Seizures + Epilepsy Flashcards
What is epilepsy? What is the difference between epilepsy and seizures?
Tendency to have seizures, which are transient episodes of abnormal electrical activity
No clear/organic cause for seizures
Epilepsy and seizures both involve abnormal synchronous electrical activity BUT epilepsy = increased tendency w/o specific precipitating factor i.e. experience spontaneous recurrent seizures
If someone was suspected to have epilepsy, how would they be investigated acutely?
Bloods
-can look for evidence that seizure was non-epileptic i.e. has organic cause:
Infection/electrolyte disturbance/lactate/creatinine kinase
-lactate= can differentiate between seizure + pseudoseizure i.e. muscle contractions will lead to rise in lactate (produced due to anaerobic respiration)
Brain imaging:
- CT= SOL (tumour or haemorrhage)
- MRI brain= looking for structural problems which might be causing seizures i.e. gliosis/fibrosis (temporal lobe epilepsy)
Blood glucose= exclude hypo
ECG= rule out problems with heart
What are the main different types of seizure?
Generalised tonic-clonic
Focal seizures
Absence seizures
Atonic seizures
Myoclonic seizures
Infantile spasms/West syndrome
What are the features of a generalised tonic-clonic seizure? How is this type of seizure managed?
LOC
Impaired awareness due to being generalised
Muscle tensing (tonic)
Muscle jerking (clonic)
Tongue biting + incontinence
Post-ictal period= confusion/drowsy/depressed
Sodium valproate
Lamotrigine or carbamazepine
What part of the brain is affected by focal seizures? What are the features of focal seizure? How are they managed?
Temporal lobe Features: -hallucinations -memory flashbacks -deja vu -strange actions on autopilot
Carbamazepine or lamotrigine
Sodium valproate
I.e. opposite to tonic-clonic
Who is mostly likely to suffer from absence seizures? What are the features of this kind of seizure?
What would you expect to see on an EEG?
How are they managed?
Children
Become blank + stare into space
= momentary lapse in awareness
Unaware of surroundings and won’t respond
Lasts 10-20 secs then abruptly stops
Patient might not be able to recollect the attacks and may appear as if daydreaming
3Hz spike and wave
Sodium valproate or ethosuximide
What are the features of an atonic seizure? What syndrome can they be associated with? How is this type of seizure managed?
Brief lapse in muscle tone which leads to patient collapse/drop
Lennox-Gastaut syndrome (epileptic encephalopathy)
TX:
- sodium valproate
- lamotrigine
What are the features of a myoclonic seizure and when does it normally occur? How is it managed?
Sudden muscle contraction which appears as a jump
Patient awake
Associated with juvenile myoclonic epilepsy
Sodium valproate
Lamotrigine
Levetiracetam
Topiramate
What is the first line anti-epileptic drug in most types of epilepsy? What is the MOA? What are the potential SE?
Sodium valproate (except for focal= carbamazepine) MOA= increases GABA acitivity which decreases the brains excitability
SE:
- teratogenic
- liver damage + hepatitis
- hair loss
- tremor
What are the SE for carbamazepine?
Agranulocytosis
Aplastic anaemia
Induces p450= possibility of drug interactions
Makes OCP ineffective
Induces enzymes involved in own destruction so can become inaffective
Hyponatraemia
What are the SE of phenytoin?
Folate + vitamin D deficiency Megaloblastic anaemia (due to folate deficiency) Osteomalacia (vitamin D def)
What are the SE of ethosuximide?
Night terrors
Rashes
What are the SE of lamotrigine?
Stevens-Johnson syndrome or DRESS syndrome
Leukopenia
What would you be worried about if a seizure lasted >5mins? How is this situation managed?
STATUS EPILEPTICUS Medical emergency where seizure has lasted longer than 5 mins or more than 3 seizures in an hour
ABCDE approach:
- secure airway
- high concentration 02
- assess cardiac + resp function
- check blood glucose
- IV access
- IV lorazepam 4mg (repeated after 10 mins if seizure persistent)
- IV phenobarbital or phenytoin if seizure persists
How can you differentiated between non-epileptic and epileptic seizure?
Non-epileptic seizure isn’t caused by the classical abnormal synchronous electrical activity activity so no EEG abnormalities
Tends to be associated with psychiatric presentation
How can you differentiate between an episode of syncope and a seizure?
- Post ictal confusion (seizure) is only definitive way to differentiate between syncope and seizure
=presents as extreme confusion, lack of awareness of self or where they are when come out of episode
Post-syncope= relatively ok but can feel bit dazed
- Location of tongue bite
- front/tip= syncope
- back/sides= seizure
How might someone describe a syncopal episode in terms of before, during and after?
Before:
-syncopal prodrome= sweating/pallor/light headed
During:
-bitten front of tongue when collapsed/fallen
After:
-feel relatively ok
How might someone/witness describe an seizure episode in terms of before, during and after?
Before:
- aura= visual spots/certain taste
- sense of deja vu
- abnormal movements
During:
- biting back of tongue
- urinary incontinence
After:
- very fatigued= due to muscle contractions
- post-ictal confusion
How is syncope different from a seizure?
Caused by hypoperfusion of brain= induces LOC
-bradycardia and peripheral hypoperfusion
Shorter duration= 30s-2mins -»transient onset
Lack of tonic-clonic sequence BUT brief clonic jerking may occur
What are the 2 main features used to classify seizures?
Onset= where in the brain the seizure originates from
- generalised= both hemispheres affected
- motor
- non-motor= absence
- focal= specific region of brain affected
- non-motor onset vs motor onset
- aware vs impaired awareness
- unknown
Level of awareness
-impaired awareness= generalised seizure rather than focal
What changes might you see on a CT scan that implied temporal lobe epilepsy?
Fibrosis in temporal lobe area
How can you use blood tests to differentiate between epileptic and non-epileptic seizures?
Epileptic seizures:
- raised lactate= due to vigorous contraction of muscles causing them to go into anaerobic respiration
- raised creatinine kinase (CK)= due to contraction causing breakdown of muscle
What are the most important SE to consider with anti-epileptic drugs? Give an example of drug for each.
Teratogenic= Sodium valproate
Electrolyte disturbance= Carbamazepine (induces hyponatraemia due to SIADH)
Enzyme-inducing (CYP metabolic enzymes)= phenytoin + carbamazepine
When should epilepsy patients be refered for epilepsy surgery programme?
When they have failed 2 first line drugs
