Epilepsy Flashcards
what is epilepsy?
tendency to recurrent seizure without provoking factors due to abnormal electrical activity
what is the pathophysiology of epilepsy?
synchronous discharge in cortical neurones causes too much excitation or damaged neurones or too little inhibition
how is a diagnosis of epilepsy made?
based on the characteristics of the seizure episodes
what investigations would we do?
EEG= typical patterns in different forms of epilepsy and support the diagnosis
MRI brain= visualise structure of the brain to look for structural problems
what are generalised tonic-clonic seizures?
loss of consciousness and tonic (muscle tensing) and clonic (muscle jerking) episodes- typically tonic phase before clonic and maybe tongue biting, incontinence and groaning –> generalised abnormality on EEG
what happens after a tonic-clonic seizure?
prolonged post-ictal period where the person is confused, dross and feels irritable or depressed
how are tonic-clonic seizures managed?
1st line= sodium valproate and 2nd line= lamotrigine or carbamazepine
what are focal seizures?
start in the temporal lobe so affect hearing, speech, memory and emotions and can present as hallucinations, memory flashbacks, deja vu or doing strange things on autopilot –> seen as focal abnormality on EEG
how are focal seizures treated?
1st line= carbamazepine or lamotrigine and 2nd line= sodium valproate or levetiracetam
what are absence seizures?
patient becomes blank and stares into space and then abruptly returns to normal, unaware of surroundings and wont respond during the episode and typically lasts 10-20 seconds
who normally has absence seizures?
children but tend to stop having them as they get older
how are absence seizures treated?
sodium valproate or ethosuximide
what are atonic seizures?
known as “drop attacks” and are characterised by brief relapses in muscle tone and don’t last more than 3 minutes, typically begin in childhood and may be indicative of Lennox-Gastaut syndrome
how are atonic seizures treated?
1st line= sodium valproate and 2nd line= lamotrigine
what are myoclonic seizures?
sudden brief muscle contractions= like a sudden “jump” and patient usually remains awake during the episode and they occur in various forms of epilepsy but typically happen in children as part of juvenile myoclonic epilepsy
how are myoclonic seizures managed?
1st line= sodium valproate
what are infantile spasms?
also known as west syndrome, rare disorder starting in infancy and is characterised by clusters of full body spasms
how are infantile spasms treated?
prednisolone and vigabatrin
how does sodium valproate work and what is it used for?
increases activity of GABA which has a relaxing effect on the brain and is used first line for most forms of epilepsy except focal seizures
what are the side effects of sodium valproate?
teratogenic so patients need to be careful about contraception, liver damage and hepatitis, hair loss and tremor
what are the possible side effects of carbamazepine and what is it used for?
first line for focal seizures and causes agranulocytosis, aplastic anaemia, induces the P450 system so there are may drug interactions
what is status epilepticus?
medical emergency and defined as seizures lasting more than 5 minutes or more than 3 seizures in one hour
what are the risk factors for status epilepticus?
non-adherence to treatment, chronic alcoholism, refractory epilepsy, toxic or metabolic causes, acute brain injury
what are the medical treatments for status epilepticus in the community?
buccal midazolam and rectal diazepam
how is status epilepticus treated in hospital?
ABCDE approach= secure airway, give high concentration oxygen, assess cardiac and respiratory function, check blood glucose levels, gain Iv access and IV lorazepam repeated after 10 minutes if seizure continues
what is syncope?
transient loss of consciousness provoked by cerebral hypoxia and can cause myoclonic jerks, verbalisations and eye movements which can mimic seizures
what are the 3 categories of syncope?
reflex, orthostatic and cardiogenic
what is reflex syncope?
stressful situation= increased vagal tone= decreased HR and BP= syncope
what is orthostatic syncope?
normally BP related to Shen changing postions so when standing up fell faint and pass out - endocrine and ANS diseases, dehydration and antihypertensive medications increase risk
what is cardiogenic syncope?
fall in cardiac output eg arrhythmia, aortic stenosis
what are pseudo seizure/non-epileptic attack?
seizures not due to abnormal electrical activity and tend to be in people who have experienced trauma or have a chronic underlying illness
