The article is devoted to some issues of sensitivity and specificity of epileptiform activity in the electroencephalogram (EEG). Epileptiform activity – it is sharp waves and spikes on EEG. Normal EEG does not exclude the diagnosis of epilepsy and viсe versa: presence of epileptiform activity on EEG is not necessarily caused by epilepsy. Several EEGs may be needed to detect epileptiform activity in patients with epilepsy. EEG recording during sleep with the use of different activation methods (hyperventilation, rhythmic photic stimulation, sleep deprivation) can increase the probability of epileptiform activity detection. Clinical presentation should be taken into account while interpreting EEG results with registered epileptiform activity. The issues of epileptiform activity classification and differential interpretation of other electrical activity types are also discussed in the article. Main epileptiform patterns, their neurophysiological basis and correlation with clinical manifestations are described.

Objective: to evaluate the efficacy of topiramate at a dose of 1–2 mg/kg in 34 patients aged 7–17 with tic hyperkinesis and Tourette syndrome (TS).

Materials and methods. We performed clinical evaluation of hyperkinesis severity along with the assessment of somatosensory evoked potentials (SSEP) and the analysis of surface electromyography (EMG) data prior to treatment initiation and after 6 weeks of therapy. SSEP investigation was carried out in accordance with a standard protocol. Interpeak latencies on the tracks Cp–Fpz (D, S), Cerv6–Fpz (D, S), Erb’i–Erb’c (D, S) were evaluated in order to determine the afferentation between relevant brain structures: N9–N13, N13–N20, N9–N20. N20–P23 potentials reflected primary activity of somatosensory cortex. The investigation of tic hyperkinesis was conducted using surface EMG of facial muscles (m. orbicularis oculi), the muscles of the shoulder girdle (m. supraspinatus), and the muscles of the upper extremities (m. flexor digitorum superficialis) according to the standard protocol. Interference curve was recorded at rest and after hyperkinesis stimulation with the use of provocative tests. High-amplitude (more than 500 mkV) oscillations were considered as burst activity. The severity of clinical manifestations was evaluated using the Yale Global Tic Severity Scale (1989) and the method of tics counting during 20 minutes (V.P. Zykov, 2009). The control group comprised 15 healthy children matched for sex and age.

Results. The use of topiramate in patients with chronic motor/vocal tics and TS has significantly decreased the severity of hyperkinesis manifestations, evaluated both by the Yale Global Tic Severity Scale (p < 0,05) and by the method of tics counting during 20 minutes (p < 0,05). It also helped to decrease the prevalence of burst activity in EMG while registering hyperkinesis in different muscle groups. SSEP data showed the normalization of interpeak latency values and the decrease of N20–P23 potentials amplitude, which reflects the decline in the activity of brain somatosensory system, represented by thalamo-cortical structures.

Conclusion. Surface EMG and SSEP methods can be used for evaluation of treatment efficacy in cases of tic hyperkinesis and TS.

Background. The review provides information on the nature and the modern methods of diagnosis of the lesions in organ of vision in patients with tuberous sclerosis.

Objective: to explore available publications devoted to studying of the eye lesions in patients with TS.

Materials and methods. The review of available full text publications in foreign and Russian databases is carried out.

Results. Presented literature review indicates a high variability of the lesions of organ of vision in tuberous sclerosis in the clinical course (slowly progressive, stationary, and rapidly progressive), severity (from asymptomatic to severe disabling), and clinical forms.

Conclusion. During the observation of patients (probands) with tuberous sclerosis and their family members, a comprehensive examination, accompanied by widespread introduction into clinical practice of modern diagnostic methods, including dynamic control of asymptomatic members of family genealogy, is important. The multidisciplinary approach has great significance for diagnostics, treatment and dispensary observation of tuberous sclerosis.

Phelan–McDermid syndrome (PMS) is a microdeletion syndrome associated with the loss of terminal segments in chromosome 22, sometimes with development of the ring chromosome 22. Clinical manifestations of PMS include epilepsy and mental disorders (autism, mental deficiency, lack of expressive speech, sleep disorders, mood disorders since adolescence). Neurologic status is characterized by diffuse muscle hypotonia since birth, delayed development of motor skills, functional gastrointestinal disorder. Children over 1 year develop autism spectrum disorders; they have a specific awkward gait with frequent falls and decreased sensitivity to pain. Severe delay in the development of verbal intelligence (when expressive speech is absent or represented by individual words) are typical for these patients. Epileptiform activity appearing in a form of benign epileptiform discharges of childhood is usually diagnosed in all PMS patients; epileptic seizures are documented in half of the cases. The disease is characterized by secondarily generalized, age-related epileptic seizures with oral-pharyngeal manifestations. In some cases epilepsy becomes drug-resistant. Current article describes 2 clinical cases of PMS.

FIRES (febrile infection-related epilepsy syndrome) – an epileptic syndrome that presents with multifocal refractory status epilepticus in previously normal children following a nonspecific febrile illness and evolves into a chronic, refractory, focal epilepsy with associated cognitive and behavioral difficulties. The article provides an overview of the literature on the etiology, diagnosis, clinical manifestations and treatment of this disease. We describe our own experience of observing the 4 patients with FIRES with the onset at the age from 4 to 14 years, with status epilepticus of duration from 3 to 27 days. All patients required intensive care treatment using burst-suppression coma and ventilatory support. Analysis of the cerebrospinal fluid, magnetic resonance imaging were no significant during the acute period in all patients. In one case, herpes simplex virus 6 type was detected by polymerase chain reaction in the serum and leucocytes. All patients were treated with antiepileptical, antiviral and antimicrobial drugs, steroids and IVIG. After status epilepticus drug-resistant epilepsy developed in all children. Two patients had mild cognitive impairment, the other 2 – severe. Light motor disturbances occurred in 2 children, 1 child had severe spastic tetraparesis. Interictal electroencephalography in chronic phase in 3 of 4 patients identified diffuse slowing of cortical rhythm, in 2 cases – epileptiform activity in the form of a spike-and-wave, sharp–slow wave in the fronto-temporal areas, in 1 case – the continuation irregular slow in the frontotemporal region. Follow-up magnetic resonance imaging was performed in 3 cases: 2 were normal and 1 had mild diffuse cortical atrophy.

FIRES resulted in the development of drug-resistant epilepsy and cognitive impairment in all cases.

Among drug-resistant epilepsies, epileptic syndromes, characterized by combination of several types of seizures, are considered to be the most difficult in terms of treatment. Lennox–Gastaut syndrome is one of them. It manifests with polymorphic seizures (tonic axial, myatonic, atypical absence seizures, status epilepticus of minor motor seizures, myoclonic, generalized convulsive, and focal seizures). This is a heterogeneous disease, represented by a complex of clinical and electroencephalographic manifestations with various etiology. Current review is devoted to a novel antiepileptic drug rufinamide, which has a new mechanism of action. The drug has been registered in Russia in 2015. The authors also describe their own experience of rufinamide usage in the treatment of drug-resistant focal epilepsy as a part of multicomponent therapy for polymorphic seizures. One patient achieved clinical remission for 16 months; the second one had more than 50 % decrease in seizures frequency with a remission of drop-attacks.