Presentation for the Pediatric Acute Care Symposium
Division of Pediatric Neurology
Department of Pediatrics
Emory University School of Medicine

Terms: Seizures and Status Epilepticus

A seizure is paroxysmal disturbance of brain electrical activity. Its onset may be focal or generalized. Focal-onset seizures may or may not become generalized. A clinical seizure is abnormal brain electrical activity that occurs in time locked association with abnormal clinical behavior change. Clinical behavior change can be motor or sensory activity.

Status Epilepticus-Definitions

• 1903: The maximum development of epilepsy, in which one paroxysm so closely follows another that the coma and exhaustion are continuous between seizures. (Clark and Prout, Am J of Insanity 1903/04; 60:291-306.)
• 1964: Whenever a seizure persists for a sufficient length of time or is repeated frequently enough to produce a fixed and enduring epileptic condition. (Commission on Terminology ILAE, Epilepsia 1964; 5:297-306.)
• 1981: Whenever a seizure persist for a sufficient length of time or is repeated frequently enough that recovery between attacks does not occur. (Commission on Terminology ILAE, Epilepsia 1981; 22:489-501.)
• 1993: Status Epilepticus is two or more seizures without regaining consciousness or a single seizure that last more than 30 minutes. (JAMA 1993; 270:854-859.)
• 1999: Operational Definition for Children over 5 years and adults: Any seizure lasting more than 5 minutes or two or more discrete seizures between which there is incomplete recovery of consciousness.(Epilepsia 1999; 40: 120-124., Ann Neurol. 49:659-664, 2001.)

Status Epilepticus is a Medical Emergency

The practical definition for Status Epilepticus is: seizures lasting longer than 10 minutes, or seizures on presentation to the Emergency Room, or seizures recurring in the ER. Remember basics of Seizure First Aid.

Types of Status Epilepticus

1. Generalized
   • Tonic Clonic Status- One focus of this presentation
   • Absence Status
2. Focal Status
   • Epilepsia Partialis Continua
   • Complex Partial Status
3. Refractory Status Epilepticus - Another focus of this presentation
   • Defined as status epilepticus lasting longer than 60 minutes despite adequate doses of a benzodiazepine and a second antiepileptic (AED) drug.
   • 9-31% of all status

Incidence of Status Epilepticus

• 50,000-250,000 times per year in the U.S.
• 21% are less than 1 year of age
• 64% are less than 5 years of age
• 10-25% have more than one episode of status

Status Epilepticus and Epilepsy

• Less than 50 % of individuals with status epilepticus have a history of Epilepsy
• 15% of epileptics will have status epilepticus
• 10% of epileptics present with status epilepticus

Outcome and Etiology are closely linked. Status has much less morbidity in children, except with progressive CNS disease.

Physiologic Changes with Status, (Meldrum, 1983)

• Early Changes (less than 60 minutes)
  • Local metabolic abnormalities
  • Reversible 1st 10-60 minutes
• Late Changes (more than 60 minutes)
  • Increased Temperature
  • Decreased Glucose and Blood Pressure
  • Increased Pulmonary Congestion

Outcome of Status Epilepticus

• Duration of the seizure activity

  Duration of Status	Mortality
  Seizure for less than 1 hour	3%
  Seizure for more than 1 hour	32%

  
  
• Etiology of the Status influences outcome as well as the need and type of further anti-seizure therapy.
  
  

  Etiology of Status	Mortality
  Idiopathic	4%
  Symptomatic	20%

  (Gilbert et.al., 1999)
  

  Etiology of Status	Risk of Epilepsy	Risk of Recurrent Status	Chronic AED Rx	Diastat®
  Idiopathic	0%	3%	No!	Yes?
  Remote Symptomatic	++	50%	Yes!	Yes!
  Febrile	+	+	No?	Yes?
  Acute Symptomatic	15-30%	+	Yes?	Yes?
  Progressive	++	50%	Yes!	Yes!

Outcome of Status over the Decades

Currently, status epilepticus has 1/5 the morbidity and 1/3 the mortality of pre-1970. Still, morbidity for status in children is at least 3% and as high as 30% in children with refractory status (Sahin et. al., 2001) and 30% in adults. Improvements reflect study referral bias, use of retrospective data, and changes in definitions of status (from greater than 60 minutes to much shorter duration of seizures). The most important factor for improved outcomes is improved care.

Outcome is determined by etiology, age, duration and treatment. You can affect only treatment.

Treatment and Evaluation of Status Epilepticus

• Injury may begin before the formal criteria for the diagnosis is met.

• No single protocol is superior - be prepared in advance!
• IV treatments are favored. Know a drug and be comfortable using that drug. Lorazepam has advantages over diazepam. (Alldredge et al. NEJM 2001)
• Some approaches are inferior
• Rectal diazepam gel (Diastat®) may be available in field by EMTs or at home by parents.

The goal of treatment is the cessation of both clinical and electrical seizures.

Evaluation and Treatment of Status Epilepticus

Pharmacologic Coma for Refractory Status Epilepticus

Status Epilepticus Evaluation - Treatment Reminders

• Ventilation is to be anticipated. Use of AEDs to stop seizures and respiration for intubation is better than giving neuromuscular blockade alone.
  
  
• Most easily missed diagnosis of causes of status epilepticus
  • Bacterial meningitis
  • Encephalitis
  • Abuse/unsuspected trauma
  • Drug ingestion
  
  
• Lumbar Puncture should be performed in most cases
  • All cases of status epilepticus and fever
  • Only after the the patient is stabilized
  • Unlessspecific contraindication to LP exist
  
  
• Contraindications to LP
  • Skin infection at LP site
  • Cardiovascular instability
  • Signs of Increased Intracranial Pressure
    • Papilledema
    • Herniation
    • Posturing
  • Coaggulopathy
  
  
• Neuro-Imaging
  • CT Scan may be necessary:
    • To evaluate safety of LP
    • To rule out hemorrhage or large mass lesion
  • MRI will almost always be performed later, even if CT is normal.
  
  
• Use correct and adequate Anti-seizure drug doses. Epileptics and non-epileptics in status require the same drug doses. Remember, outcome is determined by etiology, age, duration and treatment. You can affect only the treatment.

Status Epilepticus Summary

Status epilepticus is a common and serious condition. Children are more Susceptible to the occurrence of status, but more resistant to injury. Normal children and children with febrile status have a favorable prognosis. In all respects, children with prior, new or progressive CNS injury are more prone to have refractory status epilepticus. As a group they have higher morbidity and mortality, including later epilepsy, recurrent status, and the need for prolonged anti-epileptic drug therapy.

Improved outcome is a result of timely and appropriate evaluation and treatment.

References

Available on line at www.pediatrics.emory.edu/NEURO/status.htm

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