Russian Journal of Child Neurology

Background. The problem of clarification of the mechanisms of joint formation of epilepsy and extrapyramidal motor defects is of particular interest in the medical community.

Aim. To study the relationship of epilepsy with extrapyramidal motor defects in patients with neurological forms of hepatolenticular degeneration (HLD), who have homozygous and compound heterozygous mutations in the ATP7B gene.

Materials and methods. A follow-up study of 100 patients with neurological forms of HLD and an analysis of the brain bioelectrical activity (electroencephalography) was performed in 46 of them. The molecular genetic study was carried out using the Sanger sequencing method of the ATP7B gene, the clinical study – taking into account the requirements of the Leicester scale (2001), the identification of the leading syndromes and 4 neurological forms – according to the classification of N.V. Konovalov (1960), neurophysiological (electroencephalography) – on a digital electroencephalograph Biola NeuroScope 420F (Russia) using montage of leads according to the “10–20” system (Jasper, 1954) during visual analysis of electroencephalogram curves with subsequent data processing on a personal computer in the SPSS Statistics v.23.0 software package (IBM, USA).

Results. The maximum registration of epileptic seizures in HLD was established in childhood, when motor defects have not yet acquired features specific to defects of extrapyramidal origin. Epileptiform activity on the electroencephalogram in patients with HLD corresponds to typical epileptiform patterns. No reliable differences in the frequency of registration of alpha, theta, delta and beta activity in carriers of different types of mutations in the ATP7B gene are observed. The distinctive features of electroencephalogram for HLD are: predominance of slow-wave activity with a decrease in the functional mobility of cortical processes, alternation of episodes of desynchronization with periods of hypersynchronization of high-amplitude wave oscillations, “explosive” nature of bursts of sharp-wave patterns, similar to the reflection of myographic artifacts that coincide with an increase in the severity of hyperkinesis.

Conclusion. The complexity of interpreting reflections of motor defects of extrapyramidal origin and epileptiform patterns in scalp curves of patients with HLD excludes the advisability of including electroencephalography in the complex of its main diagnostic criteria. However, the development of epileptic seizures in patients with any motor defects should be the basis for an in-depth diagnostic search aimed at excluding HLD.

Duchenne muscular dystrophy is the most severe form of hereditary myopathies in boys, caused by mutations in the DMD gene, located on the X chromosome at the Xp21.2–p21.1 locus and encoding the dystrophin protein. The most common mutations are deletions of one or more exons (about 70 % of cases), which disrupt the reading frame and lead to the synthesis of a shortened and non-functional dystrophin protein, which causes the breakdown of skeletal muscle fibers (rhabdomyolysis) and progressive muscle weakness. The disease clinically manifests at the age of 2–5 years and rapidly progresses to the loss of the ability to walk independently by 8–12 years and death in the second or third decade of life due to respiratory and cardiac failure.

The authors present Russian experience in the use of a gene therapy drug for the treatment of Duchenne muscular dystrophy using the exon skipping method, exemplified by the only registered drug of this class in Russia for Duchenne muscular dystrophy therapy – viltolarsen (Viltepso®).

The déjà vu phenomenon, despite its high prevalence in the general population, is a key symptom in patients with mesial temporal lobe epilepsy (MTLE), where it occurs in 50–80 % of cases. This lecture summarizes current concepts of the neurobiological and cognitive mechanisms of déjà vu, examining it through both the model of pathology (MTLE) and its occurrence in healthy individuals.

Based on a review of the literature, the article demonstrates that the hippocampal system, particularly the parahippocampal gyrus, is the central neuroanatomical substrate of déjà vu. Direct evidence comes from studies of MTLE patients, where intracranial electroencephalography and electrical stimulation unequivocally link the onset of déjà vu aura to pathological activity in the mesial temporal lobe. Cognitive models (e.g., Dual Processing, Neural Delay/Mismatch, Global Matching hypotheses) interpret déjà vu as a temporary “glitch” in memory systems, involving a dissociation between the feeling of familiarity (mediated by the perirhinal cortex) and the mechanism of detailed contextual recollection (hippocampus). The contribution of specific subregions of the hippocampal formation (dentate gyrus, СА1–СА3 fields, entorhinal cortex) to pattern separation and completion processes, whose impairment underlies false recognition, is examined.

Thus, the déjà vu phenomenon serves as a unique “window” into the mechanisms of memory function. The clinical model of MTLE demonstrates its direct link to pathological activity in the mesial temporal lobe, while cognitive models explain its occurrence in healthy people because of transient dysfunction of the same hippocampal mechanisms. Future research should focus on identifying specific electrophysiological patterns and clarifying the role of impaired inhibitory control and pattern separation mechanisms in the genesis of this phenomenon.

Autoimmune GFAP astrocytopathy is a rare neurological disorder first described in 2016, characterized by immune-mediated damage to astrocytes in the central nervous system. Associated with antibodies to glial fibrillary acidic protein (GFAP), the disease presents diverse clinical symptoms, including meningoencephalomyelitis and visual system involvement. Timely diagnosis and treatment are crucial due to the high efficacy of corticosteroids and the potential for relapses.

The most common manifestations are meningoencephalomyelitis (55–60 % of cases) and meningoencephalitis (40–45 % of cases). Symptoms include headache, fever, nausea, vomiting, delirium, epileptic seizures, and motor disturbances (ataxia, tremor, myoclonus). Visual system involvement occurs in 25 % of patients, presenting as optic disc edema, blurred vision, and rarely, optic neuritis. In children, the clinical picture resembles that of adults but more frequently includes encephalitis and epileptic seizures.

The article presents two clinical cases. The first involves a 14-year-old girl with meningoencephalomyelitis who developed visual impairment, ataxia, and other neurological symptoms following a viral infection. Magnetic resonance imaging revealed multiple demyelination foci, and cerebrospinal fluid analysis confirmed GFAP antibodies. The second case involves a 6-year-old girl with sudden vision loss after a viral infection, diagnosed with optic disc edema and GFAP antibodies in the cerebrospinal fluid.

The primary diagnostic marker is the detection of GFAP antibodies in cerebrospinal fluid. Magnetic resonance imaging findings include linear perivascular enhancement in white matter and T2/FLAIR hyperintense lesions. Differential diagnosis includes multiple sclerosis, sarcoidosis, infectious diseases, and other autoimmune conditions.

Corticosteroids (methylprednisolone, prednisolone) are the cornerstone of treatment, showing high efficacy. Intravenous immunoglobulin and plasma exchange are used for non-responsive cases. Immunosuppressants (mycophenolate mofetil, rituximab) are employed to prevent relapses. Treatment duration ranges from 2 to 5 years, with lifelong therapy considered in cases of relapse.

With adequate treatment, the prognosis is generally favorable. Most patients achieve significant improvement, although relapses occur in 20–50 % of cases. Children tend to have better short-term outcomes compared to adults.

Autoimmune GFAP astrocytopathy remains poorly understood, necessitating further research to elucidate its pathogenesis and optimize treatment strategies. The presented cases underscore the importance of early diagnosis and personalized therapy.