[Cerebrovascular disease with neurocognitive impairment]

[Meta-analysis of randomized controlled trials of the effectiveness of Prospekta in the treatment of vascular cognitive impairment of varying severity]

OBJECTIVE

To conduct a meta-analysis of randomized controlled trials (RCTs) to evaluate the efficacy of Prospekta in the treatment of SCI of varying severity.

MATERIAL AND METHODS

The meta-analysis included the results of RCTs of the efficacy of Prospekta in the treatment of VCI, the severity of which was assessed using the Montreal Cognitive Scale (MoCA). The pooled effect estimate included all publications of double-blind, placebo-controlled RCTs that provided sufficient MoCA efficacy data to support further statistical analysis. The main result of the meta-analysis was obtained for the final values of the efficacy indicator in the groups of patients receiving the drug Prospekta, in comparison with the placebo group.

RESULTS

A meta-analysis of the effectiveness of Prospekta in the treatment of SCI of varying severity was carried out based on data from 3 RCTs and 2 CTs involving 12.701 patients aged 18 years and older. When using the mixed models method, the effect size for the endpoint «change in total MoCA score from baseline to follow-up visit» was 3.4 points for Prospekta (2.7 points for placebo, p<0.0001); for the end point «∆ between changes in the total score on the MoCA scale while taking Prospekta and placebo» - 0.6736 points (p<0.0001).

CONCLUSION

A statistically significant improvement in cognitive function according to the MoCA scale was demonstrated in patients with VCI using the drug Prospekta.

[Disruption of corpus callosum microstructural integrity by diffusion MRI as a predictor of progression of cerebral microangiopathy]

OBJECTIVE

To assess the microstructural integrity of the corpus callosum in patients with cerebral small vessel disease (cSVD) using signal and biophysical diffusion MRI models and to identify the most sensitive markers of disease progression.

MATERIAL AND METHODS

Diffusion MRI (3 Tesla) was performed in 166 patients (51.8% women; mean age 60.4±7.6) with cSVD and cognitive impairment of varying severity and in 44 healthy volunteers (65.9% women; mean age 59.6±6.8), followed by calculation of signal (diffusion tensor and diffusion kurtosis) and biophysical (WMTI, NODDI, MC-SMT) models, from which profiles of three corpus callosum segments were constructed.

RESULTS

The best results were obtained for metrics in the forceps minor and body of the corpus callosum. Among the metrics of the signal models in the forceps minor, fraction anisotropy (FA) and mean diffusion (MD), which characterize the overall loss of microstructural integrity and increase in extra-axonal water, as well as indirect markers of demyelination when considering transverse diffusion parameters (radial diffusion and radial kurtosis), had the larger area under the curve according to the ROC analysis. Among the metrics of the biophysical models in the forceps minor, a larger area under the curve was found in the MC-SMT model for extra-axonal transverse diffusion (ETR), mean diffusion (EMD), and intra-axonal water fraction (INTRA), and in the WMTI model for intra-axonal water fraction (AWF). ETR had high inverse correlations with INTRA and AWF, while INTRA and AWF had high direct intercorrelations.

CONCLUSION

Metrics of signaling (FA, MD, RD, RK) and biophysical patterns (ETR, EMD, INTRA, AWF) in the forceps minor and the corpus callosum body can be considered as indicators of cSVD progression. They indicate disease progression, mainly by an increase in extra-axonal water with the development of demyelination and tissue degeneration in the corpus callosum.

[Nitric oxide availability in cerebral microangiopathy]

OBJECTIVE

To develop a test of individual nitric oxide (NO) availability based on changes in erythrocyte rheological properties after incubation with a NO donor and to evaluate the role of these disorders in brain damage and development of cognitive impairment (CI) in cerebral small vessel disease (cSVD).

MATERIAL AND METHODS

In 73 cSVD patients (48 (65.8%) women, mean age 60.1±6.5), the rheological properties of erythrocytes before and after incubation with 10 μmol/L L-arginine-NO donor were evaluated using a laser-optical rotating cell analyzer, and the blood-brain barrier (BBB) permeability by MRI-T1 dynamic contrast.

RESULTS

Among the studied parameters of erythrocyte rheological properties, the best characteristic by ROC analysis was the rate of erythrocyte disaggregation (y-dis) after incubation with L-arginine (area under the curve 0.733 (0.609-0.856), sensitivity 67%, specificity 79%). Patients with a y-dis threshold >113 sec-1 had more severe CI, arterial hypertension, white matter lesions, and increased BBB permeability in gray matter and normal-appearing white matter.

CONCLUSION

The prolonged rate of erythrocyte disaggregation in cSVD patients after incubation with L-arginine indicates the risk for disease progression due to decreased NO bioavailability/disruption of the functional L-arginine-eNOS-NO system. This test can be used to assess individual NO bioavailability and potentially identify indications for modifying therapy with NO donors such as L-arginine. Clinical trials are needed to standardize and evaluate the efficacy of NO donor therapy in patients with cSVD and CI.