Simple partial seizures

• Presentation depends on the site of origin of the discharge, eg those arising from the motor cortex cause rhythmic movements of the contralateral face, arm or leg (Jacksonian seizures).
• Seizures arising from sensory regions or areas responsible for emotions and memory may produce olfactory, visual or auditory hallucinations, feelings of déjà vu or jamais vu, fear, panic or euphoria.

Complex partial seizures

• An epileptic seizure that is limited to one cerebral hemisphere and causes impairment of awareness or responsiveness.
• Temporal lobe epilepsy may be simple partial seizures without loss of awareness (with or without aura) or complex partial seizures (with loss of awareness).

Anti-epileptic drugs used for partial seizures^[1]

• First-line treatment: offer carbamazepine or lamotrigine. Levetiracetam, oxcarbazepine or sodium valproate should be considered if carbamazepine and lamotrigine are unsuitable or not tolerated. If the first AED tried is ineffective, offer an alternative from these five AEDs.
• Consider adjunctive treatment if a second well-tolerated AED is ineffective.
• Adjunctive treatment: offer carbamazepine, clobazam, gabapentin, lamotrigine, levetiracetam, oxcarbazepine, sodium valproate or topiramate as adjunctive treatment if first-line treatments are ineffective or not tolerated.
• Retigabine is recommended as an option for the adjunctive treatment of partial-onset seizures with or without secondary generalisation in adults aged 18 years and older with epilepsy, only when previous treatment with carbamazepine, clobazam, gabapentin, lamotrigine, levetiracetam, oxcarbazepine, sodium valproate and topiramate has not provided an adequate response, or has not been tolerated.^[3]
• Other AEDs that may be considered by the tertiary epilepsy specialist are eslicarbazepine acetate, lacosamide, phenobarbital, phenytoin, pregabalin, tiagabine, vigabatrin and zonisamide.

NB: carefully consider the risk-benefit ratio when using vigabatrin because of the risk of an irreversible effect on visual fields.

Interactions^[4]

• Interactions between anti-epileptic drugs (AEDs) are complex and may enhance toxicity without a corresponding increase in anti-epileptic effect.
• These interactions are very variable and unpredictable.

Initiation of drug treatment

• 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:
  • There is a neurological deficit.
  • The electroencephalogram (EEG) shows unequivocal epileptic activity.
  • The patient considers the risk of having a further seizure unacceptable.
  • Brain imaging shows a structural abnormality.

Continuation of drug treatment

• Maintain a high level of vigilance for adverse effects of treatment.
• Continuing anti-epileptic drug (AED) therapy should be planned by a specialist as part of an agreed treatment plan and the needs of the child, young person or adult and their family and/or carers should be taken into account.
• If management is straightforward, continuing AED therapy can be prescribed in primary care if local circumstances and/or licensing allow.
• Adherence to treatment can be optimised with the following:
  • Educating children, young people and adults and their families and/or carers in the understanding of their condition and the rationale of treatment.
  • Reducing the stigma associated with the condition.
  • Using simple medication regimens.
  • Positive relationships between healthcare professionals, the child, young person or adult with epilepsy and their family and/or carers.
• Regular blood test monitoring is not recommended as routine, and should be done only if clinically indicated. Indications for monitoring of AED blood levels are:
  • Detection of non-adherence to the prescribed medication.
  • Suspected toxicity.
  • Adjustment of phenytoin dose.
  • Management of pharmacokinetic interactions (eg changes in bioavailability, changes in elimination, and co-medication with interacting drugs).
  • Specific clinical conditions, eg status epilepticus, organ failure and certain situations in pregnancy.
• Examples of blood tests include:
  • Before surgery - clotting studies in those on sodium valproate.
  • FBC, electrolytes, liver enzymes, vitamin D levels, and other tests of bone metabolism (eg serum calcium and alkaline phosphatase) every 2-5 years for adults taking enzyme-inducing drugs.
  • Asymptomatic minor abnormalities in test results are not necessarily an indication for changes in medication.

Withdrawal of drug treatment

• The decision to continue or withdraw medication should be taken after a full discussion of the risks and benefits of continuing or withdrawing anti-epileptic drug (AED) therapy. Withdrawal of AEDs must be managed by, or be under the guidance of, the specialist.
• The risks and benefits of continuing or withdrawing AED therapy should be discussed when the person with epilepsy has been seizure-free for at least two years.
• Withdrawal of AED treatment should be carried out slowly (at least 2-3 months) and one drug should be withdrawn at a time.
• Particular care should be taken when withdrawing benzodiazepines and barbiturates (may take up to six months or longer) because of the possibility of drug-related withdrawal symptoms and/or seizure recurrence.
• There should be an agreed plan that if seizures recur, the last dose reduction is reversed and medical advice is sought.