Epilepsy in Adults

See also the separate articles:

First Seizure
Epilepsy in Elderly People
Managing Epilepsy in Primary Care
Status Epilepticus Management

An epileptic seizure is the transient occurrence of signs or symptoms due to abnormal electrical activity in the brain, leading to a disturbance of consciousness, behaviour, emotion, motor function or sensation.¹ Epilepsy is characterised by the occurrence of at least 2 unprovoked episodes of periodic disturbance in neurological function.

Accurate diagnosis is essential but misdiagnosis remains a problem. A wrong diagnosis of epilepsy can cause severe restrictions on a patient's lifestyle as well as unnecessarily risk side-effects from long-term medication. Seizures can be classified as being generalised or partial:²

• Generalised seizures may be tonic-clonic (grand mal), isolated tonic or clonic, myoclonic (brief, shock-like muscle contractions) or absence (petit mal).
• Partial may be divided into simple partial (motor or sensory) with retained awareness or complex partial (impaired awareness). Partial seizures may progress into generalised seizures. There is a separate article covering Temporal Lobe Epilepsy.

• Approximately 1 person in 2,000 is newly diagnosed with epilepsy each year.
• Epilepsy most commonly starts in children or in people older than 60 years of age.
• Epilepsy is much more common in people with a learning disability.

• Most are idiopathic; seizures due to underlying diseases affecting the brain are more likely to have a focal onset.
• Cerebrovascular disease such as cerebral infarction, cerebral haemorrhage, and venous thrombosis.
• Head injury: head trauma is more significant when it occurs with loss of consciousness lasting longer than 30 minutes, post-traumatic amnesia lasting longer than 30 minutes, focal neurological findings, or neuro-imaging findings suggesting a structural brain injury.
• Post cranial surgery.
• CNS infections such as meningitis or encephalitis.
• Neurodegenerative diseases: epilepsy is more common in people with Alzheimer's disease or multi-infarct dementia.
• Autoimmune disease.
• Brain neoplasm.
• Genetic diseases.
• Drugs: for example, phenothiazines, isoniazid, tricyclic antidepressants; binge alcohol drinking; drug (e.g. benzodiazepines) or alcohol withdrawal.
• Metabolic medical disorders such as uraemia, hypoglycaemia, hyponatraemia, hypernatraemia, hypercalcaemia and hypocalcaemia.

Accurate history-taking is essential with particular reference to an eyewitness if possible. Must include family history, past medical history, medication history as well as alcohol and illicit drugs.

• Generalised seizures cause a disturbance in consciousness.
• The classic grand mal seizure progresses through tonic, clonic and post-ictal phases. The post-ictal phase is often associated with headache and drowsiness. Grand mal seizures are often associated with tongue-biting and incontinence.
• Whatever the cause, the patient may have amnesia for both the event and its exact circumstances.
• Petit mal seizures cause an interruption to mental activity for less than 30 seconds. They rarely persist into adulthood.
• Complex partial seizures may have features of:
  • Motor: automatism, lip-smacking, plucking at clothes, hair
  • Sensory: transient paraesthesiae
  • Autonomic: odd epigastric sensation, nausea, abnormal taste or smell
  • Psychiatric: unreality, déjà vu, fear

Symptoms

• There may be a clear precipitating cause, e.g. inadequate sleep, alcohol abuse or medications such as tricyclic antidepressants, which lower the seizure threshold.
• Possible seizure-related symptoms include:
  • Sudden falls
  • Involuntary jerky movements of limbs whilst awake
  • Blank spells
  • Unexplained incontinence of urine with loss of awareness, or in sleep
  • Odd events occurring in sleep, e.g. fall from bed, jerky movements, automatisms
  • Episodes of confused behaviour with impaired awareness
  • Possible simple partial seizures
  • Epigastric fullness sensation
  • Déjà vu
  • Premonition
  • Fear
  • Elation, depression
  • Depersonalisation, derealisation
  • Inability to understand or express language (written or spoken)
  • Loss of memory, disorientation
  • Olfactory, gustatory, visual, auditory hallucinations
  • Focal motor or somatosensory deficit, or positive symptoms (jerking, tingling)

Signs

• Examination is usually unremarkable.
• Check for any neurological or cerebrovascular signs.
• Skin examination may reveal café-au-lait spots (neurofibromatosis), port wine stain (Sturge-Weber Syndrome) or adenoma sebaceum (tuberous sclerosis).

• Syncope
• Cardiac arrhythmias
• Transient ischaemic attack
• Migraine
• Drop attacks
• Sleep disorders: narcolepsy
• Hyperventilation
• Transient global amnesia
• Movement disorder
• Paroxysmal vertigo
• Psychogenic non-epileptic seizures

• Electroencephalograph (EEG) with photic stimulation and hyperventilation:
  • To support a diagnosis of epilepsy if the clinical history suggests it.
  • To help determine seizure type and epilepsy syndrome.
  • To assess the risk of seizure recurrence after a first unprovoked seizure.
  • If an EEG is necessary, it should usually be performed only after the second epileptic seizure. It should not be used to exclude a diagnosis of epilepsy or in the case of probable syncope (as there is a risk of false-positive result).
• Neuroimaging:
  • To identify structural abnormalities that cause certain types of epilepsy.
  • Not used routinely when a diagnosis of idiopathic generalised epilepsy has been made.
  • MRI: is the imaging investigation of choice for people with epilepsy. It is particularly important for children:
    • Who have developed epilepsy before the age of 2 years.
    • Who have any suggestion of a focal onset from history, examination or EEG (unless there is clear evidence of benign focal epilepsy).
    • In whom seizures continue in spite of first-line medication.
  • CT scan is an alternative to MRI:
    • If MRI is contra-indicated or unavailable.
    • In an acute situation, to determine whether a seizure has been caused by an acute neurological lesion or illness.
• Single proton emission computed tomography (SPECT).
• Positron emission tomography (PET).
• Blood tests (including glucose, electrolytes, calcium, renal function, liver function) and urine biochemistry to exclude other diagnoses and to determine an underlying cause of the epilepsy.
• ECG, echocardiography and other non-neurological investigations if the diagnosis is uncertain.

Non-pharmacological support

• New and ongoing diagnosis of epilepsy may have severe psychological and social consequences.
• Disease education and explanation are important as well as education about triggers, first aid, free prescriptions.
• Support groups and referral to an epilepsy liaison nurse can be useful.
• Provide regular structured review at least once a year, but probably more frequently (every 3-12 months) depending on need.

Drug treatment

• Use monotherapy whenever possible.
• The formulation or brand of the anti-epileptic drug (AED) should not be changed (variations in bioavailability or different pharmacokinetic profiles may increase the potential for reduced effect or excessive side-effects).
• Asymptomatic minor abnormalities in blood test results are not necessarily an indication for changes in medication.
• Anti-epileptic treatment is associated with a small risk of suicidal thoughts and behaviour. The increased risk applies to all anti-epileptics and is seen as early as 1 week after starting treatment.⁴
• Patients should therefore be alert to any mood changes, distressing thoughts, or feelings about suicide or harming themselves at any point during treatment.⁴
• Indications for monitoring AED blood levels:
  • Detection of non-adherence to the prescribed treatment.
  • Suspected toxicity.
  • Adjustment of phenytoin dose.
  • Management of pharmacokinetic interactions.
  • Specific clinical conditions (e.g. status epilepticus, organ failure or pregnancy).
• Withdrawing treatment:
  • May be considered after 2 years of being seizure-free.
  • Refer for specialist advice before discontinuing, especially as risk of further seizure may have significant social and psychological consequences (e.g. driving, employment).
  • The decision to withdraw medication should be taken by the patient and the specialist after a full discussion of the risks and benefits of withdrawal.
  • Withdraw gradually (over 2-3 months or longer); be aware of possible seizure recurrence.
  • Withdraw one drug at a time.
  • Agree with the patient a fail-safe plan of action if seizures recur (last dose reduction reversed, medical help sought).
• First line anti-epileptic drugs:
  • Generalised tonic-clonic seizures only: drugs of choice are carbamazepine, lamotrigine, and sodium valproate. Clobazam, levetiracetam, oxcarbazepine, and topiramate are second-line drugs.⁵
  • Focal epilepsies: carbamazepine, lamotrigine, oxcarbazepine, and sodium valproate are the drugs of choice for partial (focal) seizures; second-line drugs include clobazam, gabapentin, levetiracetam, pregabalin, tiagabine, topiramate, and zonisamide.⁵
  • Benign epilepsy with centrotemporal spikes: carbamazepine, lamotrigine, oxycarbazepine, sodium valproate.
  • Benign epilepsy with occipital paroxysms: carbamazepine, lamotrigine, oxycarbazepine, sodium valproate.
  • Continuous spike wave of slow sleep: clobazam, clonazepam, ethosuximide, lamotrigine, sodium valproate, steroids.
  • Myoclonic astatic epilepsy: clobazam, clonazepam, sodium valproate, topiramate.

Surgery

• Modern techniques for the accurate localisation of epileptic discharge and the recognition of specific seizure patterns have increased the role of surgery in the management of drug-resistant epilepsy.⁶
• Operations include temporal lobectomy, hemispherectomies and division of the corpus callosum.
• Vagal nerve stimulation with a stimulator attached to the left vagus nerve has been shown to reduce the number of seizures in patients with chronic partial seizures.

• Some anti-epileptic drugs (hepatic enzyme inducers) interact with the contraceptive pill (both COC and POP).
• If possible use an anti-epileptic which doesn't do this (e.g. sodium valproate).
• If this is unavoidable, the present recommendation is to use 50 mcg of oestrogen preparations in the combined pill and to run 3 or 4 packs together ("tri-cycling").
• Progesterone-only pills are not recommended if on hepatic enzyme inducer (at least double the dose of POP should be used in patients on enzyme inducers who are unwilling or unsuitable for other methods).
• A double dose of levonorgestrel should be used when emergency contraception is required.
• Intramuscular medroxyprogesterone acetate (Depo-Provera®) can be used, but should be scheduled every 10 weeks rather than 12-weekly.
• Women should be counselled about the increased risk of pregnancy (contraceptive failure) and any harmful effects of medication on fetus.

Pre-conception counselling

• Essential for all women of child-bearing age.
• Consider referral for specialist opinion before conception to reduce or change drug treatment if possible.
• Counsel about the balance between the possible harm done by medication compared with that done by seizures (to both mother and fetus).
• Fetal malformations (most commonly neural tube defects, cleft lip/palate and cardiac malformations) occur in 4% of those diagnosed with epilepsy but not taking medication and increase to 6% when taking medication (polytherapy with certain drugs can have a much higher risk).
• Recommend folic acid 5 mg per day before conception and up to 12 weeks following conception.

• DVLA recommends avoiding driving for 1 year after a first seizure.
• Allowed to drive if seizures only whilst asleep for 3 years.
• If medication is being withdrawn, must stop driving until 6 months after medication-free.
• Group 2 drivers need to be seizure-free for 10 years, not be on any anti-epileptic drug during that time and have no continuing liability to epilepsy.

• There is an increased risk of sudden death, probably due to unwitnessed seizures.
• Accidents resulting from a seizure often cause injuries, e.g. head injuries, lacerations, fractures and burns.
• Depression and anxiety disorders are more common in people with epilepsy.

• Remission becomes less likely with longer persistence of seizures.
• Factors suggesting a poorer prognosis include a combination of complex partial and tonic-clonic seizures, clustering of seizures, abnormal physical signs, and the presence of learning difficulties.