Anticonvulsivants utilisés pour les crises focales

Focal seizures (now referred to as focal rather than partial) originate in a focal region of the cortex and can be subdivided into those that do not impair consciousness (simple focal) and those that do (focal dyscognitive seizures). Both types of focal seizure can spread rapidly to other cortical areas, resulting in secondary generalised tonic-clonic (GTC) seizures.

Relevant separate articles include Épilepsie chez les enfants et les jeunes, Épilepsie chez les Adultes et Épilepsie chez les personnes âgées.

Grossesse¹

• 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.

• An epileptic seizure that is limited to one cerebral hemisphere and causes impairment of awareness or responsiveness.

• Épilepsie du lobe temporal may be simple focal seizures without loss of awareness (with or without aura) or focal dyscognitive seizures (with loss of awareness).

Not all epilepsy is lifelong and it is defined as having resolved when people have remained seizure-free for more than ten years, with no drug treatment for at least five years. Approximately 70% of all adults and children with epilepsy will go into remission. The chances of remission vary with the type of epilepsy, the response to antiepileptic drugs (AEDs) and the frequency of seizures. Withdrawal of medication, if wanted, should be done slowly, with the acknowledgement that it always carries a risk of further seizures.⁶

The National Institute for Health and Care Excellence (NICE) advice on treatment of focal seizures is as follows. Unsuccessful treatment is defined as treatment which either does not reduce or stop seizures, or has intolerable side-effects.

• First-line treatment: offer lamotrigine or levetiracetam, moving to the other of these two drugs if the first one tried is unsuccessful.

• If both of these first-line monotherapies are unsuccessful, consider a second-line monotherapy option, choosing between carbamazepine, oxcarbazepine or zonisamide. Try all of these three in turn if the first one is unsuccessful.

• Consider lacosamide as third-line monotherapy if all the second-line drugs are unsuccessful.

• If monotherapy is unsuccessful, consider any of the drugs listed above, or topiramate, as first-line add-on options, considering other drugs from this list if the first one tried is unsuccessful.

• Si la monothérapie est inefficace, un traitement adjuvant devrait être envisagé :
  

  • First-line options for adjunctive treatment include carbamazepine, lacosamide, lamotrigine, levetiracetam, oxcarbazepine, topiramate, or zonisamide.

  • Second-line options include brivaracetam, cenobamate⁷ , eslicarbazepine acetate, perampanel, pregabalin, or sodium valproate (in males, and females unable to have children).

  • Third-line add-on treatments include phenobarbital, phenytoin, tiagabine and vigabatrin.

Some drugs used in clinical practice can exacerbate seizures in those with absence or myoclonic seizures, including juvenile myoclonic epilepsy.

• Interactions between AEDs are complex and may enhance toxicity without a corresponding increase in antiepileptic effect.

• These interactions are very variable and unpredictable.

• Changes in medication should therefore always be done by a neurologist.

• La thérapie par AED ne doit être commencée qu'une fois le diagnostic d'épilepsie confirmé, sauf dans des circonstances exceptionnelles. La thérapie par AED doit être initiée par un spécialiste.

• Le traitement par thérapie AED est généralement recommandé après une deuxième crise d'épilepsie. La thérapie AED doit être envisagée et discutée après une première crise non provoquée si :
  

  • Il y a un déficit neurologique.

  • The electroencephalograph (EEG) shows unequivocal epileptic activity (however a normal EEG should not be used to exclude the diagnosis of epilepsy, and should prompt consideration of a sleep-deprived EEG).

  • The patient or their family or carers consider the risk of having a further seizure unacceptable.

  • L'imagerie cérébrale montre une anomalie structurelle.

• La dose de chaque médicament doit être ajustée lentement jusqu'à la dose maximale tolérée ou le niveau maximal recommandé dans le British National Formulary. L'effet peut être surveillé par la fréquence des crises enregistrée par le patient.

• Les formulations des AED ne sont pas interchangeables et la substitution générique ne devrait pas être effectuée de manière routinière. Il convient d'éviter les changements de fabricants d'AED de manière systématique.

• Maintenez un haut niveau de vigilance pour les effets indésirables du traitement.

• Continuing 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 pathways and/or licensing allow.

• Adherence to treatment can be optimised with the following:
  

  • Éduquer les enfants, les jeunes et les adultes ainsi que leurs familles et/ou leurs aidants à comprendre leur condition et la logique du traitement.

  • Réduire la stigmatisation associée à la condition.

  • Utiliser des schémas médicamenteux simples.

  • Relations positives entre les professionnels de santé, l'enfant, le jeune ou l'adulte atteint d'épilepsie et leur famille et/ou leurs aidants.

• Regular blood test monitoring is not recommended as routine and should be done only if clinically indicated. The pharmacokinetics of some AEDs are non-linear, so specialist knowledge is needed to interpret drug levels. Indications for monitoring of AED blood levels include:

  • Detection or suspicion of non-adherence to the prescribed medication.

  • Uncontrolled seizures.

  • Side-effects.

  • A specific clinical condition needing closer supervision (eg, pregnancy or renal failure).

  • Ajustement de la dose de phénytoïne.

  • Assessment of toxicity.

  • Otherwise unexplained loss of seizure control.

• Drug-resistant epilepsy has been defined as failure to achieve sustained seizure freedom after trials of two tolerated and appropriate AED schedules (as monotherapy or in combination). The majority of patients with newly diagnosed epilepsy respond well to AEDs. Failure to do so may be due to:

  • Un diagnostic incorrect d'épilepsie.

  • Un choix inapproprié de médicament antiépileptique pour le syndrome épileptique.

  • Omission de prendre le médicament antiépileptique prescrit.

  • An underlying cerebral neoplasm, metabolic condition, or immune process.

  • Usage concomitant de drogues ou d'alcool.

• Given a correct diagnosis of epilepsy, failure to control seizures completely with the first well-tolerated AED is a predictor of drug-resistant epilepsy. Once two AEDs have failed as monotherapy the chance of seizure freedom with further monotherapy is low. Improvement in seizure control may be obtained by combining AEDs.

• A range of different AEDs appropriate to the epilepsy syndrome should be added as necessary in sequence, increasing the dose of each slowly to obtain the best response. It may be worthwhile trying the addition of a small dose of a third AED but it may be necessary to accept the persistence of some seizures.

• Failure to respond to appropriate AEDs should prompt a review of the diagnosis of epilepsy and adherence to medication.

• The guidance gives specific regimes for various epilepsy syndromes which are too numerous to list here.

• The decision to continue or withdraw medication should be taken after a full discussion of the risks and benefits of continuing or withdrawing AED therapy. Withdrawal of AEDs must be managed by, or be under the guidance of, the specialist, after an individualised assessment which considers the risk of seizure recurrence and sudden unexplained death in epilepsy (SUDEP).

• Les risques et les avantages de poursuivre ou d'arrêter le traitement par AED doivent être discutés lorsque la personne atteinte d'épilepsie est sans crise depuis au moins deux ans.

• Le retrait du traitement par AED doit être effectué lentement (au moins 2-3 mois) et un médicament doit être retiré à la fois.

• Une attention particulière doit être portée lors de l'arrêt des benzodiazépines et des barbituriques (cela peut prendre jusqu'à six mois ou plus) en raison de la possibilité de symptômes de sevrage liés aux médicaments et/ou de récurrence des crises.

• Il devrait y avoir un plan convenu selon lequel, si les crises réapparaissent, la dernière réduction de dose est annulée et un avis médical est recherché.

• Discontinuation of medications after epilepsy surgery should be done under guidance from the epilepsy surgery centre.