Assessment of cognitive status in pediatric anti-NMDA receptor encephalitis during inpatient rehabilitation: A retrospective cohort

Isolated Psychiatric Symptoms in Children With Anti-N-Methyl-d Aspartate Receptor Encephalitis

BACKGROUND

Isolated psychiatric symptoms can be the initial symptom of pediatric anti-N-methyl-d-aspartate (NMDA) receptor autoimmune encephalitis (pNMDARE). Here we report on the prevalence of isolated psychiatric symptoms in pNMDARE. We also assess whether initial neurodiagnostic tests (brain magnetic resonance imaging [MRI], electroencephalography [EEG], and/or cerebrospinal fluid [CSF] white blood cell count) are abnormal in children with isolated psychiatric symptoms and pNMDARE.

METHODS

This multicenter retrospective cohort study from CONNECT (Conquering Neuroinflammation and Epilepsies Consortium) from 14 institutions included children under age 18 years who were diagnosed with pNMDARE. Descriptive statistics using means, medians, and comparisons for continuous versus discrete data was performed.

RESULTS

Of 249 children included, 12 (5%) had only psychiatric symptoms without other typical clinical features of autoimmune encephalitis at presentation. All but one (11 of 12 = 92%) had at least one abnormal finding on initial ancillary testing: eight of 12 (67%) had an abnormal EEG, six of 12 (50%) had an abnormal MRI, and five of 12 (42%) demonstrated CSF pleocytosis. The single patient with a normal MRI, EEG, and CSF profile had low positive CSF NMDA antibody (titer of 1:1), and symptoms improved without immunotherapy.

CONCLUSIONS

Isolated first-episode psychiatric symptoms in pNMDARE are uncommon, and the majority of children will exhibit additional neurodiagnostic abnormalities. Delaying immunotherapy in a child with isolated psychiatric symptoms and normal neurodiagnostic testing may be warranted while awaiting confirmatory antibody testing.

Rate of Autoimmune Encephalitis in Children With First-Episode Psychosis

BACKGROUND

Autoimmune encephalitis (AE) can present as first-episode psychosis (FEP) in children. An FEP diagnostic algorithm has been proposed, but how this algorithm applies to children is unknown. We assess the FEP diagnostic algorithm in children with FEP.

METHODS

The FEP algorithm was applied to a retrospective cohort of children with FEP without other neurological symptoms.

RESULTS

Twenty-four patients were included, with five AE (anti-N-methyl-d-aspartate receptor encephalitis) and 19 non-AE patients (12 primary psychiatric, two headaches, mycoplasma-related encephalitis, post-coronavirus disease 2019 encephalitis, drug reaction with eosinophilia and systemic symptoms [DRESS] syndrome, cobalamin C deficiency, and two unknown). Some non-AE patients (five of 19 = 26%) received immunotherapies, with symptom resolution in one of five (20%) with immunotherapy and in four of 14 (29%) without immunotherapy. The FEP algorithm recommended cerebrospinal fluid (CSF) testing in all (five of five = 100%) patients with AE and in six of 19 (32%) non-AE patients, resulting in 100% sensitivity (95% confidence interval [CI]: 100% to 100%) and 45.5% specificity (95% CI: 16% to 75%), with a negative predictive value of 100% (95% CI: 100% to 100%).

CONCLUSIONS

FEP can occur in children from different causes, including AE and metabolic conditions. Evaluation of FEP should be broad, especially without CSF evidence of inflammation. The FEP algorithm is useful to assess patients who would benefit from CSF testing and should be assessed in larger cohorts.

Aetiology and Prognosis of Encephalitis in Korean Children: A Retrospective Single-Centre Study, 2005-2020

PURPOSE

Encephalitis is a heterogeneous syndrome that occurs in childhood and is not rare. However, epidemiological studies of encephalitis based on the International Encephalitis Consortium (ICS) and expert recommendations are lacking. We investigated the aetiology and prognosis of encephalitis in Korean children.

MATERIALS AND METHODS

This retrospective study included children aged <19 years hospitalised for encephalitis at Severance Children's Hospital between 2005 and 2020. The 2013 ICS criteria were used to diagnose encephalitis, and causality was classified according to the site from which the specimen was obtained. Neurological sequelae were categorised using the modified Rankin Scale (mRS) score.

RESULTS

In total, 551 children were included, with 7% classified as possible, 77% as probable, and 15% as proven cases. A cause was identified in 42% of the cases (n=222), with viruses being the most common (42%), followed by bacteria (38%) and autoimmune encephalitis (12%). In cases of proven/probable encephalitis (n=65), bacteria accounted for 52%, followed by viruses (25%) and autoimmune encephalitis (22%). In cases with a single pathogen, the anti-N-methyl-D-aspartate receptor autoantibody (n=14) was the most common, followed by Group B streptococcus (n=13), herpes simplex virus (n=11), enterovirus (n=4), and others. Approximately 37% of patients had severe sequelae (mRS score ≥3) at discharge, which decreased to 31% 6 months after discharge.

CONCLUSION

This large-scale study showed that autoimmune and infectious causes accounted for a significant proportion of encephalitis in Korean children. Further studies are needed to determine whether early targeted treatment following early diagnosis leads to a favourable prognosis in these populations.

The Impact of Neuroimmunologic Disease and Developing Nervous System

Over the last two decades, neuroimmunologic disorders of childhood have been increasingly described, phenotyped, and treated. These disorders remain rare in the general population and while sharing common therapeutic interventions due to their immune pathophysiology, are heterogeneous with regard to presentation and risk of recurrence. As such, the impact of these disorders on the developing brain has come into the forefront of emerging research in pediatric neuroimmunology. Investigations into the singular impact of monophasic disease on long-term development and the impact of early and aggressive disease-modifying therapy in relapsing conditions are quickly becoming areas of ripe investigation as the field's most optimal way to treat and monitor these conditions over time. Although critically important in evaluating the developing brain, research has been heterogeneous among these diseases and limited by small cohort size. This narrative review details the role of common neuroimmunologic disorders in long-term neurological and cognitive outcomes in children as they develop.

Sleep Characteristics in Pediatric Anti-N-methyl-d-aspartate (NMDA) Receptor Encephalitis: A Retrospective Cohort Study

Background: Rates of sleep problems in children with anti-N-methyl-d-aspartate (NMDA) receptor encephalitis are unknown. Methods: We used a retrospective observational cohort database of children with a diagnosis of NMDA receptor encephalitis at a single freestanding institution. One-year outcomes were assessed with the pediatric modified Rankin Score (mRS), with 0 to 2 as good and 3 or greater as poor outcome. Results: Ninety-five percent (39/41) of children with NMDA receptor encephalitis had sleep dysfunction at onset; 34% (11/32) reported sleep problems at 1 year. Sleep problems at onset and propofol use were not associated with poor outcomes at 1 year. Poor sleep at 1 year correlated with mRS scores (range 2-5) at 1 year. Discussion: High rates of sleep dysfunction occur in children with NMDA receptor encephalitis. Persistent sleep problems at 1 year may correlate with outcomes as assessed by mRS at 1 year. Further studies comparing the relationship of poor sleep with outcomes in NMDA receptor encephalitis are needed.