Cause Of Encephalitis In Children Research Articles

Treatment Approaches in Pediatric Relapsing Autoimmune Encephalitis

Abstract Purpose of review Autoimmune encephalitis (AE) is increasingly recognized as a treatable cause of encephalitis in children. While prior observational studies demonstrate improved motor outcomes with early immunotherapy, less is known about long-term management and treatment for relapsing disease. In this review, we present current treatment approaches to pediatric AE, in particular relapse risk and treatment for relapsing AE in children. Recent findings A recent meta-analysis of anti-NMDAR encephalitis demonstrated that disease onset in adolescence was associated with an increased odds of relapse whereas treatment with rituximab and IVIG for 6 months or longer were associated with a non-relapsing course. However, no specific pediatric sub-analyses were reported. A single-center study on adult and pediatric AE showed that rituximab use was associated with a reduction in time to relapse and recurring relapses although the data for the pediatric cohort did not achieve statistical significance. Summary The use of second-line immunotherapy during the initial attack may reduce the risk for relapsing disease in pediatric AE. Larger studies are needed to investigate relapse risk and treatment in both anti-NMDAR and non-NMDAR encephalitis in children.

Study protocol: The clinical features, epidemiology, and causes of paediatric encephalitis in southern Vietnam

Encephalitis is a major cause of morbidity and mortality worldwide. The clinical syndrome of encephalitis consists of altered mental status, seizures, neurologic signs, and is often accompanied by fever, headache, nausea, and vomiting. The encephalitis in children has been known that more common than in adult, with the incidence rate of infants was 3.9 times higher than that of people 20-44 years of age. The reported incidence of hospitalization attributed to paediatric encephalitis ranged from 3 to 13 admissions per 100,000 children per year with the overall mortality ranging from 0 to 7%. There are however more than 100 pathogens that can cause encephalitis and accurate diagnosis is challenging. Over 50% of patients with encephalitis are left undiagnosed despite extensive laboratory investigations. Furthermore, recent studies in high-income settings have suggested autoimmune encephalitis has now surpassed infectious aetiologies, mainly due to increased awareness and diagnostic capacity, which further challenges routine diagnosis and clinical management, especially in developing countries. There are limited contemporary data on the causes of encephalitis in children in Vietnam. Improving our knowledge of the causative agents of encephalitis in this resource-constrained setting remains critical to informing case management, resource distribution and vaccination strategy. Therefore, we conduct a prospective observational study to characterise the clinical, microbiological, and epidemiological features of encephalitis in a major children's hospital in southern Vietnam. Admission clinical samples will be collected alongside meta clinical data and from each study participants. A combination of classical assays (serology and PCR) and metagenomic next-generation sequencing will used to identify the causative agents. Undiagnosed patients with clinical presentations compatible with autoimmune encephalitis will then be tested for common forms of the disease. Finally, using direct- and indirect costs, we will estimate the economic burden of hospitalization and seven days post hospital discharge of paediatric encephalitis in our setting.

Autoimmune Encephalitis.

Autoimmune encephalitis is a common and treatable cause of encephalitis in children and adults. Individuals present with a variety of symptoms, including altered mental status, behavioral changes, irritability, insomnia, developmental regression, seizures, dyskinetic movements, and autonomic instability. Evaluation includes electroencephalography, magnetic resonance imaging, and lumbar puncture. Once infectious and other causes are reasonably ruled out, treatment should be started empirically without waiting for antibody confirmation. Early clinical suspicion is key, as the outcome depends on early initiation of immunotherapy, including corticosteroids, intravenous immunoglobulin, and/or plasmapheresis. Severe or refractory cases require other treatments, such as rituximab, cyclophosphamide, or other immunotherapies using novel monoclonal antibodies. Psychiatry should be involved early for the management of behavioral issues. Additional considerations include management of seizures and dyskinesias. ICU admission may be required for management of hypoventilation necessitating mechanical ventilation (either intrinsic or iatrogenic, eg, from sedatives), refractory seizures, and dysautonomia. Anti-N-methyl-d-aspartate receptor and other forms of autoimmune encephalitis are less often associated with neoplasia (such as ovarian teratoma) in children compared with adults, but screening and removal of tumor if present should be performed.

The role of clinical diagnostic criteria for anti-N-methyl-D-aspartate receptor encephalitis in children: A case report

Encephalitis is a neurological disorder that develops rapidly into a progressive encephalopathy caused by inflammatory processes in the brain. The incidence of encephalitis in developed countries is 5-10 per 100,000 per year. Encephalitis can affect all ages and cause long-term effects on patients, their families, and society.1-3 Autoimmune encephalitis, including anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis, is increasingly recognized as a cause of encephalitis in children and has a considerable mortality rate of 5-7%.4  Physicians should suspect anti-NMDAR encephalitis in patients with prominent neuropsychiatric symptoms and movement disorder.1-3 We report here a case of anti-NMDAR encephalitis and discuss the role of clinical criteria in diagnosing anti-NMDAR encephalitis in children.

Study protocol: The clinical features, epidemiology, and causes of paediatric encephalitis in southern Vietnam.

Encephalitis is a major cause of morbidity and mortality worldwide. The clinical syndrome of encephalitis consists of altered mental status, seizures, neurologic signs, and is often accompanied by fever, headache, nausea, and vomiting. The encephalitis in children has been known that more common than in adult, with the incidence rate of infants was 3.9 times higher than that of people 20-44 years of age. The reported incidence of hospitalization attributed to paediatric encephalitis ranged from 3 to 13 admissions per 100,000 children per year with the overall mortality ranging from 0 to 7%. There are however more than 100 pathogens that can cause encephalitis and accurate diagnosis is challenging. Over 50% of patients with encephalitis are left undiagnosed despite extensive laboratory investigations. Furthermore, recent studies in high-income settings have suggested autoimmune encephalitis has now surpassed infectious aetiologies, mainly due to increased awareness and diagnostic capacity, which further challenges routine diagnosis and clinical management, especially in developing countries. There are limited contemporary data on the causes of encephalitis in children in Vietnam. Improving our knowledge of the causative agents of encephalitis in this resource-constrained setting remains critical to informing case management, resource distribution and vaccination strategy. Therefore, we conduct a prospective observational study to characterise the clinical, microbiological, and epidemiological features of encephalitis in a major children's hospital in southern Vietnam. Admission clinical samples will be collected alongside meta clinical data and from each study participants. A combination of classical assays (serology and PCR) and metagenomic next-generation sequencing will used to identify the causative agents. Undiagnosed patients with clinical presentations compatible with autoimmune encephalitis will then be tested for common forms of the disease. Finally, using direct- and indirect costs, we will estimate the economic burden of hospitalization and seven days post hospital discharge of paediatric encephalitis in our setting.

Study protocol: The clinical features, epidemiology, and causes of paediatric encephalitis in southern Vietnam

Encephalitis is a major cause of morbidity and mortality worldwide. The clinical syndrome of encephalitis consists of altered mental status, seizures, neurologic signs, and is often accompanied by fever, headache, nausea, and vomiting. The encephalitis in children has been known that more common than in adult, with the incidence rate of infants was 3.9 times higher than that of people 20-44 years of age. The reported incidence of hospitalization attributed to paediatric encephalitis ranged from 3 to 13 admissions per 100,000 children per year with the overall mortality ranging from 0 to 7%. There are however more than 100 pathogens that can cause encephalitis and accurate diagnosis is challenging. Over 50% of patients with encephalitis are left undiagnosed despite extensive laboratory investigations. Furthermore, recent studies in high-income settings have suggested autoimmune encephalitis has now surpassed infectious aetiologies, mainly due to increased awareness and diagnostic capacity, which further challenges routine diagnosis and clinical management, especially in developing countries. There are limited contemporary data on the causes of encephalitis in children in Vietnam. Improving our knowledge of the causative agents of encephalitis in this resource-constrained setting remains critical to informing case management, resource distribution and vaccination strategy. Therefore, we conduct a prospective observational study to characterise the clinical, microbiological, and epidemiological features of encephalitis in a major children’s hospital in southern Vietnam. Admission clinical samples will be collected alongside meta clinical data and from each study participants. A combination of classical assays (serology and PCR) and metagenomic next-generation sequencing will used to identify the causative agents. Undiagnosed patients with clinical presentations compatible with autoimmune encephalitis will then be tested for common forms of the disease. Finally, using direct- and indirect costs, we will estimate the economic burden of hospitalization and seven days post hospital discharge of paediatric encephalitis in our setting.

Study protocol: The clinical features, epidemiology, and causes of paediatric encephalitis in southern Vietnam

Encephalitis is a major cause of morbidity and mortality worldwide. The clinical syndrome of encephalitis consists of altered mental status, seizures, neurologic signs, and is often accompanied by fever, headache, nausea, and vomiting. The encephalitis in children has been known that more common than in adult, with the incidence rate of infants was 3.9 times higher than that of people 20-44 years of age. The reported incidence of hospitalization attributed to paediatric encephalitis ranged from 3 to 13 admissions per 100,000 children per year with the overall mortality ranging from 0 to 7%. There are however more than 100 pathogens that can cause encephalitis and accurate diagnosis is challenging. Over 50% of patients with encephalitis are left undiagnosed despite extensive laboratory investigations. Furthermore, recent studies in high-income settings have suggested autoimmune encephalitis has now surpassed infectious aetiologies, mainly due to increased awareness and diagnostic capacity, which further challenges routine diagnosis and clinical management, especially in developing countries. There are limited contemporary data on the causes of encephalitis in children in Vietnam. Improving our knowledge of the causative agents of encephalitis in this resource-constrained setting remains critical to informing case management, resource distribution and vaccination strategy. Therefore, we conduct a prospective observational study to characterise the clinical, microbiological, and epidemiological features of encephalitis in a major children's hospital in southern Vietnam. Admission clinical samples will be collected alongside meta clinical data and from each study participants. A combination of classical assays (serology and PCR) and metagenomic next-generation sequencing will used to identify the causative agents. Undiagnosed patients with clinical presentations compatible with autoimmune encephalitis will then be tested for common forms of the disease. Finally, using direct- and indirect costs, we will estimate the economic burden of hospitalization and seven days post hospital discharge of paediatric encephalitis in our setting.

Childhood Infectious Encephalitis: An Overview of Clinical Features, Investigations, Treatment, and Recent Patents.

Infectious encephalitis is a serious and challenging condition to manage. This overview summarizes the current literature regarding the etiology, clinical manifestations, diagnosis, management, and recent patents of acute childhood infectious encephalitis. We used PubMed Clinical Queries as a search engine and used keywords of "encephalitis" AND "childhood" Patents were searched using the key term "encephalitis" in google.patents.- com and patentsonline.com. Viral encephalitis is the most common cause of acute infectious encephalitis in children. In young children, the clinical manifestations can be non-specific. Provision of empiric antimicrobial therapy until a specific infectious organism has been identified, which in most cases includes acyclovir, is the cornerstone of therapy. Advanced investigation tools, including nucleic acid-based test panel and metagenomic next-generation sequencing, improve the diagnostic yield of identifying an infectious organism. Supportive therapy includes adequate airway and oxygenation, fluid and electrolyte balance, cerebral perfusion pressure support, and seizure control. Recent patents are related to the diagnosis, treatment, and prevention of acute infectious encephalitis. Viral encephalitis is the most common cause of acute infectious encephalitis in children and is associated with significant morbidity. Recent advances in understanding the genetic basis and immunological correlation of infectious encephalitis may improve treatment. Third-tier diagnostic tests may be incorporated into clinical practice. Treatment is targeted at the infectious process but remains mostly supportive. However, specific antimicrobial agents and vaccines development is ongoing.

Detection of recent infection of Japanese encephalitis virus in swine population using IgM ELISA: A suitable sentinel to predict infection in humans

Japanese encephalitis (JE) is a mosquito-borne flaviviral zoonotic disease and is one of the major causes of encephalitis in children. Swine, being an amplifier host of Japanese encephalitis virus (JEV), play an important role in its epidemiology. Therefore, early detection of either JEV or antibodies against JEV in swine is a feasible alternative for initiating necessary measures to prevent the spread of infection to humans. Since IgM antibodies appear early in swine sera, recombinant NS1 protein based indirect IgM ELISA was developed in the present study with the objective to know the recent infection of swine population with JEV. The relative diagnostic sensitivity and specificity of the developed ELISA was 95.34% and 98.6%, respectively. The developed ELISA was found to have excellent reproducibility on inter-laboratory and inter-institutional validation studies. A total of 3,027 field swine sera samples were screened using the developed ELISA and 488 samples were found positive for IgM against JEV with an overall sero-positivity of 16.12% in swine population of India. The highest sero-positivity was observed in swine population of Eastern zone of India which coincided with the maximum number of human JE cases reported from this zone during the same period. Further, antibody kinetics study revealed that the IgM antibodies against NS1 protein of JEV started appearing in swine sera at day 5 and disappeared completely by day 40. The IgG antibodies started appearing at day 7, and remained for more than 365 days indicating the suitability of IgM ELISA to know the recent infection of JEV. The developed IgM ELISA can be readily incorporated into surveillance programs for detection of JEV activity in swine population so that outbreaks in humans can be prevented by taking suitable preventive measures.

Autoimmune Encephalitis in Children: A Case Series at a Tertiary Care Center.

Autoimmune encephalitis is the third most common cause of encephalitis in children. We provide a detailed account of presenting symptoms, diagnosis, and response to treatment in pediatric autoimmune encephalitis patients evaluated at University of California San Francisco within a 2.5-year period. Eleven were identified: anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis (n = 4), antibody-negative autoimmune encephalitis (n = 4), steroid-responsive encephalopathy associated with thyroiditis (SREAT) (n = 2), and glial fibrillary acidic protein (GFAP)-associated encephalitis (n = 1). Most common presenting symptoms included seizures and behavior changes (54%). More than 90% of patients showed improvement following first-line immunotherapy (high-dose corticosteroids, intravenous immunoglobulin, and/or plasma exchange). A total of 64% received second-line treatment with rituximab, cyclophosphamide, or mycophenolate mofetil. One patient with NMDAR encephalitis died despite escalating immunotherapy. None of the patients showed complete recovery after median follow-up of 9 months (range 0.5-66). Children with autoimmune encephalitis have a diverse clinical presentation and may lack an identifiable autoantibody. Majority of patients show a good response to immunotherapy; however, recovery can be delayed.

Cerebral 18FluoroDeoxy-Glucose Positron Emission Tomography in paediatric anti N-methyl-d-aspartate receptor encephalitis: A case series

BackgroundAnti-N-methyl-d-aspartate receptor (NMDAR) encephalitis is a frequent and severe cause of encephalitis in children with potential efficient treatment (immunotherapy). Suggestive clinical features are behavioural troubles, seizures and movement disorders. Prompt diagnosis and treatment initiation are needed to guarantee favourable outcome. Nevertheless, diagnosis may be challenging because of the classical ancillary test (magnetic resonance imaging (MRI), electroencephalogram, standard cerebro-spinal fluid analysis) have limited sensitivity. Currently, immunological analyses are needed for the diagnostic confirmation. In adult patients, some studies suggested a potential role of cerebral 18FluoroDeoxy-Glucose Positron Emission Tomography (FDG-PET) in the evaluation of anti-NMDAR encephalitis. Nevertheless, almost no data exist in paediatric population. MethodWe report retrospectively clinical, ancillary tests and cerebral FDG-PET data in 6 young patients (median age=10.5years, 4 girls) with immunologically confirmed anti-NMDAR encephalitis. ResultsOur patients presented classical clinical features of anti-NMDAR encephalitis with severe course (notably four patients had normal MRI). Our series shows the feasibility and the good sensitivity of cerebral FDG-PET (6/6 patients with brain metabolism alteration) in paediatric population. We report some particular features in this population: extensive, symmetric cortical hypometabolism especially in posterior areas; asymmetric anterior focus of hypermetabolism; and basal ganglia hypermetabolism. We found also a good correlation between the clinical severity and the cerebral metabolism changes. Moreover, serial cerebral FDG-PET showed parallel brain metabolism and clinical improvement. ConclusionOur study reveals the existence of specific patterns of brain metabolism alteration in anti-NMDAR encephalitis in paediatric population.

Encephalitis in Australian children: contemporary trends in hospitalisation.

The clinical epidemiology of childhood encephalitis in Australia is inadequately understood. We aimed to describe recent trends in childhood encephalitis-related hospitalisation. We identified encephalitis-related hospital admissions (2000-2012) in national datasets among children ≤14 years using ICD encephalitis codes. We calculated hospitalisation rates and analysed trends by year, age, gender, location, indigenous status and aetiology. Rates of childhood encephalitis hospitalisations significantly declined over an 11-year period (2000-2012; average hospitalisation rate 3.2/100 000). Varicella encephalitis hospitalisations decreased significantly, associated with high levels of varicella vaccine coverage since 2006. Acute disseminated encephalomyelitis (ADEM) was the most common 'specified' cause of encephalitis hospitalisation (15%-17%), and its rate has significantly increased. The highest hospitalisation rates occurred in the <1 year age group (5.8/100 000) and varied by location (highest in Northern Territory). The majority (58.9%) of hospitalised encephalitis had no cause identified; this proportion was highest in the <1 year age group (77%). The most common specified infectious causes included: herpes simplex virus, enterovirus, bacterial meningoencephalitis and varicella. When aggregated, the proportion of childhood encephalitis coded as viral was 21.2%. Hospitalisation of childhood encephalitis has slightly decreased in Australia. High rates of childhood immunisation have been associated with a reduction of varicella-associated encephalitis in Australian children. ADEM, an immune-mediated encephalitis, is the most common recognised cause of encephalitis in children. Young children (<1 year) have the highest admission rates. The high proportion of 'unspecified' encephalitis deaths and hospitalisations is an ongoing challenge.

Case of a Two-Year-Old Boy With Recurrent Seizures, Abnormal Movements, and Central Hypoventilation

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis was first described in young women with ovarian teratoma. Typical presentations include subacute onset of neuropsychiatric symptoms, seizures, altered awareness, movement disorders, and autonomic dysfunction. Growing evidence indicates that anti-NMDAR encephalitis is one of the most common causes of encephalitis in children and young adults. We present a case of a 2 year-old boy with anti-NMDAR encephalitis to illustrate and discuss the differences in neurological presentation, frequency of symptoms, and association with underlying tumor between children and adults.

Identification of human bocaviruses in the cerebrospinal fluid of children hospitalized with encephalitis in China

BackgroundEncephalitis is a major cause of death and disability in adults and children; different members in the family Parvoviridae are known to be associated with encephalitis to some extent. ObjectivesTo determine the presence of human bocaviruses (HBoVs) and corresponding HBoV-specific immunoglobulins (Igs) in cerebrospinal fluid from children with suspected viral encephalitis. Study designEmploying real-time PCR and nested touchdown PCR, 67 cerebrospinal fluid (CSF) samples from children with suspected viral encephalitis were screened for HBoV and routine encephalitis-causing viruses. Using ELISA, Western blot and IFA, HBoV-specific Ig were determined in the samples. ResultsNine samples (134%) were HBoV1 DNA-positive, while one sample (15%) was HBoV2 DNA-positive. HBoV-specific IgM and IgG antibodies were detected in the CSF samples from three children; two samples were HBoV1 DNA-positive and one sample was negative. One death was recorded; CSF from this child was the only HBoV-IgM-positive CSF samples among the 67 CSF tested. ConclusionWe screened CSF samples obtained from children with encephalitis for the presence of HBoV1 and HBoV2 and specific IgM- or IgG-responses. Detection of viral DNA and/or immunological response to HBoV1/HBoV2 highlights the significance of these viruses as causes of encephalitis in children. Further studies are needed to examine the role of HBoV infection in children encephalitis.

Molecular Epidemiological Study of Enteroviruses Associated with Encephalitis in Children from India

Enteroviruses have been reported in encephalitis cases. However, clinical and epidemiological characteristics of enteroviruses in encephalitis are not fully established. We prospectively investigated 204 children with encephalitis over a period of 2 years (2009 to 2010) for enterovirus. Enterovirus was detected in 45 specimens (22.1%); of these, 40 were typed by seminested reverse transcription-PCR (RT-PCR) and sequencing of the VP1 gene. Molecular typing of enterovirus revealed the predominance of echovirus 21 associated with an epidemic during the rainy seasons of 2010 and the circulation of echovirus 1, coxsackievirus B1, enterovirus 75, enterovirus 76, coxsackievirus B5, and echovirus 19. The nucleotide divergence among echovirus 21 strains was 0 to 2% at the nucleotide level. This study suggests that enterovirus is an important cause of encephalitis in children from India. To our knowledge, this is the first report of echovirus 21 in encephalitis cases worldwide.

Chikungunya virus is a cause of encephalitis in children in bellary, India

Introduction: Chikungunya virus, a single stranded RNA Alphavirus of the family Togaviridae, is transmitted to humans by the bite of Aedes aegypti, Aedes albopictus and other mosquitoes. An epidemic starting in Reunion Islands in March 2005 spread to Southern India, affecting 1.3 million people between Oct 2005 and Oct 2006. The epidemic reached Bellary, Karnataka in southern India by Dec 2005. Methods: From Oct 2005 to Dec 2007, children admitted to the paediatric department of the Vijayanagar Institute of Medical Sciences with an acute encephalitis syndrome were prospectively studied. All children presenting to the paediatric ward were recruited if they had suspected CNS infection or acute flaccid paralysis [and] fever or history of fever in the previous 2 weeks, together with one or more of the following: meningism (neck stiffness), photophobia, severe headache meriting lumbar puncture, altered mental state, reduced consciousness, convulsions, focal neurological signs or acute flaccid paralysis. Results: 243 patients have been recruited to date. Between April and Oct 2006, 8 children had positive plasma PCR tests for Chikungunya RNA and are described in more detail. Viral RNA was also detected by PCR in the CSF of 3 of these 8. Mean age was 6 years, range 8 months to 11 years, 5 were girls. 3 children had a rash at some stage in their illness and one had conjunctivitis. Altered mental state was reported in 7, and 6 had a GCS of less than 15 at admission. One had deafness, 3 had nausea and vomiting, and 3 had meningism. 7 had seizures, amongst whom 4 had an episode of status epilepticus (seizure lasting more than 30 minutes). 3 were aphasic during their illness and 4 had extensor plantar reflexes. There were no fatalities. At discharge, 2 patients had ongoing aphasia. The remaining 4 with a reduced GCS at admission had recovered to full coma score. Sequencing information obtained from the E1 envelope gene from plasma and CSF samples confirmed that the chikungunya genomes are of the East African lineage, which appears to have caused the more severe epidemic form of illness, compared to the Asian genotype which previously circulated in India. Conclusions: Chikungunya virus causes encephalitis in children and may be found in the CSF. It can cause severe neurological disease sequelae although the extent to which these sequelae will persist is uncertain. Given frequent travel between Asia and Europe and the potential for autochtonous transmission, as has occurred in Italy, we need to be increasingly aware of global disease outbreaks. A CASE OF HYPERCALCAEMIA IN THE RETURNING

A NEW GENETIC VARIANT OF LA CROSSE VIRUS (BUNYAVIRIDAE) ISOLATED FROM NEW ENGLAND

La Crosse virus (LACV) is found primarily in the Midwestern and Appalachian regions of the United States where it is a leading cause of mosquito-borne encephalitis in children. To determine whether the distribution of this virus extends further east into New England, we analyzed a bunyavirus that was isolated from a pool of eastern tree-hole mosquitoes, Ochlerotatus triseriatus (= Aedes triseriatus), collected from Fairfield, Connecticut (CT) in 2005. Nucleotide and encoded amino acid sequences from portions of the S, M, and L segments were more similar to the prototype strain of La Crosse virus than that of closely related snowshoe hare virus. Phylogenetic analysis of sequences from the M segment indicated that the CT isolate represents a distinct lineage of La Crosse virus, diverging earliest from other strains found in southeastern, central, and northeastern United States. Despite low sequence homology with other viral strains, the CT isolate was antigenically similar to the prototype strain of LACV by plaque-reduction neutralization tests with polyclonal and monoclonal antibodies. This represents the first isolation of LACV in New England to our knowledge and suggests long-term independent evolution of the CT isolate.

Periodic lateralized epileptiform discharges of pediatric patients in Taiwan

Periodic lateralized epileptiform discharges are special electroencephalographic abnormalities present in adults with stroke, brain tumor, intracranial hemorrhage, or other rare etiologies. Few reports focused on the etiologies in pediatric patients. We retrospectively reviewed 8002 of our pediatric electroencephalographic records for the past 12 years and listed all associated illness and their outcomes. Forty-four children with periodic lateralized epileptiform discharges were collected. We found that there was an obvious difference in etiologies of our pediatric patients from those reported in the literature. Nearly two thirds of our patients (28 children) were associated with central nervous system infections. The other etiologies included head injury, encephalopathy, epilepsy, and others. Herpes simplex virus was responsible for two thirds (12) of the 18 children with identified pathogens causing a central nervous system infection. Ten patients failed to have a defined pathogen. Periodic lateralized epileptiform discharges have a different clinical significance in pediatric patients than in adults. In Taiwan, central nervous system infection is the most common etiology of periodic lateralized epileptiform discharges in pediatric patients. Herpes simplex virus, although the most common pathogen, should not be considered to be the only cause of encephalitis in children with periodic lateralized epileptiform discharges.

California encephalitis in children.

The California group of arboviruses are now recognized as a significant cause of encephalitis in children. Fifty children with California encephalitis were seen at Columbus Children's Hospital between 1966 and 1970. The illness characteristically began abruptly with fever, lethargy, vomiting, and progressive encephalitic findings during the first two to four days and with recovery in seven to ten days. Focal neurologic findings were present in 20% and electroencephalograms revealed asymmetrical delta-wave activity in 40% of the children during the acute phase of the illness.