Seizures

Question 1

Define Seizures and Epilepsy

Answer 1

Epilepsy is the recurrent tendency to spontaneous, disordered electrical discharge in the brain manifesting as alteration in motor, sensory or psychological function. Generalised seizures arise in the brain of anyone subjected to the appropriate stimulus, therefore a seizure does not make the diagnosis of epilepsy.

Question 2

Aetiology of Seizures

Answer 2

Unknown in about 1/3

• Tumours
• Intracranial infections
• Metabolic
• Cerebrovascular disease
• Cerebral anoxia
• Drugs
• Developmental brain abnormalities
• Degenerative brain disease

Thought to be an imbalance between GABAergic inhibition and glutamatergic excitation.

Question 3

Seizure Types

Answer 3

Primary Generalised Epilepsy

• Typical Childhood Seizure (‘petit mal’)
• Myoclonic Jerks
• Generalised Tonic-Clonic Seizures (‘grand mal’)

Localisation-Related Epilepsy

• Simple Partial Seizures
• Complex Partial Seizures
• Complex Partial with Secondary Generalisation

Question 4

Define Typical Childhood Seizure (‘petit mal’)

Answer 4

Onset of age is 3-6 years and are associated with brief interruptions of 3-5s in awareness, with minimal or no motor manifestation.
Characteristic 3Hz spike on EEG

Question 5

Define Myoclonic Jerks

Answer 5

Develops later in childhood. It is associated with early morning myoclonic jerks (twitching), which may appear as clumsiness.

Question 6

Define generalised tonic-clonic seizures

‘grand mal’

Answer 6

A brief tonic stiffening (contraction) of the limbs associated with sudden loss of consciousness followed by a variable period of clonic jerking (relaxation)
There may be an aura which manifest as deja vu, a taste, smell or discomfort.

Question 7

Define Simple Partial Seizures

Answer 7

There is a normal conscious level with affects of a focal area of the brain. Affects can vary from flashing lights to unpleasant tingling over the body to jerking of a muscle group.

Question 8

Define Complex Partial Seizures

Answer 8

There is an abnormal conscious level with focal areas of electrical activity. Often there is a forewarning aura.

Question 9

Define Complex Partial with Secondary Generalisation

Answer 9

This is common, a complex partial seizure where electrical activity spreads all over the brain resulting in generalised tonic-clonic seizure.

Question 10

Define Primary Generalised Epilepsy

Answer 10

This refers to electrical activity on the EEG arising in both hemispheres simultaneously. It usually begins in childhood or adolescence, there may be a family history. CT and MRI are normal. It is often triggered by flashing lights (photosensitive).

Question 11

Define Localisation-related Epilepsy

Answer 11

There is a clear electrical focus point on the EEG. Often there is an abnormality on imaging (hippocampal sclerosis, benign tumours, arteriovenous malformations, cortical dysplasia). There is no family history.

Question 12

Seizure Investigations

Answer 12

The diagnosis of epilepsy is clinical, based on a history from the patient and reliable observers.

Electroencephalography (EEG)

• Of patients with true seizures 50% have normal EEGs
• Generalised seizures
• • 3Hz spike and wake discharge triggered by flashing lights
• Localisation-related seizures
• • Focal spike discharges

Question 13

Epilepsy Management

Answer 13

Generalised

• Tonic Clonic
• • Valproate or Iamotrigine
• Petit Mal
• • Ethosuximide or Valproate
• Myoclonic
• • Valproate

Partial

• Carbamazepine
• • 2nd: phenytoin, valproate, gabapentin, clobazam

Question 14

Define Status Epilepticus

Answer 14

Status epilepticus refers to either continuous seizure activity or repeated seizures without full recovery of consciousness between attacks. It is a medical emergency.

Question 15

Management for Status Epilepticus

Answer 15

• Basic Life Support
• Urgent glucose (fingerprick), electrolytes and toxicology
• 10mg diazepam IV - can be repeated
• Phenytoin IV infusion and transfer to ICU