Epidemiology

There is an 8-10% lifetime risk of one seizure and a 3% chance of epilepsy.^[2]

Risk factors

25-30% of first seizures have an underlying cause. Provoking factors include:^[2]

• Fever.
• Head injury.
• Excessive alcohol intake; withdrawal from alcohol or drugs.
• Hypoglycaemia; electrolyte disturbance.
• Brain infection: meningitis, encephalitis.
• Ischaemic stroke, intracranial haemorrhage.
• Eclampsia.
• Potentially proconvulsive drugs, eg tramadol, theophylline, baclofen.

Seizures may be triggered by specific stimuli (eg stroboscopic lights, reading, severe psychological stress or sleep deprivation) in susceptible individuals with an underlying epilepsy disorder.

Presentation

The clinical decision as to whether an epileptic seizure has occurred should be based on the combination of the description of the attack and different symptoms. Diagnosis should not be based on the presence or absence of single features. Prospective recording of events, including video recording and written descriptions, can be very helpful in reaching a diagnosis. When a child, young person or adult presents with a seizure, a thorough physical examination should be performed, including cardiac, neurological and mental state. An assessment of development is important for children presenting with a seizure.^[3]

• Many people presenting with a dramatic first generalised tonic-clonic grand-mal seizure have had previous, undiagnosed simple or complex partial seizures, absence seizures, or epileptic myoclonus.
• A detailed history from the patient and any witness is essential.
• Tongue-biting and postictal confusion suggest a seizure.

Differential diagnosis

• Syncope may provoke a post-anoxic convulsion (convulsive syncope).
• Transient ischaemic attack.
• Metabolic encephalopathy (including hypoglycaemia or electrolyte disturbance).
• Sleep-walking.
• Night terrors.
• Complex migraines.
• Cardiac arrhythmias.
• Psychogenic non-epileptic seizures (attacks resembling epileptic seizures but with psychological causes, and no EEG changes of epilepsy).

Investigation^[3]

• Electroencephalograph (EEG):
  • If performed within 24-48 hours of a first seizure, EEG shows substantial abnormalities in about 70% of cases. The yield may be lower with longer delays after the seizure. If the standard EEG is negative, sleep-deprived EEG will detect epileptiform discharges in an additional 13-31% of cases.^[2]
  • An EEG should be performed only to support a diagnosis of epilepsy where the clinical history suggests that the seizure is likely to be epileptic in origin. The EEG should not be used in isolation to make a diagnosis of epilepsy.
  • If an EEG is considered necessary, it should be performed after the second epileptic seizure but may, in certain circumstances as evaluated by the specialist, be considered after a first epileptic seizure. Following a first unprovoked seizure, unequivocal epileptiform activity shown on EEG can be used to assess the risk of seizure recurrence.
  • Photic stimulation and hyperventilation should remain part of standard EEG assessment but the patient should be made aware that such activation procedures may induce a seizure.
  • An EEG should not be performed in the case of probable syncope because of the possibility of a false-positive result.
  • An EEG may be used to help to determine seizure type and epilepsy syndrome.
  • Repeated standard EEGs may be helpful when the diagnosis of the epilepsy or the syndrome is unclear. However, if the diagnosis has been established, repeated EEGs are not likely to be helpful. Repeated standard EEGs should not be used in preference to sleep or sleep-deprived EEGs.
  • When a standard EEG has not contributed to diagnosis or classification, a sleep EEG should be performed.
  • Long-term video or ambulatory EEG may be used in the assessment when there are diagnostic difficulties after clinical assessment and standard EEG.
• Neuro-imaging:
  • Neuro-imaging should be used to identify structural abnormalities that cause certain epilepsies. MRI is the imaging investigation of choice. MRI is particularly important in those:
    • Who have any suggestion of a focal onset on history, examination or EEG (unless clear evidence of benign focal epilepsy).
    • In whom seizures continue in spite of first-line medication.
  • Neuroimaging should not be routinely requested when a diagnosis of idiopathic generalised epilepsy has been made.
  • CT should be used to identify underlying gross pathology if MRI is not available or is contra-indicated. CT may be used 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).
• Other tests:
  • In adults, appropriate blood tests (eg glucose, electrolytes, calcium, renal function, liver function, and urine biochemistry) to identify potential causes and/or to identify any significant comorbidity should be considered.
  • A 12-lead ECG should be performed in adults with suspected epilepsy. In cases of diagnostic uncertainty, a referral to a cardiologist should be considered.

Neuropsychological assessment^[3]

Neuropsychological assessment should be considered when it is important to evaluate learning disabilities and cognitive dysfunction, particularly in regard to language and memory. Referral for a neuropsychological assessment is indicated:

• When the person with epilepsy is having educational or occupational difficulties.
• When an MRI scan has identified abnormalities in cognitively important brain regions.
• When there are reported memory or other cognitive deficits, and/or cognitive decline.

Management^[3]

• It is recommended that all adults having a first seizure should be seen as soon as possible by a specialist in the management of the epilepsies, to ensure precise and early diagnosis and initiation of therapy as appropriate to their needs.^[3]
• Advise the family or carers of the person with suspected epilepsy how to recognise and manage a seizure and to record further episodes of possible seizures.
• Essential information on how to recognise a seizure, appropriate first aid measures, and the importance of reporting further attacks should be provided to a child, young person or adult who has experienced a possible first seizure, and their family/carer/parent as appropriate. This information should be provided while the child, young person or adult is awaiting a diagnosis.^[3]
• Advise the person with suspected epilepsy to stop driving while waiting to see the specialist, and to avoid potentially dangerous work or leisure activities, eg avoid swimming and ensure bathing is undertaken with supervision.
• Continued restrictions of potentially dangerous activities need to be assessed individually. Individuals should probably be suspended from working with dangerous machines for at least six months.^[2]
• Driving is permitted after one year's freedom from seizures after an unprovoked seizure and on a case-by-case basis for provoked seizures.
• Commercial driving after an unprovoked seizure is usually not permitted until 10 years' freedom from seizure with anti-epileptic drug treatment.

Drugs

See also separate articles Anticonvulsants used for Generalised Seizures and Anticonvulsants used for Partial Seizures.

• Anti-epileptic drug (AED) therapy should only be started once the diagnosis of epilepsy is confirmed, except in exceptional circumstances. AED therapy should be initiated by a specialist.
• Treatment with AED therapy is generally recommended after a second epileptic seizure. AED therapy should be considered and discussed after a first unprovoked seizure if:
  • The child, young person or adult has a neurological deficit.
  • The EEG shows unequivocal epileptic activity.
  • The child, young person or adult and/or their family and/or carers consider the risk of having a further seizure unacceptable
  • Brain imaging shows a structural abnormality.

Driving^[4]

Following the first unprovoked epileptic seizure or solitary fit:

• Any patient should be advised to stop driving and notify the Driver and Vehicle Licensing Agency (DVLA) and their motor insurance company following a seizure.
• Group 1 (private car or motorcycle): six months off driving from the date of the seizure unless there are clinical factors or investigation results which suggest an unacceptably high risk of a further seizure, ie. 20% or greater per annum.
• Group 2 (large goods vehicle (LGV) or passenger carrying vehicle (PCV): five years off driving from the date of the seizure if the licence holder has undergone recent assessment by a neurologist and there are no clinical factors or investigation results (eg EEG, brain scan) which indicate that the risk of a further seizure is greater than 2% per annum. They should have taken no anti-epilepsy medication throughout the five-year period immediately prior to the granting of the licence.

Prognosis

• Risk factors for seizure recurrence include:
  • Static or progressive brain abnormalities.
  • Focal neurological findings.
  • Focal or generalised epileptiform activity on EEG.
  • Status epilepticus.
  • Family history of epilepsy.
  • Previous febrile seizures.
• A first seizure caused by an acute disturbance of brain function (acute symptomatic or provoked) is unlikely to recur (3-10%).
• If a first seizure is unprovoked, 30-50% will recur. 60-70% of recurrences are within six months of the first seizure.^[1]
• After a second unprovoked seizure, 70-80% will recur, justifying the diagnosis of epilepsy.
• Seizures associated with reversible metabolic or toxic disturbances are associated with a minor risk of subsequent epilepsy.
• Seizures provoked by disorders that cause permanent damage to the brain, such as brain abscess, have a higher risk (10%) of recurrence.