Hyponatremia as the cause of seizures in infants: a retrospective analysis of incidence, severity, and clinical predictors

Incidence and Clinical Presentation of Pre- and Postoperative Seizures in Patients With Posterior Fossa Meningiomas

INTRODUCTION

Seizures are a common symptom of supratentorial meningiomas with pre- and postoperative seizure rates of approximately 30% and 12%, respectively, especially in parasagittal and convexity meningiomas. Less is known about the association between seizures and posterior fossa meningiomas. This study evaluates the prevalence, potential causes, and outcomes of seizures in patients who have undergone surgery for posterior fossa meningioma.

METHODS

This is a retrospective, observational, single-center study of consecutive patients who underwent surgical resection of posterior fossa meningiomas between 2009 and 2017. We retrospectively identified patients with seizures and analyzed patient demographics, tumor characteristics, and procedural characteristics.

RESULTS

A total of 44 patients (mean age: 59.8 ± 13.5 years) were included. Twenty-six tumors were located at the cerebellar convexity and tentorium (59.1%), 12 at the cerebellopontine angle (27.3%), four at the clivus (9.1%), and two at the foramen magnum (4.5%). Seizures were the presenting symptom of cerebellar meningioma in two patients. Patients were seizure-free after surgery. Three patients had their first seizure after surgery (interval between surgery and first seizure: two days to 17 months). Analysis of these three patients revealed possible causes of postoperative seizures: radiation necrosis and edema, hyponatremia, and preoperative hydrocephalus. In all patients with postoperative seizures, long-term seizure control was achieved with the administration of antiepileptic drugs.

CONCLUSIONS

The incidence of seizures in patients with posterior fossa meningiomas is relatively low. Antiepileptic drugs can help to achieve seizure control.

A unique presentation of hyponatremia and seizures in a 2-month-old child with cystic fibrosis: a case report

Cystic fibrosis is an autosomal recessive disorder that causes a broad range of clinical findings and can present unusually as electrolyte disturbance, such as hyponatremia that causes seizures in children.

CASE PRESENTATION

We report a case of a 2-month-old infant who presented with an episode of grand mal seizure induced by hyponatremia and moderate episodes of milky vomiting after breastfeeding.

CLINICAL DISCUSSION

Proper investigations showed normal cardiac and renal functions. Ultrasonography showed no pathological changes. Laboratory tests performed showed hyponatremia, mild hypokalemia, and hypochloremia. Urinary electrolyte results were normal. While broadening the scope of differential diagnosis in order to reach a final diagnosis, the sweat chloride level was elevated, which confirmed the diagnosis of cystic fibroses.

CONCLUSION

We aim to share our case to keep cystic fibroses in mind as a differential diagnosis when dealing with hyponatremic seizures in children.

Hypochloremia Secondary to Diuretics in Preterm Infants: Should Clinicians Pay Close Attention?

Diuretic therapy, commonly used in the newborn intensive care unit, is associated with a variety of electrolyte abnormalities such as hyponatremia, hypokalemia, and hypochloremia. Hypochloremia, often ignored, is associated with significant morbidities and increased mortality in infants and adults. Clinicians respond in a reflex manner to hyponatremia than to hypochloremia. Hypochloremia is associated with nephrocalcinosis, hypochloremic alkalosis, and poor growth. Besides, the diuretic resistance associated with hypochloremia makes maintaining chloride levels in the physiological range even more logical. Since sodium supplementation counters the renal absorption of calcium and lack of evidence for spironolactone role in diuretic therapy for bronchopulmonary dysplasia (BPD), alternate chloride supplements such as potassium or arginine chloride may need to be considered in the management of hypochloremia due to diuretic therapy. In this review, we have summarized the current literature on hypochloremia secondary to diuretics and suggested a pragmatic approach to hypochloremia in preterm infants.

Length of stay linked to neurodiagnostic workup for seizures presenting to the pediatric emergency department

INTRODUCTION

Patients presenting to the pediatric emergency department (ED) often undergo unnecessary testing that leads to prolonged ED visits. Lower ED length of stay has been linked to improved patient experience and may reduce ED overcrowding, a costly burden on a health system.

METHODS

This is a retrospective cohort study involving patient records over the period of 6 months at an urban tertiary children's hospital who presented with seizures. Febrile seizures, seizures associated with trauma, and charts of patients who did not present initially through our ED were excluded.

RESULTS

328 charts were obtained through this search criteria. Head imaging was performed in 52 (16%) patients and consisted of 81% CT (n = 42) and 19% (n = 10) magnetic resonance imaging (MRI). Obtaining an MRI was associated with a 3.5 h longer ED visit (p = 0.07); obtaining a CT was associated with a 1.5 h longer ED visit (p = 0.005). An Electroencephalogram (EEG) was obtained for 67 (20%) visits and was associated with a 3.0 h longer ED length of stay (p < 0.001). Ten % of the CT scans showed new or progressive findings and 40% of the MRIs done provided useful information for management. Thirty-seven % of EEGs performed in new onset seizure patients revealed epileptiform findings and 5% of EEGs in established seizure patients provided meaningful findings important to management.

CONCLUSION

Obtaining neurodiagnostic studies significantly prolongs duration of stay in the ED. Electroencephalograms appear to have the greatest yield in new onset seizure patients and can help make a diagnosis of an epilepsy syndrome in children.

Acute Seizures-Work-Up and Management in Children

Seizures are common in the pediatric population; however, most children do not go on to develop epilepsy later in life. Selecting appropriate diagnostic modalities to determine an accurate diagnosis and appropriate treatment as well as with counseling families regarding the etiology and prognosis of seizures, is essential. This article will review updated definitions of seizures, including provoked versus unprovoked, as well as the International League Against Epilepsy operational definition of epilepsy. A variety of specific acute symptomatic seizures requiring special consideration are discussed, along with neonatal seizures and seizure mimics, which are common in pediatric populations.

Hyponatremia in children under 100 days old: incidence and etiologies

Hyponatremia is one of the most common electrolyte disorders in hospitalized children. The underlying mechanisms are poorly understood and potentially multifactorial, making management difficult, particularly in neonates. This retrospective study aimed to determine the incidence and etiologies of hyponatremia in hospitalized children under the age of 100 days, in our pediatric tertiary care hospital over a 1-year period. The etiology of hyponatremia was determined by reviewing the data noted in each patient's medical reports. Neonatal hyponatremia had a prevalence of 4.3% (86/2012 patients) and was mostly hospital-acquired (74/86 patients). Fifty-nine patients (68.9%) were preterm neonates. The etiology was iatrogenic in 26 cases (30.2%). In other cases, hyponatremia was due to transient (23 patients, 26.7%) or genetic abnormalities of the renal mineralocorticoid pathway (3 patients, 3.4%), SIADH (12 patients, 14%), digestive disease (3 patients, 3.5%), acute renal failure (3 patients, 3.5%), or heart failure (1 patient, 1.2%).Conclusion: Our findings confirm that hyponatremia is a frequent electrolyte disorder in neonates. Various mechanisms underlie this condition, most of which could be prevented by optimized management. The prevalence of genetic hypoaldosteronism and pseudohypoaldosteronism was higher than expected. We provide a simple diagram to help physicians identify the mechanisms underlying neonatal hyponatremia. What is Known: • In neonates, hyponatremia may be multifactorial, making it difficult to treat. • Newborns display partial resistance to aldosterone, and preterms have a defect in aldosterone secretion. What is New: • Four percent of hospitalized neonates had hyponatremia, 86% hospital-acquired. Hyponatremia was due to a transient or constitutional defect of the mineralocorticoid pathway in 26/86 patients (30%) which is higher than expected. • We propose a tree diagram for improving the management of hyponatremia in neonates.

Prevalence and Clinical Significance of Hyponatremia in Pediatric Intensive Care

A retrospective chart review was conducted to estimate the prevalence and severity level of hyponatremia on admission at the pediatric intensive care unit (PICU) in a Saudi tertiary hospital. Hyponatremia was highly prevalent (67.2%) and severe hyponatremia was frequent among patients with Pediatric Risk of Mortality score > 10%. Severe hyponatremia was also associated with increased length of stay ( p  = 0.04) and a trend of increased mortality ( p  = 0.054). However, disease severity was not an independent risk factor of mortality in PICU, but might confound other risk factors that render the children requiring prolonged hospital stay, mechanical ventilation, and increased health costs.

Cost-Effectiveness of Evaluation of Children With Epilepsy in the Emergency Department: Need for Investment in Patient Education

We aimed to study cost-effectiveness of seizure evaluation of children with epilepsy in the emergency department (ED). We reviewed epilepsy patients seen at our ED for 1 year. Age, laboratory and neuroimaging results, treatment, disposition, and usefulness of the visit (need for hospitalization, clinical improvement) were analyzed. We identified 330 patients, aged 23 days-21 years, 190 (57.5%) had blood tests, 45 (13.6%) urinalysis, 2 (0.6%) cerebrospinal fluid testing, and 44 neuroimaging studies (13.3%). Tests' positive yield were 41%, 11%, 0%, and 4.5%, respectively. One-third of patients (n = 122) were treated with antiepileptic drugs. Other treatments were administered to 44 (13.3%). One hundred eighteen patients (35.7%) were admitted to our hospital, 208 (63%) discharged to home. Two hundred eight visits were useful (63%). One-third of visits did not provide useful patient care. Their visits were expensive and not very cost-effective. Investment in patient education could decrease unnecessary ED visits.

Diagnostic and Therapeutic Management of a First Unprovoked Seizure in Children and Adolescents With a Focus on the Revised Diagnostic Criteria for Epilepsy

By definition, unprovoked seizures are not precipitated by an identifiable factor, such as fever or trauma. A thorough history and physical examination are essential to caring for pediatric patients with a potential first unprovoked seizure. Differential diagnosis, EEG, neuroimaging, laboratory tests, and initiation of treatment will be reviewed. Treatment is typically initiated after 2 unprovoked seizures, or after 1 seizure in select patients with distinct epilepsy syndromes. Recent expansion of the definition of epilepsy by the ILAE allows for the diagnosis of epilepsy to be made after the first seizure if the clinical presentation and supporting diagnostic studies suggest a greater than 60% chance of a second seizure. This review summarizes the current literature on the diagnostic and therapeutic management of first unprovoked seizure in children and adolescents while taking into consideration the revised diagnostic criteria of epilepsy.

Review of a Large Clinical Series: Outcome of Pediatric Status Epilepticus Admitted to Intensive Care

The authors determine the relationship between seizure duration, etiology, and outcome in a modern intensive care setting and assess the usefulness of computed tomography (CT) and the empiric use of antimicrobial therapy. The design was a retrospective chart review. The setting was a tertiary pediatric critical care unit. Patients included 161 consecutive admissions to the critical care unit at the Hospital for Sick Children, Toronto, with status epilepticus over a 3-year period. There were no interventions. The overall mortality was 5.6%. A further 11% experienced an adverse neurological outcome as determined on hospital discharge. Mean seizure duration was 1.5 ± 2.8 hours in those children with a normal outcome, 1.7 ± 1.2 hours in those survivors with an abnormal neurological outcome ( P > 0.05), and 6.8 ± 12 hours in those who died ( P < 0.05). The CT scan was abnormal in 41% of cases. New findings that directly affected immediate management decisions were found in 20% of CT scans. Both the duration and etiology of status epilepticus affect the outcome. CT scanning should be done without delay, once the patient is stable. Antiviral therapy should be started empirically now that encephalitis is far more common than bacterial meningitis in this group of patients. Studies are lacking that compare the efficacy of drugs available to treat status epilepticus. These studies need to be done, as the findings could affect the duration of status.

Clinical Manifestations of Hyponatremia and Hypernatremia in Under-Five Diarrheal Children in a Diarrhea Hospital

OBJECTIVE

To study clinical manifestations and outcome of hyponatremia and hypernatremia in children with diarrhea.

METHOD

We compared children aged 0-59 months hospitalized from 1 January to 31 December 2013 with hyponatremia (serum sodium <130 mmol/l), hypernatremia (serum sodium >150 mmol/l) and normonatremia (serum sodium 135-145 mmol/l).

RESULTS

The case fatality was significantly higher among the children with hypernatremia and hyponatremia than normonatremia. A logistic regression analysis adjusting for potential confounders revealed that children with hyponatremia are more likely to have convulsions, have severe acute malnutrition and be of older age compared with children with normal serum sodium. Children with hypernatremia are more likely to have convulsions and dehydration than normonatremic children (for all p < 0.05).

CONCLUSION

Early diagnosis and prompt management of hypo- and hypernatremia by identifying simple clinical predicting factors of these two conditions in diarrheal children <5 years of age is critically important to prevent deaths in such children, especially in resource-limited settings.

Acute Symptomatic Seizures Caused by Electrolyte Disturbances

In this narrative review we focus on acute symptomatic seizures occurring in subjects with electrolyte disturbances. Quite surprisingly, despite its clinical relevance, this issue has received very little attention in the scientific literature. Electrolyte abnormalities are commonly encountered in clinical daily practice, and their diagnosis relies on routine laboratory findings. Acute and severe electrolyte imbalances can manifest with seizures, which may be the sole presenting symptom. Seizures are more frequently observed in patients with sodium disorders (especially hyponatremia), hypocalcemia, and hypomagnesemia. They do not entail a diagnosis of epilepsy, but are classified as acute symptomatic seizures. EEG has little specificity in differentiating between various electrolyte disturbances. The prominent EEG feature is slowing of the normal background activity, although other EEG findings, including various epileptiform abnormalities may occur. An accurate and prompt diagnosis should be established for a successful management of seizures, as rapid identification and correction of the underlying electrolyte disturbance (rather than an antiepileptic treatment) are of crucial importance in the control of seizures and prevention of permanent brain damage.

Low sodium status in cystic fibrosis-as assessed by calculating fractional Na(+) excretion-is associated with decreased growth parameters

BACKGROUND

In CF infants, normonatremic Na(+) depletion (NNaD), identified by fractional Na(+) excretion (FENa) values <0.5%, was recently linked to impaired growth. Our paper investigates the relationship between FENa and growth in CF children >2years.

METHODS

FENa values were calculated in 35 CF and 24 control children, and tested for correlations with z-scores for weight, height and BMI.

RESULTS

All CF children and controls had normal plasma Na(+) concentrations. A total of 25 of 35 (71.4%) CF patients had decreased FENa values <0.5% (group I). FENa results of 10 CF patients (group II) and 23/24 controls (group III) were normal. In Na(+)-depleted CF children, compared to normal controls, mean z-scores for weight (-0.18±0.87 vs +1.03±0.57, p<0.001), height (-0.06±0.89 vs +0.53±0.72, p=0.009) and BMI (-0.22±0.87 vs +1.00±1.06, p<0.001) were significantly reduced. Also, we found positive correlations between FENa values and z-scores for weight (r=0.521), height (r=0.292) and BMI (r=0.468), respectively.

CONCLUSION

NNaD may contribute to poor growth in CF.

Neonatal endocrine emergencies: a primer for the emergency physician

The resuscitation principles of securing the airway and stabilizing hemodynamics remain the same in any neonatal emergency. However, stabilizing endocrine disorders may prove especially challenging. Several organ systems are affected simultaneously and the clinical presentation can be subtle. Although not all-inclusive, the implementation of newborn screening tests has significantly reduced morbidity and mortality in neonates. Implementing routine screening tests worldwide and improving the accuracy of present tests remains the challenge for healthcare providers. With further study of these disorders and best treatment practices we can provide neonates presenting to the emergency department with the best possible outcomes.

Disorders of sodium and water balance

Dysnatremias occur simultaneously with disorders in water balance. The first priority is to correct dehydration; once the patient is euvolemic, the sodium level can be reassessed. In unstable patients with hyponatremia, the clinician should rapidly administer hypertonic saline. In unstable patients with hypernatremia, the clinician should administer isotonic intravenous fluid. In stable patients with either hyponatremia or hypernatremia, the clinician should aim for correction over 24 to 48 hours, with the maximal change in serum sodium between 8 to 12 mEq/L over the first 24 hours. This rate of correction decreases the chances of cerebral edema or osmotic demyelination syndrome.

Risk Factors of Early Seizure Recurrence in Epileptic Patients Presented to an Emergency Department in Hong Kong

Introduction

While epilepsy is a well-known disease, little is known about early recurrence of seizures, and some patients are admitted to medical ward for the risk of recurrence of epilepsy. The aim of this study was to determine the frequency and risk factors of early seizure recurrence (ESR) among the epileptic adult patients attending the emergency department (ED).

Methods

In this retrospective observational study, medical records of all patients presenting to a regional ED in Hong Kong with seizures from 1 January 2010 to 31 December 2011 were reviewed. Their demographic data and clinical features were analysed to look for the relationship with ESR. ESR was defined as a seizure recurrence during the first 24 hours since the last seizure.

Results

A total of 339 patient records were analysed. The ESR rate was 13.7% at 24 hours and 80% occurred in the first six hours after the last seizure. Age≥40, female sex, repeated seizure in past one day, and abnormal plasma sodium and calcium levels were found to be statistically significantly associated with ESR by univariate analysis. These risk factors remain statistically significant after repeated multivariate logistic regression analysis.

Conclusion

The ESR rate is about 13.7% in our emergency department setting and 80% of them occur within six hour since their last seizure. Five risk factors, namely age group, sex, repeated seizure in past one day and abnormal blood sodium and calcium level are significant factors associated with ESR. We conclude that it is not necessary to admit all the adult epileptic patients with simple breakthrough seizures to hospital. (Hong Kong j.emerg.med. 2014;21:37-43)

Pediatric seizures

Seizures are a commonly encountered condition within the emergency department and, because of this, can engender complacency on the part of the physicians and staff. Unfortunately, there is significant associated morbidity and mortality with seizures, and they should never be regarded as routine. This point is particularly important with respect to seizures in pediatric patients. The aim of this review is to provide a current view of the various issues that make pediatric seizures unique and to help elucidate emergent evaluation and management strategies.

Perioperative seizure incidence and risk factors in 223 pediatric brain tumor patients without prior seizures

OBJECT

The incidence of, and risk factors for, perioperative seizures and the need for perioperative antiepileptic drugs (AEDs) in previously seizure-free children with brain tumors remains unclear. The authors have undertaken a review of previously seizure-free pediatric patients with brain tumors undergoing resection to identify the incidence of seizures in the perioperative period, and to characterize risk factors for perioperative seizures in this population.

METHODS

A retrospective review was conducted of all patients between 0 and 19 years of age without prior seizures who underwent intracranial tumor resection at the authors' institution between January 2005 and December 2009.

RESULTS

Of the 223 patients undergoing 229 operations, 7.4% experienced at least 1 clinical seizure during the surgical admission. Over half of all tumors were supratentorial. Only 4.4% of patients received prophylactic AEDs. Independent factors associated with perioperative seizures included supratentorial tumor, age < 2 years, and hyponatremia due to syndrome of inappropriate antidiuretic hormone or cerebral salt wasting. Tumor type, lobe affected, operative blood loss, and length of surgery were not independently associated with seizure incidence.

CONCLUSIONS

Perioperative seizures in previously seizure-free children undergoing resection of brain tumors are associated with supratentorial tumor location, age < 2 years, and postoperative hyponatremia. Perioperative seizures are not associated with tumor pathology, tumor size, or frontotemporal location. Due to the low incidence of seizures in this series in patients more than 2 years old with normal serum sodium, the authors recommend that pediatric patients with brain tumors not routinely receive perioperative prophylactic AEDs. However, the role for prophylaxis in patients younger than 2 years of age deserves further study.

The effect of cardioplegic solution-induced sodium concentration fluctuation on postoperative seizure in pediatric cardiac patients

BACKGROUND

Despite potential benefits of histidine-tryptophan-ketoglutarate (HTK) solution as a cardioplegic solution, it can cause hyponatremia, especially in pediatric patients. Fluctuations in the sodium concentration during cardiopulmonary bypass (CPB) can adversely affect the central nervous system. We evaluated the relationship between the cardioplegic solution, the fluctuation of sodium concentration, and the incidence of postoperative seizure in pediatric cardiac patients.

METHODS

The medical records of 628 patients were reviewed for the occurrence of a postoperative seizure, type of cardioplegic solution (HTK or del Nido solution), and intraoperative data. A change of sodium concentration exceeding 15 mmol/L (ΔNa>15) during CPB was defined as a significant fluctuation of sodium concentration.

RESULTS

Postoperative seizures were detected in 18 patients (2.9%). The ΔNa>15 was detected in 63 of 189 patients (33.3%) who received the HTK solution and in 14 of 439 patients (3.2%) who received the del Nido solution (p<0.001). The incidence of ΔNa>15 was strongly associated with postoperative seizure (odds ratio, 6.3; 95% confidence interval, 2.4 to 16.4, p=0.001). After adjusting for potential confounders, the ΔNa>15 remained significantly associated with postoperative seizure (odds ratio, 3.9; 95% confidence interval, 1.3 to 12.3, p=0.018).

CONCLUSIONS

Histidine-tryptophan-ketoglutarate solution during CPB frequently causes fluctuations of sodium concentration, usually combined with hyponatremia, which is associated with postoperative seizure. Special attention to sodium concentration is required, particularly when HTK solution is used in pediatric cardiac patients.

Study of outcomes associated with hyponatremia and hypernatremia in children

Sodium is usually included in hospitals' critical values lists; however, the values at which sodium is considered to be life threatening (critical) vary among hospitals. Studies of outcomes associated with hyponatremia and hypernatremia in pediatric patients have not been published. We performed a retrospective chart review of sodium values of <124 mmol/L and >155 mmol/L that occurred during a 6-month period. Univariate and multivariate analyses for mortality risk were performed with the different variables. A total of 702 (1.32%) sodium tests fell in the study reference range, with 166 being <124 mmol/L and 536 being >155 mmol/L. Although not statistically significant, mortality was higher (38.5%) in patients with sodium values ≤ 120 mmol/L than in those with values ≥ 170 mmol/L (25%) or in patients with other values (<14%). Underlying conditions prevented assessment of morbidity associated with hyponatremia or hypernatremia. Treatment was instituted within 4 hours in 80% of cases (50% within 1 hour). Multivariate analysis showed increased risk of death for hyponatremic patients if they were premature or had heart abnormalities, while for hypernatremic patients the risk increased when other critical values were present. In conclusion, sodium levels of ≤ 120 mmol/L and ≥ 170 mmol/L have increased mortality in children; however, the risk of death is not statistically different when compared to risk in patients with milder hyponatremia and hypernatremia. Risk factors for death in hyponatremic and hypernatremic patients may primarily reflect the severity of the underlying conditions present in these children, such as prematurity and heart abnormalities, rather than the sodium derangement.

Afebrile pediatric seizures

Most well-appearing children who have had an afebrile seizure can be managed as outpatients with instructions for an outpatient electroencephalogram and primary care physician follow-up. Laboratory studies are needed only in children younger than 6 months, in patients with prolonged seizures or altered level of consciousness, or in those with history of a metabolic disorder or dehydration. Emergent neuroimaging is not recommended in children with a first unprovoked afebrile seizure, although studies should be considered in children with a predisposing condition or focal seizures if younger than 3 years.

Emergency department seizure epidemiology

Although only 3% of people in the United States are diagnosed with epilepsy, 11% will have at least one seizure during their lifetime. Seizures account for about 1% of all emergency department (ED) visits, and about 2% of visits to children's hospital EDs. Seizure accounts for about 3% of prehospital transports. In adult ED patients, common causes of seizure are alcoholism, stroke, tumor, trauma, and central nervous system infection. In children, febrile seizures are most common. In infants younger than 6 months, hyponatremia and infection are important considerations. Epilepsy is an uncommon cause of seizures in the ED, accounting for a minority of seizure-related visits. Of ED patients with seizure, about 7% have status epilepticus, which has an age-dependent mortality averaging 22%.

New aspects in the pathogenesis, prevention, and treatment of hyponatremic encephalopathy in children

Hyponatremia is the most common electrolyte abnormality encountered in children. In the past decade, new advances have been made in understanding the pathogenesis of hyponatremic encephalopathy and in its prevention and treatment. Recent data have determined that hyponatremia is a more serious condition than previously believed. It is a major comorbidity factor for a variety of illnesses, and subtle neurological findings are common. It has now become apparent that the majority of hospital-acquired hyponatremia in children is iatrogenic and due in large part to the administration of hypotonic fluids to patients with elevated arginine vasopressin levels. Recent prospective studies have demonstrated that administration of 0.9% sodium chloride in maintenance fluids can prevent the development of hyponatremia. Risk factors, such as hypoxia and central nervous system (CNS) involvement, have been identified for the development of hyponatremic encephalopathy, which can lead to neurologic injury at mildly hyponatremic values. It has also become apparent that both children and adult patients are dying from symptomatic hyponatremia due to inadequate therapy. We have proposed the use of intermittent intravenous bolus therapy with 3% sodium chloride, 2 cc/kg with a maximum of 100 cc, to rapidly reverse CNS symptoms and at the same time avoid the possibility of overcorrection of hyponatremia. In this review, we discuss how to recognize patients at risk for inadvertent overcorrection of hyponatremia and what measures should taken to prevent this, including the judicious use of 1-desamino-8d-arginine vasopressin (dDAVP).

Seizure visits in US emergency departments: epidemiology and potential disparities in care

INTRODUCTION

While epilepsy is a well-characterized disease, the majority of emergency department (ED) visits for "seizure" involve patients without known epilepsy. The epidemiology of seizure presentations and national patterns of management are unclear. The aim of this investigation was to characterize ED visits for seizure in a large representative US sample and investigate any potential impact of race or ethnicity on management.

METHODS

Seizure visits from the National Hospital Ambulatory Medical Care Survey (NHAMCS) from 1993 to 2003 were analysed. Demographic factors associated with presentation, neuroimaging and hospital admission in the USA were analysed using controlled multivariate logistic regression.

RESULTS

Seizure accounts for 1 million ED visits annually [95% confidence interval (CI): 926,000-1,040,000], or 1% of all ED visits in the USA. Visits were most common among infants, at 8.0 per 1,000 population (95% CI: 6.0-10.0), and children aged 1-5 years (7.4; 95% CI: 6.4-8.4). Seizure was more likely among those with alcohol-related visits [odds ratio (OR): 3.2; 95% CI: 2.7-3.9], males (OR: 1.4; 95% CI: 1.3-1.5) and Blacks (OR: 1.4; 95% CI: 1.3-1.6). Neuroimaging was used less in Blacks than Whites (OR: 0.6; 95% CI: 0.4-0.8) and less in Hispanics than non-Hispanics (OR: 0.6; 95% CI: 0.4-0.9). Neuroimaging was used less among patients with Medicare (OR: 0.4; 95% CI: 0.2-0.6) or Medicaid (OR: 0.5; 95% CI: 0.4-0.7) vs private insurance and less in proprietary hospitals. Hospital admission was less likely for Blacks vs Whites (OR: 0.6; 95% CI: 0.4-0.8).

CONCLUSION

Seizures account for 1% of ED visits (1 million annually). Seizure accounts for higher proportions of ED visits among infants and toddlers, males and Blacks. Racial/ethnic disparities in neuroimaging and hospital admission merit further investigation.

Incidence of postoperative hyponatremia and complications in critically-ill children treated with hypotonic and normotonic solutions

OBJECTIVE

To determine the incidence and clinical consequences of postoperative hyponatremia in children.

STUDY DESIGN

We performed a retrospective analysis of postoperative admissions to the pediatric intensive care unit (excluding cardiac, neurosurgical, and renal). The incidence of severe (serum sodium < 125 mmol/L or symptoms) and moderate (serum sodium < 130 mmol/L) hyponatremia in children receiving hypotonic (HT) and normotonic (NT) fluids was calculated.

RESULTS

Out of a total of 145 children (568 sodium measurements; 116 HT and 29 NT), we identified 16 with hyponatremia (11%). The incidences of moderate (10.3% vs 3.4%, P = .258) and severe (2.6% vs 0%; P = .881) hyponatremia were not significantly different in the HT and NT groups. There were no neurologic sequelae or deaths related to hyponatremia.

CONCLUSIONS

In our study group, hyponatremia was common, but morbidity and death were not observed. Careful monitoring of serum sodium level may be responsible for this lack of adverse outcomes. Larger, prospective studies are needed to determine whether the incidence of hyponatremia differs between the HT and NT groups.

Hyponatremia-induced seizure during carbamazepine treatment

We report the case of a 54-year-old woman who was admitted for benzodiazepine withdrawal. After 6 weeks of carbamazepine treatment (600, then 200 mg) the patient suddenly suffered from a grand mal seizure. Laboratory findings revealed a clinical significant hyponatremia of Na 125 mmol/l (baseline: 143 mmol/l). CCT and ECG were normal. To our knowledge, this is the first description of a seizure related to hyponatremia in an adult carbamazepine-treated patient.

Diagnosis and Treatment of the First Epileptic Seizure: Guidelines of the Italian League Against Epilepsy

The diagnosis and treatment of a first epileptic seizure are made by physicians with different types of expertise. Heterogeneous patterns of care are thus expected, which explain the need for shared patterns of care. These guidelines were developed by a group of experts from the Italian League against Epilepsy (LICE) in accordance with the requirements of evidence-based medicine. An accurate assessment of the seizure is required, with active questioning about circumstances of occurrence, clinical manifestations, and postictal symptoms. For seizures with loss of consciousness, the presence of cyanosis, hypersalivation, tongue biting, and postictal disorientation has a specific diagnostic value. Laboratory tests and toxicological screening should be performed only in the presence of circumstances suggesting a metabolic or toxic encephalopathy. Elevated prolactin levels 10-20 min. after the event help in differentiating generalized tonic-clonic or partial seizures from psychogenic nonepileptic seizures. Except for infants less than six months of age, CSF examination is recommended only when a cerebral infection is suspected. An EEG should be performed within 24 h. after a seizure, particularly in children. If the EEG is normal during wakefulness, a sleep EEG is recommended. A CT scan is strictly indicated when a severe structural lesion is suspected or when the etiology is unknown. MRI may not be indicated in the emergency room, but it should be preferred to CT as part of the diagnostic assessment. The added value of other diagnostic tools (neuropsychological tests, ambulatory EEG, functional MRI, SPECT, and PET) is as yet unknown. These tests may be used on a case-by-case basis. In the presence of an acute symptomatic seizure, treatment of the cause is recommended. Symptomatic therapy is not justified unless the seizure has the characteristics of status epilepticus. Long-term treatment may be considered in patients with abnormal EEG and imaging data and after consideration of the social, emotional, and personal implications of seizure relapse.

Erreur diététique et intoxication par l'eau : une pathologie évitable

CASE REPORT

The authors report the case of an infant presenting with status epilepticus, apneas and hypothermia, related to hyponatremia. The cause was water intoxication, secondary to feeding a dilute formula and free water. The parents were notoriously challenged by the care of their children. Such disorder could have been prevented.

CONCLUSION

Dietary history may be key to the diagnosis of hyponatremia in children. Water intoxication of nutritional origin can be prevented.

Seizures in children

Seizures are the most common pediatric neurologic disorder. Four to ten percent of children suffer at least one seizure in the first 16 years of life. The incidence is highest in children less than 3 years of age, with a decreasing frequency in older children. Epidemiologic studies reveal that approximately 150,000 children will sustain a first-time unprovoked seizure each year, and of those, 30,000 will develop epilepsy. This article describes the types, diagnoses, and management and disposition of this pediatric neurologic disorder.

Preventing neurological complications from dysnatremias in children

Dysnatremias are among the most common electrolyte abnormalities encountered in hospitalized patients. In most cases, a dysnatremia results from improper fluid management. Dysnatremias can occasionally result in death or permanent neurological damage, a tragic complication that is usually preventable. In this manuscript, we discuss the epidemiology, pathogenesis and prevention and treatment of dysnatremias in children. We report on over 50 patients who have suffered death or neurological injury from hospital-acquired hyponatremia. The main factor contributing to hyponatremic encephalopathy in children is the routine use of hypotonic fluids in patients who have an impaired ability to excrete free-water, due to such causes as the postoperative state, volume depletion and pulmonary and central nervous system diseases. The appropriate use of 0.9% sodium chloride in parenteral fluids would likely prevent most cases of hospital-acquired hyponatremic encephalopathy. We report on 15 prospective studies in over 500 surgical patients that demonstrate that normal saline effectively prevents postoperative hyponatremia, and hypotonic fluids consistently result in a fall in serum sodium. Hyponatremic encephalopathy is a medical emergency that should be treated with hypertonic saline, and should never be managed with fluid restriction alone. Hospital-acquired hypernatremia occurs in patients who have restricted access to fluids in combination with ongoing free-water losses. Hypernatremia could largely be prevented by providing adequate free-water to patients who have ongoing free-water losses or when mild hypernatremia (Na>145 mE/l) develops. A group at high-risk for neurological damage from hypernatremia in the outpatient setting is that of the breastfed infant. Breastfed infants must be monitored closely for insufficient lactation and receive lactation support. Judicious use of infant formula supplementation may be called for until problems with lactation can be corrected.

The Emergency Department Approach to Newborn and Childhood Metabolic Crisis

For most emergency medicine physicians, the phrases "newborn workup" and "metabolic disease" are, at best, uncomfortable. This article, however, provides a simple approach to the recognition,evaluation, and treatment of infants with all manners of metabolic issues, including hypoglycemia, inborn errors of metabolism, jaundice, and electrolyte abnormalities. The disorders are grouped based on symptomatology, and have simple guidelines for work-up and management, with an emergency department practitioner perspective in mind.

Predictors and prognosis of refractory status epilepticus treated in a neurological intensive care unit

OBJECTIVE

To assess risk factors and prognosis in patients with refractory status epilepticus (RSE).

METHODS

We retrospectively analysed all episodes of status epilepticus (SE) treated between 1993 and 2002 on the neurological intensive care unit (NICU) of the Charite-Universitatsmedizin Berlin. The predictive and prognostic features of RSE were compared with non-RSE (NRSE). All patients with "de novo" SE were followed up to identify the possible development of post-SE symptomatic epilepsy.

RESULTS

A total of 83 episodes fulfilled our criteria of SE. Of these 43% were refractory to first line anticonvulsants. The mean age of patients with SE was 53.3 (SD 19) years, with only two patients younger than 18 years. Encephalitis was significantly more often the primary cause in RSE (p<0.05), whereas low levels of antiepileptic drugs were significantly more often associated with NRSE (p<0.001). Hyponatraemia within the first 24 hours after onset of status activity was significantly more often associated with RSE (p<0.05). In RSE, compared with NRSE, significantly longer duration of seizure activity (p<0.001), more frequent recurrence of epileptic activity within the first 24 hours after the end of seizure activity (p<0.001), longer stay in the NICU and in hospital (p<0.001 and p<0.01, respectively), and more frequent development of symptomatic epilepsy (p<0.05) were seen.

CONCLUSIONS

SE treated in the NICU is frequently refractory to first line anticonvulsant drugs. Encephalitis is a predictor for RSE, which is associated with markedly poor outcome, in particular, the development of post-SE symptomatic epilepsy. Thus prevention of this most severe form of SE should be the primary target of treatment of SE.

Pertussis pneumonia complicated by a hyponatremic seizure

We present the case of a 6-week-old male infant who had a convulsion due to pertussis pneumonia. He was admitted to our emergency department because of lethargy and hypothermia. He developed a generalized tonic-clonic convulsion, requiring various treatments, including artificial ventilation. A chest CT showed bilateral pneumonia and laboratory data revealed hyponatremia with other features of the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Although SIADH has been recognized as a cause of hyponatremia in association with pneumonia, there is little in the literature regarding SIADH caused by pertussis. Hyponatremia caused by SIADH must be considered as a differential diagnosis of seizures in pertussis infection of infants.

Hyponatremic seizures in infancy: association with retinal hemorrhages and physical child abuse?

We present two cases of infants with hyponatremic seizures who had an unexpected finding of retinal hemorrhages. A review of the literature found no prior association between hyponatremic seizures and retinal hemorrhages. The retinal hemorrhages found in the first patient were a result of shaken baby syndrome (SBS) and associated with long bone fractures and a subdural hematoma. The second patient had retinal hemorrhages and cerebral edema, presumed to be a result of SBS. We suggest that children who become hyponatremic owing to neglect, lack of education, or intentional water poisoning may be at risk for other forms of child abuse. Additional research needs to be done to further elucidate the relationship between hyponatremic seizures and child abuse.

Utility of laboratory testing for infants with seizures

OBJECTIVES

Study objectives were to 1) determine the frequency with which laboratory studies are obtained, 2) determine the proportion of results that are clinically significantly abnormal, and 3) define the clinical characteristics of those with abnormal results, among infants with nonfebrile seizures (NFSz).

METHODS

A retrospective consecutive cohort study of infants < or = 12 months old presenting to the ED of a tertiary care, children's hospital following a seizure. A 2-year review was performed. Serum chemistry results were classified as "normal," "outside of the normal range," or "clinically significantly abnormal."

RESULTS

Sixty-seven of 134 (50%) with a NFSz were tested compared to 19/80 (24%) with a febrile seizure (FSz, P < 0.001). Nine (5 with hyponatremia and 4 with hypocalcemia) of the 67 (13%) tested NFSz infants had a clinically significant abnormality, as did 9 of 21 (43%) NFSz infants who seized in the ED compared to 0/46 (0%) without ED seizure activity (P < 0.0001). Hypothermia (T < 36.5 degrees C) and age less than 1 month were common characteristics of infants with clinically significant abnormalities.

CONCLUSIONS

This is one of the only studies to have assessed the utility of laboratory testing for infants with seizures. Abnormal serum chemistries accounted for a greater proportion of seizures among this cohort compared to that reported previously for older children. Laboratory testing is recommended for NFSz infants who 1) are actively seizing in the ED, 2) have a temperature below 36.5 degrees C, or 3) are less than 1 month of age.