Epilepsy Flashcards
If a patient has at least 2 unprovoked (or reflex) seizures occurring more than 24 hours apart, what could this be?
Epilepsy
If a patient has one unprovoked (or reflex) seizure and a probability of further seizures are similar to the general recurrence risk of after 2 unprovoked seizures (at least 60%), over the next 10 years, what diagnosis is this?
Epilepsy
‘The transient occurrence of signs or symptoms due to abnormal excessive or synchronous neuronal activity in the brain’ - is the definition of what?
A seizure
If a patient has a Seizure that lasts more than give minutes or recurrent one after another with no recovery time in between what is this called?
Status Epilepticus
What can Status Epilepticus be triggered by?
Head injury, metabolic disturbance (hypoglycaemia), cerebrovascular event (stroke) or alcohol withdrawal.
How should Status Epilepticus be managed non-pharmacologically in the community?
1) Note start time of seizure
2) Provide first aid, when stops put in recovery position
If a patient in the community is in ‘status epilepticus’ what and when should drug management be given?
5+ minutes of seizure or 3 seizures in one hour.
First line - Buccal Midazolam or Rectal Diazepam , if continues call 999.
What medications can be given if the patient is still seizing after 5-20 mins?
IV lorazepam (0.1mg/kg MAX 4mg)
NO IV access? - Buccal midazolam
NO response after 10-20 mins *Give second dose = NO MORE THAN TWO DOSES!!
After 20-40 minutes the patient is in established status epilepticus, what medications should be given IV?
AED’s
* Levetiracetam
* Sodium valproate
*Phenytoin or fosphenytoin
If a patient is in refractory Status Epilepticus (40-60 mins), what should be done?
Transfer to ITU.
What is SUDEP?
Sudden unexpected death in epilepsy
What is the cause of Epilepsy?
○ Structural - stroke, trauma, injury
○ Genetic
○ Infectious - TB, Malaria
○ Metabolic
○ Immune - Anti NMDA encephalitis
Idiopathic
What are the risk factors of Epilepsy?
○ Premature birth
○ Febrile seizures (high temp causes!)
○ Brain development malformation
○ Family history of epilepsy or neurological disease
○ Head trauma
○ Infections (meningitis and encephalitis)
○ Tumours ○Cerebrovascular disease/stroke
○ Dementia and neurodegenerative disorders (Alzheimer’s disease)
○Drugs and alcohol withdrawal
What is gold standard for diagnosis of neonates having seizures?
EEG
What testing will be done on a patient who has a new onset of Seizures?
Antibody testing
What are the three seizure types?
1) Focal
2) Generalised
3) Unknown
What are the types of Focal seizures?
Aware/impaired awareness - Motor or Non-motor onset. - Focal or bilateral tonic-clonic
What are the types of Generalised seizures?
Motor (tonic-clonic/other motor)
Nonmotor (absence)
What are the types of unknown seizures?
Motor (tonic-clonic/other motor)
or unclassified
What types of epilepsy are there?
-Focal
-Generalised
-Combined generalised and focal
-Unknown
What is a tonic seizure?
Sustained increased muscle contraction (tense and rigid muscles)
What does ‘motor’ mean during a seizure?
Movement during a seizure
What does ‘non-motor’ mean during a seizure?
No movement during a seizure
What is a myoclonus seizure?
Muscle twitching (can involve single or multiple muscle groups)
What is a Atonic seizure?
Muscles becoming limp (opposite to tonic)
What is a Clonic seizure?
Jerking rhythmic twitching movements
What is a tonic-clonic seizure type?
Starts off in a tonic phase then goes into a clonic phase including loss of control of bladder/bowel.
After a seizure a patient can get a post-ictal phase
What is an absence seizure?
Vacant staring and movement stops.
When is combination therapy used in Epilepsy?
When monotherapy has been tried and the patient is still not seizure free
Blood testing is not routinely recommended and only done if clinically needed and recommended, when might this be done?
- Identify non-adherence
- Investigate suspected toxicity
- Adjustment of phenytoin doses
- Managing interactions with other medication
*For specific clinical conditions - organ failure / pregnancy
When might vitamin D supplementation be given to a patient with epilepsy?
1) If immobile for long periods of time
2) Inadequate sun exposure
3) Inadequate dietary intake
If a patient displays symptoms of Antiepileptic hypersensitivity syndrome what must happen?
STOP AED’s immediately as this can be fatal
Can a AED cause suicidal behaviours?
YES - med review needed immediately
what AED’s are inhibitors?
Sodium Valproate,
What AED’s are inducers?
Carbamazepine, Phenobarbital, Phenytoin
Primary indication for Sodium Valproate?
First line for: Generalised Tonic-Clonic Seizures, Myoclonic seizures, Tonic or Atonic seizures, Idiopathic.
2nd line for: Absence seizures if other AEDs ae not suitable / not tolerated
Potential 1st line agent for: Dravet’s syndrome, Lennox-Gastaut syndrome
Adjunctive (add-on): to other AEDs in certain epilepsies.
What other than Epilepsy can Sodium Valproate be used for?
Migraine prophylaxis (unlicensed)
Mania in Bipolar disorder (either as sodium valproate or as semi-sodium valproate.
Notable pharmacokinetics for Sodium Valproate?
INHIBITOR
* Crosses into through the placenta
* Half-life 8-20 hours (usually shorter in children)
* Metabolised through the liver via glucuronidation
Monitoring for Sodium Valproate?
Before
LFT’s
FBC
During
LFTs within 6 months
Monitoring of blood dyscrasias
Liver disorders - Jaundice, tiredness, lethargy, drowsiness, loss of strength, anorexia, swelling
Pancreatitis (N&V, Abdo pain)
Primary indication for Carbamazepine?
2nd line for: Focal seizures, other types of epilepsy that include benign epilepsy with centrotemporal spikes.
Considered in: Generalised tonic clonic seizures *beware can exacerbate myoclonic and absence seizures, if these are present this is not suitable.
Adjunctive (add-on): In focal seizures
What other than epilepsy can Carbamazepine be used for?
Prophylaxis in bipolar disorder unresponsive to lithium
Trigeminal neuralgia
Adjunct to acute alcohol withdrawal (unlicensed)
Diabetic neuropathy (unlicensed)
What are the notable pharmacokinetics for Carbamazepine?
INDUCER
* It is metabolised in the liver
*Clearance affected by other drugs causing enzyme induction/inhibition AND by autoinduction of its own metabolism - thus altering the half-life of the drug after continued administration
*Interacts with other AED’s
Monitoring for Carbamazepine?
Before
If Patient is Han Chinese or Thai origin test for allele HLA-B1502 as this increases risk of Steven-Johnson Syndrome
During
1-2 weeks plasma concentration optimum response 4-12mg/L
FBC, LFT, Renal function
Monitor for blood dyscrasias, liver or skin disorders; fever, rash, bruising, mouth ulcers.
Carbamazepine has other formulations what is important when swapping between them?
The other forms aren’t bioequivalent, therefore dose conversions need to be done.
What is the primary indication for Ethosuximide?
First line and adjunctive (add-on) for: Absence seizures, including childhood absence epilepsy.
3rd line for: Epilepsy with myoclonic-atonic seizures (Doose syndrome)
Also: Licensed for myoclonic seizures
What are the notable pharmacokinetics for Ethosuximide?
NON-ENZYME INDUCER
* Metabolised in the liver
What monitoring needs to happen for a patient on Ethosuximide?
Before
Patient counselling on: fever, rash, mouth ulcers, bruising or bleeding development. Also monitoring for suicidal behaviours.
During
FBC
Monitor for any blood dyscrasia’s
What is the primary indication for Lamotrigine?
First line and adjunctive for: Focal seizures, generalised tonic-clonic seizures, absence seizures (If ethosuximide or sodium valproate is not suitable/tolerated), tonic or atonic seizures, idiopathic generalised epilepsy.
Second or third line for: Myoclonic seizures *Caution as can exacerbate these seizures
Also can be an option for: Certain epilepsy syndromes.
What other than epilepsy can Lamotrigine be used for?
Bipolar disorder (monotherapy and as an adjunctive)
Neuropathic pain (unlicensed)
What are the notable pharmacokinetics for Lamotrigine?
Induces own metabolism
* When given with drugs that are hepatic enzyme inducers or inhibitors, the half life of the drug is altered.
=Dosage of the drug needs to be adjusted to accommodate for this.
What needs monitoring in a patient taking lamotrigine?
Counselling of patients on:
-Skin reactions *Hypersensitivity
-Bone marrow failure - anaemia, bruising or infection *Hb, Pale, Weak, SOB
What is the primary indication for Levetiracetam?
First line for: Generalised tonic-clonic seizures, focal seizures, myoclonic seizures, idiopathic generalised seizures.
Second line for: Absence seizures, myoclonic seizures, idiopathic generalised seizures, other epilepsy syndromes.
Adjunctive for: Focal seizures, generalised tonic-clonic seizures, myoclonic seizures.
What are the notable pharmacokinetics for Levetiracetam?
- Oral bioavailability is almost 100% with linear pharmacokinetic profile
*Plasma levels more predictable = no blood monitoring
*Large proportion is excreted through the kidneys unchanged
*Some of the drug is metabolised through hydrolysis and does not involve the CYP450 hepatic isosforms.
What monitoring do patients require on Levetiracetam?
None except for general counselling of AED’s
What is the primary indication for Phenobarbital?
No first line indications
NICE recommends it’s use as an adjunctive (add-on) 2nd line for: generalised tonic-clonic seizures. 3rd line add-on for: focal seizures and myoclonic seizures.
Licensed for all epilepsy types except: Typical absence seizures but as stated, also used in status epilepticus as IV form.
What are the notable pharmacokinetics for Phenobarbital?
ENZYME INDUCER *POTENT
* Partly metabolised in the liver and some is excreted unchanged from the kidneys.
* Crosses the placenta barrier and is present in breast mild
What does a patient need monitoring when on Phenobarbital?
Optimum plasma concentration levels of phenobarbital are 15-50mg/L, however due to tolerance occurring with phenobarbital, measuring these levels may not be as useful as with other AED’s.
Monitor for suicidal behaviours
Skin reactions - report signs and symptoms of a rash or hypersensitivity syndrome