Submitted to AskTheNeurologist.Com in 2007Author Anon.
The first seizureIs it really first event?
If established that it is, in fact first, unprovoked event decision to treat depends on - risk factors for recurrence - risks of drug treatment - patient preference
Epilepsy in the ER
Seizure recurrenceOver 50% of patients who will have recurrence following first seizure will do so within 6 monthsRecurrence rate varies from 36 – 77%If careful history taken to ensure seizure is definitely “ first ever” then recurrence rate drops to 35%Recurrence rate following second seizure is 80-90%Risk factors for seizure recurrenceHistory of prior neurological injury or lesion
History of epilepsy in a sibling
Transient neurological deficit ( Todd’s )
EEG with generalised epileptiform dischargesTreatment of status epilepticusAcute Epilepsy emergency management - Prevents injuryEpilepsy Emergency in the ER Rational drug administration - Limits morbidity due to systemic changes or seizure-induced neuronal damageDefinitionsILE: “ seizure that persists for a sufficient length of time or is repeated frequently enough that recovery between attacks does not occur”Most literature specifies time period of 20-30 minutes as estimate of time necessary to cause injury to CNSOperational definition“ Continuous seizures lasting at least 5 minutes or 2 or more discrete seizures between which there is incomplete recovery of consciousness”Predictors of outcomeAgeCause - Metabolic - Infection - CVA - Trauma
OutcomesOverall mortality is 20%Patients whose first ever seizure is status epilepticus have substantial risk of future episodes and the developmennt of chronic epilepsyPredominant factor affecting outcome is causeMyoclonic status epilepticus after hypoxia carries especially grave prognosisDuration of status epilepticus is correlated with neurological morbidity and lack of responsiveness to drug treatmentAssessment and supportive measuresABC - protect airway100 % O2BP control
GlucoseHypoglycemia should be excluded
Usually treat empirically with 50ml of 50% glucose
Should always precede glucose administration with 100mg thiamine IVBlood pressureHypertension usually occurs early in course
Subsequently BP labile and often drops
Fluids and vasopressors may be required
Aim for high/normal rangeBody temperatureMay often be result of seizures themselves rather than co-existing infection
Should be treated with passive coolingSystemic treatmentAvoid over-hydration ( cerebral oedema )Blood tests ( including Ca, Mg)Monitor oxygenationMonitor rectal temperature
1st line drug treatmentsBenzodiazepines - Diazepam vs Lorazepam
Phenytoin vs Fosphenytoin
PhenobarbitalBenzodiazepinesLorazepam“ Despite their equivalence as initial therapies, lorazepam has a longer duration of antiseizure effect ( 12-24 hours ) than diazepam ( 15-30 minutes)…..lorazepam preferable to diazepam for the treatment of status epilepticus”FosphenytoinWater-soluble prodrug form of phenytoinDoes not contain propylene glycol ( which is main limiting factor for rate of treatment as contributes to cardiovascular side effects)Less irritantCan be given at a maximum rate of 150 phenytoin equivalents / minute Phenytoin itself may only be administered at a maximum rate of 50mg/minMaximal brain concentrations of phenytoinAttainable in 20-25 minutes when phenytoin infused at maximal rate
Attainable within 10 minutes when Fosphenytoin infused at maximal ratesPhenobarbital“ Highly effective”
Recommend 20mg/kg at rate of 50 – 75 mg/min
Risk of apnea….especially if patient has received BZD’sIV Valproic acidEffective in some forms of status epilepticus
At time of publication insufficient experience availableRefractory status epilepticusFailure to control seizures with BZD’s, phenytoin and phenobarbitalRequires administration of iv anaesthetic agent - Barbiturates - Midazolam - PropofolEEG performed at 12hrs and thereafter every 24 hoursseizures in the ER