Status epilepticus (SE) is a neurologic emergency associated with significant mortality and morbidity.

Definition : Conventionally defined as " prolonged seizure activity lasting longer than 30 min or series of seizures without recovery of consciousness in the interim".

The term refractory SE is used when there is failure to respond to first line drugs and seizures persist for more than 60 minutes.

Early recognition of SEis of utmost importance because longer the SE, the more difficult the control and more the risk of neurologic sequelae. Therefore, SE should be considered and treatment initiated when patient presents in emergency with continuous seizures or series of seizures without recovery of consciousness lasting 10 or even 5 min.

Incidence : SE is more common in children (more often in less than 3 yr olds) than adults with frequency of around 3.7%.

Classification : Any seizure type can present as SE.Generalised tonic clonic is the most common form and also the one with highest mortality and morbidity.

International classification is as follows ;

Convulsive (generalized) SE ;

• Tonic clonic
  
  
• Tonic
  
  
• Clonic
  
  
• Myoclonic

Nonconvulsive

• Absence status

Partial SE

1. Simple partial SE ; epilepsia partialis continua/ other types
   
   
2. complex partial status

Unilateral SE - hemiclonic status, hemiconvulsion hemiplegia syndrome.

Etiology of SE :

There are three main situations in which SE can present :

• Acute situation related : CNS infections - meningitis, encephalitis
  
  Acute anoxic insult
  
  Metabolic- hypoglycemia, inborn errors of metabolism (IEM), Reye syndrome
  
  Electrolyte imbalance
  
  CNS trauma/ haemorrhage/tumors
  
  Drugs, intoxications, poisoning
  
  Hypoxic ischemic encephalopathy and IEM in newborn period
  
  
• First unprovoked seizures presenting as SE - most commonly febrile status
  
  
• SE in patients with epilepsies - epileptics on irregular treatment, sleep deprivation, intercurrent infections and symptomatic epilepsies are more prone to developing SE.

Investigations :

Basic investigations to be carried out in all cases of SE irrespective of etiology include blood sugar,

• serum electrolytes
  
  
• blood gases , blood urea
  
  
• complete blood count
  
  
• serum Ca and Mg in neonates.

Certain other investigations may be required depending on individual situation:

• Lumbar puncture
  
  
• CT/MRI
  
  
• EEG
  
  
• Serum anticonvulsant levels
  
  
• Liver function tests, serum ammonia
  
  
• Blood cultures
  
  
• Toxicology screen.

Role of EEG : EEG is useful to recognise SE in paralyzed patients, nonconvulsive SE and in neonates. It is also of use in refractory SE which requires to be treated with midazolam infusion or general anaesthetics.