDG-PET in anti-NMDAR encephalitis.