Encephalitis In Pediatric Patients Research Articles

Expanded Spectrum of Gad-65 Associated Autoimmune Encephalitis in Pediatric Patients. (P5-5.031)

Expanded Spectrum of Gad-65 Associated Autoimmune Encephalitis in Pediatric Patients. (P5-5.031)

Diagnostic Challenges in Pediatric Anti-NMDA Receptor Encephalitis (P5-5.011)

<h3>Objective:</h3> To describe the progression of symptoms, diagnostic testing, and encounters with the health care system that pediatric patients experience prior to receiving a confirmed diagnosis of anti-NMDAR encephalitis. <h3>Background:</h3> Prompt treatment of anti-NMDAR encephalitis in pediatric patients is associated with improved outcomes, but diagnosis remains challenging. Heterogeneity in presentations, variability based on age, and broad differential diagnoses of associated symptoms in the pediatric population can complicate timely and accurate identification of the disease. <h3>Design/Methods:</h3> A retrospective chart review for patients within Primary Children’s Hospital (PCH) was conducted. ICD10 code G04.81 at PCH between January 2007 to September 2022 was queried to identify pediatric patients with “other encephalitis”. Of these 147 pediatric patients, 18 had confirmed anti-NMDAR encephalitis based on clinical features and positive NMDAR Ig antibody testing in the cerebrospinal fluid <h3>Results:</h3> We identify a cohort of pediatric patients with confirmed anti-NMDAR encephalitis, and discuss duration and progression of symptoms, diagnostic testing, interventions, number of encounters within the health care system, and involved subspecialties prior to a final diagnosis being made. We also review characteristics associated with prolonged times to diagnosis. <h3>Conclusions:</h3> Pediatric patients with anti-NMDAR encephalitis often have an evolution of symptoms, extensive diagnostic evaluations, and multiple encounters with the healthcare system prior to confirmation of diagnosis. Factors associated with prolonged time until diagnosis may aid in identifying those at risk for diagnostic delays. Additionally, recognition of the path to diagnosis these children often take may help physicians better understand the challenges and stressors patients and families face, not only following a diagnosis of anti-NMDAR encephalitis, but also leading up to it. <b>Disclosure:</b> Dr. Wright has nothing to disclose. The institution of an immediate family member of Dr. Liu has received research support from NIH. Mr. Wong has nothing to disclose. Dr. Noroozi Gilandehi has nothing to disclose. Miss Shapiro has nothing to disclose. Dr. Smith has nothing to disclose. The institution of Dr. Peterson has received research support from Kronus. Dr. Clardy has received personal compensation for serving as an employee of Veterans Health Administration (VHA). Dr. Clardy has received personal compensation for serving as an employee of University of Utah Health. Dr. Clardy has received personal compensation in the range of $10,000-$49,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Neurology/AAN Publications. The institution of Dr. Clardy has received research support from Sumaira Foundation for NMO. The institution of Dr. Clardy has received research support from Western Institute for Veteran Research. The institution of Dr. Clardy has received research support from NIH/NINDS. Dr. Clardy has received personal compensation in the range of $500-$4,999 for serving as a AAN Summer Meeting CoDirector Travel and Lodging with AAN. Dr. Clardy has received personal compensation in the range of $500-$4,999 for serving as a Grand Rounds Travel and Lodging with U of Iowa. Dr. Clardy has received personal compensation in the range of $500-$4,999 for serving as a Speaker Honoraria for Grand Rounds with Barrow Neurological Institute. Dr. Clardy has received personal compensation in the range of $500-$4,999 for serving as a Speaker Honoraria for Grand Rounds with Beaumont Health.

The experience of using FilmArray Meningitis/Encephalitis Panel for the diagnosis of meningitis and encephalitis in pediatric patients.

Central nervous system infections can cause severe complications and even death in children. Early diagnosis of the causative pathogen can guide appropriate treatment and improve outcomes. The BioFire® FilmArray® Meningitis/Encephalitis Panel (FA-ME) is a multiplex polymerase chain reaction (PCR) assay targeting 14 pathogens. We aimed to examine FA-ME performance compared with conventional assays and its effect on antimicrobial usage. We prospectively enrolled 55 pediatric patients with suspected meningitis or encephalitis and simultaneously performed FA-ME and conventional assays. Sixty-three hospitalized patients with CNS infection before implementing FA-ME were considered controls. We compared the FA-ME results with conventional assays and the empiric antimicrobial usage and hospital stay between the two study groups. Nine patients (16.4%) tested positive by FA-ME, four were bacterial, and five were viral. Three additional pathogens were detected by conventional assays: Enterococcus faecalis, Leptospira, and herpes simplex virus type 2. In the control group, two bacterial pathogens were detected by CSF culture and four viral pathogens by single PCRs. Compared with the control group, the FA-ME group had a shorter time for pathogen detection, but there were no significant differences in pathogen detection rate, duration of empiric antimicrobial therapy, and length of hospital stay. Although no significant difference was found in empiric antimicrobial duration and length of stay between patients tested with FA-ME and conventional assays, FA-ME had the advantage of a shorter detection time and early exclusion of potential causative pathogens. The FA-ME results should be interpreted carefully based on the clinical presentation.

Human Astrovirus VA1 Encephalitis in Pediatric Patients With Cancer: Report of 2 Cases and Review of the Literature

Novel human astroviruses (HAstVs) have recently been implicated as rare causes of fatal encephalitis in immunocompromised patients, for which there is no proven treatment. We report 2 cases from our institution in which HAstV-VA1 was detected in the cerebrospinal fluid by metagenomic next-generation sequencing after the initial evaluation revealed no etiology.

Thyroid Function and Anti-thyroid Antibodies in Pediatric Anti-NMDAR Encephalitis.

Objective: Recent studies found that changes of thyroid antibodies (ATAbs), thyroid hormone, and non-thyroidal illness syndrome (NTIS) characterized by thyroid hormone inactivation with low triiodothyronine and high reverse triiodothyronine followed by suppressed thyroid-stimulating hormone (TSH) in adult anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis were associated with disease severity. This study aimed to explore thyroid function and ATAbs in pediatric anti-NMDAR encephalitis and their clinical association.Methods: We retrospectively analyzed the clinical data of 51 pediatric cases with anti-NMDAR encephalitis hospitalized in Guangzhou Women and Children's Medical Center from August 2016 to 2019.Results: A percentage of 52.9% of patients belonged to the ATAb (+) group, with 26 cases both positive for anti-thyroid peroxidase antibodies (TPOAb) and anti-thyroglobulin antibodies (TGAb), and one patient only positive for TPOAb. A percentage of 62.7% of patients had at least one abnormality in terms of FT3, free thyroxin (FT4), or TSH levels. Meanwhile, 45.1% of patients were diagnosed with NTIS. Among 25 cases retested for thyroid function 2 months after the initial test, the respectively decreased FT3 and FT4 in 13 and 11 cases on admission returned to normal or closer normal than before; TPOAb in eight cases and TGAb in 12 cases were changed from positivity to negativity. Compared with onset, the level of TPOAb and TGAb at relapse remained stable or significantly decreased, respectively. Compared with the ATAb (–) group, the ATAb (+) group had an older onset age, a higher ratio of movement disorders, elevated rate of sleep disorders, increased anti-nuclear antibody positivity rate, and higher ratio of more than one course of intravenous immunoglobulin treatment. There were no significant differences between the NTIS and non-NTIS groups in clinical characteristics.Conclusion: Anti-thyroid antibody positivity, abnormality of FT3, FT4, or TSH levels and NTIS are frequent in pediatric anti-NMDAR encephalitis. Thyroid antibody and thyroid hormone abnormalities could be improved through the course of treatment of anti-NMDAR encephalitis. Cases with ATAbs (+) are at older onset ages and more likely to be treated by intravenous immunoglobulin therapy more than once. Unlike adult anti-NMDAR encephalitis, NTIS might not be associated with the clinical characteristics of anti-NMDAR encephalitis in pediatric patients.

Clinical Characteristics and Prognostic Factors of Children With Anti-N-Methyl-D-Aspartate Receptor Encephalitis.

Objective: Anti-N-methyl-D-aspartate (anti-NMDA) receptor encephalitis is the most common autoimmune encephalitis in pediatric patients. The study aimed to investigate the clinical characteristics and prognostic factors of anti-NMDA receptor encephalitis in children in South China.Methods: This was a retrospective study of children diagnosed with anti-NMDA receptor encephalitis between 01/2014 and 12/2017 at Hunan Children's Hospital. Laboratory, brain magnetic resonance imaging (MRI), and electroencephalography data were collected. The short-term (6-month) outcomes were assessed using the Liverpool score by the same pediatric neurologist. The children were divided into good (scores 4–5) and poor (score <3) clinical outcomes.Results: Among the 51 patients, 21 (41.2%) were male. The most common clinical symptoms were dyskinesia (88.2%), personality change (84.3%), seizure (82.4%), and cognitive disorder (31.4%). Two were transferred to another hospital, 45 (91.8%) received intravenous immunoglobulins, 41 (83.7%) received methylprednisolone, and 8 (16.3%) received plasma exchange. Eight (16.3%) received rituximab for second-line treatment, six after intravenous immunoglobulin and methylprednisolone treatment, and two after plasma exchange therapy failed. Seven were lost to follow-up. The short-term outcome was good in 23 patients. Cognitive disorder [odds ratio (OR): 23.97, 95% confidence interval (CI): 1.12–513.30, P = 0.042) and abnormal brain MRI (OR: 14.29, 95% CI: 1.36–150.10, P = 0.027] were independently associated with a poor short-term outcome after adjustment for age, GCS, and rituximab use.Conclusions: MRI abnormalities and cognitive disorders are independently associated with poor short-term outcomes in children with anti-NMDA receptor encephalitis. The use of rituximab is not associated with the 6-month outcomes.

Automated diagnosis of encephalitis in pediatric patients using EEG rhythms and slow biphasic complexes.

Slow biphasic complexes (SBC) have been identified in the EEG of patients suffering for inflammatory brain diseases. Their amplitude, location and frequency of appearance were found to correlate with the severity of encephalitis. Other characteristics of SBCs and of EEG traces of patients could reflect the grade of pathology. Here, EEG rhythms are investigated together with SBCs for a better characterization of encephalitis. EEGs have been acquired from pediatric patients: ten controls and ten encephalitic patients. They were split by neurologists into five classes of different severity of the pathology. The relative power of EEG rhythms was found to change significantly in EEGs labeled with different severity scores. Moreover, a significant variation was found in the last seconds before the appearance of an SBC. This information and quantitative indexes characterizing the SBCs were used to build a binary classification decision tree able to identify the classes of severity. True classification rate of the best model was 76.1% (73.5% with leave-one-out test). Moreover, the classification errors were among classes with similar severity scores (precision higher than 80% was achieved considering three instead of five classes). Our classification method may be a promising supporting tool for clinicians to diagnose, assess and make the follow-up of patients with encephalitis.

Clinical, laboratory and immune aspects of Zika virus-associated encephalitis in children

ObjectiveTo evaluate the clinical, laboratory, and immune characteristics of Zika virus (ZIKV)-associated encephalitis in pediatric patients after the epidemic in Huila, southern Colombia. MethodsA pediatric neuro-surveillance hospital study was conducted in a referral health center in southern Colombia, from October 2016 to October 2017. Cases of encephalitis were confirmed by nucleic acid amplification tests and serological methods in cerebrospinal fluid (CSF), plasma, and/or urine. Levels of six cytokines were evaluated by flow cytometry. Patients underwent daily clinical and laboratory follow-up. ResultsTwenty children with probable encephalitis were included for further studies and 16 of them were confirmed. Four cases of bacterial meningoencephalitis (Streptococcus pneumoniae, group B Streptococcus, Staphylococcus epidermidis, and Escherichia coli) and 12 cases of viral encephalitis were identified, six of them associated with ZIKV infection. Other viral encephalitis cases were caused by herpes viruses (n=3), enterovirus (n=2), and dengue virus type 2 (DENV-2; n=1) infections. ZIKV-associated encephalitis symptoms subsided faster than those of patients with encephalitis caused by other agents. CSF analysis revealed lymphocytic pleocytosis. Compared to healthy controls, children with ZIKV-associated encephalitis presented modest plasma interleukin (IL)-10 but not IL-2, IL-4, IL-6, interferon gamma (IFN-γ), or tumor necrosis factor alpha (TNF-α). Cytokine expression was differentially regulated, as dramatically elevated IL-6, IL-10, and IFN-γ levels were observed in CSF but not in paired plasma samples in one of the patients with ZIKV detectable in CSF. ConclusionsThis study provides evidence that ZIKV is responsible for pediatric encephalitis in endemic areas, and the local presence of the virus may induce cephalic but not systemic expression of cytokines.

Japanese encephalitis-induced anti-N-methyl-d-aspartate receptor encephalitis: A hospital-based prospective study

ObjectivesA hospital-based prospective study was performed to determine: 1) whether Japanese encephalitis (JE) normally triggers anti-N-methyl-d-aspartate receptor (NMDAR) immunoglobulin G (IgG) synthesis, especially in monophasic JE patients; and 2) the incidence of JE-induced anti-NMDAR encephalitis in pediatric patients with JE. MethodsWe detected the level of anti-NMDAR IgG in the serum and cerebral spinal fluid (CSF) of JE patients within one week of onset. If patients relapsed during the convalescence phase, we detected JE virus RNA in the CSF and anti-NMDAR IgG in both the serum and CSF. For patients who did not relapse during the convalescence phase, serum was collected and anti-NMDAR IgG was detected during the 30–60-day course of the disease. ResultsWe enrolled 65 JE patients, who were negative for anti-NMDAR IgG in the serum and CSF during the acute phase, of which 63 patients were successfully followed up. Five patients relapsed during the convalescence phase, for whom JE virus RNA in the CSF was negative and excluded latent JE reactivation. The distinctive symptoms of four younger patients were choreoathetosis, whereas the psychiatric and behavioral manifestations were the distinctive symptoms experienced by the teenager. Anti-NMDAR IgG in the CSF of three patients was positive and they were diagnosed with anti-NMDAR encephalitis. The other two patients were negative for anti-NMDAR IgG in both the serum and CSF. For the 58 patients who did not relapse during the convalescence phase, anti-NMDAR IgG was negative in the serum of all patients at 30–60 days during the course of the disease. ConclusionsJE does not typically trigger anti-NMDAR IgG synthesis. Besides anti-NMDAR IgG, other unknown autoantibodies can also cause autoimmune encephalitis in the convalescence phase of JE. The incidence of JE-induced autoimmune encephalitis in pediatric patients with JE was 7.9%, and the incidence of JE-induced anti-NMDAR encephalitis was 4.7%.

Clinical Features, Treatment, and Outcomes Among Chinese Children With Anti-methyl-D-aspartate Receptor (Anti-NMDAR) Encephalitis.

Objective: Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is the most common form of autoimmune encephalitis in pediatric patients. In this study, we aimed to investigate the clinical features and long-term outcomes of pediatric patients with anti-NMDAR encephalitis in China.Methods: We conducted a retrospective study of children (age range: 0–18 years) with anti-NMDAR encephalitis treated at Children's Hospital of Fudan University between July 2015 and November 2018. Demographic characteristics, clinical features, treatment, and outcomes were reviewed.Results: Thirty-four patients with anti-NMDAR encephalitis were enrolled (age range: 5 months to 14 years; median age: 7 years; female: 18). The median follow- up duration was 20 months (range: 6–39 months). Eighteen (52.9%) patients initially presented with seizures and 10 (29.4%) with abnormal (psychiatric) behaviors or cognitive dysfunction. Thirty (88.2%) patients exhibited more than two symptoms during the disease course. No neoplasms were detected. Twelve (35.2%) patients had abnormal cerebrospinal fluid (CSF) findings, including leukocytosis, and increased protein concentration. Eighteen (52.9%) patients exhibited normal brain MRI findings. Electroencephalography revealed abnormal background activity in 27 (79.4%) patients, and epileptiform discharges in 16 (47.0%) patients prior to immunotherapy. All patients received first-line immunotherapy, with 30 (88.2%) and four (11.8%) patients achieving good (Modified Rankin Scale [mRS] score of 0–2) and poor outcomes (mRS score of 3–5), respectively. Initial mRS scores differed significantly between the good and poor outcome groups. Fourteen out of 18 patients (77.7%) with seizures accepted anti-epileptic drug (AED) administration, and seizure freedom was achieved in 12 out of 14 (85.7%) patients at the last follow-up. Ten of these 12 (83.3%) patients withdrew from AED treatment within 1 year.Conclusions: Most patients achieved seizure freedom, so long-term use of AEDs may not be necessary for pediatric patients with anti-NMDAR encephalitis. Among our patients, 83.3% were sensitive to first-line immunotherapy and achieved good outcomes. Higher mRS scores before immunotherapy predicted poor outcomes, highlighting the need for a comprehensive assessment of patients with anti-NMDAR encephalitis.

Early Functional Outcomes for Pediatric Patients Diagnosed with Anti-N-Methyl-D-Aspartate Receptor Encephalitis during Inpatient Rehabilitation.

The aims of the current study were to characterize the demographic and clinical presentation of pediatric patients diagnosed with anti-N-methyl-D-aspartate receptor encephalitis who require inpatient rehabilitation, to examine early functional outcomes, and to investigate predictors of early recovery. A retrospective chart review was conducted for 27 pediatric patients diagnosed with anti-N-methyl-D-aspartate receptor encephalitis who received intensive inpatient neurorehabilitation. On average, patients were 10.6 yrs of age (range, 2-18 yrs) at the time of symptom onset. Average time to treatment from symptom onset was 27.2 days (range, 5-91 days). Patients displayed significant improvements between admission and discharge Functional Independence Measure for Children (WeeFIM) Developmental Functional Quotient (DFQ) scores across patients (P < 0.01). Mean Functional Independence Measure for Children Total Developmental Functional Quotient score at admission was 28.6 (range, 15.0-62.6) and at discharge was 54.3 (range, 14.2-91.9). Younger age at onset, seizures, and number of treatments received were associated with worse functional outcomes at discharge. Time to initiate treatment was not found to be associated with early functional outcomes. Pediatric patients diagnosed with anti-N-methyl-D-aspartate receptor encephalitis displayed significant functional gains during inpatient rehabilitation, despite persistent functional deficits at discharge, suggesting the need for ongoing monitoring and intervention. Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to (1) Recognize the clinical presentation of anti-N-methyl-D-aspartate receptor encephalitis in pediatric patients, (2) Appreciate the role of rehabilitation in the care of the pediatric patient with anti-N-methyl-D-aspartate receptor encephalitis, and (3) Identify demographic and clinical variables that predict poor functional outcomes after rehabilitation in pediatric patients with anti-N-methyl-D-aspartate receptor encephalitis. Advanced. The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Atypical presentation of anti-N-methyl-D-aspartate receptor encephalitis: two case reports

BackgroundAnti-N-methyl-D-aspartate receptor encephalitis is a rare autoimmune disease characterized by severe neurological and psychiatric symptoms and a difficult diagnosis.The disease is often secondary to a neoplastic lesion, seldom diagnosed years later. Psychiatric symptoms are prevalent in adults; neurologic symptoms are more evident in children, who typically present primarily with neurological symptoms. To the best of our knowledge, the association with juvenile idiopathic arthritis has not been described.Case presentationWe report the cases of two caucasian girls with an atypical presentation.The first patient was an 8-year-old girl with normal psychomotor development. Over a 4-month period she developed behavioral problems, speech impairment, and deterioration in academic skills. Within 8 months from the onset of symptoms, choreic movements gradually appeared. Hematological, neuroradiological, and neurophysiological examinations were negative; however, her symptoms worsened and treatment with prednisone was started. Although her choreic movements improved within 1 month, her neuropsychological and behavioral symptoms continued. Anti-N-methyl-D-aspartate receptor antibodies in cerebrospinal fluid and in blood were detected. Therapy with intravenously administered immunoglobulins was administered, without improvement of symptoms. After 2 months of steroid treatment, she suddenly started to pronounce some words with a progressive improvement in language and behavior.The second patient was a 14-year-old girl with classic anti-N-methyl-D-aspartate receptor encephalitis, treated successfully with intravenously administered immunoglobulins and methylprednisolone, followed by orally administered prednisone, who developed chronic arthritis of the hip. The arthritis was confirmed by magnetic resonance imaging and associated to antinuclear antigen antibody positivity.One year after the encephalitis presentation, an ovarian cystic mass was identified as a teratoma. The surgical resection of the mass was followed by the resolution of the psychotic spectrum and arthritis.ConclusionsAnti-N-methyl-D-aspartate receptor encephalitis in pediatric patients can present initially with neuropsychological and behavioral symptoms.In the literature, the association of anti-N-methyl-D-aspartate receptor encephalitis with juvenile idiopathic arthritis is not yet described: to the best of our knowledge, this is the first case reported. The link to a neoplastic lesion can explain the favorable course of encephalitis and arthritis, after the surgical resection of the mass. Early diagnosis and treatment can improve the patient’s outcome.

Predictive and Prognostic Factors of Viral Encephalitis in Pediatric Patients

Predictive and Prognostic Factors of Viral Encephalitis in Pediatric Patients

Enteroviral central nervous system infections in children treated at a hospital in Lima, Peru

To determine the frequency and clinical features of central nervous system infections caused by enterovirus in children treated at the Hospital Nacional Cayetano Heredia in Lima, Peru. A prospective, descriptive study was performed from April 2008 to March 2010. Patients aged 1 month - 14 years with clinical diagnosis of encephalitis or aseptic meningitis were included. We investigated the presence of enterovirus, herpes simplex virus 1 (HSV-1), herpes simplex virus 2 (HSV-2) and varicella-zoster virus (VZV) by polymerase chain reaction (PCR). 97 patients were included, out of which 69 % had acute encephalitis and 31 % acute meningitis. Enteroviruses were identified in 52,6% of all acute non-bacterial central nervous system infections; corresponding to 83,3 % of meningitis and 38,8 % of encephalitis. There were no cases of infection due to HSV-1, HSV-2 or VZV. Enterovirus infections reached 82,9 % in the warm months (November-January) and 28,6 % in the colder months (May-July). Enteroviruses are the principal etiologic agents in acute aseptic meningitis and encephalitis in pediatric patients in Lima, Peru. Enteroviruses have a seasonal epidemiological pattern with a clear increase in the number of cases during the summer months. It is useful to have this rapid diagnostic method available as an aid in the management of acute central nervous system infections.

Infecciones del sistema nervioso central por enterovirus en niños atendidos en un hospital de Lima, Perú

Objectives. To determine the frequency and clinical features of central nervous system infections caused by enterovirus in children treated at the Hospital Nacional Cayetano Heredia in Lima, Peru. Materials and methods. A prospective, descriptive study was performed from April 2008 to March 2010. Patients aged 1 month – 14 years with clinical diagnosis of encephalitis or aseptic meningitis were included. We investigated the presence of enterovirus, herpes simplex virus 1 (HSV-1), herpes simplex virus 2 (HSV-2) and varicella-zoster virus (VZV) by polymerase chain reaction (PCR). Results. 97 patients were included, out of which 69 % had acute encephalitis and 31 % acute meningitis. Enteroviruses were identified in 52,6% of all acute non-bacterial central nervous system infections; corresponding to 83,3 % of meningitis and 38,8 % of encephalitis. There were no cases of infection due to HSV-1, HSV-2 or VZV. Enterovirus infections reached 82,9 % in the warm months (November-January) and 28,6 % in the colder months (May-July). Conclusions. Enteroviruses are the principal etiologic agents in acute aseptic meningitis and encephalitis in pediatric patients in Lima, Peru. Enteroviruses have a seasonal epidemiological pattern with a clear increase in the number of cases during the summer months. It is useful to have this rapid diagnostic method available as an aid in the management of acute central nervous system infections.

Early electro-clinical features may contribute to diagnosis of the anti-NMDA receptor encephalitis in children

ObjectiveTo describe initial and follow-up electroencephalographic (EEG) characteristics in anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis. MethodsConsecutive polygraphic video-EEG recordings were analyzed in nine pediatric patients with anti-NMDAR encephalitis at the initial stage of the disease and during the intermediate period until motor recovery. EEG characteristics in waking and sleep stages as well as EEG correlates of abnormal movements are described. ResultsIn six of nine patients with anti-NMDAR encephalitis, the waking EEG showed preserved background activity and either focal or unilateral hemispheric slowing. During non-rapid eye movement (NREM) sleep, a decrease in the expected slow waves and unilateral or diffuse theta-alpha band rhythms were also observed in six of nine children. They all had more favorable outcome than the three children with diffuse slowing. Clinically, unilateral abnormal movements contra-lateral to hemispheric or focal slowing were also indicative of milder severity when compared to generalized abnormal movements and diffuse slowing. ConclusionsIn pediatric patients presenting behavioral disorders and abnormal movements, early EEG patterns may be suggestive of anti-NMDAR encephalitis. Moreover early electro-clinical presentation contributes to outcome prediction. SignificanceThis case series demonstrates that early EEG patterns may be suggestive of anti-NMDAR encephalitis in pediatric patients with behavioral disorders and abnormal movements.

Subtype-specific, probe-based, real-time PCR for detection and typing of human herpesvirus-6 encephalitis from pediatric patients under the age of 2 years

To investigate the frequency of human herpesvirus-6 (HHV-6) encephalitis in pediatric patients under 2 years of age, we developed a method for the simultaneous detection and differentiation of the 2 variants of HHV-6 (HHV-6A and HHV-6B) using subtype-specific, probe-based, real-time PCR (SSPBRT-PCR) and which were further evaluated on 405 cerebrospinal fluid (CSF) specimens from children with suspected encephalitis. A total of 23 (5.70%) out of 405 CSF specimens were positive by SSPBRT-PCR, including 3 cases of HHV-6A and 20 cases of HHV-6B. The positive rate of HHV-6B was significantly higher than that of HHV-6A ( P = 0.0004). Compared with the results of the conventional real-time PCR, the sensitivity and specificity of the SSPBRT-PCR assay were 95.24% and 99.22%, respectively. This study suggests a role for both variants of HHV-6 in the pathogenesis of viral encephalitis. SSPBRT-PCR can provide rapid, sensitive, and specific results for identification of HHV-6A and HHV-6B and management of HHV-6 encephalitis.

Mycoplasma pneumoniae Encephalitis and Cytokines: In Reply

We appreciate Dr Narita's letter in response to our article describing Mycoplasma pneumoniae –associated encephalitis in pediatric patients.1 Dr Narita describes 1 potential mechanism of encephalitis …

Pathogenesis of enterovirus 71 brainstem encephalitis in pediatric patients: roles of cytokines and cellular immune activation in patients with pulmonary edema.

Taiwan experienced several epidemics of enterovirus 71 (EV71) infections, which were associated with brainstem encephalitis (BE) and pulmonary edema (PE). To elucidate the role of immune mechanisms in the pathogenesis of BE caused by EV71 and its fatal complication, PE, we analyzed the laboratory findings, cytokine, and immunophenotypes of 73 EV71-infected patients with BE. Patients were stratified by disease: PE (n=14), autonomic nervous system (ANS) dysregulation (n=25), and isolated BE (n=34). The mortality rate for PE was 64.3%. Leukocytosis and thrombocytosis were significantly more frequent among patients with PE. A significant elevation of plasma interleukin (IL)-10, IL-13, and interferon (IFN)-gamma levels observed in patients with PE. Patients with PE also had lower circulating CD4(+) T cells, CD8(+) T cells, and natural killer (NK) cells. An extensive peripheral and central nervous system inflammatory response with abnormal IL-10, IL-13, and IFN-gamma cytokine production and lymphocyte depletion appears to be responsible for the pathogenesis of EV71-associated PE.