Epilepsy Flashcards
What is it?
Epilepsy is an umbrella term for a condition where there is a tendency to have seizures. Seizures are transient episodes of abnormal electrical activity in the brain. There are many different types of seizures.
A diagnosis of epilepsy is made by a specialist based on the characteristics of the seizure episodes.
Investigations
An electroencephalogram (EEG) can show typical patterns in different forms of epilepsy and support the diagnosis.
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.
Other investigations can be used to exclude other pathology, particularly an ECG to exclude problems in the heart.
Generalised Tonic-Clonic Seizures + treatment
These are what most people think of with an epileptic seizure. There is loss of consciousness and tonic (muscle tensing) and clonic (muscle jerking) episodes. 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 depressed.
Management of tonic-clonic seizures is with:
First line: sodium valproate
Second line: lamotrigine or carbamazepine
Focal Seizures
Focal seizures start in 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 they are the reverse of tonic-clonic seizures:
First line: carbamazepine or lamotrigine
Second line: sodium valproate or levetiracetam
Absence Seizures
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 10-20 seconds. Most patients (> 90%) stop having absence seizures as they get older. Management is:
First line: sodium valproate or ethosuximide
Atonic Seizures
Atonic seizures are also known as “drop attacks”. They are characterised by brief lapses in muscle tone. These don’t usually last more than 3 minutes. They typically begin in childhood. They may be indicative of Lennox-Gastaut syndrome. Management is:
First line: sodium valproate
Second line: lamotrigine
Myoclonic Seizures
Myoclonic seizures present as sudden brief muscle contractions, like a sudden “jump”. The patient usually remains awake during the episode. They occur in various forms of epilepsy but typically happen in children as part of juvenile myoclonic epilepsy. Management is:
First line: sodium valproate
Other options: lamotrigine, levetiracetam or topiramate
Infantile spasms
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
Sodium Valproate s/e:
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:
Teratogenic so patients need careful advice about contraception
Liver damage and hepatitis
Hair loss
Tremor
Carbamazepine s/e:
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 s/e:
Notable side effects:
Folate and vitamin D deficiency
Megaloblastic anaemia (folate deficiency)
Osteomalacia (vitamin D deficiency)
Ethosuximide s/e:
Notable side effects:
Night terrors
Rashes
Lamotrigine
Notable side effects:
Stevens-Johnson syndrome or DRESS syndrome. These are life threatening skin rashes.
Leukopenia
Status Epilepticus
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 seizures lasting more than 5 minutes or more than 3 seizures in one hour.
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 4mg, repeated after 10 minutes if the seizure continues
If seizures persist: IV phenobarbital or phenytoin
Medical options in the community:
Buccal midazolam
Rectal diazepam
