[Hypothalamic hamartoma dissection using focused ultrasound under MRI control. The first successful experience in Russia]

Treatment of motor disorders by MRI-guided focused ultrasound is an alternative to neuro- and radiosurgery such as stereotactic radiofrequency ablation and thalamotomy with a gamma knife. However, safety, efficacy and feasibility of this technology for intracranial neoplasms are still unclear. The authors report successful hypothalamic hamartoma dissection by MRI-guided focused ultrasound in a 32-year-old woman with drug-resistant gelastic epilepsy and violent laughter and crying attacks. Magnetic resonance imaging revealed type II hypothalamic hamartoma. The last one was detached from surrounding brain tissue by MRI-guided focused ultrasound without side effects. Symptoms regressed immediately after surgery. No laughter and crying attacks were observed throughout 6-month follow-up.

[Neurological manifestations of hypoparathyroidism: diagnostic difficulties. Case report]

Hypoparathyroidism is a rare condition characterized by reduced production of parathyroid hormone or tissue resistance which leads to hypocalcemia and hyperphosphatemia. Neurological manifestations often occur as the first symptoms of hypoparathyroidism and are characterized by a wide variety of symptoms of both the central and peripheral nervous systems dysfunction, which requires a differential diagnosis with a wide range of neurological diseases. Two clinical cases illustrating the features of subacute and chronic hypoparathyroidism are presented. In the case of subacute hypoparathyroidism, a young woman presented with severe tetany involving the oculomotor muscles (paroxysmal strabismus), laryngeal muscles (respiratory stridor), body muscles (opisthotonus, «obstetrician's hand») and the development of secondary myopathy. In another case with a long-term chronic course of postoperative hypoparathyroidism, the patient's adaptation to severe hypocalcemia was noted; the clinical features were dominated by cerebral syndromes due to brain structures calcification (Fahr's syndrome). Possible reasons for late diagnosis of hypoparathyroidism, the importance of active detection of symptoms of neuromuscular hyperexcitability and laboratory testing of phosphorus and calcium metabolism are discussed.

[Gerstmann-Sträussler disease: a familial case with common PRNP mutation and atypical features]

Gerstmann-Sträussler disease (GSD) is a very rare autosomal dominant late-onset neurodegenerative disorder related to prion protein gene PRNP. Mutation p.Pro102Leu produces about 80% of cases, which are often named GSD-102. DNA testing provides exact diagnosis. In the presented Russian family there were 3 patients: a female index case, age 32 years, her brother, age 37 years (age of onset in both is 27 years) and their deceased father (onset in 35 years, death in 44 years). GSD was not suspected until whole exome sequencing in the female detected PRNP mutation p.Pro102Leu confirmed in her and in the brother by Sanger sequencing. Atypical features of the case are: early onset in siblings, absence of mental and behavioral problems in the female and in the father and mild disturbances in the brother; epilepsy in the brother; atypical onset with transient signs in the brother. Other intrafamilial differences are prevailing spastic paraparesis in the female in contrast to predominant ataxia in the brother and dysarthria absence in the female. The case illustrates GSD-102 variability, complicating clinical diagnostics.

[Diagnosis and treatment of early forms of cognitive impairment: possibilities of influencing neuronal energy metabolism. Resolution of the Council of Experts]

Diagnosis and treatment of early forms of cognitive impairment: possibilities of influencing neuronal energy metabolism. Resolution of the Council of Experts.

[Cognitive impairment and tactics of using the drug Cerebrolysin. Resolution of the International Council of Experts (May 12, 2023)]

The aging of the population and the associated increase in the share of cognitive impairments in the structure of a wide range of diseases are a serious challenge for modern healthcare. Difficulties in the treatment of cognitive disorders are determined by many factors, including the age of patients, comorbidity, forced polypragmasia and the adequacy of the dosage of drugs that restore cognitive activity. The experts discussed information about the therapeutic potential of the drug Cerebrolysin in the treatment of cognitive disorders of various origins, stated significant experience of its effective and safe use in many clinical studies in mild and moderate forms of dementia. At the same time, there was a lack of consistent and systematic data on the dosage regimen, frequency, and duration of use of the drug in different forms of cognitive impairment and the degree of their severity. The aim of the international council of experts was to determine the optimal dosage regimens of the drug Cerebrolysin in patients with various etiologies and severity of cognitive impairment. The result of the work was the approval of a unified scheme for the use of the drug Cerebrolysin, considering the severity of the disease and its duration.

[Experience of staged and simultaneous bilateral thalamotomy using MR-guided focused ultrasound in the treatment of essential tremor]

OBJECTIVE

To show that effective and safe bilateral MR-guided focused ultrasound (MRgFUS) treatment of essential tremor (ET) is achievable.

MATERIAL AND METHODS

Four male patients underwent bilateral thalamotomy. Two patients underwent staged thalamotomy, with the ≥12 month interval between operations. Two patients underwent simultaneous bilateral thalamotomy.

RESULTS

After six months, all patients noted a significant reduction in symptoms on both sides: when assessing tremors with the Clinical Rating Scale for Tremor, the severity of hyperkinesis decreased by 57.5-69.7%. We did not observe any complications in any of the cases.

CONCLUSION

Our experience indicates that simultaneous bilateral MRI-guided focused ultrasound treatment of ET can be performed safely and effectively. Further research is necessary to estimate the effectiveness and adverse effect rates.

[Oral disease-modifying therapy for adult patients with spinal muscular atrophy type 2]

Disease modifying therapy for adult patients with SMA still raises certain questions regarding its effectiveness, given the long-term chronic process with often significant neurological deficits at the time of initiation of therapy. This paper presents three clinical cases of adult sitter patients with SMA type 2, who began risdiplam therapy 16.5-41 years after the disease onset. All patients have been receiving therapy since 2020, at the time of observation for 2.5-3 years. All patients showed subjective and objective (using specialized scales) improvement during long-term therapy with risdiplam. In addition to an increase in muscle strength, mainly in the proximal and distal parts of the arms, several non-motor effects were also noted (including improved swallowing and breathing), which cannot be recorded using scales. No adverse events were recorded during therapy.

[Cerebellar degeneration associated with HIV infection]

OBJECTIVE

To describe the features of the clinical presentation and evaluate the incidence of HIV-associated cerebellar degeneration in patients with progressive cerebellar ataxia.

MATERIAL AND METHODS

Three hundred and seventy-seven patients with progressive cerebellar ataxia were studied. Brain MRI study, assessment by the Scale for the Assessment and Rating of Ataxia (SARA), screening for cognitive impairment by the Montreal Cognitive Assessment Scale (MoCA) were performed. In patients with HIV infection, autoimmune, deficient and other causes of ataxia, as well as opportunistic infections, multiple system atrophy and frequent forms of hereditary spinocerebellar ataxias were excluded.

RESULTS

Five patients (1.3%) were identified with a combination of cerebellar ataxia and HIV infection (2 men, 3 women, aged 31 to 52 years). The median duration of HIV infection was 5 years, the duration of ataxia was 1 year. In the clinical findings, in addition to progressive ataxia, pyramidal signs, dysphagia, less often ophthalmoparesis, dystonia, postural hand tremor, affective and mild cognitive impairment were observed. In three patients, brain MRI revealed signs of olivopontocerebellar atrophy, two patients had isolated cerebellar degeneration (mainly of the vermis). All patients received combination of antiretroviral therapy in various regimens, but despite this, ataxia was progressive.

CONCLUSION

HIV infection is a rare cause of cerebellar degeneration. This diagnosis remains a diagnosis of exclusion to this day. Cerebellar degeneration can occur and progress even after achieving a stable remission of HIV infection while taking highly active antiretroviral therapy.

Visual analysis of nigrosome-1 in the differential diagnosis of Parkinson's disease and essential tremor

Differentiation between Parkinson’s disease, especially in its early stages, and essential tremor, which is a phenotypically similar movement disorder, still remains an unsolved challenge for neurology. The aim of this study was to assess the diagnostic significance of nigrosome imaging (nigrosomes are dopaminergic neuron clusters in the substantia nigra of the midbrain) using 3T high-resolution SW-MRI. The study was conducted in 20 patients with Parkinson’s disease and 10 patients with essential tremor. Visual analysis of the acquired nigrosome-1 images was performed using a 4-point ordinal rating scale. Differences in sex, age and duration of the disease were calculated using the Fisher exact test and the Mann–Whitney U test. The diagnostic value of the method was assessed using Pearson’s chisquared test. Nigrosome-1 was bilaterally or unilaterally absent in 70% of parkinsonian patients. Less specific changes to the substantia nigra (SN) were observed in two more parkinsonian patients (10%), whose nigrosome-1 appeared reduced in size. By contrast, nigrosome-1 was bilaterally intact in all patients (100%) with essential tremor (p < 0.001). Our preliminary findings demonstrate the high potential of noninvasive nigrosome-1 imaging in the differential diagnosis of Parkinson’s disease and essential tremor.

Ultrasound imaging of vagus nerves in patients with Parkinson's disease

Parkinson’s disease (PD) is a neurodegenerative multisystem disorder characterized by pathologic α-synuclein aggregation affecting, among other things, vagal fibers. The aim of this study was to investigate the cross-sectional area (CSA) of the vagus nerve (VN) in patients with PD using ultrasound imaging. The study was conducted in 32 patients with PD (15 men and 17 women; mean age 58 ± 10 years) and 32 healthy controls comparable with the main group in terms of sex and age. All study participants underwent ultrasound examination of the VN using a high-resolution transducer. Left VN CSA was significantly smaller in patients with PD than in the control group (1.78 ± 0.52 mm2 vs 2.11 ± 0.41 mm2; р = 0.007). A similar result was obtained for right VN CSA at the trend level. ROC analysis demonstrated that the threshold CSA value of < 2.10 mm2 for the left VN has low diagnostic sensivity (59%) for VN atrophy in patients with PD. Right VN CSA was significantly larger than left VN CSA in both groups (p < 0.001). The analysis of the PD group did not reveal any associations between VN CSA and age, duration and stage of the disease, motor (UPDRS III) and non-motor (NMSQ) scores. Patients with akinetic-rigid form of PD had smaller left VN CSA than patients with the mixed form of the disease (р < 0.05). A moderate inverse correlation was established between left VN CSA and the area of substantia nigra hyperechogenicity on both sides (р < 0.04); for the right VN a similar correlation was established at the trend level. High-resolution ultrasound of patients with PD demonstrated atrophy of the VN and the association of VN CSA with the clinical form of the disease and the ultrasound features of the substantia nigra.

[The influence of parasomnia on clinical and functional characteristics of extrapyramidal disorders]

OBJECTIVE

To compare clinical and functional features of the essential tremor (ET) and Parkinson's disease (PD) with- or without rapid eye movement (REM) sleep behavior disorder (RBD).

MATERIAL AND METHODS

Sixty patients with PD and 52 patients with ET were examined. Cognitive functions, anxiety, asthenia and depression, autonomic disorders and sleep disorders were assessed with scales and questionnaires. All patients underwent polysomnography (PSG). Based on the results of PSG, patients were divided by the presence or absence of parasomnia, known as REM sleep behavior disorder.

RESULTS

Patients with PD and ET suffering from RBD were more likely to be overweight, more likely to develop cognitive impairment, obstructive sleep apnea, and emotional disorders. In addition, presence of RBD has adverse effects on the sleep structure. The profile of memory, attention, psychoemotional and sleep disorders in patients with PD and ET had common features, which suggests that it is RPBDH that affects the change in the clinical picture.

CONCLUSION

Presence of RBD aggravates non-motor manifestations of such extrapyramidal diseases as PD and ET. On the one hand it helps to predict the course of the disease, on the other hand let us suspect RBD when we see non-motor symptoms worsening.

Brain atrophy patterns in patients with frontotemporal dementia: voxel-based morphometry

Frontotemporal dementia (FTD) is a neurodegenerative disorder characterized by language and behaviour deficits, which is considered the second most common cause of early-onset dementia. Detection of brain atrophy patterns is important for FTD diagnosis. However, the visual assessment of magnetic resonance imaging data may not be sensitive enough requiring the use of objective gray matter (GM) volume determination method. The study was aimed to assess the GM atrophy pattern in patients with FTD compared to control group patients using voxel-based morphometry (VBM). The study included 16 patients with FTD (12 patients with nonfluent agrammatic variant primary progressive aphasia (nfvPPA), three patients with behavioral variant of FTD, and one patient with logopenic variant PPA) and 10 healthy volunteers. VBM of patients with FTD and healthy controls revealed three significant (pFWE-corr < 0.05) atrophy areas in the left inferior frontal, left fusiform, and left supramarginal gyri. Taking into account the predominance of patients with nfvPPA in the group of FTD patients, the additional VBM of this group and control group was carried out, which revealed a distinct atrophy pattern: the reduced GM volume was detected in the left inferior frontal and left middle frontal gyri (pFWE-corr < 0.05). The results obtained indicate that regardless of the clinical variant, there is a certain atrophy pattern characteristic of FTD, which involves both frontotemporal areas and parietal lobe. The example of nfvPPA shows that each variant of the disease is associated with distinct localization of atrophy.

[C9orf72-associated frontotemporal dementia in the Russian population]

OBJECTIVE

To evaluate the frequency of C9orf72-associated frontotemporal dementia (FTD) in the Russian population and to study clinical features of GGGGCC-repeat expansion carriers.

MATERIAL AND METHODS

Twenty-eight patients with FTD are included in the study: 15 with a behavioral variant of FTD (bvFTD) and 13 with a agrammatic/non-fluent variant of primary progressive aphasia (avPPA). The mean age was 62 years (34-80), the mean disease duration was 4 years (1-10). The positive family history was noted in 46% of cases. DNA diagnosis was performed using repeat-primed polymerase chain reaction.

RESULTS

The frequency of the C9orf72 repeat expansion in patients with FTD was 14%, in patients with bvFTD 20%, in patients with avPPA 8%. The mean age of disease onset in the expansion carriers was 63 (55-75) years. The frequency of the C9orf72 repeats expansion in familial FTD cases was 31%, in sporadic cases 7%. bvFTD with parkinsonian syndrome was noted in two out of four cases, bvFTD with amyotrophic lateral sclerosis (ALS) was shown in one case, avPPA with ALS was shown in one case. One female patient with bvFTD with parkinsonian syndrome presented with cognitive fluctuations that required a differential diagnosis with Lewy body disease.

CONCLUSION

This is the first study of the genetic structure of FTD in the Russian population. The prevalence and clinical characteristics of C9orf72-associated FTD were defined, in particular, the spectrum of motor symptoms was shown along with behavioral and aphasic disturbances. DNA diagnosis plays an important role in confirming the diagnosis and selection of patients for potential disease-modifying treatment.

C9orf72 Gene Expression in Frontotemporal Dementia and Amyotrophic Lateral Sclerosis

We studied the expression of C9orf72 gene in pathologies associated with hexanucleotide repeats expansion in this gene: frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). The study included 7 patients with hexanucleotide repeats expansion in the C9orf72 gene and 9 patients of the control group. The expression of C9orf72 mRNA was evaluated in blood leukocytes by real-time PCR. Methylation of CpG-sites in C9orf72 promotor region was evaluated by DNA sequencing after bisulfite conversion. A 2-fold decrease in the C9orf72 gene expression was found in patients with hexanucleotide repeats expansion in comparison with controls, though the difference did not reach statistical significance due to small sample size. The highest expression was shown for ALS in comparison with FTD and FTD-ALS phenotype. A trend to inverse correlation between C9orf72 mRNA level and promoter methylation of this gene as well as between mRNA level and age of disease onset was demonstrated.

[Clinical and morphological analysis of a caseof Parkinson's disease]

Parkinson's disease (PD) is a neurodegenerative disease that belongs to a group of cerebral proteinopathies. The main pathomorphological signs of PD are neuronal degeneration in the midbrain substantia nigra and detection of pathological forms of the synaptic protein α-synuclein in the nigral neurons. At the same time, the pathological forms of α-synuclein in this disease have been recently shown to accumulate in the cells of not only the central, but also peripheral autonomic nervous system. The paper provides a clinical and morphological description of a PD case in a 70-year-old patient, which demonstrates that there are typical α-synuclein-positive inclusions in the brain regions (substantia nigra, caudate nucleus, and frontal cortex), salivary glands and colon. The systemic nature of α-synucleinopathy in PD is important in both clarifying the pathogenesis of the disease and elaborating new approaches to its diagnosis and, in the future, to targeted therapy.

[Genetic Diversity in Frontotemporal Dementia]

Frontotemporal dementia is a progressive neurodegenerative disorder with high clinical, genetic, and pathomorphological diversity It is the third most common cause of dementia in all ages and the most common cause of early onset dementia (below 65). Despite its multifactorial nature, up to 40% of patients have a family history where the autosomal dominant inheritance type is seen in a quarter of cases. In this review, we describe key genes whose mutations can result in the development of frontotemporal dementia, the possible pathogenic mechanisms of the degenerative process, and provide information on the clinical features of the disease for different genetic variants. Special emphasis is placed on the frontotemporal dementia phenotype that is associated with amyotrophic lateral sclerosis.

Thymoquinone as a Potential Neuroprotector in Acute and Chronic Forms of Cerebral Pathology

Thymoquinone is one of the main active components of the essential oil from black cumin (Nigella sativa) seeds. Thymoquinone exhibits a wide range of pharmacological activities, including neuroprotective action demonstrated in the models of brain ischemia/reperfusion, Alzheimer's and Parkinson's diseases, and traumatic brain injury. The neuroprotective effect of thymoquinone is mediated via inhibition of lipid peroxidation, downregulation of proinflammatory cytokines, maintenance of mitochondrial membrane potential, and prevention of apoptosis through inhibition of caspases-3, -8, and -9. Thymoquinone-based mitochondria-targeted antioxidants are accumulated in the mitochondria and exhibit neuroprotective properties in nanomolar concentrations. Thymoquinone reduces the negative effects of acute and chronic forms of brain pathologies. The mechanisms of the pharmacological action of thymoquinone and its chemical derivatives require more comprehensive studying. In this paper, we formulated the prospects of application of thymoquinone and thymoquinone-based drugs in the therapy of neurodegenerative diseases.

Generation of induced pluripotent stem cell line ICGi018-A from peripheral blood mononuclear cells of a patient with Huntington's disease

Huntington's disease (HD) is an autosomal dominant neurodegenerative disease caused by CAG repeat expansion in the HTT gene. HD patient-specific induced pluripotent stem cells (iPSCs) represent an excellent model for the disease study. We generated iPSC line from blood mononuclear cells of HD patient with 38 CAG repeats in the HTT exon 1 using integration free episomal plasmids expressing Yamanaka factors. The iPSC line retained the disease causing mutation and expressed pluripotency markers. It also displayed a normal karyotype and the ability to differentiate into derivatives of three germ layers.

[Epigenetic regulation of clinical manifestations of Friedreich's disease]

AIM

To study a methylation profile of FXN gene and its influence on the clinical phenotype of Friedreich's desease (FD).

MATERIAL AND METHODS

The methylation pattern was analyzed in 17 patients with FD. Forty-five CpG-sites in the promoter region and the region of intron 1 of FXN: before the GAA-expansion (UP-GAA) and after the GAA-expansion (DOWN-GAA), were studied.

RESULTS

Correlations between the methylation level of CpG-sites in UP-GAA and DOWN-GAA and the number of GAA repeats in both expanded FXN alleles in patients with FD were found. An analysis revealed an earlier onset and a more severe course of FD in cases with hypermethylation of several CpG-sites in the UP-GAA region. The correlation between the methylation pattern and the presence of extraneural manifestations of FD was also revealed. In FD patients with cardiomyopathy, a hypomethylated CpG-site in the promoter region was found. In FD patients with carbohydrate metabolism disorders, two hypomethylated CpG-sites in the DOWN-GAA region were observed.

CONCLUSION

The results indicate a significant contribution of epigenetic modifications of FXN to the clinical presentation of FA.

Parkinson's Disease-Associated Changes in the Expression of Neurotrophic Factors and their Receptors upon Neuronal Differentiation of Human Induced Pluripotent Stem Cells

Parkinson's disease (PD) is a neurodegenerative pathology resulting from the degeneration of dopaminergic (DA) neurons in the substantia nigra (SN). Neurotrophic factors (NTFs) and their receptors are key regulators of the survival, differentiation, and development of neurons. However, the role of these factors in the pathogenesis of PD is still unclear. Here, we analyzed the expression of NTFs and their receptors in human induced pluripotent stem cells (iPSCs) derived from the fibroblasts of patients with PD and healthy donors (HDs). Four PD-derived iPSC lines with different mutations and three cell lines from HDs at different stages of neuronal differentiation were used for RT-qPCR analysis and ELISA. We found that the mRNA levels of most analyzed genes were altered in PD-derived cells compared with those in HD-derived cells at all stages. Importantly, irrespective of PD-associated mutations, the mRNA levels of the BDNF and GDNF genes were mostly increased or unchanged in predominantly DA terminally differentiated neurons (TDNs) compared with those in HD-derived cells. Strikingly, in contrast to BDNF and GDNF mRNA levels, BDNF and GDNF protein levels were lower in almost all PD-derived TDNs than in HD-derived cells, thus indicating the dysregulation of NTF expression at the post-transcriptional level. We suggest that this dysregulation is one of the important signs of PD development.

Generation of an induced pluripotent stem cell line, ICGi014-A, by reprogramming peripheral blood mononuclear cells from a patient with homozygous D90A mutation in SOD1 causing Amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by death of motor neurons. To date, neither etiology nor pathogenesis of ALS are known, which leads to the absence of an effective treatment strategy. ALS patient-specific induced pluripotent stem cells (iPSCs) represent an excellent tool for the disease study. We obtained iPSCs line from peripheral blood mononuclear cells of the patient with homozygous Asp90Ala mutation in the SOD1 gene using non-integrating episomal vectors. The iPSCs line retained pathological genotype and expressed pluripotency markers. It also displayed a normal karyotype and the ability to differentiate into derivatives of three germ layers.

The Use of Human Induced Pluripotent Stem Cells for Testing Neuroprotective Activity of Pharmacological Compounds

Development of therapeutic preparations involves several steps, starting with the synthesis of chemical compounds and testing them in different models for selecting the most effective and safest ones to clinical trials and introduction into medical practice. Cultured animal cells (both primary and transformed) are commonly used as models for compound screening. However, cell models display a number of disadvantages, including insufficient standardization (primary cells) and disruption of cell genotypes (transformed cells). Generation of human induced pluripotent stem cells (IPSCs) offers new possibilities for the development of high-throughput test systems for screening potential therapeutic preparations with different activity spectra. Due to the capacity to differentiate into all cell types of an adult organism, IPSCs are a unique model that allows examining the activity and potential toxicity of tested compounds during the entire differentiation process in vitro. In this work, we demonstrated the efficiency of IPSCs and their neuronal derivatives for selecting substances with the neuroprotective activity using two classes of compounds - melanocortin family peptides and endocannabinoids. None of the tested compounds displayed cyto- or embryotoxicity. Both melanocortin peptides and endocannabinoids exerted neuroprotective effect in the neuronal precursors and IPSC-derived neurons subjected to hydrogen peroxide. The endocannabinoid N-docosahexaenoyl dopamine exhibited the highest neuroprotective effect (~70%) in the differentiated cultures enriched with dopaminergic neurons; the effect of melanocortin Semax was ~40%. The possibility of using other IPSC derivatives for selecting compounds with the neuroprotective activity is discussed.

[Diagnostic algorithm for autosomal recessive ataxia]

AIM

To develop a complex algorithm for autosomal recessive ataxia (ARA) diagnosis applicable for Russian patients with degenerative ataxias.

MATERIAL AND METHODS

48 patients with of presumably degenerative ataxias were examined. Clinical evaluation was performed with the use of the SARA and ICARS scales (for ataxia) and MoCA (cognitive functions), and a set of laboratory tests was carried out, including electromyography, brain MRI, and DNA analysis of mutations responsible for Friedreich's disease and spinocerebellar ataxias (SCAs) types 1, 2, 3, 6 and 17. 28 patients underwent mutation screening using a multigenic MPS panel.

RESULTS

8 patients (16.7%) with non-hereditary causes of ataxia were identified: cerebellar alcoholic degeneration (n = 6) and multiple system atrophy of cerebellar type (n = 2); 3 patients (6.3%) with genetic ataxias were identified using routine DNA tests, such as with SCA type 1, 2 and 17, and 9 (18.8%) patients with Friedreich's disease. The MPS panel enabled molecular diagnosis of ARA in 8 patients (28.6%): ataxia-telangiectasia (n = 2), SANDO syndrome (n = 2), ataxia with oculomotor apraxia type 2 (n = 1), SCAR10 (n = 1), SCAR16 (n = 1), and atypical form of neuroaxonal dystrophy (n = 1). The diagnosis was not established in 20 patients.

CONCLUSION

We have proposed an appropriate algorithm for degenerative ataxia diagnosis which is recommended to be used when examining patients with sporadic and autosomal recessive cases of the disorders with dyscoordination of movements.

Expression and Functional Properties of NMDA and GABAA Receptors during Differentiation of Human Induced Pluripotent Stem Cells into Ventral Mesencephalic Neurons

Ionotropic glutamate and GABA receptors regulate the differentiation and determine the functional properties of mature neurons. Both insufficient and excessive activity of these neurotransmission systems are associated with various nervous system diseases. Our knowledge regarding the expression profiles of these receptors and the mechanisms of their regulation during the differentiation of specialized human neuron subtypes is limited. Here the expression profiles of the NMDA and GABA_A receptor subunits were explored during in vitro differentiation of human induced pluripotent stem cells (iPSCs) into ventral mesencephalic neurons. The correlation between the neuronal maturation and the expression dynamics of these genes was investigated, and the functional activity of these receptors was assessed by calcium imaging. The role of NMDA and GABA_A receptors in neurite outgrowth and the development of spontaneous activity was analyzed using the viral transduction of neural progenitors with the reporter genes TagGFP and TagRFP. The data indicate that agonists of the investigated receptors can be employed for optimization of existing protocols for neural differentiation of iPSCs, in particular for acceleration of neuronal maturation.

A Platform for Studying Neurodegeneration Mechanisms Using Genetically Encoded Biosensors

Patient-specific induced pluripotent stem cells (iPSCs) capable of differentiation into required cell type are a promising model for studying various pathological processes and development of new therapeutic approaches. However, no conventional strategies for using iPSCs in disease research have been established yet. Genetically encoded biosensors can be used for monitoring messenger molecules, metabolites, and enzyme activity in real time with the following conversion of the registered signals in quantitative data, thus allowing evaluation of the impact of certain molecules on pathology development. In this article, we describe the development of a universal cell-based platform for studying pathological processes associated with amyotrophic lateral sclerosis. For this purpose, we have created a series of plasmid constructs for monitoring endoplasmic reticulum stress, oxidative stress, apoptosis, and Ca2+-dependent hyperexcitability and generated transgenic iPSC line carrying mutation in the superoxide dismutase 1 gene (SOD1) and healthy control cell line. Both cell lines have specific transactivator sequence required for doxycycline-controlled transcriptional activation and can be used for a single-step biosensor insertion.

[A comparative analysis of allele frequencies of rs1801133 and rs1801131 of MTHFR in patients with stroke and healthy people from the Moscow region]

AIM

To study genetic characteristics of the population of the Moscow region and analyze the association of rs1801133 and rs1801131 of MTHFR with the risk of ischemic stroke (IS).

MATERIAL AND METHODS

A sample of 170 and 115 patients with atherothrombotic and cardioembolic subtypes of IS and 360 residents of the Moscow region without IS were examined. MTHFR alleles were determined by a multiplex real-time polymerase chain reaction.

RESULTS AND CONCLUSION

No association between the frequencies of MTHFR alleles and the risk of ischemic stroke was found. The comparison of allele frequencies with those in Caucasian populations published in the dbSNP (NCBI) and 1000 Genomes Project databases revealed significant differences for rs1801133 from the EUR 1000 Genomes Project. The allele frequency data for MTHFR could increase the accuracy and reliability of the individual risk calculation for multifactorial diseases in the Russian population.

Genetic Association between Alzheimer's Disease Risk Variant of the PICALM Gene and Auditory Event-Related Potentials in Aging

Aging and genetic predisposition are major risk factors in age-related neurodegenerative disorders. The most common neurodegenerative disorder is Alzheimer's disease (AD). Genome-wide association studies (GWAS) have identified statistically significant association of the PICALM rs3851179 polymorphism with AD. The PICALM G allele increases the risk of AD, while the A allele has a protective effect. We examined the association of the PICALM rs3851179 polymorphism with parameters of the P3 component of auditory event-related potentials (ERPs) in 87 non-demented volunteers (age, 19-77 years) subdivided into two cohorts younger and older than 50 years of age. We found statistically significant association between the AD risk variant PICALM GG and increase in the P3 latency in subjects over 50 years old. The age-dependent increase in the P3 latency was more pronounced in the PICALM GG carriers than in the carriers of the PICALM AA and PICALM AG genotypes. The observed PICALM-associated changes in the neurophysiological processes indicate a decline in the information processing speed with aging due, probably, to neuronal dysfunction and subclinical neurodegeneration of the neuronal networks in the hippocampus and the frontal and parietal cortical areas. Such changes were less pronounced in the carriers of the PICALM gene A allele, which might explain the protective effect of this allele in the cognitive decline and AD development.

Molecular Pathogenesis in Huntington's Disease

Huntington's disease (HD) is a severe autosomal dominant neurodegenerative disorder characterized by a combination of motor, cognitive, and psychiatric symptoms, atrophy of the basal ganglia and the cerebral cortex, and inevitably progressive course resulting in death 5-20 years after manifestation of its symptoms. HD is caused by expansion of CAG repeats in the HTT gene, which leads to pathological elongation of the polyglutamine tract within the respective protein - huntingtin. In this review, we present a modern view on molecular biology of HD as a representative of the group of polyglutamine diseases, with an emphasis on conformational changes of mutant huntingtin, disturbances in its cellular processing, and proteolytic stress in degenerating neurons. Main pathogenetic mechanisms of neurodegeneration in HD are discussed in detail, such as systemic failure of transcription, mitochondrial dysfunction and suppression of energy metabolism, abnormalities of cytoskeleton and axonal transport, microglial inflammation, decrease in synthesis of brain-derived neurotrophic factor, etc.

Genome Editing and the Problem of Tetraploidy in Cell Modeling of the Genetic Form of Parkinsonism

The prevalent form of familial parkinsonism is caused by mutations in the LRRK2 gene encoding for the mitochondrial protein kinase. In the review, we discuss possible causes of appearance of tetraploid cells in neuronal precursors obtained from induced pluripotent stem cells from patients with the LRRK2-associated form of parkinsonism after genome editing procedure. As LRRK2 protein participates in cell proliferation and maintenance of the nuclear envelope, spindle fibers, and cytoskeleton, mutations in the LRRK2 gene can affect protein functions and lead, via various mechanisms, to the mitotic machinery disintegration and chromosomal aberration. These abnormalities can appear at different stages of fibroblast reprogramming; therefore, editing of the LRRK2 nucleotide sequence should be done during or before the reprogramming stage.

[Complex assessment of the contribution of genetic factors to the risk of ischemic stroke]

AIM

To develop a method of the complex assessment of genetic risk for ischemic stroke (IS) and evaluate its effectiveness.

MATERIAL AND METHODS

Genotyping of 182 patients with atherothrombotic and cardioembolic subtypes of IS and 360 healthy individuals of 48 single nucleotide polymorphic loci (SNP) associated with the risk of II and its subtypes was performed.

RESULTS AND CONCLUSION

In each group of SNPs, composite indicators of genetic risk of IS in groups of patients and healthy controls were identified. Differences between the calculated values of the genetic risk in these groups were significant (p <0,05). The quality of the binary classification validated by ROC-analysis confirmed the predictive potential of the proposed method of risk calculation for determining the genetic predisposition to the development of IS.

[Differential diagnosis of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy]

Cerebral autosomal dominant arteriopathy with subcortical infarctions and leucoencephalopathy (CADASIL) is an inherited CNS disease, which is caused by mutations in the NOTCH3 gene. Selective disorders of small vessels underlie the disease pathogenesis. Clinically CADASIL is characterized by headaches, multiple stroke-like disorders (in most cases transient ischemic attacks and lacunar strokes), and different focal neurological symptoms and dementia. There are specific MRI signs of the disease: multiple lacunar infarctions located in the basal ganglia, brain steam and cerebellum, focal lesions of temporal poles, capsula externa, periventricular and subcortical areas; diffuse white matter changes and leukoaraiosis can be observed as well. The differential diagnosis of CADASIL is made with many diseases, which are manifested by multiple brain matter lesions, including demyelinating disorders. It should be taken into account that CADASIL is characterized by headaches as one of the initial symptoms, multiple lacunar and diffuse brain matter lesions based on MRI data with an absence of atherosclerosis and arterial hypertension. Family history and autosomal dominant mode of inheritance is also typical of CADASIL. Detection of the NOTCH3 gene mutation is necessary for the definite diagnosis of CADASIL.

A 30-year history of MPAN case from Russia

We present a patient with progressive spastic ataxia, with dystonia and anarthria undiagnosed until detailed genetic analysis revealed an MPAN mutation. Highlighting the worldwide MPAN distribution, a 30year history of absent diagnosis and the impact and cost saving of an early but detailed genetic analysis in complex progressive movement disorders, particularly the anarthric NBIA group.

Peptides semax and selank affect the behavior of rats with 6-OHDA induced PD-like parkinsonism

Parkinson's disease (PD) is the second most common severe neurodegenerative disorder that is characterized by progressive degeneration of dopaminergic neurons (DA neurons) in the substantia nigra pars compacta (SNpc) region of the brain. In the present study, we investigated the effects of the synthetic regulatory peptides Semax (analog of an ACTH 4-10 fragment (ACTH4-10)) and Selank (analog of immunomodulatory taftsin) on behavior of rats with 6-hydroxidopamine (6-OHDA) induced PD-like parkinsonism. It was showed that both peptides did not affect motor activity of rats in elevated cross shaped maze and passive defensive behavior of the animals. At the same time, Selank decreased level of anxiety of rats with toxic damage of DA neurons in elevated cross shaped maze. Previously such effects of Selank were revealed in healthy rodents (rats and mice) with different models of psycho-emotional stress. Therefore, toxic damage of substantia nigra does not affect the response of the rat organism on this peptide.

[Levodopa-carbidopa intestinal gel in the treatment of patients with Parkinson disease: results of a 12-month open study]

AIM

To evaluate the long-term safety and efficacy of intrajejunal levodopa-carbidopa intestinal gel (LCIG) infusion in the treatment of patients with severe stages of Parkinson disease (PD) who did not respond adequately to treatment with oral drugs.

MATERIAL AND METHODS

A large-scale international prospective open-label 54-week study of LCIG in patients with PD with severe motor fluctuations was carried out. A total of 48 patients were enrolled in Russia, 46 patients (95.8%) had PEG-J inserted, and 43 of them completed the study. The safety, including adverse events (AEs), infusion system and pump failures analysis, number of patients completely terminated the study, and efficacy (duration of "off" periods, "on" periods with or without troublesome dyskinesias, UPDRS scores, Clinical Global Impression, Quality of Life (PDQ-39, EQ-5D и EQ-VAS) dynamics, an analysis of patient's diaries) were assessed throughout the whole study.

RESULTS

The majority of AEs were mild or moderate with most AEs connected with infusion system application (28.3% patients) including procedure pain. Serious AEs were registered in 8 patients (16.7%). 3 patients (6.3%) discontinued their participation in the study due to AEs. Mean duration of "off" periods by the end of the study decreased by 5.35±2.59 hours (p<0.001), duration of "on" periods without troublesome dyskinesia increased by 5.74±3.91 hours (p<0.001), reduction of "on" periods duration with troublesome dyskinesia became statistically significant by week 36 (p=0.020). The statistically significant improvement of UPDRS (generally and in respect to sub-scales), Clinical Global Impression, and Quality of Life scores was observed throughout the study. Levodopa dose remained stable throughout the 54 treatment weeks. Forty-three patients (93.5%) received LCIG monotherapy throughout the whole study.

CONCLUSION

LCIG intrajejunal infusion during 54 weeks showed the favorable safety profile, high tolerability, and efficacy in PD motor symptoms correction.

Oligomeric α-synuclein and glucocerebrosidase activity levels in GBA-associated Parkinson's disease

Alpha-synuclein oligomerization plays a key role in the development of Parkinson's disease (PD). Being the most common genetic contributor to PD, glucocerebrosidase 1 (GBA) mutations have been associated with decreased GBA enzymatic activity in PD patients with mutations in the GBA gene (GBA-PD). However, it is unknown whether the activities of other lysosomal hydrolases are being altered in GBA-PD patients and are accompanied by an increase in alpha-synuclein oligomerization. The aim of our study was to estimate GBA enzymatic activity as well as the activities of five other lysosomal hydrolases (galactocerebrosidase, alpha-glucosidase, alpha-galactosidase, sphingomyelinase, alpha-iduronidase) in dried blood spots with assessing plasma oligomeric alpha-synuclein levels in sporadic PD (sPD) patients, in GBA-PD patients and in controls. GBA enzymatic activity and plasma oligomeric alpha-synuclein levels were assessed in sPD patients (N=84), in GBA-PD patients (N=21) and controls (N=62) by LC-MS/MS and ELISA methods accordingly. GBA-PD patients showed lower GBA enzymatic activity compared to controls (p=0.001) and to sPD (p=0.0001). We also found the reduction of GLA enzymatic activity (but not of other lysosomal hydrolases) in GBA-PD (p=0.001). At the same time plasma oligomeric alpha-synuclein levels were increased in GBA-PD group compared to sPD and controls (p=0.002 and p<0.0001, respectively). Our results suggest that the decrease in enzymatic activity of lysosomal hydrolases in GBA mutation carriers may contribute to PD pathogenesis by increasing the level of neurotoxic oligomeric alpha-synuclein species.

Investigation of the effects of GABA receptor agonists in the differentiation of human induced pluripotent stem cells into dopaminergic neurons

The influence of GABA receptor agonists on the terminal differentiation in vitro of dopaminergic (DA) neurons derived from IPS cells was investigated. GABA-A agonist muscimol induced transient elevation of intracellular Ca²⁺ level ([Ca²⁺] _i ) in the investigated cells at days 5 to 21 of differentiation. Differentiation of cells in the presence of muscimol reduced tyrosine hydroxylase expression. Thus, the presence of active GABA-A receptors, associated with phenotype determination via Ca²⁺-signalling was demonstrated in differentiating human DA neurons.

ITPR1 gene p.Val1553Met mutation in Russian family with mild Spinocerebellar ataxia

Background

Spinocerebellar ataxias (SСAs) are a highly heterogeneous group of inherited neurological disorders. The symptoms of ataxia vary in individual patients and even within the same SCA subtype. A study of a four-generation family with autosomal dominant (AD) non-progressive SCA with mild symptoms was conducted. The genotyping of this family revealed no frequent pathogenic mutations. So the objective of this study was to identify the genetic causes of the disease in this family with the technology of whole-exome sequencing (WES).

Methods and results

WES, candidate variant analysis with further Sanger sequencing, mRNA secondary structure prediction, and RSCU analysis were performed; a heterozygous missense mutation in ITPR1 was identified.

Conclusion

Our study confirms the fact that ITPR1 gene plays a certain role in the pathogenesis of SCAs, and, therefore, we suggest that c.4657G>A p.Val1553Met) is a disease-causing mutation in the family studied.

[Identification of people at the latent stage of Parkinson's disease (the PARKINLAR study): first results and an optimization of the algorithm]

AIM

To work out an optimal algorithm to identify people at the latent stage of neurodegenerative process of «parkinsonian» type in the Russian population.

MATERIAL AND METHODS

Authors launched a two-step study aimed at identifying people at the latent stage of Parkinson's disease (PD) in the Russian population - the PARKINLAR (PARKINsonism, LAtent stage, Russia). As the first step, we formed a group of «primary risk» by the identification in neurologically healthy people of at least one of the following confirmed PD risk factors: a) the substantia nigra hyperechogenicity (ultrasound screening was performed in 193 people); b) mutations in «parkinsonian» genes (genetic screening was performed in 29 relatives of PD patients from families with LRRK2, PARK2 and GBA mutations). Thereby, 37 people comprised the «primary risk» group, of whom 23 agreed to continue further examination (44±10.2 years). A matched group of people without the aforementioned primary biomarkers of PD served as control. As the second step, we undertook in the prescreened groups a complex of investigations assessing the presence of secondary («minor») biomarkers of PD: Sniffin' Sticks olfactory testing; color visual evoked potentials; analysis of goal-directed eye-head-hand movements with the use of a special neuro-cybernetic system; assessment of motor and non-motor symptoms with the use of UPDRS and NMSS scales.

RESULTS

When comparing the «primary risk» group with controls, maximal differences in the occurrence of symptoms were seen for goal-directed eye movements (43.5% vs. 20.0%) and color vision (39.1% vs. 26.7%). Among these individuals, we found two people with 4 secondary biomarkers and one with 3, and no such observations in controls. People with the combination of a primary biomarker with several secondary biomarkers of PD comprised a group of «high risk» in our study.

CONCLUSION

Optimization of this algorithm of population screening of people predisposed to the development of PD may be done by expanding the spectrum of biomarkers and assessing their validity in a long-term prospective observational study.

Role of zinc and copper ions in the pathogenetic mechanisms of Alzheimer's and Parkinson's diseases

Disbalance of zinc (Zn2+) and copper (Cu2+) ions in the central nervous system is involved in the pathogenesis of numerous neurodegenerative disorders such as multisystem atrophy, amyotrophic lateral sclerosis, Creutzfeldt-Jakob disease, Wilson-Konovalov disease, Alzheimer's disease, and Parkinson's disease. Among these, Alzheimer's disease (AD) and Parkinson's disease (PD) are the most frequent age-related neurodegenerative pathologies with disorders in Zn2+ and Cu2+ homeostasis playing a pivotal role in the mechanisms of pathogenesis. In this review we generalized and systematized current literature data concerning this problem. The interactions of Zn2+ and Cu2+ with amyloid precursor protein (APP), β-amyloid (Abeta), tau-protein, metallothioneins, and GSK3β are considered, as well as the role of these interactions in the generation of free radicals in AD and PD. Analysis of the literature suggests that the main factors of AD and PD pathogenesis (oxidative stress, structural disorders and aggregation of proteins, mitochondrial dysfunction, energy deficiency) that initiate a cascade of events resulting finally in the dysfunction of neuronal networks are mediated by the disbalance of Zn2+ and Cu2+.

[Functional properties of dopaminergic neurons obtained from fibroblasts of a patient with PARK2 form of Parkinson's disease]

OBJECTIVE

To carry out a functional analysis of dopamine transporter (DAT) in autosomal recessive Parkinson's disease caused by mutations in the PARK2 gene.

MATERIAL AND METHODS

Cultures of dopaminergic neurons were obtained from fibroblasts of a patient with PARK2 form of Parkinson's disease and a healthy donor with the use of the cell reprogramming technology. DAT expression in both cell cultures was assessed at the RNA and protein levels, and DAT activity was tested with the use of the fluorescent dopamine analogue ASP+.

RESULTS AND CONCLUSION

In the cells with PARK2 mutations, the level of DAT expression was significantly higher than in normal neurons, but the intensity of ASP+ capture by mutant dopaminergic neurons was 25% down from normal neurons. For the study of competitive inhibition of DAT, dopamine was added to the incubation medium containing ASP+: it was shown that dopamine binding by the normal cells was almost twice as much relative to PARK2 mutant neurons. Therefore, dopaminergic neurons carrying mutations in the PARK2 gene are characterized by functional failure of dopamine transport systems. One of cell mechanisms of compensation of this defect seems to be an early increase of expression of the DAT transporter protein.

[Experimental approach to the gene therapy of motor neuron disease with the use of genes hypoxia-inducible factors]

Motor neuron disease (MND), or amyotrophic lateral sclerosis, is a fatal neurodegenerative disorder characterized by a progressive loss of motor neurons in the spinal cord and the brain. Several angiogenic and neurogenic growth factors, such as the vascular endothelial growth factor (VEGF), angiogenin (ANG), insulin-like growth factor (IGF) and others, have been shown to promote survival of the spinal motor neurons during ischemia. We constructed recombinant vectors using human adenovirus 5 (Ad5) carrying the VEGF, ANG or IGF genes under the control of the cytomegalovirus promoter. As a model for MND, we employed a transgenic mice strain, B6SJL-Tg (SOD1*G93A)d11 Gur/J that develops a progressive degeneration of the spinal motor neurons caused by the expression of a mutated Cu/Zn superoxide dismutase gene SOD1. Delivery of the therapeutic genes to the spinal motor neurons was done using the effect of the retrograde axonal transport after multiple injections of the Ad5-VEGF, Ad5-ANG and Ad5-IGF vectors and their combinations into the limbs and back muscles of the SOD1(G93A) mice. Viral transgene expression in the spinal cord motor neurons was confirmed by immunocytochemistry and RT-RCR. We assessed the neurological status, motor activity and lifespan of experimental and control animal groups. We discovered that SOD1(G93A) mice injected with the Ad5-VEGF + Ad5-ANG combination showed a 2-3 week delay in manifestation of the disease, higher motor activity at the advanced stages of the disease, and at least a 10% increase in the lifespan compared to the control and other experimental groups. These results support the safety and therapeutic efficacy of the tested recombinant treatment. We propose that the developed experimental MND treatment based on viral delivery of VEGF + ANG can be used as a basis for gene therapy drug development and testing in the preclinical and clinical trials of the MND.

Patient-Specific Induced Pluripotent Stem Cells for SOD1-Associated Amyotrophic Lateral Sclerosis Pathogenesis Studies

The genetic reprogramming technology allows one to generate pluripotent stem cells for individual patients. These cells, called induced pluripotent stem cells (iPSCs), can be an unlimited source of specialized cell types for the body. Thus, autologous somatic cell replacement therapy becomes possible, as well as the generation of in vitro cell models for studying the mechanisms of disease pathogenesis and drug discovery. Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disorder that leads to a loss of upper and lower motor neurons. About 10% of cases are genetically inherited, and the most common familial form of ALS is associated with mutations in the SOD1 gene. We used the reprogramming technology to generate induced pluripotent stem cells with patients with familial ALS. Patient-specific iPS cells were obtained by both integration and transgene-free delivery methods of reprogramming transcription factors. These iPS cells have the properties of pluripotent cells and are capable of direct differentiation into motor neurons.

[Analysis of mutations in patients with suspected autosomal dominant form of the Parkinson disease]

The Parkinson disease (PD) is a severe neurological disorder. Diverse genetic systems and environmental factors are involved in the pathogenesis of this disease. However, despite extensive research into the disease, its causes are not fully elucidated, and the exact spectrum of genes and mutations involved in the development of hereditary forms of PD has not been fully clarified yet. The present work is devoted to the analysis of mutations that lead to the development of monogenic forms of PD in patients with suspected autosomal dominant form of PD using Multiplex Ligation-dependent Probe Amplification (MLPA). We have identified several mutations (G2019S in LRRK2, heterozygous deletions of 2-3, 3-4 exons and heterozygous duplication of 2-4 exons in PARK2, deletion of 3 exon in PARK7) that lead to the development of PD in only 7 people out of 70 (18.4%), which suggests the need for further search of new mutations, for example, using exome sequencing. In the future it will help to develop the molecular genetic tests for early preclinical diagnosis and risk evaluation of the development of PD, and to understand better the causes and mechanisms of this disease.

[SOD1 gene mutations in patients with amyotrophic lateral sclerosis: potential for the method of molecular]

The molecular modeling method is promising for the assessment of protein structure, being able to present an energetically beneficial protein conformation with atomic precision. This method is of great importance for studying molecular interactions and confirming pathogenic significance of the changes in the protein structure caused by particular mutations. In the present study we used molecular modeling for the assessment of mutations in the SOD1 gene in patients with amyotrophic lateral sclerosis (ALS), a severe neurodegenerative disorder characterized by the loss of the spinal and cerebral motor neurons. The product of SOD1 is a cytosolic dimeric enzyme Cu/Zn superoxide dismutase (SOD1) responsible for detoxification of the cellular superoxide radicals. We showed that all 8 revealed coding point mutations of the gene led to moderate or significant changes of the SOD1 protein energy. Mutation His49Arg increased the protein energy, and reconstruction of the respective model pointed out to spatial destabilization of the molecule and abnormal interaction with the metal ion inside the active center. The other 7 mutations (Gly17Ala, Leu85Mal, Asn87Ser, Asp91Ala, Serl06Leu, Glu134Gly, and Leul45Phe), on the contrary, led to decrease of the protein energy and increase of the spatial stability of SOD1, which is usually accompanied by increased propensity of the 'inert' mutant molecule to misfolding and cellular aggregation. Thereby, the results of in silico analysis of the SOD1 gene mutations confirm staying of ALS within the class of the so-called conformational diseases of the central nervous system, a characteristic feature of which is forming of cytotoxic insoluble protein inclusions in neurons.

[Analysis of the rs12720208 single-nucleotide polymorphism of the FGF20 gene in Russian patients with sporadic Parkinson's disease]

Parkinson's disease (PD) is a multifactorial neurodegenerative disease whose pathogenesis involves a number of genes and environmental factors. The FGF20 gene encoding the fibroblast growth factor and paying an important role neuron proliferation and survival is one of candidate genes of PD. There is evidence that this gene is also involved in the control of alpha-synuclein (SNCA) gene expression. The rs12720208 single-nucleotide polymorphism (SNP) in the FGF20 gene has been found to be associated with PD; it has been located to the 3'-UTR binding site for microRNA-433, which is involved in the control of FGF20 expression. Therefore, the frequency distribution of rs12720208 genotypes in the FGF20 gene has been analyzed in a sample of patients with sporadic PD and a control sample of the Russian population. The results have not shown any effect of rs12720208 in the FGF20 gene on the risk of PD in patients residing in Russia (OR = 0.95, the 95% confidence interval (CI) is 0.55-1.63, p = 0.9).

[A combined preparation stalevo in Parkinson's disease: a 5-year experience of continuous dopaminergic stimulation]

Levodopa remains a 'gold standard' for the treatment of patients with Parkinson's disease (PD), but its chronic use is accompanied by fluctuations of symptoms and dyskinesias related to unfavorable pharmacokinetics of levodopa and progressing loss of the nigrostriatal neurons. Prescribing inhibitors of catechol-O-methyl-transferase (enzyme of dopamine metabolism), entacapone or tolcapone, is a perspective approach to the correction of the above-mentioned complications. We followed up 402 patients with PD who received long-term therapy with a combined preparation Stalevo (levodopa/carbidopa/entacapone) for 2-5 years (2.9 ± 0.9 years). The high (92.8%) compliancy and good tolerance of the drug in patients with PD was shown. Stalevo leads to the stabilization of the response to levodopa, improvement of patients' functional capacities, increase in their everyday activity, and improvement of quality of life. Stalevo may be regarded as a preparation of choice in the treatment of motor complications in elderly patients, correction of night symptoms of PD and in a number of other clinical situations arising in hospital and outpatient practice.

[Mexidant increases the effectiveness of levadopa treatment of Parkinson's disease]

The efficiency of mexidant therapy in patients with Parkinson's disease (PD) has been evaluated. The study included 49 patients aged 58-65 with a trembling-rigid and trembling forms of PD at an disease duration of 6.5 +/- 3.8 years. All patients were treated with levadopa-containing drugs, dopamine receptor agonists and/or amantadine. In addition, 27 patients received mexidant at a dose of 200 mg/day (i.v.) for the first 10 days, followed by intramuscular injections of 100 mg (twice a day) for 10 days. The dynamics of symptoms in the group of patients receiving mexidat showed that the inclusion of this drug into the therapeutic regime significantly decreased the degree of levadopa therapy side effects. Mexidant reduced the oxidative damages of blood plasma lipoproteins by neutralizing the growth of lipid hydroperoxide and increased the endogenous antioxidant status. The presented data show that mexidant enhances the efficiency of PD therapy.