LETTER TO EDITOR
|Year : 2018 | Volume
| Issue : 1 | Page : 122-123
Pediatric N-methyl-d-aspartate receptor autoimmune encephalitis
Department of Psychiatry, IQRAA International Hospital and Research Centre, Calicut, Kerala, India
|Date of Web Publication||16-May-2018|
Dr. N A Uvais
Department of Psychiatry, IQRAA International Hospital and Research Centre, Calicut, Kerala
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Uvais N A. Pediatric N-methyl-d-aspartate receptor autoimmune encephalitis. J Pediatr Neurosci 2018;13:122-3
I have read the review on “Pediatric autoimmune encephalitis,” with interest.N-methyl-d-aspartate receptor (NMDAR) encephalitis, a newly discovered autoimmune encephalitis with auto-antibodies that target neuronal surface or synaptic antigens, has been identified as a frequent cause of encephalitis among pediatric population. Through this letter, we tried to highlight some recently available information about this disease in pediatric population.
As authors pointed out, anti-NMDAR encephalitis presents with a variety of neuropsychiatric symptoms. A recent case series from a teaching hospital in India reported clinical details of 21 cases from 2010 to 2016, of which 16 were girls, with mean age of the sample between 10 and 11 years. Interestingly, all the children had psychiatric symptoms at clinical presentation, and 47% had it as the first symptom. Mainly mood symptoms such as inappropriate crying, social withdrawal, unprovoked anger outbursts, and unprovoked screaming were reported. Hallucinations, fearfulness, hyperactivity, violence, and inappropriate laughing were infrequently reported. Furthermore, 52.4% of the sample was diagnosed with a psychiatric disorder according to International Classification of Diseases-10: organic mood disorder, organic hallucinosis, organic catatonic disorder, and obsessive compulsive disorder. Majority of the children also had seizures and movement disorder at clinical presentation.
The diagnosis of anti-NMDAR encephalitis requires identification of the antibodies in cerebrospinal fluid and/or serum. Electroencephalogram (EEG) and magnetic resonance imaging (MRI) of the brain are also commonly used to support the diagnosis. The aforementioned case series reported abnormal EEG in 18 children and abnormal MRI of the brain in 8 children.
The role of functional MRI in understanding and diagnosing adult anti-NMDAR encephalitis has been highlighted by a recent study, where authors used structural and resting-state functional MRI to investigate alterations in connectivity in patients with anti-NMDAR encephalitis. The study results showed widespread alterations of functional connectivity even in patients with a normal structural MRI, which correlated with clinical measures. Memory impairment was found to correlate with hippocampal and medial temporal lobe network connectivity, and schizophrenia-like symptoms were correlated with functional connectivity changes in frontoparietal networks. Furthermore, the study identified frontoparietal and frontotemporal connections as reliably discriminating features between patients and controls, yielding an overall accuracy of 81%.
Authors mentioned the association of ovarian teratoma with anti-NMDAR encephalitis. However, in pediatric population, the comorbidity of ovarian teratoma was less frequently found. A past study reported that only ~6% girls younger than 12 years with anti-NMDAR encephalitis had a tumor. In the aforementioned case series from India, none of the patients had a comorbid ovarian teratoma.
The treatment of anti-NMDAR encephalitis includes high-dose corticosteroids, intravenous immunoglobulin (IVIg), and plasma exchange as first-line therapy, and rituximab and/or cyclophosphamide as second-line therapy. In the aforementioned case series from India, all the patients were initially treated with high-dose corticosteroids (30mg/kg/day intravenous infusion for more than 4–5h for 5 days). Thirteen patients needed additional immune modulation (nine received plasmapheresis and four received IVIg). No patient received any second-line therapy, indicating the effectiveness of immunotherapy in pediatric anti-NMDAR encephalitis.
The authors mentioned low efficacy of antipsychotics in controlling psychiatric symptoms and advocated sedative and sleep medications other than benzodiazepines for the same. However, in the aforementioned recent case series from India, 13 children (61.9%) required psychotropic medications for the management of psychiatric symptoms, of which mostly prescribed medications were atypical antipsychotics (quetiapine, risperidone, and olanzapine) and benzodiazepines (clonazepam and lorazepam).
In conclusion, pediatric anti-NMDAR encephalitis is a challenging clinical situation for diagnosis and management, with good prognosis. However, we need further studies in identifying specific neuropsychiatric symptoms in pediatric population, which could be different from adult population. The recent case series highlighted mood-related neuropsychiatric symptomatology in pediatric anti-NMDAR encephalitis. It will be interesting to see functional connectivity abnormalities in functional MRI in pediatric anti-NMDAR encephalitis in comparison to adult anti-NMDAR encephalitis. Furthermore, there is an urgent need of a guideline for the pharmacological management of psychiatric symptoms in pediatric anti-NMDAR encephalitis, which often differ from center to center.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Barbagallo M, Vitaliti G, Pavone P, Romano C, Lubrano R, Falsaperla R. Pediatric autoimmune encephalitis. J Pediatr Neurosci 2017;13:130-4.
Basheer S, Nagappa M, Mahadevan A, Bindu PS, Taly AB, Girimaji SC. Neuropsychiatric manifestations of pediatric NMDA receptor autoimmune encephalitis: A case series from a tertiary care center in India. Prim Care Companion CNS Disord 2017;13. pii: 17m02110. doi: 10.4088/PCC. 17m02110.
Peer M, Prüss H, Ben-Dayan I, Paul F, Arzy S, Finke C. Functional connectivity of large-scale brain networks in patients with anti-NMDA receptor encephalitis: An observational study. Lancet Psychiatry 2017;13:768-74.
Titulaer MJ, McCracken L, Gabilondo I, Armangué T, Glaser C, Iizuka T, et al
. Treatment and prognostic factors for long-term outcome in patients with anti-NMDA receptor encephalitis: An observational cohort study. Lancet Neurol 2013;13:157-65.