Epilepsy Flashcards
what are the important parts of a seizures history
-Onset
-What were they doing?
-Environment, etc
-Light-head or other syncopal symptoms
-What did they look like
-Pallor, breathing (presyncope)
-Posturing of limbs, head turning (seizure)
Event itself
-Type of movements
-Tonic phase, clonic movements
-Corpopedal spasms, rigor
-Responsiveness and awareness throughout
Afterwards
-Speed of recovery (recover fast after faint), sleepiness/disorientation, deficits
if there is bilateral movement and retained consciousness is it a seizure
no
what type of seizure causes right hand to go up and the head to turn
frontal lobe seizures
is biting your tongue and incontinence specific to seizures
no
what are the risk factors for epilepsy
birth developmental delay previous seizures (inc 2+ more febrile seizures) head injury family Hx drugs alcohol
when can epilepsy be a problem for a patients occupation
if HGV driver or if they carry a firearm
what medications can lower seizure threshold
antibiotics (penicillin, cephalosporins, quinolones) analgesics (tramadol) anti-emetics (prochlorperazine) opioids (diamorphine, pethidine) aminophyline/ theophyline
what exams for seizures in clinic
don’t usually examine in first clinic
if diagnosis of syncope do cardio exam, lying and standing BP
can do neuro exam if see them shortly after event
what investigations should you do for a collapse/ seizure
ALWAYS DO ECG
prolonged QT can provoke seizure
can do imaging- MRIb/ CTb if indicated
what is an EEG useful for
classification of epilepsy
confirmation of non epileptic attacks
surgical evaluation
confirmation of non convulsive attacks= actually only time its used
never used in acute attack to diagnose
when are CT scans done acutely
Clinical or radiological skull fracture Deteriorating GCS
Focal signs- might suggest stroke/ bleed
Head injury with seizure
Failure to be GCS 15/15 4 hours after arrival Suggestion of other pathology – eg SAH
should you do an EEG
not really
positive/ negative test means nothing in diagnosis of epilepsy
when after a seizures can you drive
1st seizure – car = 6 months, 5 years for HGV/PCV
Epilepsy – car = 1 year or 3years during sleep (nocturnal seizures), 10 years off medication for HGV/PCV
what is epilepsy
a tendency to recurrent, usually spontaneous seizures
what are the features of global (primary generalised) epilepsy
(who gets it, when, what are seizures like)
genetic predisposition
present in childhood and adolescence
can have tonic clonic, abscence, myoclonic, clonic and tonic seizures
what is seen on EEG in global epilepsy
generalised spike wave abnormalities
what is an epileptic seizures
abnormal synchronisation of neuronal activity (usually excitatory) which interrupts normal brain activity (can be focally or generalised) and is usually brief
why do you get epileptic seizures
too much excitation too little inhibition changes: -cell number/ type -connectivity -synaptic function -voltage gates channel function
genetic, acquired brain, metabolic, toxic and environmental factors
what is juvenile myclonic epilepsy
form of primary generalised epilepsy
get early morning jerks
generalised seizures
risk factors- sleep deprivation, flashing lights
what is the treatment for primary generalised epilepsy
sodium valproate (is teratogenic and cosmetic effects) lamotrigine alternative
what is focal epilepsy
seizures that occur around an abnormal area of brain (stroke/ tumour) which irritates the brain and causes abnormal electrical activity
what is generalised epilepsy
when abnormal electrical activity hits a pathway and spreads to other part of brain (corticothalamic circuitry)
seizure can start from a focal point, and then secondary generalisation
what are the types of partial/ focal epileptic seizures
simple- without impaired consciousness
complex- with impaired consciousness
or
- motor (rhythmic jerking, posturing, head and eye deviation, automatisms, volacisation)
- sensory (somatosensory, olfactory, gustatory, visual, auditory)
- pyschic (memories, deja vu, jamais vu, depersonalisation, aphasia, complex visual hallucinations)
what are the types of generalised epileptic seizures
absence (go blank, stare into distance) myoclonic (jerking of limbs) atonic (loose muscle tone) tonic tonic clonic
what is the age of onset of focal onset epilepsy
can be any age- due to underlying structural cause
what is the treatment for focal onset epilepsy
initially:
lamotrigine (1st line)/ carbamazepine
(sodium valproate works well but not given because of SEs)
can then add on: Gabapentin Tiagabine Pregabalin Zonisamide Vigabatrin Clonazepam Clobazam
how do antiepileptic drugs work
inhibit v activates Na+ channels (reduces pre synaptic excitability and the ability of APs to spread) (carbamazepine, oxcarbazepine, phenytoin, lamotrigine)
enhances activity of v gated K+ channels (stabilises neurone, reduces its excitability) (retigabine)
inhibition of V activates Ca+ channels that trigger neurotransmitter release (gabapentin and prehabalin)
what is the treatment for generalised absence seizures
sodium valproate
ethosuximide
what is the treamtment for generalised myoclonic seizures
sodium valproate
levetiracetam
clonazepam
what is the treamtment for generalised Atonic, Tonic, Generalised tonic clonic
seizures
sodium valproate
when is phenytoin used
acute management only
when do you give carbamazepine
Focal onset seizures
Can make primary generalized epilepsies worse
Dont give in generalized epileosy
when do you medicate epilepsy
when patient wants drug- balance benefits and side effects
if high risk of recurrence
which anti convulsants induce hepatic enzymes
IMPORTANT KNOW THIS IN EXAM
carbamazepine oxcarbazepine phenobarbitol phenytoin primidone topiramate
how do anticonvulsants affect women in particular
IMPORTANT KNOW IN EXAM
Can alter efficacy of combined oral contraceptive pill
Shouldn’t use progesterone only
pill
Morning after pill not adequate if taking enzyme inducing AEDs – dose should be increased
Balance risk of uncontrolled seizures vs teratogenicity
Folic acid and vitamin K- high dose folic acid 3 months before conception
Side effects may not be as acceptable in ladies (sodium valporate- fat and bald)
what does hippocampal sclerosis give
focal epilepsy
what is status epilepticus
recurrent epileptic seizures without full recovery of consciousness
continuous seizure activity lasting more than 30 mins
what are the types of status epilepticus
generalised convulsive status epilepticus
non convulsive (conscious but in altered state)
epilepsia partialis continua (continual focal seizures, consciousness preserved)
when do you start treatment for status epilepticus
at 10 mins
what can precipitate status epilepticus
severe metabolic disorders (hyponatraemia, pyridoxine deficiency)
infection
head trauma
sub arachnoid haemorrhage
abrupt withdrawal of anti convulsants
treating abscence seizures with carbamazepine
what is convulsive status
generalised convulsions without cessation
what can convulsive status cause
Excess cerebral energy demand and poor substrate delivery causes lasting damage:
- respiratory insufficiency and hypoxia
- hypotension
- hyperthermia
- rhabdomyolysis
death due to metabolic hyperpyrexia (50-69mins) or after this due to organ failure
what happens pathologically in uncontrolled status epilepticus
Glutamate release
Excitotoxicity
Neuronal death
what is the treatment for status epilepticus
IMPORTANT WILL BE IN EXAM
ABC- stabilise patient, always check glucose
IDENTIFY CAUSE- bloods, CT
for immediate control: (anticonvulsants) 1st line- benzodiazepines (lorazepam, diazepam, midazolam) 2nd- phenytoin 3rd- valproate 4th- keppra
for sustained control -if established epileptic re establish AED Tx via Ng tube/ orally/ IV for phenytoin - in other patients/ if ongiong seizures --fosphenytoin with ECG monitoring --phenytoin with ECG monitoring --phenobarbital maintain levels with NG/IV/orally
give 50mls 50% glucose if any suggestion of hypo
give thiamine if alcoholism/ impaired nutritional status
if status persists transfer to ICU within 1 hour. monitor with full EEGs or cerebral function monitor
control status with anaesthesia (thiopentone or propofol)
why should you be careful of benzodiazpeines
never give more than 2 doses - admit to ICU
what is parital status epilpeticus
should be considered in acute confusion
confirm with EEG
tx same as status epilepticius (minus anaesthesia and ICU)
when do you treat a seizure
at 10 mins
most get better
only after 10 mins think about benzodiazepams
