Epilepsy

Question 1

What is epilepsy? What are convulsions?

Answer 1

Recurrent tendency to spontaneous, intermittent, abnormal electrical activity in part of the brain manifesting as seizures.

Convulsions are the motor signs of electrical discharges

Question 2

What are the elements of a seizure

Answer 2

Preceding prodromal may be experienced - change in mood or behaviour
Aura implies a focal seizure often from the temporal lobe - may be a strange feeling in the gut, an experience such as deja vu or strange smells or flashing lights
Post-ictally there may be headache, confusion, myalgia, temporary weakness after a focal seaisure or dysphasia.

Question 3

What is the difference between generalised and focal seizures?

Answer 3

• Focal seizures start in a specific area on one side often brain,
• Level of awareness can vary in focal seizures:
  Focal aware (simple partial)
  Focal impaired awareness (complex partial)
  Awareness unknown
• Focal seizures can be classified as motor, non-motor or having aura
• Generalised seizure involve networks on both sides of the brain at the onset
• Consciousness is lost immediately
• Can be further classified into motor (tonic-clonic) and non-motor (absence)

Question 4

What are the subclasses of focal seizures?

Answer 4

Focal aware - without impairment of consciousness with focal motor, sensory, autonomic or psychic symptoms. No post-ictal symptoms.

Focal impaired awareness - awareness is impaired either at seizure onset or following a simple partial aura.
Most commonly arise from the temporal lobe. Post-ictal confusion.

Evolving to a bilateral convulsive seizure
(Secondary generalised) In 2/3 patients with focal seizures, electrical disturbance which starts focally spreads widely causing generalised seizure

Question 5

What are the specific types of generalised seizures?

Answer 5

Absence seizures: <10s pauses, presents in childhood
Tonic-clonic (grand-mal) - LOC, Limbs stiffen then jerk
Tonic
Clonic
Myoclonic - sudden jerk of a limb, face or trunk. Patient may be thrown suddenly to the ground or have a violently disobedient limb

Atonic (akinetic) - sudden loss of muscle tone causing a fall, no LOC

Question 6

What are localising temporal lobe feartures of focal seizures?

Answer 6

Automatisms (lip smacking, chewing, swallowing, manual movements, complex actions.
Dysphasia
Deja vu
Jamais vu (everything is strangely unfamiliar)
Emotional disturbance - terror, panic, anger, elaciton
Hallucinations of smell, taste, sound
Delusional behavious
Bizarre associations

Question 7

What are localising frontal lobe feartures of focal seizures?

Answer 7

Motor features such as posturing or peddling movements of the legs
Jacksonian march ( a spreading focal motor seizure with retained awareness, often starting with the face or a thumb)
Motor arrest
Subtle behavioural disturbances
Dysphasia/speech arrest
Post-ictal weakness - Todd’s palsy (transient neurological deficit)

Question 8

What are localising parietal lobe feartures of focal seizures?

Answer 8

Paraesthesia
Sensory disturbances - tingling, numbness, pain
Motor symptoms (due to spread to precentral gyrus)

Question 9

What are localising occipital lobe feartures of focal seizures?

Answer 9

Visual phenomena such as spots, lines and flashes

Question 10

Describe infantile spasms.
What is seen on EEG?
What is treatment?

Answer 10

West’s syndrome
Childhood epilepsy present in first 4 to 8 months of life, more common in males

Salaam attacks - flexion of head trunk and arms followed by extension of the arms
Lasts only 1-2 seconds but may be repeated
Progressive mental handicap

EEG shows hypsarrhythmia in 2/3
CT demonstrates diffuse/localised brain disease e.g. tuberous sclerosis

Vigabatrin first line
- inhibits GABA breakdown

Question 11

What is Lennox Gastaut syndrome? EEG?

Answer 11

Extension of infantile spasms
Onset 1-5 years
Atypical absences falls jerks
90% moderate-severe mental handicap
EEG - slow spike
Ketogenic diet may help

Question 12

What is benign rolandic epilepsy? EEG?

Answer 12

Paraesthesia usually on waking up

Centro temporal spikes

Question 13

What is juvenile myoclonic epilepsy? EEG? Mx?

Answer 13

Janz syndrome

Teens, girls

Infrequent gneeralised seizures, often in morning
Daytime absences
Sudden, shock like myoclonic seizure
Can have myoclonic, tonic-clonic and absence seizures. They can be photosensitive

EEG - Polyspike waves

Sodium valproate

Question 14

What are symptoms of signs of epilepsy

Answer 14

Tongue biting resulting in bleeding from mouth
Incontinence of urine
Foaming at mouth due to lack fo saliva swallow
Post-ictal drowsy, tiredness for 15 mins

Question 15

What should you ask about?

Answer 15

Head injury
Tongue biting
Slow recovery
Incontinency
Past funny turns/odd behavious
Deja vu
Fear
Triggers
Other causes

Question 16

What are other causes of seizures?

Answer 16

Trauma
Stroke
Haemorrhage
RICP
Alcohol withdrawal seizures
Febrile convulsions
Metabolis disturbance ( hypoxia, hyponatraemia, hypocalcaemia, hyper/hypoglycaemia, uraemia)
Infection
Psychogenic non-epileptic pseudo seizures
Drugs - tricyclics, cocaine

Question 17

What investigations in seizure?

Answer 17

EEG - electroencephalogram
Neuroimaging - MRI for strutturai lesions
Drug levels
Drugs screen
LP if meningitis is suspected

Question 18

What are absence seizures?
Features?
EEG?
Mx?

Answer 18

3-10 years olds
Girls> boys

Absences last a few seconds with quick recovery
Seizures may be provoked by hyperventilation or stress
Child is unaware of seizure
May occur many times a day

EEG: Bilateral, symmetrical 3Hz spike and wave pattern

Sodium valproate and ethosuximide

Question 19

How can you differentiate psychogenic seizures (pseudo seizures) from epileptic seizures?

Answer 19

Factors favouring pseudoseizures

pelvic thrusting
family member with epilepsy
much more common in females
crying after seizure
don't occur when alone
gradual onset

Factors favouring true epileptic seizures

tongue biting
raised serum prolactin