Clinical Neuroscience

[Genetic background of epilepsies]

KELEMEN Anna, SZŰCS Anna, RÁSONYI György, JANSZKY József, HOLLÓ András, HALÁSZ Péter

JUNE 10, 2004

Clinical Neuroscience - 2004;57(05-06)

[In this article we review epilepsies with monogenic inheritance. Most of these diseases are caused by abnormal function of ligand- and voltage gated ion channels caused by a genetic defect, therefore belonging to the channelopathies. From the inherited epilepsies the genetics of the autosomal dominant partial epilepsies is clarified the best. Mutations of the nicotinic acetylcholine receptor subunits are found in familial nocturnal frontal lobe epilepsy, while defects in the voltage gated potassium channels (KCNQ2 and KCNQ3) have been identified in benign familial neonatal convulsions. Familial temporolateral epilepsy was associated with mutations of a tumor suppressor gene. From the generalized epilepsies, the syndrome of generalized epilepsy with febrile seizures plus (GEFS+) can be caused by mutations of the sodium channel subunits and of the GABAA receptor subunits. These important results would probably lead to new findings in the genetics of the more common forms of idiopathic generalized epilepsies, which have presumed polygenic origin. Although without definite conclusions, sodium channel and GABA receptor dysfunction is presumed. The accumulated knowledge about channelopathies enables insight to the cellular mechanism of epileptogenesis as well.]

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[In this article the possibilities, indications, methods and results of surgery in epilepsy are summarized in general with the Hungarian experience emphasized. Surgery may provide effective treatment in about 5-10% of the epileptic population. Surgical solution nowadays became an essential treatment in medial temporal epilepsy, if hippocampal sclerosis or other lesion is present, in therapy resistent lesional extratemporal epilepsies and in catastrophic childhood epilepsies if the epileptic disorder is restricted to one hemisphere (Rasmussen syndrome, hemimegalencephaly, Sturge-Weber disease and posttraumatic or postencephalitic hemispherial epilepsies). The algorhythms of the presurgical evaluation and the current methods for study the pacemaker area, forbidden zones, and hemispherial functions are treated. The currently used type and techniques of surgery, such as lesionectomy, temporal lobe resections, hemispherotomy, callosotomy, multiple subpial transsections and their indications are described. The newest surgical approaches, as deep brain stimulation, vagal nerve stimulation, and irradiation techniques are also briefly touched. Lastly, we deal with prognostical factors of the surgical outcome, reasons of surgical failures and complications. In a brief chapter the importance of postsurgical rehabilitation is emphasized.]

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[Questions of epileptogenesis and prevention in symptomatic epilepsies]

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[Symptomatic epilepsies usually report themselves after a longer period of time after brain injury, after the so-called latent period. During this period progressive functional and structural changes occur which finally cause an increased excitatory condition. The process of epileptogenesis may be examined in animal models, such as in the kindling, status epilepticus, hypoxicischaemic models. Data gained from such sources support the hypothesis that the first injury results in a lower seizure threshold, but genetical and enviromental factors also contribute to the development of epilepsy and most probably further insults may be needed. The development of epilepsy can be traced back to several reasons. In spite of this, the latent period provides opportunity for the prevention of epilepsy or for the influence of epileptogenesis in such a manner that later treatment can become more succesful. Prevention should be an aim in clinical practice, as well. Medication used presently are more like to have anticonvulsive properties and their antiepileptogenic effect is questionable. Due to this fact, development of new drugs is necessary with new theoretical background. The most important influence on the incidence of epilepsy in recent years has been provided by the improvement in neonatal care. This highlights the fact that such optimal medical care should be provided in the acute period of brain injury which can terminate or lessen the risk of epilepsy.]

Clinical Neuroscience

[Antiepileptic drug treatment]

SZUPERA Zoltán

[Antiepileptic drug treatment is essential and provides excellent therapeutic effects in more than the two-third of the epileptic patients. The antiepileptic drugs influence the chronic hyperexcitability of the brain developed during the epileptogenesis. As an effect, it decreases the excitability and/or increases the inhibition of the pathological cells, which prevents the precipitation of the epileptic seizure (anticonvulsive effect). The anticonvulsive effect comes into operation by the influence of the transport of one ore more ion-channels. The anticonvulsive effect is only symptomatic and it doesn’t cure the disorder. The drug selection is based on the knowledge of the therapeutic markers and the effectiveness of the drug to be used. This can occure on the basis of the action of the drug or in syndromespecific way. The pharmacokinetic properties of the drugs determine how they can be used in the practice. The drug interactions can take place in several levels. Among them, the change of the metabolism is the most important. Acute dosedependent side effects, organ-specific chronic interactions and idiosyncratic reactions must be taken into consideration during the use of antiepileptic drugs. The patient's individual aspects must be considerably taken into account during the treatment. There are other medical areas that can benefit from the antiepileptic drugs. Among them, the most important diseases are: restless legs syndrome, neuropathic pain, trigeminal neuralgia, essential tremor, bulimia and bipolar disorders. There are other pharmacological (adrenocorticotropic hormone, immunoglobulins, neurosteroids) and dietary methods, which may be effective at certain epileptic syndromes. The principles of the pharmacotherapy have been changing continuously during the past decades and since. New drugs have been introduced into the marketing and new expectations are coming into the limelight concerning the treatment. As a consequence this will bring on the modification of antiepileptic drug therapeutic habits.]

Clinical Neuroscience

[Hungarian Epilepsy League]

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Clinical Neuroscience

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[Decisional collisions between evidence and experience based medicine in care of people with epilepsy]

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Clinical Neuroscience

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Clinical Neuroscience

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