Introduction
It is life threatening medical emergency. It occurs in patients who are already living with epilepsy or can be presenting feature of epilepsy. It occurs in all ages. The guidelines in identification and management has remained same more or less for last three decades while use of new or second line antiepileptic is not much recommended as on now. The management of status epilepticus in pregnancy is very challenging and new guideline is framed by Indian authors in year 2018. Despite advances in investigation modalities, the pharmacological therapy when timely applied holds the key in management of patients.
Epilepsy
It describes a condition in which a person has recurrent seizures due to a chronic, underlying process.
It refers to a clinical phenomenon rather than a single disease entity.
Seizure
It is a paroxysmal event due to abnormal, excessive, hypersynchronous discharges from an aggregate of central nervous system neurons.
Status Epilepticus
It refers to continuous seizures or repetitive, discrete seizures with impaired consciousness in the interictal period.
Types
The status epilepticus is divided in t hree types. They are
Generalised Convulsive Status EpilepticusIt is characterized by persistent generalised, tonic-clonic movements, electrographic seizures and Coma
Nonconvulsive Status Epilepticus
Epilepsia Partialis Continua it is a continuous seizure activity in one part of the body such as finger or a limb, without loss of consciousness.
Etiology
Status epileptic is the first manifestation in 10% of cases with epilepsy (1)
The causes / precipitants of status epilepticus are
Withdrawal of anticonvulsants
Noncompliance with anticonvulsants
Metabolic disturbances
Drug intoxication
Central Nervous System Infections
Central Nervous System Tumours
Refractory epilepsy
Head trauma
First unprovoked seizure
Noncompliance with medication was precipitating factor in 53% of those with prior seizure history.1
Clinical features
The patient present with tonic-clonic seizures lasting 2-3 minutes without regaining of consciousness between seizures, but continuous seizures also occur.
Paroxysmal episodes of hyperthermia, tachycardia and pupillary dilatation also occurs.
The non-convulsive status epilepticus presents with stupor, a confused state, clouding of consciousness, and little or no motor activity.
The duration of seizures activity sufficient to meet definition of status epilepticus has traditionally been specified of thirty minutes2 When the seizure activity prolongs for more than 30 minutes it leads to epileptic encephalopathy.
Refractory status epilepticus
The status epileptic that does not abate with benzodiazepines and two other anticonvulsant drugs is called refractory status epilepticus.2
Electroencephalogram (EEG)
The generalized atypical spike-wave of 1- to 2.5-Hz are seen on EEG. The waves may be grossly slowed and asymmetrical, being lower of amplitude on the side of causative focus.
It also plays important role in identifying non - convulsive status epilepticus. It is characterized by irregular spike-wave activity, less well formed than that of typical in absence seizure and often waxing and waning.
In prolonged status, the ictal pattern may become progressively less dramatic and the interictal disturbances more severe.
The other investigations that need to be carried out are
1. Random blood sugar levels
2. CT Brain
3. MRI Brain
4. Serum electrolytes
5. Blood levels of antiepileptic drug(s) if taking prior.
6. Renal function tests
7. Liver function tests.
In, 15% of cases, no cause can be found after thorough investigations1
Treatment
The goal of the treatment is to eliminate seizure activity, identify and treat the underlying cause.
On arrival of patient, look for acute cardio respiratory problem and hyperthermia. Ensure airway, oxygenation by nasal canula, rehydration, correction of acidosis, maintain blood pressure and monitor cardiac function.
Normal Saline should be initial fluid of choice as all the parenteral antiepileptics go well with it.
Perform a brief medical / neurological examination
Establish intravenous access and send blood for investigations.
Administer Injection Thiamine 100mg intravenously followed by IV 25% / 50% glucose in appropriate circumstances.
Start antiepileptic drugs immediately as per protocol in figure one.
Emphasis should be on ensuring adequate doses of the drug administered and while shifting from parenteral to oral therapy. Avoid phenytoin in patient with heart blocks while Phenobarbitone is safe in patient with heart blocks and in older people.
If status returns, the same drugs can be repeated.
Non-convulsive status epilepticus can be treated with intravenous lorazepam or Valproic acid or both.
In case, where in there is difficulty to access intravenous line or the patient is in community, Lorazepam or Midazolam can be given intramuscularly3
Treatment of Refractory Status Epilepticus
The refractory status epilepticus is treated by Phenobarbital 100mg/minute until the seizures have stopped or a total dose of 20mg/kg is reached.
The common side effects of phenobarbital are hypotension and prolonged state of stupor. These side effects can be over come by simultaneous use of dopamine, intravenous fluids and neosynephrine.4
Status epilepticus in elderly
In, elderly population it is 2 to 5 times more common than in young adults
It has an incidence of 86 per 100,000 annually among older people.5 In elderly up to 30% of acute seizures present as Status Epilepticus.6
The common causes of status epilepsy in the elderly are stroke, degenerative disease, neoplasm, infection, and trauma.7
The differential diagnosis for status epilepticus are convulsive syncope, asterixis, myoclonus, and psychogenic nonepileptic attacks in older people.
The mortality rate in patients aged 60 years is 38%, and nearly 50% for those over the age of 80 years6 while the refractory status epilepticus has mortality of 76%.8
Status epilepticus in pregnancy
Status epilepticus (SE) in pregnancy is rare.It can occur during gestation, labor, or puerperium.
The common causes are eclampsia, viral encephalitis, systemic lupus erythematosus, cavernoma, reversible cerebral vasoconstriction syndrome, pyridoxine deficiency, and N‑ methyl ‑ D ‑ aspartate N-methyl-D-aspartate (NMDA) receptor antibody mediated autoimmune encephalitis9,10,11
Another important cause found by Rajiv KR et al (2017) is posterior rev ersible encephalopathy syndrome12
The treatment of status epileptic in pregnancy is challenging and care to be taken regarding the teratogenicity of antiepileptic drugs.
A very useful protocol is framed by Rajiv KR et al (2018) for man agement of Status epilepticus in pregnancy. This helps the clinicians to treat with better outcomes both in mother and foetus.13 The readers are informed that the protocol can be downloaded from the web site http://www.neurologyindia.com
Mortality
The mortality rate in status epilepticus in a study by Rowan AJ et al14 in year 1970. was 21% while the study by Hanhan UA et al15 in year 2001 is 3 to 20%. There is no much change in mortality rates in last 40 years despite advances in treatment modalities. Status epilepticus as such will not produce death. The causes of death are hypoglycemia, rhabdomyolysis, acidosis, hypertension, renal failure and injury sustained as result of convulsions. The catecholamines that are released during seizures leads to fatal cardiac arrythmias.
The common post recovery sequalae is subtle or severe cognitive impairment.
Conclusion
The status epilepticus is dial emergency and treatment should be on priority with use of antiepileptics. Clinical diagnosis with support of biochemical measures and EEG still plays a vital role in diagnosis and management strategies. The prolonged phase of seizure activity and delay in initiating treatment leads to hypoxic brain injury which at time may delay the recovery. The status epilepticus occurs in all age groups and challenges are in managing in special categories like pregnancy and older people.
Article DOI
