In spite of a notable advance made in epileptology, resistant epilepsies account for approximately 30 % of all forms of epilepsy particularly in patients with focal seizures. One of the main causes of therapy-resistant focal epilepsies is focal cortical dysplasias (FCD). This term was first introduced by D. Taylor et al. in 1971. FCD belongs to abnormal cortical development. Among all abnormalities of cortical development, FCD in surgically treated children amounts to 75 %. FCD is the most common cause of resistant epilepsy in children and the most frequent reason for diagnosing cryptogenic focal epilepsy with intractable seizures. The author gives a detailed literature review dedicated to FCD as a cause of resistant epilepsy, including the classification and histologic characteristics of FCD, its clinical manifestations and prognosis, and approaches to medical and surgical treatments. 

Mutation in the PCDH19 gene was first described by L.M. Dibbens et al. in 2008. Mutations in this gene are associated with epilepsy and mental retardation limited to females. The clinical manifestations that are observed in some patients with PCDH19 mutation and Dravet syndrome that is caused by mutation in the SCN1A gene include the onset of febrile and afebrile seizures in infancy, serial seizures during fever, and regression in development after the onset of seizures. Due to the fact that the two diseases have common clinical signs, it is best to test for PCDH19 mutation in patients with the clinical picture of Dravet syndrome and a negative test for SCN1A. In general, the number of scientific papers devoted to analysis and recommendations for the choice of therapy in patients with rare genetic pathology is small now. We analyzed the specific features of clinical signs and therapy in our two observed female patients aged 4 and 11 years with verified PCDH19 mutation. Both patients were noted to have severe epilepsy with febrile convulsions with the development of status epilepticus and to be unresponsive to antiepileptic therapy. The use of different antiepileptic drugs (valproate, oxcarbazepine, phenobarbital, topiramate, levetiracetam) at different combinations failed to control the course of epilepsy in the 4-year-old patient whereas the 11-year-old patient who took a combination of valproic acid and benzodiazepines achieved a positive effect.

The authors provide a review of the clinical and genetic characteristics of hereditary diseases and syndromes accompanied by febrile convulsions, which is illustrated by examples of their own observations. The paper sets forth the possibilities and limitations of using current methods for the molecular genetic diagnosis of idiopathic and symptomatic epilepsies. The most effective and less expensive technique of molecular genetic analysis is shown to be an exome sequencing test using the panels of genes responsible for the occurrence of diseases with simi1ar clinical symptoms. The paper also presents the structure of the panel of genes responsible for the occurrence of monogenic epilepsies, which has been designed at the Genomed Clinic and includes 448 genetic variants. It also determines the significance of using a chromosomal microarray analysis to diagnose both chromosomal and monogenic diseases accompanied by convulsions. 

Despite the rather high efficiency of treatment for epilepsy (overall, 65–70 % of patients can achieve remission or show a considerable decrease in the frequency of seizures), there remains a challenge due to the need to use antiepileptic drugs long and regularly: therapy adherence, compliance, treatment tolerability, and impact of therapy on quality of patent’s life. One of the aspects of this problem is a very common tendency to switch brand-name antiepileptic drugs to their generics that are 1ess expensive, but also less predictably effective and tolerable. The authors review the literature on the interchangeability of brand-name and generic drugs and describe their case. 

Despite a considerable advance made in epileptology, resistant epilepsies account for approximately 30 % of all forms of epilepsy particularly in patients with focal seizures. The most common structural cause of resistant epilepsies in children is focal cortical dysplasias that are varieties of abnormal cortical development. The term “focal cortical dysplasia” was first mentioned by D. Taylor et al. in 1971 to denote local abnormalities of cortical development in our 10 described patients with resistant epilepsy. According to К. Watanabe et al. (1996), focal cortical dysplasias as a cause of epilepsy are detected in 3.0–4.3 % of patients with different forms of epilepsy. Among all abnormalities of cortical development in children who have undergone surgery for epilepsy, focal cortical dysplasias amount to 75 %, as shown by the data obtained by I. Blümcke et al. (2009).

In resistant epilepsy, there is a hope for successful neurosurgical treatment and synthesis of novel antiepileptic drugs (AEDs). The authors present a review dedicated to the novel AED perampanel and consider its mechanism of action, pharmacokinetic features, indications for use, and the results of clinical trials and postmarket researches of the efficacy, tolerability, and safety of the drug, including its recent investigations. The paper describes a clinical case of successfully using perampanel in a patient with therapy-resistant epilepsy caused by focal cortical dysplasia. Based on the data available in the literature and the authors’ own cases, it тay be concluded that perampanel is a promising drug in treating epilepsy (even in epilepsies resistant to many other AEDs) with favorable indicators of tolerability.