Status Epilepticus
Introduction
Status epilepticus is a relatively common medical and neurologic emergency that requires prompt evaluation and treatment.
It is defined as a single epileptic seizure of >30 minutes duration or multiple seizures over that time without complete recovery in between.
After 30 minutes of ongoing seizure activity, the risk of long-term complications increases significantly. Because of the clinical urgency in treating status epilepticus, a 30-minute definition is not appropriate in clinical practice. Once seizures have continued for more than a few minutes, treatment should begin without further delay
Causes of Status Epilepticus
Occurs in 10% of adults and 20% of children with diagnosis of epilepsy at some point
Non compliance with anti seizure medication
Acute or chronic brain injury/lesion e.g. bleed, stroke, tumour, abscess, previous surgery
Infection e.g. encephalitis, meningitis
Drug withdrawal e.g. alcohol, benzodiazepines
Metabolic Abnormalities e.g. hypoglycaemia, hyponatraemia, hypocalcaemia, hepatic encephalopathy
Use of, or overdose of drugs that lower seizure threshold e.g. Tricyclic antidepressants, theophylline, propranolol, cocaine, amphetamine, GHB
Non convulsive status epilepticus
Eclampsia in women in late 2nd + 3rd trimester of pregnancy
Clinical Features
Patients with convulsive status epilepticus present with characteristic motor manifestations that vary according to the seizure type.
Generalised convulsive status epilepticus:
Obvious bilateral tonic and clonic motor activity and loss of consciousness.
Focal motor status epilepticus:
Progressive focal jerking activity of a limb with or without impaired consciousness.
Myoclonic status epilepticus:
Characterised by frequent myoclonic jerks that are more rapid but lower amplitude, either generalised or focal.
Tonic status epilepticus:
Rare in adults, being more common in children, it consists of maintenance of a tonic posture, particularly of axial musculature, rather than frank convulsions.
Clinical Investigations
Generalised convulsive status epilepticus is a clinical diagnosis with the role of investigations being to search for an underlying cause, which may be readily correctable.
Bedside
Rapid finger stick glucose should always be checked and hypoglycaemia treated if necessary
Venous blood gas – Low pH, High Lactate characteristic in status. Also gives rapid Na, K, ionised Ca + BM
ECG – In all patients following a seizure. Check QT Interval in particular.
Urine BhCG on all women of child bearing age (BHCG can be undetectable in late pregnancy so always look at a seizing woman’s abdomen to check for gravid uterus)
Urine toxicology – if concerned for possible OD e.g. cocaine, amphetamine
NB negative urine tox does not out rule toxin ingestion
Laboratory
Routine bloods – FBC, U&E, LFT, CoAg, Mg, Ca
look for underlying medical or metabolic cause for seizure
Blood cultures if signs of sepsis
Anti Epileptic Drug Levels may have role in some cases. Not done routinely
Radiology
CT Brain – if first seizure to exclude any structural abnormality.
All patients who have status should have CTBrain due to change in pattern of seizures
CXR
if concerned about sepsis or aspiration
MRI brain
if first seizure to further interrogate for structural abnormality. Not part of acute work up. Can happen as outpatient
EEG
can be useful in diagnosing underlying cause of status epilepticus once seizures have resolved or can be used to diagnose more subtle forms of status
Management & Disposition
Initial assessment and treatment of a patient in status epilepticus should proceed simultaneously.
Initial Resuscitation
Rapid assessment and attention to airway, breathing, and circulation
Continuous Cardiac monitoring and pulse oximetry
IV Access
O2 as clinically indicated
Seek and treat reversible causes e.g. hypocalcaemia, hyponatremia, hypocalcaemia, hypoglycaemia, eclampsia
Specific Treatment
First line treatment = Benzodiazepines.
2-4mg Lorazepam IV. If seizures continue dose can be repeated to max of 8mg.
If no IV access 5-10mg intranasal, buccal or IM midazolam are effective alternatives or PR Diazepam 10mg
Second Line = Load with IV anti-epileptic
E.g. IV Phenytoin 20mg/kg or IV Levetiracetam 30mg/kg
Third Line (if seizures ongoing despite all of above)
Rapid Sequence Induction à Intubation and Ventilation
Consider using thiopentone or Midazolam as induction agents
Disposition
All patients with status epilepticus require admission to hospital
If intubated they will be admitted to ICU
If 1st or 2nd line treatments are successful in ED they can be admitted to ward for observation and neurology review
References
1. Drislane, F et al. Convulsive status epilepticus in adults: Treatment and prognosis. uptodate.com
2. Drislane, F et al. Convulsive status epilepticus in adults: Classification, clinical features, and diagnosis. uptodate.com
3. Tintinalli J. Tintinalli's Emergency Medicine. 9th ed. McGraw-Hill Education; 2019.
4. Status Epilepticus. www.rcemlearning.co.uk
This blog was written by Dr. David Hogan and was last updated in December 2020