Epilepsy and Seizures: Diagnosis, Drugs and Status Epilepticus

A seizure is a sudden burst of abnormal electrical activity in the brain, which can change movement, sensation, behaviour or awareness. Epilepsy is a tendency to have recurrent unprovoked seizures. It affects people of all ages and, with the right treatment, most patients become seizure-free.

Definition of epilepsy (ILAE)

Epilepsy is usually diagnosed after:

• two or more unprovoked seizures more than 24 hours apart, or
• one unprovoked seizure with a high risk of recurrence (for example clear EEG or imaging abnormalities), or
• an epilepsy syndrome.

Types of seizures

• Focal onset: starts in one area of the brain, with or without impaired awareness. Examples:
  • jerking of one limb
  • strange smells
  • déjà vu
  • lip-smacking
  It can spread to become a bilateral tonic-clonic seizure.
• Generalised onset:
  • tonic-clonic
  • absence (brief staring spells, typically in children)
  • myoclonic
  • atonic (drop attacks)

Provoked seizures — look for a cause

• Metabolic: low glucose, low sodium, low calcium.
• Substances: alcohol withdrawal, drugs and toxins.
• Brain infections: meningitis, encephalitis.
• Structural causes: stroke, tumour, head injury.
• Eclampsia in pregnancy.
• Febrile seizures in young children.

Assessment after a first seizure

• A witness account is the most valuable information. Phone video recordings help.
• Distinguish seizures from syncope (fainting) and other mimics:
  • prolonged confusion afterwards, a bitten side of the tongue and a long post-ictal phase favour a seizure
  • brief jerks can occur in syncope
• Tests:
  • glucose and electrolytes
  • ECG (exclude cardiac arrhythmias)
  • brain imaging (MRI preferred)
  • EEG

Treatment

• Antiseizure medicines are usually started after a diagnosis of epilepsy. The choice depends on seizure type, age, sex, other conditions and drug interactions. Common examples:
  • levetiracetam
  • lamotrigine
  • sodium valproate
  • carbamazepine
• Sodium valproate is highly teratogenic: it carries risks of birth defects and developmental problems. It must not be used in women and girls who could become pregnant, unless other options are unsuitable and a pregnancy prevention programme is in place (strict UK MHRA and European rules).
• Carbamazepine and phenytoin are enzyme inducers. They interact with many drugs, including hormonal contraception.
• Specialist options for drug-resistant epilepsy:
  • epilepsy surgery
  • vagus nerve stimulation
  • dietary therapy
• Lifestyle and safety advice:
  • sleep
  • avoiding alcohol excess
  • water safety
  • driving restrictions according to local law
  • awareness of SUDEP (sudden unexpected death in epilepsy)

Status epilepticus — an emergency

A convulsive seizure lasting 5 minutes or more, or repeated seizures without recovery in between.

1. ABC, oxygen, check glucose (treat hypoglycaemia), protect the patient from injury, and time the seizure.
2. First-line: a benzodiazepine:
   • IV lorazepam if there is IV access
   • otherwise buccal midazolam or rectal diazepam
   It can be repeated once.
3. Second-line if seizures continue: IV levetiracetam, sodium valproate or (fos)phenytoin.
4. Refractory status: anaesthesia and intensive care.

Look for and treat the cause, for example infection, drug levels or metabolic problems.

Exam pearls

• Always check glucose in a fitting patient.
• A seizure lasting 5 minutes or more is status epilepticus. Treat it, don't wait.
• Avoid valproate in women of childbearing potential.

See also Meningitis, Pre-eclampsia and Eclampsia and our Exam Night Notes 1.0: Neurology.

Test yourself

5 exam-style single-best-answer questions. Choose your answer, then tap “Show answer”.

1. A convulsive seizure has lasted 5 minutes. What is this called and what is first-line treatment?

   1. Status epilepticus; a benzodiazepine
   2. Syncope; raise the legs
   3. Absence seizure; valproate
   4. Febrile seizure; paracetamol
   5. Normal seizure; wait
   Show answer

   Answer: A. Status epilepticus; a benzodiazepine
   Seizures lasting 5 minutes or more are status epilepticus; give IV lorazepam or buccal midazolam/rectal diazepam.

2. Which antiseizure drug must be avoided in women of childbearing potential unless strict conditions are met?

   1. Levetiracetam
   2. Sodium valproate
   3. Lamotrigine
   4. Lacosamide
   5. Clobazam
   Show answer

   Answer: B. Sodium valproate
   Valproate is highly teratogenic and requires a pregnancy prevention programme.

3. What is the first bedside test in a fitting patient?

   1. Blood glucose
   2. CT head
   3. EEG
   4. Lumbar puncture
   5. Chest X-ray
   Show answer

   Answer: A. Blood glucose
   Hypoglycaemia is a reversible cause of seizures.

4. Brief staring spells in a child with 3 Hz spike-wave on EEG suggest:

   1. Focal seizures
   2. Syncope
   3. Tics
   4. Febrile seizures
   5. Absence seizures
   Show answer

   Answer: E. Absence seizures
   Typical absence seizures show 3 Hz spike-and-wave discharges.

5. Which feature favours a seizure over simple syncope?

   1. Rapid recovery
   2. Prolonged post-ictal confusion and lateral tongue biting
   3. Pallor before collapse
   4. Brief jerks only
   5. Standing for long
   Show answer

   Answer: B. Prolonged post-ictal confusion and lateral tongue biting
   Long confusion afterwards and a bitten side of the tongue suggest seizure.

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Disclaimer

For education and exam preparation only. This is not medical advice and must not be used to diagnose or treat patients. Always follow current clinical guidelines and the advice of qualified senior colleagues.