Overview
Definition:
Status epilepticus (SE) is a medical emergency characterized by a prolonged seizure (typically defined as lasting >5 minutes for a single seizure or recurrent seizures without full recovery of consciousness between them)
In pediatrics, SE is defined by guidelines as a continuous epileptic seizure lasting longer than 5 minutes, or two or more seizures within a 5-minute period without the individual returning to baseline consciousness
It can lead to neuronal injury, systemic complications, and increased mortality.
Epidemiology:
The incidence of status epilepticus in children varies, with estimates ranging from 10 to 40 per 100,000 children per year
It is more common in neonates and infants than older children
Etiologies are diverse and include infections (encephalitis, meningitis), metabolic derangements (hypoglycemia, electrolyte imbalances), hypoxic-ischemic encephalopathy, central nervous system malformations, genetic disorders, and known epilepsy syndromes
Approximately 5-10% of children experiencing SE will have epilepsy diagnosed later.
Clinical Significance:
Status epilepticus poses a significant threat to pediatric patients due to the risk of neuronal damage, cognitive impairment, and long-term neurological sequelae
Prompt and effective management is crucial to terminate seizure activity, prevent complications such as respiratory compromise, hyperthermia, and rhabdomyolysis, and reduce the risk of mortality
Understanding the stepwise approach to treatment, including the role of benzodiazepines, second-line agents, and escalation strategies, is paramount for effective pediatric emergency care and for success in DNB and NEET SS examinations.
Clinical Presentation
Symptoms:
Motor seizures are the most common manifestation
This can include generalized tonic-clonic activity with rhythmic jerking of limbs
Focal motor seizures may present with clonic movements of one limb or side of the body
Non-convulsive status epilepticus may present with altered mental status, behavioral changes, ophthalmoplegia, or subtle motor phenomena like facial twitching or repetitive automatisms.
Signs:
During SE, vital sign abnormalities are common, including tachycardia, hypertension, tachypnea, and fever
Neurological examination may reveal a depressed level of consciousness, focal neurological deficits (though these can be transient), nystagmus, or posturing
Pupil examination may show fixed and dilated pupils in severe cases.
Diagnostic Criteria:
The definition of status epilepticus is time-based: a single seizure lasting >5 minutes, or recurrent seizures without return to baseline consciousness between them
In practice, a 5-minute threshold for a single convulsive seizure is often used to initiate treatment
EEG confirmation is the gold standard but is not always immediately available in the emergency setting
clinical diagnosis often drives initial management.
Diagnostic Approach
History Taking:
Key history points include the onset and duration of the seizure, presence of any preceding illness or injury, history of fever or infections, known neurological disorders or epilepsy, recent head trauma, medication adherence, and exposure to toxins
Red flags include prolonged seizure duration (>5-10 minutes), fever in a young infant, known congenital malformations, and a history of previous SE.
Physical Examination:
A rapid but thorough physical examination is essential
This includes assessing airway, breathing, and circulation (ABCs)
A neurological examination should focus on level of consciousness, pupillary responses, motor activity, and the presence of any focal deficits
A complete examination for signs of infection (meningitis, encephalitis), trauma, and metabolic abnormalities should be performed.
Investigations:
Immediate investigations should include bedside glucose measurement to rule out hypoglycemia
Other crucial laboratory tests include complete blood count (CBC), electrolytes (sodium, potassium, calcium, magnesium), renal function tests, liver function tests, and blood gas analysis
In febrile children, lumbar puncture for CSF analysis is essential to rule out meningitis or encephalitis
EEG is critical for diagnosis, classification (convulsive vs
non-convulsive), determining seizure origin, and monitoring treatment response
Neuroimaging (CT or MRI brain) is indicated to identify structural lesions, inflammation, or vascular events
Toxicology screens may be considered based on history.
Differential Diagnosis:
Other conditions mimicking SE include syncope, breath-holding spells, shuddering attacks, paradoxical movement disorders, psychogenic non-epileptic seizures (PNES), and opisthotonos
Distinguishing features include the presence of rhythmic, stereotyped jerking movements in SE, and absence of post-ictal confusion in many non-epileptic events
However, a high index of suspicion is required, especially for non-convulsive SE.
Management
Initial Management:
The primary goal is to terminate seizure activity rapidly
Initial management follows a stepwise approach
First, ABCs must be secured
Supplemental oxygen should be provided
IV access is crucial for medication administration
The initial drug of choice is typically a benzodiazepine.
Medical Management:
Benzodiazepines are the first-line agents: Lorazepam IV (0.1 mg/kg, max 4 mg per dose) is preferred due to its longer duration of action and better safety profile compared to diazepam
If IV access is not immediately available, Rectal Diazepam (0.3-0.5 mg/kg) or Intranasal Midazolam (0.2 mg/kg) are effective alternatives
If seizures persist after the first dose of benzodiazepine, a second dose can be administered
If seizures continue for >10 minutes from the start of the first drug, second-line antiepileptic drugs (AEDs) are initiated
Commonly used second-line agents include Fosphenytoin (15-20 mg PE/kg IV over 30-60 min), Valproic acid (20-30 mg/kg IV over 10-20 min, max 1000 mg), or Levetiracetam (20-40 mg/kg IV over 5-15 min)
If seizures persist after a second-line agent, a third-line agent may be considered, such as Lacosamide or Phenobarbital
Refractory status epilepticus (SE that persists despite two or more AEDs) may require continuous IV infusion of Midazolam or Propofol, often in an intensive care unit setting, with EEG monitoring.
Surgical Management:
Surgical management is rarely indicated for acute status epilepticus unless there is a surgically correctable underlying lesion (e.g., tumor, vascular malformation) causing refractory SE
In select cases of medically intractable epilepsy with a focal origin, epilepsy surgery might be considered as a long-term management strategy, but not for acute termination of SE.
Supportive Care:
Supportive care is vital
Continuous cardiac and respiratory monitoring is necessary
Maintain normothermia and adequate hydration
Monitor urine output and electrolytes
Prevent aspiration by positioning the patient appropriately and considering nasogastric or orogastric tube placement if prolonged intubation is anticipated
Manage potential complications like seizures-induced hyperthermia, rhabdomyolysis, and aspiration pneumonia aggressively
Close monitoring of neurological status and vital signs is paramount.
Complications
Early Complications:
Early complications include respiratory depression, hypoxia, aspiration pneumonia, hyperthermia, rhabdomyolysis, cardiac arrhythmias, and hypoglycemia
Cerebral edema can develop
Status epilepticus can also lead to secondary insult from underlying causes like stroke or infection.
Late Complications:
Long-term sequelae can include intellectual disability, learning disabilities, behavioral problems, and the development of chronic epilepsy
The severity and duration of SE, as well as the underlying etiology, significantly influence the long-term outcomes
Neuronal injury, particularly in the hippocampus and amygdala, can occur with prolonged seizures.
Prevention Strategies:
Prevention focuses on prompt recognition and treatment of seizures, particularly in children with known epilepsy
Adherence to antiepileptic drug regimens is crucial
For individuals with known prolonged seizure patterns, home administration of rescue medication (e.g., rectal diazepam or intranasal midazolam) by caregivers may be prescribed
Public awareness and education on seizure first aid are also important.
Prognosis
Factors Affecting Prognosis:
Prognosis is influenced by the etiology of SE (e.g., SE due to a reversible metabolic cause has a better prognosis than SE due to a stroke or severe hypoxic-ischemic injury), age at onset (neonatal SE generally carries a poorer prognosis), duration of SE before treatment, and the presence of fever or status epilepticus in utero
Early and effective treatment improves outcomes.
Outcomes:
With prompt treatment, many children recover without long-term sequelae
However, prolonged or refractory SE can lead to significant neurological deficits
Mortality rates for pediatric SE are generally low (around 1-3%), but can be higher in specific populations or due to severe underlying etiologies.
Follow Up:
Patients who have experienced status epilepticus require close neurological follow-up
This includes regular assessments of cognitive function, behavior, and school performance
If epilepsy develops, long-term antiepileptic drug management and regular monitoring are essential
Neuroimaging and EEG may be repeated to assess for ongoing abnormalities and treatment efficacy.
Key Points
Exam Focus:
Master the benzodiazepine dosing and administration routes (IV, PR, IN)
Understand the stepwise approach to second-line and third-line agents
Recognize the importance of ABCs and rapid intervention
Differentiate convulsive vs
non-convulsive SE.
Clinical Pearls:
Always check bedside glucose first
Treat even if unsure about diagnosis if seizure activity is prolonged
Consider intranasal midazolam as an excellent pre-hospital or ER alternative if IV access is delayed
Continuous EEG monitoring is essential for refractory SE.
Common Mistakes:
Delaying treatment due to uncertainty about the diagnosis or waiting for IV access
Inadequate dosing of first-line agents
Not escalating treatment promptly when seizures persist
Failure to consider non-convulsive SE in patients with altered mental status and no obvious motor seizures.