Epilepsy Flashcards
After what time do seizures become self sustaining
What can occur after this time
15-30 minutes
Neuronal injury
What is status epilepticus
A generalised seizure that last more than 30 minutes or multiple seizures without recovery
What is the incidence of status epilepticus
10-41/100,000
Lifetime risk 10% (pts with epilepsy)
What is the mortality rate of status epilepticus?
9-60%
Status >30 minutes 20% mortality
Severe neurological/cognitive morbidity 11-16
How does convulsive status epilepticus present
Convulsions associated with rhythmic jerking
Generalised tonic clonic movements
Mental status impaired
What happens neurophysiologically when a seizure converts to status
Receptors move from synaptic membranes and endosomes
Inhibitory GABA receptors destroyed
Become less responsive to GABAergic drugs (ie benzos)
Excitatory NMDA and AMPA receptors move to synaptic membrane causing further excitation
How much less effective are benzos after 30 minutes
20
Phenytoin less so
NMDA blockers less likely to lose efficacy
How does status lead to increased excitability
Increased proconvulsive neuropeptides
Depletion of inhibitory neuropeptides
What occurs after extreme length status
Long term gene expression changes as a result of neuronal death &reorganisation
Seizures inhibit brain synthesis
List the aetiologies of status
Low AED levels in blood (34%) Remote symptomatic causes (24%) CVA (22%) Anoxia/hypoxia (10%) drug/ alcohol withdrawal (10%)
How do you initially manage status
First aid
Recovery position , oxygen
ABCDEFG
After a seizure of longer than ten minutes or longer than expected what should you consider the possibility of
NEAD/pregnancy
What treatments should you consider for prolonged seizure just before conversion to status
Emergency AED therapy
Glucose +/- high dose IV pabrinex if Low nutrition
Treat severe acidosis
What are the pros and cons of anesthesia in status
Pro:
Powerful AEDS
Can protect the airway
Can get scans and treat easily
Con:
Pnumonia
Hypotension and cardiac arythmias
Infection and consequences of not moving
What are the consequences of a status coma
Pressure sores DVT pnumonia Muscle weakness Organ dysfunction (GI tract , immune system) Psychological impacts (PTSD)
What are the benefits of EEG during status
Can see ongoing seizure activity
Can suggest other causes ie encephalitis NEAD
Define refractory status epilepticus
Seizures that continue despite two appropriate AEDS at appropriate doses
Mortality 23-60
Can go on for months