[Clinical effectiveness study of transcranial direct current stimulation in amblyopic children]. / Klinicheskaia éffektivnost' primeneniia transkranial'noi mikropoliarizatsii u detei s ambliopiei.

PURPOSE: to assess the neurophysiological effect and clinical effectiveness of transcranial direct current stimulation in combination with drug therapy in amblyopic children. MATERIAL AND METHODS: The study involved 32 healthy children in the age of 5-12 years and 97 patients of the same age with refractive strabismic amblyopia. All study subjects underwent standard examination including ophthalmological (visometry, refractometry in normal conditions and in cycloplegia, biomicroscopy, ophthalmoscopy, type of vision), neurophysiological methods (determination of retinal electric sensitivity threshold, electric lability of optic nerve, amplitude and latency period of visual evoked potentials, electroencephalogram wave amplitudes, localization of peak electrical activity area of the cerebral cortex), assessment of neuropsychic development and estimation of mental development coefficient with age tests. RESULTS: Dynamics of neurophysiological parameters shows that healthy children develop fully functional retina, visual cortex and cortical-subcortical connections by 12 years. Children with refractive strabismic amblyopia in all age groups show statistically significant (р<0.05) deterioration of neurophysiological parameters of the visual analyzer, retardation of cortical-subcortical connections formation and lower electrical activity of the cerebral cortex. Amblyopic children show lower coefficients of mental development accompanied by intellectual deficiency and deterioration of learning ability. Proposed treatment method improved neurophysiological parameters of the visual analyzer in 83.5% of cases and increased visual acuity in 81.4% of cases. Improvement of psychological development resulted in better logical thinking, memory reinforcement and better adaptation to school educational environment in 86.6% of children.

[Neuprotection of post-acute COVID-19 cognitive impairment]. / Neiroprotektsiya pri postkovidnykh kognitivnykh narusheniyakh.

OBJECTIVE: To evaluate the efficacy of Cortexin in the treatment of patients with post-Covid impairment. MATERIAL AND METHODS: Treatment results of 109 patients with post-Covid cognitive impairment aged from 42 to 65 years were analyzed. The main group (MG, n=52), 29 (55.8%) men and 23 (44.2%) women, average age 58.1±4.9 years, who received Cortexin continuously for 20 days at a dose of 10 mg i.m., after 3, 6 months. The comparison group included 57 people, 31 (54.4%) men and 26 (45.6%) women (average age 59.3±3.8 years). The effectiveness of therapy was assessed using neuropsychological testing with international scales. RESULTS: During treatment, statistically significant differences were obtained in MG patients in the form of improved concentration (p<0.05), increased control of exutative functions (p<0.05), and auditory-verbal memory (p=0.002). There were no adverse events in the MG. CONCLUSION: Cortexin is highly effective and safe, and can be recommended as part of a combined staged therapy for post-Covid cognitive impairment. Thus, the study confirms the feasibility of using Cortexin, which has a neurocytoprotective effect.

A novel perspective of associativity of upper limb motor impairment and cortical excitability in sub-acute and chronic stroke.

Background: The global inclination of stroke onset in earlier years of life and increased lifespan have resulted in an increased chronic post-stroke-related disability. The precise and simplistic approach such as the correlation of Fugl-Meyer Assessment (FMA) with Transcranial Magnetic Stimulation (TMS) parameters, Resting Motor Threshold (RMT) and Motor Evoked Potential (MEP), in patients with stroke might play a critical role, given the prognostic value of MEP, a measure of cortical excitability, and might be the key point in prescribing appropriate therapeutic strategies. Objective: The study aimed to determine the correlation of FMA-based impairment in the upper extremity function specifically of the wrist and hand with respect to the neurophysiological parameters of corticospinal tract integrity. Materials and methods: The Institutional Review Board approved the study and 67 (n) patients with stroke were enrolled in the Department of Neurology, AIIMS, New Delhi, India. The motor assessment was performed on patients by the upper extremity subset of Fugl-Meyer Assessment (FMA) and the clinical history was obtained. RMT and MEP of Extensor Digitorum Communis (EDC) muscle were measured via TMS. Results: A significant positive correlation was observed between Fugl-Meyer Assessment Wrist/Hand (FMA W/H) and MEP scores (r = 0.560, <0.001). Also, Fugl-Meyer Assessment Upper Extremity (FMA UE) scores demonstrated a moderate positive association with MEP responsiveness (r = 0.421, <0.001). Conclusion: MEP of the EDC muscle was found to be associated with sensorimotor control as measured by FMA. Moreover, FMA W/H score values might be a better prognostic indicator of EDC MEP responsiveness. Interestingly, a novel element comprising the range of FMA UE and FMA W/H components was observed to be a potential indicator of MEP responsiveness and could also indicate establishing FMA as a surrogate for TMS in resource-limited settings for prognostification.

Muscle strength and force development in high- and low-functioning elderly men: Influence of muscular and neural factors.

BACKGROUND: Aging leads to a loss of muscle strength and functional capacity likely resulting from a combination of neural and muscle alterations. The aim of this study was to identify possible disparities in muscle strength and force development profiles in high- and low-functioning elderly men and to investigate muscular and neurophysiological factors that could explain the differences. METHODS: Sixty community-dwelling men in good general health were divided in two groups based on a functional capacity (FC) z-score derived from 6 tests of the Short Physical Performance Battery and Senior Fitness Test (Normal and fast 4m-walk tests, normal and fast Timed-up and go, chair and stair tests). Extensor strength of the lower limbs (LL) was obtained for concentric (CLES) contraction and combined with lean masses of LL (LLLM) to yield concentric (CLES/LLLM) index. Similarly, extensor strength of the right Quadriceps Femoris (IKES) was obtained during maximal voluntary isometric contraction (MVC) and combined with right thigh lean mass (rTLM) to produce an isometric strength (IKES/rTLM) index. A muscular profile was obtained from: ascending and descending force slopes during the MVC; Vastus Lateralis (VL) muscle twitches parameters (amplitude, contraction and ½ relaxation times); the knee joint velocity (KV) as well as integrated EMG (iEMG) were determined for a sit-to-stand functional evaluation; muscle phenotype. A neurophysiological profile was established from: the spinal excitability (Hmax/Mmax ratio); motoneuron conduction velocity (CV); the completeness of muscle activation (% of force reserve), median power frequency (MPF) and mean amplitude (MA) of the VL EMG signal during MVC. RESULTS: Coincidently, age did not differ between groups. Strength and force indices, descending force slopes for MVC, KV and iEMG during the sit-to-stand evaluation and FC parameters were all significantly (p<0.05) lower in the LoFC group than in the HiFC group. In contrast, no difference was observed between groups in: LLLM and rTLM, Hmax/Mmax ratio, CV, twitch parameters and muscle phenotype. CONCLUSION: The lower concentric and isometric strengths found in the LoFC group could not be accounted for by muscular factors. Similarly, peripheral nervous systems alterations could not explain group differences. It can be suggested that modifications within the central nervous system may be responsible for the differences in the functional status of healthy elderly individuals. Finally, more complex and demanding tasks, such as those requiring greater intensity or coordination, may further clarify how healthy elderly individuals with low and high functional capacities differ.