Objective

To evaluate the frequency of anti-NMDAR encephalitis in a secondary mental health service and investigate the challenges of its diagnosis in routine clinical practice.

Methods

Patients whose electronic health records registered an indication for NMDAR-IgG assessment were selected and seropositive patients were reviewed.

Results

In 1661 patients assessed for NMDAR-IgG over 12 years, the positivity rate was 3.79% (95% confidence interval [CI]: 2.87–4.70%). The working diagnosis at assessment was new onset psychosis in 38.7% and a chronic psychotic syndrome in 34.0%. Among seropositive patients, 30 (47.6%, 95%CI: 35.8–59.7%) had a final alternative diagnosis different from encephalitis after a median period of 49 months from onset. Patients with a final diagnosis of encephalitis were more frequently female (27/35 vs 13/30, p = 0.011) than other seropositive patients and had more frequently an acute (34/35 vs 11/30, p < 0.001), fluctuating (21/23 vs 4/27, p < 0.001) or agitated (32/32 vs 10/26, p < 0.001) presentation. Nine encephalitic patients received specialized follow-up for chronic neuropsychiatric problems including learning disabilities, organic personality disorder, anxiety, fatigue, obsessive–compulsive and autism-like disorder.

Conclusions

In a psychiatric setting, NMDAR-IgG seropositivity rates were low with a positive predictive value for encephalitis around 50% when screened patients had chronic presentations and absence of other diagnostic criteria for encephalitis or psychosis of autoimmune origin. Chronic neuropsychiatric problems in anti-NMDAR encephalitis are not uncommon, so better diagnostic and treatment strategies are still needed.

中文翻译：

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评估精神病患者 N-甲基-D-天冬氨酸受体 (NMDAR-IgG) 抗体的真实经验。回顾性单中心研究

客观的

评估二级心理健康服务中抗 NMDAR 脑炎的发生率，并调查其在常规临床实践中诊断的挑战。

方法

选择其电子健康记录登记了 NMDAR-IgG 评估指征的患者，并对血清阳性患者进行审查。

结果

在 12 年的时间里对 1661 名患者进行了 NMDAR-IgG 评估，阳性率为 3.79%（95% 置信区间 [CI]：2.87–4.70%）。评估时的工作诊断为新发精神病（38.7%）和慢性精神病综合征（34.0%）。在血清阳性患者中，30 例（47.6%，95%CI：35.8-59.7%）在发病后中位 49 个月后出现了与脑炎不同的最终替代诊断。与其他血清阳性患者相比，最终诊断为脑炎的患者中女性的比例更高（27/35 vs 13/30，p = 0.011），并且急性脑炎的比例更高（34/35 vs 11/30，p < 0.001），波动性（ 21/23 vs 4/27，p < 0.001）或激动（32/32 vs 10/26，p < 0.001）。九名脑炎患者接受了针对慢性神经精神问题的专门随访，包括学习障碍、器质性人格障碍、焦虑、疲劳、强迫症和自闭症样障碍。

结论

在精神病学环境中，当筛查的患者有慢性表现且缺乏脑炎或自身免疫性精神病的其他诊断标准时，NMDAR-IgG 血清阳性率较低，对脑炎的阳性预测值约为 50%。抗 NMDAR 脑炎的慢性神经精神问题并不罕见，因此仍然需要更好的诊断和治疗策略。