Epilepsy Flashcards
What happens during the tonic phase of a tonic-clonic seizure?
lose consciousness
muscles stiffen - if standing, fall to floor
air pushes past voice box = sounds like person crying out
bite on tongue / inside of mouth
What happens during the clonic phase of a tonic-clonic seizure?
limbs jerk quickly & rhythmically
lose control of bladder ± bowels
can stop breathing/apnoea = blue tinge around mouth
What is an epileptic seizure?
an abnormal high-voltage, paroxysmal discharge of cerebral neurones due to cortical hyper-excitability
Define epilepsy.
A tendency to recurrent, usually spontaneous, epileptic seizures.
what are some risk factors for epilepsy?
birth development seizures in past (including febrile fits) head injury (including LOC) FH drugs alcohol
list some drugs which may cause epilepsy
BP meds –> vasovagal
antibiotics e.g. penicillin, cephalosporin, quinolone
tramadol (hallucinations and precipitate fits)
opioids e.g. diamorphine, pethidine
Why is an ECG essential in investigating seizures?
looking for prolonged QT syndrome
Why would you do an EEG?
to confirm non-convulsive status epilepticus - e.g. patient has prolonged absence
Patient had seizure not long after a change to their medication dose. How long until they can drive their car again?
6 months seizure free and back on previous meds for 6 months
Patient presents having had their first ever (isolated) seizure. How long until they can drive a HGV again?
5 years (can’t have been prescribed AEDs in this time either) and low risk after assessment
Patient has epilepsy and wants to know if they can keep their normal license. How long must they be free of seizures for?
1 year with/without taking AEDs
Patient with epilepsy had their last attack 8 years ago and has came off their medication around this time. How long until they can reapply for their HGV license?
in 2 years - 10 years off medication and 10 years seizure free
Patient had one-off seizure 2 years ago. How long until they can drive their lorry again?
3 more years - 5 years seizure free and off medication for 5 years
Patient has epileptic seizures when asleep but it has been a while since their last awake seizure. Are they ok to drive?
If the last awake seizure was 3 years ago and since then they have only had asleep seizures then yes they can drive.
What is SUDEP?
sudden unexpected death in epilepsy
Describe the 2 types of partial epileptic seizures.
simple = without impaired consciousness complex = with impaired consciousness
Teenager is brought to clinic by mother who reports they have a jerking arm when they go to drink their tea in the morning. They also appear to be staring into space but the parent thought this might just be due to tiredness in the morning. Teenager has habit of staying up late watching tv and doesn’t recall these episodes / why mother has brought them into clinic.
Diagnosis and treatment?
juvenile myoclonic epilepsy (JME)
sodium valproate = 1st line
if ^ unsuitable (females) / not tolerated –> levetiracetam (or topiramate)
young people should be on mono therapy
Treatment for focal onset epilepsy?
carbamazepine (affects liver and decreases efficacy of other drugs)
or
lamotrigine (2-3 months to reach effective dose and can exacerbate myoclonic seizures)
How do AEDs that act on pre-synaptic Na+ channels reduce seizures?
inhibit voltage gated na+ channels –> reduces pre-synaptic excitability and ability of action potentials to spread.
What is the effect of an AED increasing K+ channel activity in the pre-synaptic neurone?
enhancing K+ channel activity = opening them = stabilises neurone and reduces excitability = less seizure potential
How does sodium valproate work?
enhances GABA synthesis
Which AED takes 2-3 months to titrate up to full dose and why?
lamotrigine due to potential cause of steven-johnson syndrome
Which AED has large weight loss as side effect and when might it be alternatively used?
topiramate –> idiopathic intracranial hypertension
however also sedation, dysphasia - not well tolerated
Which older type of drug is for acute management only and in long term it “makes you ugly”?
phenytoin - rapid loading possible = acute management
What is the 1st line drug for most generalised seizures?
sodium valproate
Which anticonvulsants induce hepatic enzymes?
carbamazepine, oxcarbazepine, phenobarbital, phenytoin, primidone, topiramate
Female patient with new diagnosis of epilepsy - what alteration to contraceptive medication do you need to consider?
progesterone only pill and progesterone implant don’t work with enzyme-inducing AEDs
morning after pill - higher dosage needed
What supplements do females with epilepsy need to take for pregnancy?
high dose folic acid at least 3 months before conception
what is the definition for status epilepticus?
recurrent epileptic seizures without full recovery of consciousness
or
continuous seizure activity lasting >30 mins
Name the 3 types of status epilepticus.
generalised convulsive SE
non-convulsive status (conscious but in ‘altered state’)
epilepsia partialis continua
What can precipitate status epilepticus?
hyponatraemia infection head trauma Subarachnoid haemorrhage abrupt withdrawal of anticonvulsants treating absence seizures with CBZ
Describe convulsive status and what causes the lasting damage.
generalised convulsions without cessation.
excess cerebral energy demand and poor substrate delivery –> lasting damage
Patient in uncontrolled status epilepticus and suspected hypoglycaemia. management?
50ml 50% glucose on top of anticonvulsants
What anticonvulsants are given to a patient in uncontrolled status epilepticus?
phenytoin / keppra / valproate
benzodiazepines - 10mg buccal midazolam
How many doses of benzodiazepines can be given in uncontrolled status epilepticus before calling ITU? What is alternative to 1st line benzo?
2 DOSES ONLY
Lorazepam IV or diazepam IV/PR if can’t give buccal midazolam
patient who is known alcoholic presents with status epilepticus - what specific medication do they get?
250mg IV thiamine
When do you avoid using phenytoin/
if bradycardia or heart block
