Week 3: Epilepsy Flashcards
1
Q
What is epilepsy?
A
- A chronic disorder characterised by recurrent seizures
- Affects ~1% of the population
- A neuronal hyperexcitability disorder arising from excess excitability/disinhibition, most commonly characterised by impairment of motor activity
2
Q
Types of seizures
A
- Prinicipal types of seizure are:
+ Partial - Only involves 1 specific brain area
+ Generalised - Involves whole brain, including tonic-clonic/absence seizures - Further types of seizure:
+ Secondary generalisation - When partial seizures spread to affetc the whole brain
+ Complex - Impaired consciousness during seizure
+ Simple - Unaffected consciousness during seizure
3
Q
What’s the difference between a seizure + a convulsion?
A
- Epilepsy is a disorder with many symptoms
- Seizure is the principal symptom of epilepsy, whilst a convulsion is caused by epileptiform brain activity
- Specifically, convulsion is a sudden, violent, irregular movement of a limb/of the body, caused by involuntary contraction of muscles
4
Q
Possible triggers of isolated seizures
A
- CNS infection/inflammation
- Stroboscopic lighting
- Metaboolic dysfunction
- Head injury
- Fever, particularly in children
- Drug-related
5
Q
Premature mortality in people with epilepsy
A
- Premature mortality is 2-3x higher in epilepsy patients, with significant causes being:
+ SUDEP (Sudden Unexpected Death in Epilepsy)
+ Status epilepticus
+ Accidents as a consequence of a seizure
+ Aspiration pneumonia after seizure
+ Drug toxicity
+ Idosyncratic ADRs (Adverse Drug Reactions)
+ Suicides
6
Q
Co-morbidities
A
- Cognitive decline (Can be drug-related or disease related)
- Anxiety
- Depression
- Agitation, anger + emotional outbursts
- Suicide
- ADHD
- Reproductive problems
- Insomnia
- Migraine
- Co-morbidities are more frequent + severe in refractory patients
7
Q
Generalised tonic clonic seizures
A
- Used to be called grand mal
- ~1 mins: Limb extension + rigidity, respiration halting, deacation, micturition + salivation occurs
- ~2-4 mins: Violent synchronous jerks
- Patient gradually regains consciousness after a few more minutes + will likely feel confused, ill + disorientated
8
Q
Generalised absence seizure
A
- Less physically dramatic as grand mal, but may occur more frequently
- Patient typically ceases any action, stares vacantly ahead, unaware of surroundings, dangers + other people
- Paitents recovers very quickly with no after effects
9
Q
Partial seizures
A
- Seizure discharge begins + typically remains restricted to a local brain area
- Accompanied by simple symptoms:
+ Involuntary movements
+ Abnormal sensory experiences
+ Rarely loss of consciousness - Examples of partial seizures include Jacksonian epilepsy, psychomotor epilepsy
10
Q
So when do we start treating epilepsy?
A
- The question is really rather when does 1 isolated seizure become epilepsy?
- Decision to treat is complex due to:
+ All current drugs have significant side-effects
+ A diagnosis of epilepsy has legal + life-altering ramifications ie driving, employment + pregnancy
11
Q
Aims of pharmacotherapy for epilepsy
A
To render the patient seizure/minimise number of breakthrough seizures, thus to maximise QoL
12
Q
Principal treatments for epilepsy
A
- Na channel blockers
- Enhancement of GABA actions
- SV2A-mediated
- Ca2+ channel
- Ketogenic diet
- Vagal nerve stimulation
13
Q
Sodium channel blockers
A
- Action potential gneeration is dependent upon the opening of voltage-gated sodium channels
- Inhibitition of these channels has been found to prevent or ameliorate seizures
- Can include Phenytoin, Carbamazepine, Carisbamate
14
Q
Enhancement of GABA actions
A
- Enhancement of GABA-mediated Cl- channels increase inhibition + attentuates seizures
- Includes Phenobarbitone, Diazepam
