Seizures in children

New-onset seizures in pediatric emergency

BACKGROUND

Seizures account for 1% of all pediatric emergency department (ED) visits. The aim of this study was to analyze the clinical spectrum and prevalence rates of various etiologies in children with a first attack of acute seizure disorder in the ED.

METHODS

We evaluated 319 children who presented to the ED at the Changhua Children's Hospital with a first attack of seizure disorder from 2005 to 2007. Variables including demographics, clinical presentations, laboratory tests, brain imaging studies, electroencephalography, diagnoses and hospital course were compared between patients with seizures and fever, and patients with seizures without fever. These variables were also compared between patients with simple and complex febrile seizures and among different age groups.

RESULTS

Among these 319 patients, 218 (68%) presented with seizures and fever and 299 (94%) children were younger than 6 years of age. Generalized tonic-clonic seizures were the most common type (71.2%). Febrile seizures (62.1%) were the main etiology of the first seizure (p < 0.001). Seizures caused by severe electrolyte imbalance or hypoglycemia were noted in three patients. Abnormal brain images were noted in 16 (26%) of 61 patients, most (12/16, 75%) of whom had abnormal histories and physical or neurologic examinations.

CONCLUSION

Primary care pediatricians should evaluate children presenting to the ED with a first seizure for age, coexistence of fever, seizure type, associated symptoms and history of head injury. We suggest that electrolytes, blood sugar and emergent brain imaging studies should be arranged based on detailed history-taking and thorough physical examinations, but should not be performed routinely.

Febrile myoclonus: an underreported, benign condition in infancy often misinterpreted as febrile seizures

Massive myoclonic jerks, often presenting in a dramatic fashion during a febrile illness, have rarely been reported and have usually been related to as febrile seizures. Febrile myoclonus is usually a benign phenomenon with no neurological sequelae. However, it may be impressive enough to provoke unnecessary diagnostic workup and treatment in these patients. Thus, its recognition by the emergency room or by the primary care physician is important to provide reassurance to the parents or caregivers and to prevent unwarranted hospitalizations and diagnostic procedures such as lumbar puncture and electroencephalogram. We describe 3 cases of febrile myoclonus and briefly review this subject.

Differences in characteristics among new pediatric neurology patients: the effect of a newly established private pediatric neurology practice

OBJECTIVE

To investigate changes in volume and characteristics of new patients referred when a private pediatric neurology practice (PP) opened in 2004 in an area served primarily by an academic medical center's (AMC) pediatric neurology practice.

METHODS

Retrospective analysis of medical and billing records to examine changes in volume, diagnosis, and sociodemographic factors of new patients at the AMC from July 2004 to June 2005; the PP during the same period; and the AMC during the year before.

RESULTS

One year after the PP opened, 40% more new pediatric neurology patients were seen in this area than the year before. Compared with the AMC, PP saw a greater proportion of seizures (34% vs 26%, P < .05) and headaches (32% vs 17%, P < .001), and a lesser proportion of developmental delay/musculoskeletal disorders (12% vs 19%, P < .001) and congenital/metabolic disorders (<1% vs 2%, P < .001). Fewer PP patients lived >20 miles from the practice (32% vs 64%, P < .001), and fewer had public insurance (4% vs 33%, P < .001).

CONCLUSIONS

The establishment of the PP dramatically increased the volume of new pediatric neurology patients in this area. After the PP opened, the AMC continued to care for most patients with rare diseases and fewer financial resources. Future research should examine whether the increase in volume reflects relief of pent-up demand or increased referral rates due to eased access, and should elucidate how differences in patient populations at academic and private subspecialty practices relate to access to subspecialty care and financial well-being of academic practices.

EAAT2 regulation and splicing: relevance to psychiatric and neurological disorders

The excitatory amino acid transporter 2 (EAAT2) is responsible for the majority of glutamate uptake in the brain and its dysregulation has been associated with multiple psychiatric and neurological disorders. However, investigation of this molecule has been complicated by its complex pattern of alternative splicing, including three coding isoforms and multiple 5'- and 3'-UTRs that may have a regulatory function. It is likely that these sequences permit modulation of EAAT2 expression with spatial, temporal and or activity-dependent specificity; however, few studies have attempted to delineate the function of these sequences. Additionally, there are problems with the use of antibodies to study protein localization, possibly due to posttranslational modification of critical amino acid residues. This review describes what is currently known about the regulation of EAAT2 mRNA and protein isoforms and concludes with a summary of studies showing dysregulation of EAAT2 in psychiatric and neurological disorders. EAAT2 has been either primarily or secondarily implicated in a multitude of neuropsychiatric diseases in addition to the normal physiology of learning and memory. Thus, this molecule represents an intriguing therapeutic target once we improve our understanding of how it is regulated under normal conditions.

Early rapid rise in EAAT2 expression follows the period of maximal seizure susceptibility in human brain

Seizures are relatively common in the first weeks of life and can have lasting effects on brain development due to glutamate excitotoxicity. The excitatory amino acid transporter 2 (EAAT2) is responsible for the majority of glutamate uptake in the brain and mice with this gene deleted die from seizures. Therefore, we reasoned that developmental changes in the expression of EAAT2 might correlate with the period of increased susceptibility to seizures in humans, reflecting a changing vulnerability to excitotoxic insults. Expression levels of eight splice forms of EAAT2 were measured using quantitative RT-PCR from human prefrontal cortex and hippocampus at 1-2 months, 1-2 years, 8 years, 15-16 years, and 18-22 years of age. There was a significant increase in expression of most isoforms between 1-2 months and 1-2 years with isoform-specific patterns after that period. The increase in EAAT2 expression during the first 2 years of life corresponds to a period of maximal synapse formation and other changes in the glutamatergic system such as increased NMDA receptor expression. Moreover, the low expression of EAAT2 in the first months of life corresponds to the period of maximum susceptibility to seizures.