Seizures and Status Epilepticus

Khalid Al-Ansari

Introduction

Seizures are a common presentation to the emergency department
4-10% of children have at least one seizure during childhood
Majority of seizures during childhood are febrile seizures
Status epilepticus: a seizure or series of seizures lasting for ≥30 minutes without return to full consciousness
12% of children present with status epilepticus as their first seizure

International Classification of Seizures

Generalized

Partial

Febrile Seizure

Benign seizures
Occur in up to 5% of children
Elevated body temperature lowers threshold for seizures
Typical age: 6 months to 6 years
Simple seizures: generalized, duration < 15 minutes, one episode in 24 hrs, developmentally normal child, no residual neurologic deficits
Usually associated with viral illness
Child often looks well in emergency department: can be discharged with reassurance and education for future episodes
Clinical signs of meningitis may be absent in children < 12-18 months of age
Consider septic workup including lumbar puncture in young child < 1 year, unwell appearance, or complex presentation (prolonged > 15 minutes, focal presentation, > 1 seizure in 24 hrs)
Recurrence rate 30%
Risk of epilepsy 2-4%

Afebrile Seizure

First episode of afebrile seizure: consider workup including sodium, calcium, glucose
Consider magnesium, ammonia, liver function tests, toxicology as indicated by history and examination
CT head is rarely required for first afebrile seizure with nonfocal presentation unless prolonged or focal seizure, focal deficits, sick appearance, history of trauma or VP shunt, signs of increased ICP
Outpatient CT head may be useful for identifying structural anomalies
EEG should be arranged as an outpatient: usually abnormal in immediate postictal period
Known seizure disorder: most common reason for recurrent seizures is subtherapeutic levels of anticonvulsants:
- May be due to inadequate dose, noncompliance, or intercurrent illness
- Measure anticonvulsant level in blood

Status Epilepticus

80% of status epilepticus have a focal onset and then secondarily generalize
Mortality depends on underlying etiology
Increased risk of subsequent epilepsy, cognitive neurological deficit, and movement disorders
Refractory status epilepticus:
- Sustained seizures that do not respond to medication and persist > 60 minutes
- Requires ICU admission and continuous EEG monitoring
- Duration correlates directly with increased mortality

Table 47.1 Etiology by Age

NEONATES^*	CHILDREN	ADOLESCENTS
Hypoxic ischemic encephalopathy	Febrile seizure	Epilepsy
Infection	Infection	Infection
Stroke	Metabolic disturbance	Drugs
Intraventricular hemorrhage	Epilepsy	Trauma
Trauma	Trauma	Tumor
Inborn error of metabolism	Tumor	Stroke
Congenital malformation	Congenital malformation
Pyridoxine deficiency
^*See Ch. 11, Newborn Emergencies.