Definitions

Epileptic seizure

• the transient occurrence of signs or symptoms due to abnormal electrical activity in the brain. This manifests itself as a disturbance of consciousness, behaviour, emotion, motor function, or sensation.

Epilepsy

A disease of the brain defined by any of the following conditions: 

• 1. at least two unprovoked seizures occurring more than 24 hours apart. 

  2. One unprovoked seizure and a probability of further seizures similar to the general recurrence risk after two unprovoked seizures, occurring over the next 10 years. 

  3. Diagnosis of an epilepsy syndrome: there are at least 30 different epilepsy syndromes distinguished by their seizure type, age of onset, family history, neurological findings, cerebral imaging (such as CT or MRI scan), electroencephalogram (EEG) pattern, and underlying cause.

• Provoked seizures, that are not of primary cerebral origin, may occur in people who do not have epilepsy if they are exposed to a transient noxious stimulus, such as alcohol or drug withdrawal, fever, hypoxia, or hypoglycaemia.

• terms simple partial seizure and complex partial seizure have been replaced by the term focal seizure.  Focal seizures in which consciousness is impaired are described as focal dyscognitive seizures. The terms idiopathic, symptomatic and cryptogenic have been replaced by the terms genetic, structural-metabolic, and unknown. It is important to make the distinction between genetic generalised epilepsies and focal epilepsies as this affects treatment choices, investigation, prognosis and counselling.

• Status epilepticus is a continuous seizure for 30 minutes or longer, or recurrent seizures without regaining consciousness lasting 30 minutes or longer.

Diagnosis

• Should only be confirmed by a specialist in epilepsy. Clear history from the patient and an eyewitness is the most important diagnostic information. 

• ECG should be carried out in the assessment of all patients with altered consciousness, particularly those in older age groups, when disorders of cardiac rhythm may simulate epilepsy

• EEG should not be used in isolation to make a diagnosis of epilepsy. ECG recommended in adults with suspected epilepsy, and in children in cases of diagnostic uncertainty.

• Brain imaging not routinely required when there is a confident diagnosis of generalised epilepsy. MRI is the modality of choice in patients with epilepsy. CT scanning has a role in the urgent assessment of seizures to determine whether a seizure has been caused by an acute neurological lesion or illness, or when MRI is contraindicated.

Management

A ten-year-old girl is on medication for idiopathic generalised epilepsy. Her parents want to know for how long she should be seizure free before it would be appropriate to consider stopping her medication.

Which is the SINGLE MOST appropriate length of time? 

1. One year

2. Two years

3. Three years

4. Four years

5. Five years

The National Institute for Health and Care Excellence (NICE) recommends that the risks and benefits of continuing or withdrawing anti-epileptic drug (AED) therapy should be discussed if a child has been seizure free for at least two years.

If considering withdrawing AEDs, the child should be referred for specialist review and advice about whether stopping AEDs is appropriate and how to stop the child's AEDs.

When AED treatment is being discontinued, it should be carried out slowly (over at least 2–3 months) and one drug should be withdrawn at a time. There should always be a fail-safe plan agreed whereby, if seizures recur, the last dose reduction is reversed, and medical advice is sought.

Resources

• Epilepsies in children, young people and adults (NG217. 2022)

• Diagnosis and Management of Epilepsy in Adults (SIGN, 2015)

• Epilepsy (CKS)

• Epilepsies: diagnosis and management (NICE, CG137)

• Epilepsy (Mayo clinic)

• Epilepsy society