Epilepsy: Seizures and Syndromes Flashcards
important features of fall history?
onset (what were they doing? where? symptoms before? what did they look like?) event itself (any movements? responsiveness/consciousness throughout?) afterwards (speed of recovery, sleepiness/disorientation, deficits)
how do you take a history of a seizure?
ask eye witness to demonstrate the movements
general features of vasovagal syncope?
feeling unwell and unsteady
go pale and grey
hit the ground then BP restored very quickly and back to normal
tongue biting and urination are features of seizure?
no
not specifically
can be caused by lots of things
name 7 risk factors for epilepsy?
birth problems delayed development seizures in past (including febrile fits) head injury family history drugs alcohol
how is examination used in seizures?
often no examination in 1st seizure as little benefit
if syncope is diagnosed then do cardio exam and L+SBP
always do an ECG
examples of drugs which can cause seizures
analgesics (tramadol, opioids)
antibiotics (penicillins, cephlasporins, quinolones)
antiemetics (prochlormezapine)
important ECG sign to look out for after a fall or seizure?
long QT syndrome
who requires an urgent CT scan after a seizure?
clinical or radiological skull fracture deteriorating GCS focal signs head injury with seizure failure to be GCS 15/14 4 hrs after arrival suggestion of other pathology
how useful is an EEG in epilepsy?
not useful so not used
many people have abnormal EEG with no epilepsy
30% of epilepsy patients have normal EEG
indications for EEG?
classification of epilepsy
confirmation of non-epileptic attacks
surgical evaluation
confirmation of non-convulsive status
differential diagnoses for seizures?
syncope non-epileptic attack TIA migraine hypoglycaemia parasomnias paroxysmal movement disorders MS tonic spasms
first step after a fall diagnosis?
counselling
- explain diagnosis (seizure vs syncope vs epilepsy etc)
- explain seizure doesn’t mean epilepsy
- discuss risk of recurrence
- discuss driving and safety
rules for driving and seizures?
single seizure = cant drive car for 6 months, cant drive HGV for 5 years
epilepsy diagnosis = 1 year seizure free, 3 years of only nocturnal seizures, 10 years off medication to drive an HGV
what is epilepsy?
tendency to recurrent, usually spontaneous, epileptic seizures
what are epileptic seizures?
abnormal discharge of electricity in the brain
abnormal synchronisation of neuronal activity (usually excitatory with high frequency APs, sometimes predominantly inhibitory)
interruption of normal brain activity (general or focal)
why do people have epileptic seizures?
too much excitation or too little inhibition
can be due to changes in
- cell number/types
- connectivity
- synaptic function
- voltage gated ion channel function
genetic, acquired brain, metabolic, toxic and environmental factors
how common is epilepsy?
most common in infancy and old age but can be at any age
50-80 per 100,000
epilepsy mortality?
1 in 400 chance of death in a year
what is SUDEP?
sudden unexpected death from epilepsy
most common cause of death in epilepsy?
can often be a consequence of the underlying cause of the epilepsy (brain tumour, stroke etc)
suicide in younger patients (<50)
2 main classifications of epileptic seizures?
focal/partial = (abnormality in a part of the brain which irritates surrounding area of brain causing abnormal discharge of electricity = focal seizure, can hit a pathway causing it to spread causing a secondary generalised seizure generalised = discharge immediately hits pathways causing whole brain to "light up"
features of generalized?
most have genetic predisposition
present in childhood and adolescence, generalised spike-wave abnormalities on EEG
types of partial seizure?
simple = without impaired consciousness complex = with impaired consciousness
types of generalised?
absence (go blank, loose consciousness?) myoclonic atonic tonic tonic clonic
different seizure types can cause same features, true or false?
true can present the same
focal epilepsy is what?
tendency to have recurrent focal seizures
can also give 2ndary generalised seizures
generalised epilepsy is what?
discharge happens directly on network so can only have generalised seizures
“tendency to have recurrent generalised seizures”
implication of epilepsy classification?
only important in terms of medication really
how is generalised epilepsy managed?
sodium valproate = best
alternative = lamotrigine
side effects of sodium valproate?
weight gain
balding
- often patients don’t want to take it
teratogenic
example of generalised epilepsy and how does it present?
juvenile myoclonic epilepsy
early morning jerks
generalized seizures
risk factors = sleep deprivation, flashing lights
what is focal onset epilepsy?
most common epilepsy in over 50s
underlying structural cause
complex partial seizures with evidence of hippocampal sclerosis
management of focal onset epilepsy?
carbamazepine or lamotrigine
- carbamazepine has interactions and side
levotorazopam can also be used?
effects, if so swap to lamotrigine
when are anticonvulsants used?
only if recurrent seizures or single seizure with high risk of recurrence
most only need 1 drug, few need 2-3
35% are drug resistant
AED target what?
GABA system
- target GABA receptor
- target GABA transaminase
- target GABA transporter
- enhances GABA synthesis (sodium valproate)
only which 2 drugs work well together in epilepsy?
sodium valproate and lamotrigine
sodium valproate inhibits metabolism of lamotrigine
focal seizures initial treatment?
carbamazepine
lamotrigine
(or oxycarbazepine, levetiracetam, topiramate, sodium valproate)
add on drugs in partial seizures?
gabapentin
pregabalin
tiagabine
zonisamide
absence generalised seizures management?
sodium valporate
ethosuximide
myoclonic generalized seizure management?
sodium valproate
levetiracetam
clonazepam
atonic, tonic or tonic clonic generlaised epilepsy management?
sodium valporate
describe 3 old anticonvulstants and their use?
phenytoin (enzyme inducer only for acute management)
sodium valproate (like bleach, lots of side effects - weight gain, teratogenic, hair loss, fatigue)
carbamazepine (only for focal, never generalised as can make worse)
name 4 new anticonvulsants and their use?
lamotrigine (good for focal and generalised, takes long time to titrate)
levetiracetam (popular but can cause mood swings)
topiramate (causes sedation/dysphasia/weight loss, not well tolerated)
gabapentin, pregabalin (more for pain)
which anticonvulsants induce hepatic enzymes (important)
carbamazepine oxcarbazepine phenobarbital phenytoin primidone topiramate
what is the impact of hepatic enzyme inducing anticonvulsants?
can alter efficacy of combined oral contraceptive pill and morning after pill
therefore shouldn’t use
progesterone only pill
progesterone implants not effective
depot progesterone needs more frequent dosing
what must females with epilepsy be counselled on?
preconceptual counselling (risk of birth defects from condition itself and some drugs - sodium valproate) risk of uncontrolled seizures and risk of drug to baby must be balanced in pregnancy (seizure can also harm baby)
all epileptic females getting pregnant must be taking what?
high dose folic acid and vit K for 3 months before
sodium valproate not really used in young females, why?
high risk to foetus if pregnant
therefore not used if any chance of pregnancy or becoming pregnant
carbamazepine not given in which type?
generalised
what is status epilepticus?
recurrent epileptic seizures without full recovery of consciousness
or
continuous seizre activity lasting more than 30 mins
when is treatment for status started?
from 5-10 mins of seizure as unlikely to recover after that point
3 types of status?
generalised convulsive status epilepticus
non-convulsive status (conscious but in altered state)
epilepsia partialis continua (continual focal seizures, consciousness preserved)
what can cause staus?
severe metabolic disorders (hyponatraemia, pyridoxine deficiency)
infection
head trauma
sub-arachnoid haemorrhage
abrupt withdrawal of anticonvulsants
treating absence seizures with carbamazepine
what kills first in status?
peripheral metabolic effects from effort of long term tension of muscles etc (hyperpyrexia, hypoxia, hypotension, hyperthermia, rhabdomyolysis)
what kills you later?
multi organ failure
brain failure
what causes cell death in status?
glutamate > excitotoxicity > neuronal cell death
management of status?
stabilize (ABCDE)
identify cause (emergency blood tests +/- CT)
anticonvulsants
what anticonvulsants are used in status?
important
1 = phenytoin 2 = Keppra 3 = sodium valproate always trial benzodiazepines first (1 dose, wait 5 mins, another dose, wait 5 mins, if not working then start phenytoin etc) call ICU if not working after 30 mins
max benzodiazepines?
2 doses
what is given if hypoglycaemia suspected as cause of status?
50mg 50% glucose
management of alcohol induced status?
IV thiamine
which benzodiazepines can be used for immediate control of status?
lorazepam 4mg IV
diazepam 10-20mg IV or rectal
midazolam 5-10mg IM
what is used for sustained control of status?
if established epilepsy - re-establish AED by ng tube/orally/IV for phenytoin other patients or continuing seizures - fosphenytoin - phenytoin - phenobarbital
what is done if status persists over an hour?
transfer to ICU
control with general anaesthesia with thiopentone or Propofol
monitor control with full EEGs etc
what do you do if called to a seizure?
nothing unless they go into status
don’t give benzodiazepines unless going on for more than 10 mins
just do ABCDE
how does partial status epilepticus present and how is it diagnosed?
acute confusion
confirm with EEG
how is partial status epilepticus managed?
treat same as generalized tonic-clonic status (benzodiazepines > phenytoin etc)
