We present a review of the literature and our own data on the management and rehabilitation of impairment or persis‑tent loss of the olfactory function – hypo‑ and anosmia. Approaches for restoring impaired olfactory function can be divided into olfactory training, pharmacological and physiotherapy. Smell training is carried out according to a number of protocols that differ mainly in the used arsenal of smells, as well as in the frequency of their presentation. Pharma‑cologically, it is proposed to use steroids used both topically (intranasally) and systemically; there is no common view on the effectiveness of this approach. Physiotherapy involve electrical stimulation of the olfactory filaments in the area of their exit into the nasal cavity (lateral masses of the ethmoid bone). In our opinion the most rational approach is the use of training methods using different smells.

Dysimmune polyneuropathies are the etiologically heterogeneous group of diseases with autoimmune damage to the peripheral nervous system. The rarity of these diseases doesn’t exclude the possibility of their development or exacerbation in patients infected with SARS‑CoV‑2, which will require timely differential diagnosis and urgent specific therapy. The article summarizes current information on the mechanisms of development, clinical features, diagnosis and management of acute and chronic dysimmune polyneuropathies in the context of the COVID‑19 pandemic.

Background. The study of the sensitive portion of the medial plantar nerve is relevant not only in the examination of patients with tibial nerve mononeuropathy or its branches, but also in the diagnosis of polyneuropathies.

Objective: to analyze the normative parameters of the sensory potential recorded during the study of the medial plantar nerve by the orthodromic method in healthy adults.

Materials and methods. 126 sensitive fibers of the medial plantar nerves were studied on the Dantec Keypoint G4 device (Denmark) in 63 healthy individuals (31 men and 32 women; age from 20 to 80 years). 3 groups were identified taking into account age: group 1 included healthy people aged 20 to 39 years (n = 23); group 2 consisted of people aged 40 to 60 years (n = 20); and 3 – older than 60 years (n = 20). The parameters of the sensory potential of the medial plantar nerve are analyzed.

Results. The sensory potential in the study of the sensitive portion of the medial plantar nerve was registered in all 126 healthy subjects. Comparative statistical analysis did not demonstrate significant differences between groups 1–3 in the values of such parameters of the sensory potential as the latency of the onset, the duration of the negative phase and the rate of propagation of excitation. At the same time, in groups 2 and 3, the magnitude of the amplitude from peak to peak of the sensory potential was significantly lower compared to group 1, and averaged 8.92 and 7.86 MV, respectively.

Conclusion. Knowledge of the regulatory parameters will allow expanding the use of electroneuromyography of the sensitive portion of the medial plantar nerve in clinical and research practice.

Background. Trigeminal neuralgia is the most common cause of facial pain. Insufficient effectiveness and frequent side effects of pharmacological therapy, as well as the risk of complications of invasive neurosurgical manipulations, determine the relevance of the development of new treatment approaches, one of which is repetitive transcranial magnetic stimulation (rTMS).

The aim of the study is to determine the effectiveness of high‑frequency rTMS of the primary motor cortex in terms of pain intensity and quality of life in patients with trigeminal neuralgia, as well as to assess the safety of the stimulation course.

Materials and methods. This open‑label non‑randomized single arm study included 20 patients with classic trigeminal neuralgia according to the ICHD‑3 classification. All patients received 10 sessions of navigated high‑frequency rTMS of the primary motor cortex (hand area) of the hemisphere, contralateral to pain syndrome localization. The maximum and average pain intensity was assessed before and after 10 rTMS sessions according to a Numeric Pain Rating Scale (NPRS), as well as quality of life was measured according to the SF‑36 questionnaire, and the severity of affective disorders according was measured to the Beck Depression Inventory (BDI). Safety and tolerability of rTMS were assessed using self‑developed questionnaires for adverse events that occurred during stimulation and within 24 hours after the previous session.

Results. A significant decrease in the maximum (p = 0.01) and average (p <0.01) pain intensity was shown after 10 sessions of rTMS. In 50 % of patients, the maximum pain intensity decreased by more than 30 % vs baseline. Significant changes were detected in the physical health measure of SF‑36 quality of life questionnaire, particularly, in the “bodily pain” domain, as well as in such aspects of the mental health measure as “vitality” and “social functioning”. The severity of affective disorders did not change significantly. A favorable profile of rTMS tolerability has been demonstrated.

Conclusion. An open‑label study showed the possible effectiveness of 10 sessions of high‑frequency rTMS to reduceт the pain intensity in patients with trigeminal neuralgia. For the first time, the spectrum of adverse events both during stimulation and within a day after its completion was systematically analyzed.

Mutations in the PIEZO2 gene, which is involved in the formation of the mechanosensitive cation channel Piezo2, can cause distal arthrogryposis type 3 (Gordon’s syndrome), type 5, and Marden–Walker syndrome. Clinical and genetic characteristics of two patients with distal arthrogryposis with autosomal dominant inheritance and one with autosomal recessive inheritance are presented. Exome sequencing in one case revealed a de novo mutation in exon 52 of the PIEZO2gene c.8238G>A (p.Trp2746*, NM_022068.3), in the second, a known deletion of three nucleotides in exon 52 of the PIEZO2 gene c.8181_8183delAGA (p Glu2727del, NM_022068.3) was found, in the third, two mutations in the compound heterozygous state – a deletion of four nucleotides leading to a shift in the reading frame in c.1863_1866delTCAG(p.Ser621fs, NM_022068) and a deletion with putative coordinates 10785050–10789339 bp, spanning 15–16 exons of the PIEZO2 gene (NM_022068; LOD 2.40). The third patient was found to have two newly detected mutations in the compound heterozygous state – a deletion of four nucleotides, leading to a shift in the reading frame in exon 14, p.1863_1866delTCAG (p.Ser621fs, NM_022068) and a deletion with assumed coordinates 10785050–10789339 b. o., (NM_022068; LOD 2.40), spanning 15–16 exons of the PIEZO2 gene. The previous assumption was confirmed that heterozygous mutations are more often localized in exon 52 of the PIEZO2 gene and disrupt the amino acid sequence of the C‑terminal region of the protein molecule, while in patients with an autosomal recessive mode of inheritance of the mutation, the N‑terminal region is more often found.

Miller Fisher syndrome is one of the forms of Guillain–Barrе́ syndrome, characterized by a clinical triad that includes ophthalmoplegia, ataxia and areflexia, with the possible addition of moderate peripheral tetraparesis. During the year that has passed since the start of the pandemic of the new coronavirus infection COVID‑19, international publications have presented a few cases of Miller Fisher syndrome, which developed in patients at different times after the COVID‑19 infection – from 3–5 days to 3 weeks. The article presents a description of a clinical case of Miller Fisher syndrome, which occurred with 34‑year‑old man 21 days after the COVID‑19 infection. The clinical manifestations of Miller Fisher syndrome were typical and included diplopia, areflexia, and ataxia. At the beginning of the disease, there was a transient episode of speech impairment in the form of mild dysarthria. Oculomotor disorders predominated in the clinical picture over other components of the classical triad. On the background of treatment with human immunoglobulin G, there was a complete regression of symptoms.

This description of Miller Fisher syndrome, which developed after the postponed infection with COVID‑19, is the first in Russia. The presented case demonstrates the ability of the SARS‑CoV‑2 virus to induce the development of an autoimmune disease. Practitioners should take into account the possibility of Miller Fisher syndrome developing in the event of an acute onset of diplopia, ataxia and areflexia in patients after a previous COVID‑19 infection.

Background. Glutaric aciduria type 1 is an autosomal recessive disease caused by mutations in the GCDH gene, which encodes the enzyme glutaryl‑CoA dehydrogenase. Metabolic crisis in type 1 glutaric aciduria is an acute life‑threatening condition that requires careful diagnosis with a number of other conditions and the immediate initiation of pathogenetic therapy.

Materials and methods. Clinical manifestations, neuroimaging characteristics of the disease were studied in 46 patients with diagnosed glutaric aciduria type 1 confirmed by biochemical and molecular genetic methods. Methods: gas chromatography with mass spectrometry, tandem mass spectrometry, Sanger sequencing, chromosomal microarray analysis of the exon level.

Results and discussion. A retrospective analysis of anamnestic and clinical data was carried out, and the nature and age of disease manifestation, provoking factors, a spectrum of clinical manifestations and neuroimaging data were assessed.

Conclusion. How initiated treatment prevents progression of neurological symptom relief and patient adaptation. With the help of the goal, it is necessary to inform pediatricians, neurologists and neuroradiologists about this feature of the course of glutaric aciduria type 1 in order to increase the clinical alertness of this disease.