Epilepsy Flashcards
What is epilepsy?
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.
Briefly describe the diagnosis and investigations for epilepsy
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
Give examples of the different types of seizures
- Generalised tonic-clonic seizures
- Focal seizures
- Absence seizures
- Atonic Seizures
- Infantile spasms
Briefly describe the clinical features of a generalised tonic-clonic 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.
Briefly describe the management of generalised tonic-clonic seizures
Management of tonic-clonic seizures is with:
- First line: sodium valproate
- Second line: lamotrigine or carbamazepine
Briefly describe the clinical features of 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
Briefly describe the management of focal seizures
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
Briefly describe the clinical features of absent 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.
Briefly describe the management of absent seizures
Management is:
- First line: sodium valproate or ethosuximide
Briefly describe the clinical features of 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.
Briefly describe the management of atonic seizures
Management is:
- First line: sodium valproate
- Second line: lamotrigine
Briefly describe the clinical features of 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.
Briefly describe the management of myoclonic seizures
Management is:
- First line: sodium valproate
- Other options: lamotrigine, levetiracetam or topiramate
Briefly describe the clinical features of 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.
Briefly describe the management of infantile spasms
It can be difficult to treat but first line treatments are:
- Prednisolone
- Vigabatrin
What are the side effects of 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:
- 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 or women unless there are no suitable alternatives and strict criteria are met to ensure they do not get pregnant.
What are the side effects of 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
What are the side effects of phenytoin?
Notable side effects:
- Folate and vitamin D deficiency
- Megaloblastic anaemia (folate deficiency)
- Osteomalacia (vitamin D deficiency)
What are the side effects of ethosuximide?
Notable side effects:
- Night terrors
- Rashes
What are the side effects of lamotrigine?
Notable side effects:
- Stevens-Johnson syndrome or DRESS syndrome
- These are life threatening skin rashes
- Leukopenia
