[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.