Chapter 4 - Epilepsy Flashcards
1
Q
What does the ILAE define epilepsy as?
A
> 2 unprovoked seizures >24h apart
Or
One unprovoked seizure and a 60% probability of having another within 10 years
2
Q
What is seizure freedom?
A
12 months without a seizure
3
Q
What is a good therapeutic effect of an AED?
A
3 times the longest previous interval between seizures
4
Q
Does glutamate cause an excitatory or inhibitory response?
A
Excitatory
5
Q
Does GABA cause an excitatory or inhibitory response?
A
Inhibitory
6
Q
What are the two types of focal seizures?
A
Simple - remain aware
Complex - lose consciousness
7
Q
What are the five main types of motor generalised seizures?
A
Tonic-clonic Tonic Clonic Myoclonic Atonic
8
Q
What are some signs and symptoms that may be seen in a focal seizure?
A
Kicking Rocking Altered vision Numbness or tingling Muscles stiffening in one area Smelling, tasting, hearing or seeing things Behavioural changes
There may be an aura
9
Q
What is an example of a non-motor generalised seizure?
A
Absence
10
Q
What happens during a tonic-clonic seizure?
A
Muscles contract and the body becomes rigid
Loss of consciousness and falling to the floor
Violent muscle contractions
11
Q
How long to tonic-clonic seizures last for?
A
Usually 1-3 mins
>5 mins is a medical emergency
12
Q
Do people always recover straight away after a tonic-clonic seizure?
A
No, it can take a while to recover
The person may feel confused, tired, agitated etc
13
Q
If a person has bitten their tongue/cheek during a seizure, what type of seizure does this usually indicate?
A
Generalised tonic-clonic
14
Q
What is a myoclonic seizure?
A
Brief jerks of a muscle/group of muscles
15
Q
Does a person usually lose consciousness during a myoclonic seizure?
A
No, they are usually too short to affect consciousness
16
Q
What age group do absence seizures usually occur in?
A
Children
17
Q
How long do absence seizures usually last?
A
A few seconds
18
Q
What is an absence seizure?
A
A brief seizure that causes a lapse in awareness, e.g. the child may stare at something
19
Q
What groups of people are atonic and tonic seizures seen in?
A
Children
Epilepsy syndromes
20
Q
What are tonic and atonic seizures?
A
Tonic - rigidity/stiffness, usually happens I’m in sleep
Atonic - the body goes limp e.g. head may drop, eyelids mag drop, the person may drop items that they are holding
21
Q
What is a febrile seizure?
A
A seizure in a child caused by a high fever
22
Q
How are febrile seizures managed?
A
Usually with antipyretics e.g. paracetamol
> 5 mins is a medical emergency (status epilepticus)
23
Q
What is reflex epilepsy?
A
Seizures triggered by the environment
E.g. due to noises, chewing, flashing lights, sleep deprivation
24
Q
How is epilepsy diagnosed?
A
Speak to the patient and any witnesses (especially if they were unconscious)
ECG - but don’t use this alone to diagnose epilepsy
25
Why isn’t an ECG used alone to diagnose epilepsy?
It can sometimes give false positive or false negative results
26
What is status epilepticus?
A seizure lasting >5 mins
Or
Multiple seizures where the person doesn’t regain consciousness in between
27
In a person with status epilepticus, what should also be given if alcohol abuse is suspected?
Thiamine
28
What would you give for status epilepticus in the community?
Rectal diazepam
| Buccal midazolam
29
What is the first treatment for status epilepticus in hospital?
When should this be repeated if it fails or if seizures reoccur?
```
IV lorazepam
IV diazepam (carries a high risk of thromboplebitis)
```
Repeat after 10mins if necessary
30
In status epilepticus, if seizures are still occur 25mins after giving IV lorazepam/diazepam, what would you do?
Either:
IV phenytoin
IV fosphenytoin
IV phenobarbital
31
In status epilepticus, if seizures are still occur 45 mins after giving IV lorazepam/diazepam, what would you do?
Refer to ICU
Give thiopental sodium, midazolam, or propofol
32
What are the indications of lorazepam?
Status epilepticus
Febrile convulsions
Convulsions due to poisoning
Anxiety
Panic attacks
Sedation
33
If lorazepam is used for sedation, how long shouldn’t the patient drive for afterwards?
Minimum 24h
34
Why shouldn’t people have benzodiazepines and alcohol?
Both are CNS depressants
35
What are the indications of midazolam?
Status epilepticus
Febrile convulsions
Convulsions in palliative care
Sedation
36
Does midazolam have a short or long duration of action compared to other benzodiazepines?
Shorter duration of action
| And so faster recovery time
37
After a first unprovoked seizure, how long can’t a person drive for?
When can they start driving again?
6 months
Can restart if they have been assessed by a specialist and have been declared fit to drive at a low risk of another seizure
38
After an AED has been changed or stopped, how long can’t someone drive for?
Minimum 6 months (as long as there have been no seizures within this time)
39
What are the first line and alternative options for focal seizures?
First line
Lamotrigine
Carbamazepine
Alternatives
Sodium valproate
Levetiracetam
Oxcarbazine
40
What are the first line and alternative options for generalised tonic-clonic seizures?
First line
Sodium valproate
Alternatives
Lamotrigine
Carbamazepine or oxcarbazine (may worsen myoclonic or absence seizures)
41
When is adjunct therapy used in focal seizures?
When two first line AEDs haven’t worked
42
What are the first line and alternative options for absence seizures?
First line
Ethosuximide
Sodium valproate
Alternatives
Lamotrigine
43
What are the first line and alternative options for myoclonic seizures?
First line
Sodium valproate
Alternatives
Lecetiracetam
Topirmate (consider poor side effect profile)
44
What are the first line and alternative options for tonic and atonic seizures?
First line
Sodium valproate
Alternatives
Lamotrigine
45
What AEDs can worsen myoclonic, absence, tonic and atonic seizures?
```
Carbamazepine
Oxcarbazine
Gabapentin
Phenytoin
Pregabalin
Tiagabine
Vigabatrin
```
46
What are the first line and alternative options for Dravet Syndrome?
First line
Sodium valproate
Topiramate
Alternatives
Cannabinol and clobazam
47
What are the first line and alternative options for Lennox-Gastaut syndrome?
First line
Sodium valproate
Alternatives
Sodium valproate + lamotrigine
Cannabidol + clobazam
48
How effective do cannabidol and clobazam need to be in order to be continued in epilepsy syndromes?
Need to reduce seizure frequency by 30% in 6 months
49
When are antiepileptic drugs usually initiated?
After the second unprovoked seizure
50
How are AEDs initiated?
1. Monotherapy - titration to the lowest effective dose/maximum tolerated dose
2. Monotherapy with an alternative AED
3. Combination therapy
51
What is the MRHA advice regarding AEDs and suicidal thoughts/behaviour
All AEDs are associated with a small increase in suicidal thoughts or behaviour
52
How soon can suicidal thoughts or behaviour occur as a result of AEDs?
Within 1 week
53
How frequently are most AEDs usually taken?
What are the exceptions?
Twice a day
Exceptions include lamotrigine, phenytoin and phenobarbital - these have a longer half life
54
What is an advantage of giving AEDs more frequently?
Peak drug concentration will be reduced, which will reduce the adverse effects
55
Why interactions do many AEDs have in common?
Most are hepatic
| enzyme inhibitors or inducers
56
If a patient is on multiple AEDs, how should these be withdrawn?
Gradually and one at a time
57
Why should AEDs be withdrawn gradually?
Which AEDs is this particularly important for?
Because withdrawing them quickly increases the risk of rebound seizures, which may be severe
Take particular care with benzodiazepines and barbiturates
58
What is refractory epilepsy?
When two AED schedules have failed to achieve seizure freedom
59
Which AEDs do you do routine TDM for?
Phenytoin
| Carbamazepine
60
When is the risk of teratogenicity increased with the use of AEDs?
When AEDs are used in the first trimester
| When multiple AEDs are being taken
61
What are the implications of using sodium valproate in pregnancy?
```
Congenital malformations (10%)
Neurodevelopmental disorders (30-40%)
Increased risk of intra-uterine growth restriction
```
62
When used in pregnancy, which AEDs can cause:
Congenital malformations
Neurodevelopmental disorders
Increased risk of intra-uterine growth restriction?
Sodium valproate
Phenytoin
Phenobarbital
63
When used in pregnancy, which AEDs can cause:
Congenital malformations
Carbamazepine
Topiramate
Sodium valproate
Phenytoin
Phenobarbital
64
When used in pregnancy, which AEDs can cause:
Increased risk of intra-uterine growth restriction?
Topiramate
Zonisamide
Sodium valproate
Phenytoin
Phenobarbital
65
When can sodium valproate be given to females of a child bearing potential?
When they have met the conditions of the pregnancy prevention programme
When alternative treatments are not effective or not tolerated
66
Which AEDs are safest in pregnancy?
Lamotrigine
| Levetiracetam
67
If a patient on sodium valproate finds out she’s pregnant, should she stop taking her sodium valproate?
No - seek urgent medical advice first
68
Which AEDs are hepatic inducers?
Carbamazepine
Phenytoin
Phenobarbital
69
Which AEDs are hepatic inhibitors?
Sodium valproate
70
Why is folate supplementation given in pregnancy when a person is also taking AEDs?
To prevent neural tube defects
71
Pregnancy can change the concentrations of AEDs, which two AEDs can be particularly affected?
Lamotrigine
| Phenytoin
72
When switching between AEDs, what drugs are in category 1?
Carbamazepine
Phenytoin
Phenobarbital
73
When switching between AEDs, what drugs are in category 2?
```
Clobazam
Clonazepam
Lamotrigine
Oxcarbazepine
Topiramate
Valproate
Zonisamide
```
74
When switching between AEDs, what drugs are in category 3?
Pregabalin
Gabapentin
Levetiracetam
Ethosuximide
75
What is antiepileptic hypersensitivity syndrome?
A rare but potentially fatal type of anaphylactic reaction
76
What AEDs is antiepileptic hypersensitivity syndrome associated with?
```
Carbamazepine
Lamotrigine
Oxcarbazine
Phenytoin
Phenobarbital
```
77
How soon does antiepileptic hypersensitivity syndrome usually occur after exposure to an AED?
1-8 weeks
78
What are some signs and symptoms of antiepileptic hypersensitivity syndrome?
```
Rash
Fever
Hepatic dysfunction
Renal dysfunction
Pulmonary abnormalities
Multi organ failure
```
79
What is sudden unexpected death in epilepsy?
A non traumatic death
With or without evidence of a seizure
In the absence of status epilepticus
80
What are some risk factors for sudden unexpected death in epilepsy?
```
Young age
Refractory epilepsy
Nocturnal seizures
Long duration of epilepsy
Frequent convulsions
```
81
When should an ambulance be called if a person is having a seizure?
```
Duration >5 minutes
First seizure
Difficult to wake up afterwards
Difficulty breathing
Person is injured
```
82
How can you prevent injury duri bf a seizure?
Remove glasses/anything that could cause harm
Put something soft under the persons head
Don’t restrain them
83
What should you do once a persons seizure has stopped?
Check their airways
Put them in the recovery position
Monitor for injuries and manage as appropriate
84
When does liver dysfunction occur with use of sodium valproate?
Within the first 6 months
85
If sodium valproate is used in pregnancy, how should it be used?
Lowest dose possible
Prescribe m/r
Prescribe less than 1g - doses higher than this are associated with an increased risk of teratogenicity
86
When dispensing sodium valproate to women of a child bearing potential, what should you do if you can’t dispense in whole packs?
Ensure that a pregnancy warning label is either on the box or as a sticker
87
If a patient on lamotrigine develops a rash, what could this be?
Stevens-Johnson syndrome
| Antiepileptic hypersensitivity syndrome
88
If a patient on lamotrigine develops a rash, what should be done?
Discontinue lamotrigine
89
If a patient on lamotrigine develops a rash, factors increase the risk of a serious skin reaction?
Concomitant use of valproate
Starting at high doses
Titrating quickly
90
Can lamotrigine be given in pregnancy and breastfeeding?
Yes
91
What is the interaction between lamotrigine and oestrogen containing contraceptives?
Oestrogen containing contraceptives may reduce the plasma concentration of lamotrigine, which may result in a loss of seizure control
92
Can levetiracetam be given in pregnancy and breastfeeding?
Pregnancy - yes
| Breastfeeding - no
93
What is the brand name of levetiracetam?
Keppra
94
Does levetiracetam interact with hepatic enzymes?
Not as much as other AEDs - it is not extensively metabolised by the liver
95
Should carbamazepine be titrated quickly?
No
96
How long does it take for carbamazepine to reach a steady state?
About 2 weeks
97
What types of seizures can carbamazepine worsen?
Myoclonic
Absence
Tonic
Atonic
98
Does carbamazepine cause hypernatraemia of hyponatraemia?
Hyponatraemia
99
What are the optimal plasma concentrations of carbamazepine?
4-12 mg/litre
| 20-50 micromol/litre
100
What is the brand name of carbamazepine?
Tegretol
101
Is phenytoin base and phenytoin salt bioequivalent?
No
Phenytoin salt 100mg = phenytoin base 92mg
102
Why is phenytoin not commonly used?
Poor side effect profile
Narrow therapeutic window (requires lots of monitoring)
Lots of drug interactions (hepatic enzyme inducer)
Unpredictable kinetics
103
How is phenytoin given in patients who have enteral feeding?
Interrupt enteral feeding 2hours before and after the phenytoin dose
104
Can phenytoin be given IM?
No - absorption is slow and erratic
105
What type of seizures can phenytoin exacerbate?
Absence
| Myoclonic
106
What are some symptoms of phenytoin toxicity?
```
Confusion
Slurred speech
Hyperglycaemia
Ataxia
Loss of balance
Muscle weakness
```
107
What is the optimal phenytoin concentration in:
a) adults
b) children <3 years
c) children 3-18 years
a) adults 10-20mg/litre (40-80 micromol/litre)
b) 6-15mg/litre (25-60micromol/litre)
c) 10-29mg/litre (40-80 micromol/litre)
108
When might you want to measure free plasma phenytoin concentration?
When there is reduced protein binding e.g. in pregnancy and neonates
109
What increase the risk of respiratory depression in patients taking gabapentin?
Elderly
Renal impairment
Compromised respiratory function
110
What was gabapentin and pregabalin reclassified from and to in 2019
POM to schedule 3 CD
111
Why were gabapentin and pregabalin reclassified?
Risk of abuse - can be mixed with other drugs e.g. methadone
112
Is gabapentin renally or hepatically excreted?
100% renal excretion
113
At what CrCl does the dose of gabapentin need to be reduced?
<79ml/min
114
What Pre-treatment screening may be required for some patients due to the risk of Stevens-Johnson syndrome?
Test for the allele HLA-B*1502 in Han Chinese and Thai patients
These patients are at an increased risk of Stevens-Johnson syndrome
115
Which AEDs are associated with a risk of Stevens-Johnson syndrome?
Carbamazepine
Lamotrigine
Phenytoin
Phenobarbital
116
Which AEDs are associated with a risk of blood disorders?
```
Carbamazepine
Lamotrigine
Phenytoin
Phenobarbital
Sodium valproate
Ethosuximide
```
117
Which AEDs are associated with a risk of hepatic disorders?
Sodium valproate
| Carbamazepine
118
What are the symptoms of heparins disorders?
```
Jaundice
Dark urine
Abdominal pain
Vomiting
Anorexia
```
119
Why is folate supplementation used in pregnancy?
To prevent neural tube defects
