Annals of Clinical and Experimental Neurology

Introduction. The relevance of studying balance impairment in patients with Parkinson’s disease (PD) lies in the need to prevent falls and injuries while enabling patients to maintain maximum independence and mobility. Promising advances in posture and gait screening using digital image processing require a thorough understanding of fundamental balance maintenance strategies.

The study was aimed at investigating balance maintenance strategies during PD “on” and “off” periods using classical and integral stabilometric parameters.

Materials and methods. The study included 27 PD patients with the median of 61 years. The mean total daily levodopa equivalent dose was 889.71 mg. All patients underwent clinical balance assessment using the Berg Balance Scale and stabilometric platform testing during “on” and “off” periods.

Results. Berg Balance Scale scores revealed mild balance impairments in PD patients, with greater severity during the “off” period (p < 0.05). Classical Romberg test parameters during the “on” period demonstrated deteriorated balance function and increased reliance on visual strategies for balance maintenance. Analysis of vector integral parameters during the “off” period showed a significant increase in angular velocity and coefficient of abrupt direction changes (p < 0.05). Stabilometry data indicate balance impairments in both PD “on” and “off” states, accompanied by different compensatory strategies.

Conclusion. Despite clinical assessments suggesting only mild balance impairments and low fall risk in PD patients, stabilometric parameters revealed more significant static balance disorders contributing to fall risk. Notably, the diagnostic value of classical stabilometric parameters decreases during the “off” period, while vector parameters characterizing balance maintenance strategies gain importance. We propose that these integral parameters can effectively assess balance quality and fundamental compensatory strategies in PD patients undergoing treatment. The findings are valuable for developing digitalized balance analysis technologies incorporating artificial intelligence.

Introduction. Young-onset amyotrophic lateral sclerosis (yALS) is a rare neurodegenerative disease characterized by the onset of clinical manifestations before the age of 45. The global prevalence, incidence, and genetic structure of yALS remain largely unknown, and the diagnosis is based primarily on clinical presentation, neurophysiologic findings, and molecular genetic analysis.

Aim. The aim of this study was to analyze cases of yALS in the Russian Center of Neurology and Neurosciences.

Materials and methods. A total of 365 ALS cases were analyzed, of which 47 (12.8%) patients met the criteria for yALS based on the age of onset and were included in this study. All patients underwent the necessary diagnostic procedures to exclude or establish a diagnosis. The coding sequence of the SOD1 gene was analyzed, and the size of the tandem hexanucleotide repeats (GGGGCC)_n in the C9orf72 gene was evaluated. In some cases, massive parallel sequencing was performed.

Results. Mutations in causative ALS genes were detected in 15 (32%) patients: in 15% of cases, variants were found in the coding sequence of the SOD1 gene and 3’ untranslated region, and in 8.7%, hexanucleotide repeat expansions (GGGGCC)_n were found in the C9orf72 gene. In addition, in four (8.5%) yALS cases, mutations in the FUS, UBQLN2, and FIG4 genes were identified using massive parallel sequencing.

Conclusion. Early identification of both sporadic and familial forms of yALS and determination of their molecular genetic patterns is critical for timely genetic counseling and identification of potentially treatable etiologies.

Introduction. Various animal models are employed to uncover the mechanisms of Alzheimer’s disease (AD) pathogenesis. Understanding brain damage pathogenesis in animal models of neurodegenerative diseases and identifying common patterns inherent to all relevant models is essential for adequate interpretation of findings, development of new models, as well as prevention and therapy strategies.

The study aimed to assess neurogenesis and remodeling of the microvasculature in the subgranular zone (SGZ) of the hippocampal dentate gyrus in mice with two AD models.

Materials and methods. The study employed two in vivo Alzheimer’s disease models: 1) animals with intrahippocampal administration of amyloid-β protein fragment Aβ_25–35; 2) 5xFAD transgenic mice. Cognitive functions were evaluated using a passive avoidance test. On days 7 and 28 post-training, we assessed vascular network branching and density in the hippocampus using Evans Blue with subsequent software-based analysis of skeletonized images, analyzed proliferative activity of neuronal and endothelial cells, and their subpopulation composition using BrdU assay and multiparameter immunostaining of brain thin sections.

Results. Animals following intrahippocampal Aβ_{25 -35} administration demonstrated enhanced neurogenesis and neoangiogenesis over 28 days post-training, unlike 5xFAD mice which showed delayed and less pronounced proliferation of neuronal cells in the SGZ alongside transient increases in proliferating endothelial cells. Both AD models exhibited divergent changes in tip and stalk cell counts within the hippocampal SGZ, indicating non-productive neoangiogenesis confirmed by reduced vascular branching and density in the SGZ of animals from both models.

Conclusion. Cognitive deficits associated with experience-induced neurogenesis and cerebral angiogenesis mechanisms in the hippocampal neurogenic niche differ between AD models representing sporadic and familial variants, highlighting the need for fundamentally different approaches to pathogenetic therapy targeting non-productive angiogenesis and aberrant brain plasticity in various Alzheimer’s type neurodegeneration scenarios.

The article addresses the global challenge of nervous system damage and cerebral consequences in metabolic disorders. It introduces the concept of impaired cerebral metabolic health as a progredient progression of cerebral dysfunction. Delineating the sequence of changes at all stages underscores the importance of targeted timely interventions to ensure preventive measures and treatment of cerebral vascular diseases.

Alzheimer disease (AD) is a chronic neurodegenerative disorder and the most common cause of dementia in the elderly. Current international guidelines for the clinical diagnosis of AD consider the diagnosis to be both clinical and biological. It requires a specific clinical phenotype and a confirmed biological origin based on biomarkers of amyloid and tau pathology. In Russia, only a few research centers perform laboratory diagnosis of AD using cerebrospinal fluid (CSF) biomarkers. Better access to laboratory diagnosis of AD and wider use of CSF biomarkers in clinical practice will help to assess the true prevalence of AD in the Russian population and to select patients for targeted pathogenic therapies based on the use of monoclonal antibodies against abnormal brain proteins, which have been actively developed in recent years. This review summarizes information on the main CSF biomarkers of AD and their diagnostic and prognostic value.

We describe a patient who experienced a right middle cerebral artery (MCA) stroke at the age of 12. Its clinical manifestations (acute onset of left-sided hemiparesis and headache during swimming) and signs of connective tissue weakness (joint hyperflexibility, increased skin elasticity) suggested right MCA dissection as the stroke cause. However, 1.5T MRI/MRA did not confirm the clinical suspicion: blood flow in the right MCA was preserved, and no intramural hematoma was detected. Only an irregular MCA contour was noted. High-resolution 3T MRI performed seven years later revealed a double lumen in the right MCA — a characteristic dissection sign — confirming the initial clinical hypothesis. This case demonstrates that when MCA dissection is clinically suspected as the cause of ischemic stroke, high-resolution MRI is necessary to verify neuroimaging signs of dissection.