Introduction
Status Epilepticus(SE) is a common neurological
emergency with a higherrate of mortality,
neurodevelopental sequelaeand morbidity.
SE may occur as a first presentation of a seizure
disorder in the life span of epilepsy or neurologically
ill patient or due to infection ,trauma , hypoxia, or
metabolic causes.
Definition
Definition of SE to reflect the time at which
treatment should be initiated (t1)
Time at which continous seizure activity leads to
long term sequelae such as neuronal injury (t2) .
Definition con’t
The 5 mins window corresponds with the time at which
urgent treatment should begin.
The classical 30 mins cut off is based on the fact that
approximately after 30 mins of generalized seizures, the
compensatory mechanisms fails against acidosis,
hyperthermia ,hyperkalemia , and cardiocirculatory
collapse .
Thus SE induced irreversible neuronal damage occures and
seizures become self-sustained and refractory to treatment.
Definition:
Historically, status epilepticushas been conceptually
defined as “A condition characterized by an epileptic
seizure that is sufficiently prolonged or repeated at
sufficiently brief intervals so as to produce an unvarying
and enduring epileptic condition” . Roger J 1974
The International League Against Epilepsy: 30 min of
continuous seizure activity, or a series of epileptic seizures
during which function is not regained between ictalevents
in a longer than 30 min period. Epilepsia. 1993
Epidemiology
Approximatley17-23 of 100,000 children
experience SE every year.
From neonate to 1 year of age: 135–150 incidents
per 100,000 children
Between age 1-4 yrs(29 of 100,000)children,
Aged 5-9 yrs(9 of 100,000) children,
And aged 10-15 yrs(2 of 100,000) children
Mortality at 3%
Incidence
The incidence is highest in the neonatal period
Approximately 30% of patients presenting with SE
are having their first seizure and approximately
40% of these later develop epilepsy .
Classification
SE may be subclassifiedas
oConvulsive: generalized tonic-clonicmovements,
mental-status impairment, postictal focal neurologic
impairment. 90%of all SE.
oNonconvulsive: wandering confused, mental status
impairment with or without motor movements.
oRefractory: not responsive to standard treatment. It
is defined as clinical or electrographic seizures that
continue despite adequate benzodiazepine doses and
at least one acceptable antiepileptic drug (AED).
Occurs in 30% SE.
Causes
of SE
Causes of SE Con’t
Known (symptomatic):
oAcute (stroke, toxicity, derangements in serum electrolytes
and blood glucose, trauma,hypoxia, febrile seizures,
neuroinfections, and inborn errors of metabolism)
oRemote (brain scars due to above causes, genetic, brain
malformations, etc.)
oProgressive (neurodegenerative disorders and tumors)
oKnown cases of epilepsy: Lennox–Gastaut syndrome and
Dravet syndrome
Unknown cause: new-onset refractory status epilepticus
(NORSE), febrile infection-related epilepsy syndrome
(FIRES)
Mechanisms:
The establishment of sustained seizure activity seen in
SE appear to involve:
1) Failure of desensitization of AMPA (Alpha
amino -3-hydroxy-5-methyl-4-isoxazolepropionic acid)
glutamate receptors, thus causing the persistence of
increased excitability
(2) Reduction of GABA-mediated inhibition as
a result of intracellular internalization of GABA-A
receptors.
Pathogenesis
Pathogenesis
Failure of the normal mechanisms that terminate seizures
Reduced inhibitionand persistent excessive
excitation ,Ongoing seizure activity ↓GABA receptors
Pronounced excitation via glutamate analogues leads
to prolongation of seizures
Mechanism Con’t
During SE, there is an increased cerebral metabolic
rate and a compensatory increase in cerebral blood
flow.
When the brain is exposed to prolonged seizures ,
there is a rapid decrease in number of post synaptic
GABA-A and increase in the number of post synaptic
NMDA receptors .
This loss of inhibition and increase in excitation in the
brain synapses promote self sustaining prolonged
seizure and may explain the loss of efficacy of
benzodiazepines
Management
History taking, investigation and treatment go
simultaneously
Status epilepticus is a medical as well as neurologic
emergency
In children with new-onset seizures, after
continuously seizing for 5–10 min, a seizure
becomes unlikely to stop without pharmacologic
intervention
Several studies have described associations
between status epilepticus management delays
and more prolonged seizures and lower anti-
seizure medication responsiveness
Thus we have to start treatment as early as possible
Quick History
Elicit quick history
Trauma
Antecedent illness
Fever
Ingestion
Skipped medication
Management con’t
Ideal drug for treating SE
Rapid entry into CNS
Rapid onset of action
Long duration of action
Safety
Absence of sedation
Useful as maintenance AED
Management Con’t:
Stage 1: Early phase (duration from 5 to 10 minutes)
ABCDE
Maintain Airway-patient at risk for aspiration
Breathing-place O
2, be ready for intubation
Circulation-obtain IV access
Dextrose: check glucose levels
Electrolytes: check electrolytes (Na, Ca, Mg, PO
4)
Check anticonvulsant levels
Investigations
CBC
Serum electrolytes ,ABG
Ca, Mg, PO
4
Glucose
Liver function tests, S/ Creatinin
S/ Ammonia, Lactate
Anticonvulsant levels
Toxic screen
cEEG
Neuroimaging: CT Scan of Brain (use contrast if suspect brain tumor or
AVM)
Investigation Con’t
Lumbar puncture
Always defer LP in unstable patient, but never delay
antibiotic/antiviral rx if indicated
CT scan
Indicated for focal seizures or deficit, history of trauma
or bleeding
Studyofout-of-hospitaltreatmentofseizures
lorazepamvsdiazepam.
Seizureactivityterminatedin
60%ofthelorazepam-treatedpatients
43%ofdiazepam-treatedpatients
21%ofpatientswhoreceivedplacebo
Benzodiazepines
AlldredgeB.K.,Gelb A.M.,Isaacs S.M.,et al:Acomparison of lorazepam,
diazepam, and placebo for the treatment of out-of-hospital status
epilepticus. NEnglJ Med345.(9): 631-637.2001;
Status Epilepticus Treatment
Diazepam
Highly lipid soluble
Rapid CNS entry-stops seizures in 1-3 minutes
Rapid redistribution in fatty tissues
Brain concentrations fall quickly
Duration of action is 15-30 minutes
T1/2= 30 hr
Dose: <3yrs, 0.5mg/kg, >3yrs, 0.3mg/kg
Side Effects: sedation, decreased respiration and
blood pressure
Lorazepam
Less lipid soluble than diazepam
Slower CNS, stops seizures in 6-10 min
Not as rapidly redistributed to fat stores
Longer duration of action 12-24 hr
T1/2 =14 hr
Dose: 0.05—0.1mg/kg
Side Effects: decreased LOC, respiration and BP
Benzodiazepines lose effectiveness in established
SE and are suboptimal for long time anti-seizure
management; therefore next line AED should be
ordered and administered early, within 10 min of
seizure onset.
When to start 2
nd
line Anticonvulsant
Ifseizurescontinuefor10minutesafteratleast
twoinjectionsofabenzodiazepine,asecond
therapywithalong-actingantiseizuremedication
shouldbegiven(oneguideline)
Antiepilepticdrugsshouldbeadministered
concurrentlywithbenzodiazepines(one
guideline)
STAGE II: Established Status Epilepticus
(duration from 10 to 30 minutes)
The American Epilepsy Society’s guideline concludes that
There was insufficient evidence to evaluate phenytoinor
levetiracetamas second-line therapy (level U evidence)
I/V valproicacid has similar efficacy but better tolerability
than intravenous phenobarbital (level B evidence)
Comparison
Phenytoin
IV dosing 20 mg/kg load
•Onset 10-30 min
1mg/kg/min
Extravasationcauses severe
tissue injury
May cause hypotension,
dysrhythmia
Precipitates with Glucose
containing fluid
Can not be given in renal
insufficiency,
hypoalbuminemia
Fosphenytoin
IV dosing 20 mg/kg load
•Onset 5-10 min
1.5mg/kg/min
Extravasationwell tolerated
May cause hypotension
STAGE III: Refractory Status Epilepticus
(Refractory GCSE)(duration from 30 to 60
minutes)
The definition of refractory generalized CSE (GCSE) is
based on the number of anticonvulsants used
A patient is considered to have refractory SE when
Seizures continue despite first-and second-line
treatments and the seizures duration is greater than 1 hour
there is a need for general anesthesia
Refractory Status Epilepticus
Intubation
Continuous EEG monitoring
Drugs: Levetiracetum. Phenobarbiton, Sodium Valproate
Medication Coma
Pentobarbital
Midazolam
Propofol
Very high dose phenobarbiton
Treatment Stage III
Phenobarbiton
Lipid solubility < Phenytoin
Duration of action>48 hrs, T1/2= 100 hours
Dose : 15–20 mg/kg IV, may give an additional 5–10 mg/kg
Side Effects: sedation, decreased respiration and BP
Management of refractory status epilepticus
General anesthetics to achieve burst suppression
Midazolam—0.2 mg/kg IV bolus followed by infusion @1
μg/kg/ min, increasing 1 μg/kg/min, every 5–10 minutes,
till seizures stop, up to a maximum of 30 μg/kg/min,
tapering initiated after 24 hours of seizure control @ 1
μg/kg/min, every 3 hours
High-dose phenobarbitone: 5–10 mg/kg boluses every
30 minutes up to 120 mg/kg over 24 hours, target seizure
control and burst suppression, maintenance up to 40
mg/kg/day
Propofol:loading dose of 1–2 mg/kg, followed by
continuous infusion of 1–2 mg/kg/h, maximum of 5
mg/kg/h. Propofol infusion should not be used in
children due to the risk of propofol infusion
syndrome).
Thiopentone:loading dose 5 mg/kg bolus followed by 3–
5 mg/ kg/h infusion rate to achieve burst suppression
followed by tapering after 24 hours seizure free period.
Topiramatethrough orogastric/nasogastric tube (2–5
mg/kg enteral loading, increase by 5–10 mg/kg/day up to
maximum of 25 mg/kg/day) while tapering anesthetic
agents.
Ketaminecan also be tried.
Levetiracetum
Consider LevetiracetumIV Loading
High bioavailability
Few drug interaction
Low plasma protein binding
Minimal hepatic metabolism
•Can be considered second-line
•May be preferred over benzodiazepines in specific
patients with respiratory compromise and/or
hypotension
Dose: 20-60 mg/kg
Valproate
Consider IV Valproic Acid
FDA approved only for replacement or oral dosing
Rapid loading dose appears safe
25-30mg/kg rapidly infused
Side Effects: dizziness, nausea
Can be initial therapy in patients with increased risk of
cardiac or respiratory abnormalities
Concern for hepatotoxicity with valproic acid use in
children younger thantwo years).
Stage IV: Super refractory status epilepticus
(duration > 24 hours)
When treatment with an IV anesthetic for more than 24 h
is not successful in controlling SE, the condition can be
termed superrefractory SE or malignant SE.
The first line therapy includes maintaining the use of
anesthetic drugs used in Phase III although other drugs
have been reported with uncertain outcomes such as
Ketamine
enteral topiramate
perampanel
bumetanide
Other therapeutic options included :
Hypothermia
Magnesium Infusion
Pyridoxine Infusion
KetogenicDiet
Immunologic Therapy ( InjMethyl Prednisolone,
IVIG)
Emergency neurosurgery including
focal resection, multiple subpialtransection,
corpus callosotomy, and hemispherectomy
Some recommendations
When I/V access is not possible I/M fosphenytoin
( 18-20 mg/kg) can be given as a single dose
Children already getting oral phenytoin should be
cautiously given inj phenytoin @ 5 mg/kg over 5 min and
wait for blood phenytoin level
If the patient progresses to refractory status
epilepticus, urgent escalation of therapy should be
continued
At this point, options include administering
another bolus of the same second-line agent that
had been given or adding another agent from the
ones just discussed.
Status Epilepticusin Adults: A Review of Diagnosis
and Treatment.2016
Supportive Therapy
Glucose Infusion: 10% dextrose 2ml/kg
Hyperglycemia has no negative effect in SE
(as long as significant hyperosmolalityis being
avoided)
Supportive Therapy
Inj Mannitol 5ml/kg over 10 min if seizure
continues for 30 min to decrease cerebral oedema
In any step if seizure is controlled, start on
maintenance therapy-after 12hours of bolus dose
Maintenance dose of Phenobarbintone–2.5-4
mg/kg/dose 12 hourly and in case of Fosphenytoin
it is 7.5mg/kg/dose 12 hourly.
Tapering
In Pt having continuous infusion of an AED-after
cessation of seizure, the infusion should be
continued for 12-24 hours. Then gradual tapering
is advised over 24 hour
Outcome and prognosis
Factors that determine outcome include
Age of the child
Rapidity of seizurecontrol
Adequacy of care
Time from seizureonset to initiation of treatment
is inversely corelated with the % of patient who
responded to 1st line AEDs.
-at 30 mins 80% responded
-at 90 mins 44%
Periodic lateralized epileptiform discharges at any
time of SE , associated with poor outcome.
Take Home Message
Status epilepticusis a medical emergency
Better outcome if seizure stopped earlier
Early treatment and stepwise treatment is the
most important prognostic factors
Consideration of NCSE should be kept in mind
Targeted investigations should be done
Supportive management is very important
Planning should be done to prevent further attacks