Epilepsy

Question 1

Generalised Tonic Clonic Seizure

Answer 1

Generalised Tonic-Clonic Seizures

These are what most people think of with an epileptic seizure. There is loss of consciousness and tonic (muscle tensing) and clonic (muscle jerking) movements. Typically the tonic phase comes before the clonic phase. There may be associated tongue biting, incontinence, groaning and irregular breathing.

After the seizure there is a prolonged post-ictal period where the person is confused, drowsy and feels irritable or low.

Management of tonic-clonic seizures is with:

First line: sodium valproate
Second line: lamotrigine or carbamazepine

Question 2

Focal Seizure

Answer 2

Focal seizures start in the temporal lobes. They affect hearing, speech, memory and emotions. There are various ways that focal seizures can present:

Hallucinations
Memory flashbacks
Déjà vu
Doing strange things on autopilot
One way to remember the treatment is that the choice of medication is the reverse of tonic-clonic seizures:

First line: carbamazepine or lamotrigine
Second line: sodium valproate or levetiracetam

Question 3

Absence Seizure

Answer 3

Absence seizures typically happen in children. The patient becomes blank, stares into space and then abruptly returns to normal. During the episode they are unaware of their surroundings and won’t respond. These typically only lasts 10 to 20 seconds. Most patients (more than 90%) stop having absence seizures as they get older. Management is:

First line: sodium valproate or ethosuximide

Question 4

Infantile Spasm

Answer 4

This is also known as West syndrome. It is a rare (1 in 4000) disorder starting in infancy at around 6 months of age. It is characterised by clusters of full body spasms. There is a poor prognosis: 1/3 die by age 25, however 1/3 are seizure free. It can be difficult to treat but first line treatments are:

Prednisolone
Vigabatrin

Question 5

Diagnosis

Answer 5

A good history is the key to a diagnosis of epilepsy. It is important to establish that any episodes were seizures, as opposed to vasovagal episodes or febrile convulsions. Try to identify the type of seizure. Patients with a clear history of a febrile convulsion or vasovagal episode do not require further investigations.

An electroencephalogram (EEG) can show typical patterns in different forms of epilepsy and support the diagnosis. Perform an EEG after the second simple tonic-clonic seizure. Children are allowed one simple seizure before being investigated for epilepsy.

An MRI brain can be used to visualise the structure of the brain. It is used to diagnose structural problems that may be associated with seizures and other pathology such as tumours. It should be considered when:

The first seizure is in children under 2 years
Focal seizures
There is no response to first line anti-epileptic medications
Additional investigations can be considered to exclude other pathology that may cause seizures:

ECG to exclude problems in the heart.
Blood electrolytes including sodium, potassium, calcium and magnesium
Blood glucose for hypoglycaemia and diabetes
Blood cultures, urine cultures and lumbar puncture where sepsis, encephalitis or meningitis is suspected

Question 6

Anti Epileptic Drugs

Answer 6

There are a number of maintenance anti-epileptic drugs that work by raising the seizure threshold and reducing the likelihood of the patient having a seizure. These will be initiated, monitored and titrated by a paediatric specialist with expertise in epilepsy.

Sodium Valproate

This is a first line option for most forms of epilepsy (except focal seizures). It works by increasing the activity of GABA, which has a relaxing effect on the brain. Notable side effects of sodium valproate include:

Teratogenic, so patients need careful advice about contraception
Liver damage and hepatitis
Hair loss
Tremor
There are a lot of warning about the teratogenic effects of sodium valproate and NICE updated their guidelines in 2018 to reflect this. It must be avoided in girls unless there are no suitable alternatives and strict criteria are met to ensure they do not get pregnant.

Carbamazepine

This is first line for focal seizures. Notable side effects are:
Agranulocytosis
Aplastic anaemia
Induces the P450 system so there are many drug interactions

Phenytoin

Notable side effects:
Folate and vitamin D deficiency
Megaloblastic anaemia (folate deficiency)
Osteomalacia (vitamin D deficiency)

Ethosuximide

Notable side effects:
Night terrors
Rashes

Lamotrigine

Notable side effects:
Stevens-Johnson syndrome or DRESS syndrome. These are life threatening skin rashes.
Leukopenia

Question 7

Status Epilpeticus

Answer 7

Status epilepticus is an important condition you need to be aware of and how to treat. It is a medical emergency.

It is defined as a seizure lasting more than 5 minutes or 2 or more seizures without regaining consciousness in the interim.

Management of status epileptics in the hospital (take an ABCDE approach):

Secure the airway
Give high-concentration oxygen
Assess cardiac and respiratory function
Check blood glucose levels
Gain intravenous access (insert a cannula)
IV lorazepam, repeated after 10 minutes if the seizure continues
If the seizures persist the final step is an infusion of IV phenobarbital or phenytoin. At this point intubation and ventilation to secure the airway needs to be considered, along with transfer to the intensive care unit if appropriate.

Medical options in the community:

Buccal midazolam
Rectal diazepam