Neurology: Epilepsy

Question 1

What is epilepsy?

Answer 1

A tendency to intermittent abnormal electrical brain activity
A chronic disorder of the brain characterised by recurrent, unprovoked epileptic seizures
An epilepsy can be recognised after 2 or more UNPROVOKED epileptic seizures have occurred

Question 2

The abnormal neuronal activity during an epileptic seizure can be manifest as…

Answer 2

Motor, sensory, autonomic, cognitive or psychic disturbance

A convulsion is a subtype of seizure in which motor activity occurs

Question 3

In epilepsy, a diagnosis is made in a patient whom epileptic seizures recur spontaneously. An epileptic seizure can be provoked in individuals who do not have epilepsy. True or false?

Answer 3

True

Provoking insults: hypoglycaemia, fever, trauma, hypoxia

Question 4

What percentage of children will have had a seizure (not associated with a fever) by 14?

Answer 4

1%

Question 5

When classifying epileptic seizures, the initial division is into:

Answer 5

Generalised - involve both cerebral hemispheres

Partial - start in and affect one part of the brain

Question 6

Partial seizures are further classified into…

Answer 6

Simple - consciousness retained

Complex - consciousness lost

Question 7

Can a partial seizure become secondarily generalised?

Answer 7

Yes

Question 8

What types of generalised seizures are there?

Answer 8

Tonic clonic - limbs stiffen (tonic) then jerk forcefully (clonic), LOC, usually around 1 to 3 minutes
Absence - brief e.g 10 second pauses, eyes may roll up, unaware and continue what they were doing, LOC
Myoclonic - sudden jerk, usually involve both sides of body and the person may fall over. Often after waking or when tired. Very short LOC.
Atonic - all muscle tone lost and drop to ground, quickly become conscious again, risk of injury, in babies often appear as head drop
Tonic - muscles stiffen, if standing they will usually fall backwards, no jerking, LOC, more common in childhood but considered uncommon

Question 9

Describe West syndrome (infantile spasms)

Answer 9

Age of onset:3-12 months
Sudden flexion in a tonic fashion of head, trunk and limbs followed by extension of the arms
Can happen singly, but far more common to occur in clusters
Often on waking or many times per day
Common for infants to become irritable and go off feeds, social interaction deteriorates
May be misinterpreted as colic

Question 10

In West syndrome what is the characteristic EEG pattern called?

Answer 10

Hypsarrythmia
A very disorganised pattern
The EEG is always abnormal in West syndrome but sometimes only seen during sleep

Question 11

If West syndrome goes undiagnosed for many weeks, what can happen?

Answer 11

The child’s development may slow or go backwards
Drop in IQ in approximately 70%
Many of the problems will improve if spasms can be controlled and EEG improves

Question 12

What are the main treatments for West syndrome/ infantile spasms?

Answer 12

Prednisolone first line
Vigabatrin second line
Some respond better with combination of both

Question 13

Idiopathic generalised epilepsy (IGE) defined syndromes include:

Answer 13

Benign familial neonatal convulsions
Childhood absence epilepsy CAE
Juvenile absence epilepsy JAE
Juvenile myoclonic epilepsy JME

There is no apparent cause expect for genetic predisposition

Question 14

Symptomatic generalised epilepsy defined syndromes include:

Answer 14

Infantile spasms (west syndrome)
Lennox- Gastaut syndrome
Cerebral malformations
Progressive myoclonic epilepsies

The cause is known or suspected in these

Question 15

What is the cause?

Answer 15

In about 50% of children, no cause will be identified

Infection 
Hyponatraemia 
Hypoglycaemia 
Hypocalcaemia 
Hypomagnesia 
Toxins 
Trauma 
Metabolic defects 
Tuberous sclerosis
CNS tumour or malformation

Question 16

How is epilepsy diagnosed?

Answer 16

Careful and complete history - event before, during and after seizure
Video recording is useful
Distinguish true seizures from the many paroxysmal disturbances that can mimic them - reflex anoxic seizures, vasovagal syncope, cardiac dysrhythmia
Physical examination - often normal, but pay attention to skin (neurocutaneous syndromes) and to fundus as retinal changes can provide clue to aetiology
Imaging

Question 17

What investigations can be done?

Answer 17

ECG standing for all children with seizures, even when epilepsy seems most likely (the consequences of missing convulsive syncope due to an arrhythmia can be fatal
EEG - may be useful to aid diagnosis (but a routine interictal EEG does not prove or disprove diagnosis)
If seizures frequent then an ictal EEG can make diagnosis
A sleep or sleep deprived EEG may be helpful, or 24h ambulatory EEG
MRI and CT brain scans generally required unless characteristic history
PET/SPECT - detect areas of abnormal metabolism, which could be epileptogenic areas

Question 18

How should epilepsy be managed?

Answer 18

Education - both child and parent
Encourage to participate in and enjoy full social life, discourage overprotection
Percussions: swimming, bath, cycling, climbing
Consider psychological implications
Learning difficulties present in proportion of children with epilepsy, but only minority require special schooling

Anti Epileptic Drugs

• not all children with epilepsy require them
• many would not start AEDs after a single brief tonic clonic or for infrequent myoclonic or absence
• commonly used : sodium valproate and carbamazepine
• newer AEDs being increasing used : lamotrigine, topiramate, vigabatrin

Question 19

What is currently the first line treatment for generalised epilepsy?

Answer 19

Sodium valproate

Question 20

What is the current first line treatment for partial epilepsy?

Answer 20

Carbamazepine

Question 21

Mono therapy will achieve total seizure control in what percentage of children?

Answer 21

70%

Question 22

What side effect is vigabatrin associated with?

Answer 22

Permanent visual field defects

Question 23

In those with infantile spasms, is there usually an underlying cause?

Answer 23

Yes, a particular cause will be found in 7/8 out of 10 children

Question 24

Is Lennox-Gastaut epilepsy common?

Answer 24

No

It is the most common type of intractable (difficult to treat) childhood epilepsy

Question 25

What is Lennox-Gastaut epilepsy also known as?

Answer 25

Epileptic and developmental encephalopathy - because the seizures and abnormal EEG thought to be important in the developmental delay and learning difficulties

Question 26

What is the most common age of onset of Lennox-Gastaut syndrome?

Answer 26

1-3 years

Question 27

Describe the seizure pattern in Lennox-Gastaut syndrome

Answer 27

``` Multiple seizure types, but mostly atonic and tonic seizures Child may suddenly fall to ground, injuries often occur and usually happen several times per day Also atypical (subtle) absence seizures - appear vacant, unable to speak, drooling, floppy ```

Question 28

In Lennox-Gastaut syndrome, do children have developmental delay?

Answer 28

Yes or learning difficulties | Before or after seizures start

Question 29

About how many children will develop Lennox-Gastaut syndrome after West syndrome?

Answer 29

2/3 out of 10

Question 30

What does the EEG typically show with Lennox-Gastaut syndrome?

Answer 30

Inter-ictal: slow spike and slow wave activity | Ictal EEG during tonic seizure: fast spike activity

Question 31

What can cause Lennox-Gastaut syndrome?

Answer 31

Genetic conditions e.g tuberous sclerosis Brain malformation Previous brain damage - HIE, meningitis as a young baby or head injury In about half, no cause found

Question 32

Describe childhood absence epilepsy

Answer 32

Age of onset 4-12 years Momentary unresponsive stare with motor arrest, may have minimal eyelid/ mouth Sudden onset, lasts a few seconds Child has no recall, except realises they have missed something Happen less often when child is focused on an activity

Question 33

Is childhood absence epilepsy associated with developmental delay?

Answer 33

No, but can interfere with schooling

Question 34

How is it diagnosed?

Answer 34

History Episodes induced by hyperventilating- blowing on piece of paper/windmill for 2-3 mins EEG shows fast generalised spike and wave discharges, during and sometimes between absences No other tests such as scans required, unless atypical features

Question 35

Does CAE usually respond well to treatment?

Answer 35

Yes Ethosuximide, SV and lamotrigine Occasionally combination of 2

Question 36

What is the prognosis for CAE?

Answer 36

Majority become seizure free as they pass through puberty | A few evolve in juvenile absence or juvenile myoclonic epilepsy

Question 37

Benign Rolandic epilepsy (childhood epilepsy with centro-temporal spikes) is one of the most common types of epilepsy in children. True or false?

Answer 37

Yes = 15% of childhood epilepsies | It affects boys slightly more than girls

Question 38

When does childhood Rolandic epilepsy start and stop?

Answer 38

Usually starts between 4-10 years and stops around puberty

Question 39

Describe benign Rolandic epilepsy

Answer 39

Usually focal seizures Often start as child is asleep or just about to wake Tingling on one side of mouth, speech abnormality, gurgling noises Occasional spreads to bilateral tonic clonic seizure, child may be incontinent and sleepy afterwards Do not usually have LDs

Question 40

What does the EEG show with benign Rolandic epilepsy?

Answer 40

Focal sharp waves from the Rolandic area (centro-temporal) | Important to recognise as relatively benign and may not require AEDs

Question 41

Describe Panayiotopoulos syndrome (early onset benign occipital epilepsy)

Answer 41

Age of onset: 1-5 years Autonomic features with vomiting and unresponsive staring in sleep Pupils dilate, face flushed, sweating and drooling Head and eye deviation Progressing sometimes to a convulsive seizure Remits in adolescence Relatively benign and may not need AEDs

Question 42

Describe juvenile absence epilepsy

Answer 42

Age of onset: 10-20 years Absences and generalised tonic clonic seizures Often with photosensitivity Characteristic EEG Response to treatment usually good, but lifelong Remission unlikely Learning unimpaired

Question 43

Describe juvenile myoclonic epilepsy

Answer 43

Onset: 10-20 years Myoclonic seizures, generalised tonic clonic and absence may occur Mostly shortly after waking Typical history: throwing drinks and cereal about Learning unimpaired Characteristic EEG Response to treatment usually good but lifelong Remission unlikely

Question 44

The decision of whether to treat or not is related to...

Answer 44

Risk of reoccurrence How dangerous or impairing How upsetting further seizure would be

Question 45

Carbamazepine can make what seizures worse?

Answer 45

Absence and myoclonic

Question 46

What is the desired goal of treatment with AEDs?

Answer 46

Mono therapy at minimum dose to prevent seizures without adverse effects In practice more than 1 AED may be required

Question 47

Children with prolonged seizures with LOC more than 5 mins are given what?

Answer 47

Rescue therapy - usually buccal midazolam

Question 48

When can AEDs be discontinued?

Answer 48

After 2 years seizure free | Usually continued indefinitely if juvenile absence or juvenile myoclonic epilepsy

Question 49

In children with intractable epilepsies, what other treatment options are there?

Answer 49

Ketogenic diet (low carb, fat based) Vagal nerve stimulation Epilepsy surgery if well localised, structural cause: - temporal lobectomy for mesial temporal sclerosis - hemispherotomy - focal resections