Neurology

Question 1

What are the features of generalised seizures?

Answer 1

Onset in both hemispheres 
Loss of conciousness
No warning 
Symmetrical seizure 
Bilaterally synchronous seizure discharge on EEG or varying asymmetry

Question 2

What are the features of absence seizures?

Answer 2

Transient loss of conciousness
Abrupt onset and termination
Unaccompanied by motor phenomena- except for flickering of the eyelids and minor alteration in muscle tone
Can by typical (petit mal) or precipitated by hyperventilation

Question 3

What are the features of myoclonic seizures?

Answer 3

Brief, often repetitive jerking movements of the limbs, neck or trunk
Myoclonic movements are seen in hiccoughs (myoclonus of the diaphragm) or passing through stage II sleep

Question 4

What are tonic seizures?

Answer 4

Generalised increase in tone

Question 5

What are the features of tonic-clonic seizures?

Answer 5

Rhythmical contraction of muscle groups following the tonic phase
In rigid tonic phase, children may fall
They don’t breathe and become cyanosed
Followed by the clonic phase, jerking of the limbs
Breathing is irregular and cyanosis persists
Saliva may accumulate in mouth
May be biting of the tongue and incontinence of urine
Seizure lasts a few seconds to minutes- followed by unconsciousness or deep sleep for up to several hours

Question 6

What are the features of atonic seizures?

Answer 6

Often combined with a myoclonic jerk, followed by a transient loss of muscle tone causing a sudden fall to the floor or drop of the head

Question 7

What are the features of focal seizures?

Answer 7

May have aura which reflects site of origin

May be associated with change in consciousness or more generalised tonic-clonic seizure

Question 8

What are the features of different focal seizures in different parts of the brain?

Answer 8

Frontal- motor phenomena
Temporal- auditory or sensory (smell or taste)
Occipital- positive or negative visual phenomena
Parietal lobe seizures- contralateral altered sensation (dysaethesia)

Question 9

What is status epilepticus?

Answer 9

Can be convulsive with tonic/clonic movements or it can be non-convulsive with impairment of consciousness and often subtle twitching
Seizure lasting >30 mins or repeated seizures lasting >30 mins without recovery of consciousness

Question 10

Which syndromes are associated with epilepsy?

Answer 10

o West syndrome (4-6 months)
o Lennox-Gastaut syndrome (1-3 years)
o Childhood absence epilepsy (4-12 years)
o Benign epilepsy
o Early onset benign childhood occipital epilepsy
o Juvenile myoclonic epilepsy

Question 11

What are the features of West syndrome?

Answer 11

4-6 months
EEG shows hypsarrhythmia (chaotic background of slow wave activity with sharp multi-focal components). Pattern of seizure is violent flexor spasms of the head, trunk and limbs followed by extension of the arms. Spasms occur for 1-2 seconds and repeat 20-30 times

Question 12

What are the features of Lennox-gastaut?

Answer 12

1-3 years

Most drop attacks, tonic seizures and atypical absences

Question 13

What are the features of childhood absence?

Answer 13

4-12 years

EEG shows 3/second spike and wave discharge which is bilaterally synchronous

Question 14

What are the features of benign epilepsy?

Answer 14

Tonic-clonic seizures in sleep or simple focal seizures with awareness of abnormal feelings. EEG shows focal sharp waves from the Rolandic area

Question 15

What are the features of early onset benign childhood occipital epilepsy?

Answer 15

Periods of unresponsiveness in young children and hallucinations/visual disturbance in older children. EEG shows occipital discharges

Question 16

What are the features of juvenile myoclonic epilepsy?

Answer 16

Myoclonic seizures but generalised tonic-clonic or absences may also occur, mostly shortly after waking. There is a characteristic EEG.

Question 17

When is an EEG indicated?

Answer 17

Whenever epilepsy is suspected- it can identify a background level of activity that is
abnormal for the child’s age
o Asymmetry or slowing that might suggest underlying structural abnormalities
o Evidence of neuronal hyperexcitability eg. sharp waves or spike-wave complexes
• Many children with epilepsy have a normal initial EEG and many children without epilepsy have abnormal EEGs
• Unless a seizure is actually captured- an EEG does no more than add supportive evidence to the diagnosis
• NB – if the standard EEG is normal, a sleep or sleep-deprived record can be helpful

Question 18

What is the structural imaging for seizures?

Answer 18

o MRI & CT scans are not required routinely for childhood generalised epilepsies
o They are indicated if there are neurological signs between seizures, or if seizures are focal
o They are used to identify a tumour, vascular lesion or area of sclerosis which could be treatable
o MRI FLAIR sequences better detect mesial temporal sclerosis in temporal lobe epilepsy

Question 19

What are the functional scans for epilepsy?

Answer 19

o Detects area of abnormal metabolism suggestive of seizure foci
o These include PET and SPECT scanning- which use isotopes & ligands taken upy my metabolically active cells
o Both can be used between seizures to detect areas of hypometabolism in epileptogenic lesions

Question 20

What are the investigations for seizures?

Answer 20

EEG- first line
Imaging- MRI and CT if structural abnormality or symptoms between seizures
Metabolic inv- warranted when there is developmental regression or seizures related to feeding or fasting
Genetic studies- Genetic deletions causing abnormalities of sodium and other ion channel- SCN1A mutation in severe myoclonic epilepsy

Question 21

What is important to consider with management of seizures?

Answer 21

Monotherapy at the minimum dose is desired
Drug levels aren’t measured routinely
AED can be discontinued after 2 seizure free years
Children with prolonged seizures are given rescue therapy (usually rectal or buccal diazepam)

Question 22

What are the medications used for the different types of seizures?

Answer 22

Tonic-clonic: valproate, carbamazepine (2nd lamotrigine, topiramate)
Absence: valproate, ethosuximide (2nd lamotrigine)
Myoclonic: valproate (2nd lamotrigine)
Focal: Carbamazepine, valproate, lamotrigine (most effective).
(2nd topiramate, levetiracetam, oxcarbazepine, gabapentin, tiagabine, vigabatrin)

Question 23

What are other treatment options in seizures?

Answer 23

o Ketogenic- diets may be helpful in some children
o Vagal nerve stimulation- delivered using an external programmable wire or magnet
o Surgery- if well localised with useful EEG and MRI findings, but involves removal of sections of brain