Epilepsy

Question 1

Definition of epilepsy, and different types:

Answer 1

Recurrent tendency to spontaneous, intermittent, abnormal electrical activity in a par to the brain, which then manifests as a seizure
• Clinically defined as at least 2 seizures occurring >24 hours apart

Types of seizure:
• FOCAL SEIZURE:
◦ Seizures that arise from one portion of the brain
◦ Temporal lobe origin is the most common
◦ Can be further split into:
◦ 1) Focal aware seizures: Where consciousness is preserved
◦ 2) Focal impaired seizures: Where there is loss of awareness, memory loss of the event and reduced responsiveness

		• GENERALISED SEIZURE:
						◦ Seizures that can affect the entire brain (a single portion not localised)
						◦ Characterised by loss of consciousness and tonic stiffening of limbs, followed by repetitive clonic jerking
						◦ Different types of generalised seizures are:
						◦ -Tonic clonic
						◦ -Absence 
						◦ -Myoclonic
						◦ -Atonic
						◦ -Tonic

Question 2

Aetiology of epilepsy

Answer 2

• The majority of cases are IDIOPATHIC

• Other causes are:
◦ Traumatic brain injury
◦ CNC infection
◦ Brain tumours
◦ Stroke
◦ Family history/genetics
◦ Vascular malformations
◦ Electrolyte imbalances
◦ Drugs

Question 3

Pathophysiology of epilepsy

Answer 3

• Seizures are caused by inappropriate hyperexcitability and hypersynchrony.
◦ This is likely due to an imbalance in the inhibitory and excitatory neurotransmitters/impulses in the brain

Question 4

History and Examination for epilepsy

Answer 4

• Ensure to ask about:
‣ Rapidity of onset
‣ Duration of episode
‣ Loss of consciousness?
‣ Tongue biting, incontinence?
‣ Post-ictal period (confusion, tired for a prolonged time after)
‣ Limb jerking
‣ Triggers (alcohol, drugs etc)

Focal seizure presentation:
• Temporal lobe focal seizure: (more common)
• Automatisms: picking at clothes, smacking of lips, fiddling
• Dysphasia: may have post-ictal aphasia as well as it being a first symptom
• Emotional disturbance: sudden terror, panic, anger, deja vu

• Frontal lobe:
• Motor features (movement of legs)
• Jacksonian march
• Motor arrest
• Post-ictal Todd’s palsy (paralysis following seizure)

Generalised seizures:
• Tonic-clonic:
• Loss of consciousness
• Limbs stiffen (tonic)
• Repetitive jerk of muscles (clonic)
• Post-ictal confusion and drowsiness
• Tongue biting

• Absence:
• Brief (<10 seconds) pauses (e.g suddenly stops talking mid-sentence)
• Onset in childhood
• No post-ictal phase

• Myoclonic:
• Sudden jerk of limb, face or trunk
• May be violently thrown to the ground or violently disobedient limb

Question 5

Risk factors of epilepsy

Answer 5

• Family history
• Previous CNS infection or trauma
• Prior seizure event
• History of dementia

Question 6

Investigations for epilepsy

Answer 6

• FBC: check for infection
• Blood glucose: cause may be severe hypoglycaemia
• Electrolyte panel: may provoke a tonic-clonic seizure
• Toxicology screen: test for drugs
• EEG: Can help to confirm diagnosis and classify the epilepsy
• CT head: To check for structural lesion

Question 7

Treatment for epilepsy

Answer 7

Focal seizures:
1) Anticonvulsant Monotherapy:
◦ A trial of anticonvulsants should be started after 2 spontaneous seizures
◦ Only treat with one drug and slowly build up the dose until seizures have been controlled
◦ Lamotrigine Levetiracetam, or Oxcarbazepine are the recommended 1st line drugs

Generalised seizures:
1) Anticonvulsant Monotherapy:
◦ Sodium Valproate (nausea is very common, monitor LFTs). Teratogenic (can cause birth defects)

Question 8

Prevention and prognosis of epilepsy

Answer 8

• Avoid triggers
• Good sleep hygiene and avoid alcohol
• Careful of drug interactions

Anticonvulsant monotherapy is effective in just over half of patients. If doesn’t work, try alternative monotherapy, then dual therapy

Question 9

Complications of epilepsy

Answer 9

• Medication adverse effects
• Status elipiticus: >5 minutes of continuous seizure activity (Administer benzodiazepines- Lorazepam and Diazepam, to terminate)