[Identifying the neurostimulation target for treatment of cognitive impairment in aging and early cerebral small vessel disease]. / Vybor misheni neiromodulyatsii dlya korrektsii kognitivnykh rasstroistv pri starenii i rannei tserebral'noi mikroangiopatii.

OBJECTIVE: To develop individualized approaches to the use of neuromodulation as a non-pharmacological treatment of cognitive impairment (CI) based on the assessment of compensatory brain reserves in functional MRI (fMRI). MATERIAL AND METHODS: Twenty-one adults over 45 years of age, representing a continuum from healthy norm to mild cognitive impairment due to aging and early cerebral small vessel disease, were studied. All participants underwent fMRI while performing two executive tasks - a modified Stroop task and selective counting. To assess the ability to compensate for CI in real life, functional activation and connectivity were analyzed using the BRIEF-MoCA score as a covariate, which is the difference in ratings between the Behavior Rating Inventory of Executive Function (BRIEF) and the Montreal Cognitive Assessment Scale (MoCA). RESULTS: Both fMRI tasks were associated with activation of areas of the frontoparietal control network, as well as supplementary motor area (SMA) and the pre-SMA, the lateral premotor cortex, and the cerebellum. An increase in pre- SMA connectivity was observed during the tasks. The BRIEF-MoCA score correlated firstly with connectivity of the left dorsolateral prefrontal cortex (DLPFC) and secondly with involvement of the occipital cortex during the counting task. CONCLUSIONS: The developed technique allows identification of the functionally relevant target within the left DLPFC in patients with CI in aging and early cerebral microangiopathy.

[Disruption of corpus callosum microstructural integrity by diffusion MRI as a predictor of progression of cerebral microangiopathy]. / Narushenie mikrostrukturnoi tselostnosti mozolistogo tela po dannym diffuzionnoi MRT kak prediktor progressirovaniya tserebral'noi mikroangiopatii.

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.

Individual Variability of Broca's Area of the Brain in Women.

In this article, we studied individual features of the macroscopic structure of Broca's area of the brains in 9 women (18 hemispheres) aged from 20 to 30 years, without any mental or neurological disorders. By using MRI, the structures of the sulci and gyri of the pars triangularis and pars opercularis of Broca's area were studied: the anterior and ascending rami of the lateral sulcus, the radial, diagonal, precentral, inferior frontal, and lateral sulci. We also studied the relationship between the pars triangularis and pars opercularis as well as their relationships with neighboring cortical structures. We measured the volume of the pars triangularis and pars opercularis and the thickness of their cortex. Significant individual variability in the location and relationships between the anterior ramus of the lateral sulcus and the ascending ramus of the lateral sulcus, as well as structural features of the pars triangularis and pars opercularis of Broca's area were demonstrated.

[Gender morphology of Broca's motor speech area]. / Gendernaya morfologiya rechedvigatel'noi zony Broka.

OBJECTIVE: To study the general patterns and differences in the macroscopic structure of Broca's motor speech area in the left and right hemispheres of male and female brains. MATERIAL AND METHODS: The study was conducted on MRI images of the brains of 9 men and 9 women (36 hemispheres in total). All the people were between the ages of 20 and 30, without any mental or neurological disorders. The localization and structure of the main sulci and gyri of Broca's area, namely the pars triangularis and pars opercularis, were studied. In addition, the topography of the main sulci in Broca's motor speech area, namely their shape, length, and relative position to the other sulci, was analyzed. RESULTS: The features of the localization of the sulci in Broca's area, the differences in the number of additional sulci in the pars triangularis and pars opercularis of male and female brains, as well as the degree of asymmetry of Broca's area in the left and right hemispheres of the brains of men and women were established.In modern neuroscience a new scientific direction of genderology, which studies the behavior and cognitive functions of males and females, is rapidly developing. CONCLUSION: Broca's motor speech area of the brain of men and women differs in macroscopic structure.

[Nitric oxide availability in cerebral microangiopathy]. / Dostupnost' oksida azota pri tserebral'noi mikroangiopatii.

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.

[Quantitative susceptibility mapping in assessment of inflammation and neurodegeneration in multiple sclerosis]. / Kolichestvennoe kartirovanie vospriimchivosti v otsenke vospalitel'nogo i neirodegenerativnogo protsessov pri rasseyannom skleroze.

Quantitative susceptibility mapping (QSM) is a relatively new MRI technique that may potentially help estimate iron concentrations in the brain. It plays a big role in diagnosis of many pathological processes, including multiple sclerosis (MS). Iron metabolism in the brain is a complex and not fully understood process. It is known that the content of iron in the brain increases with age; in addition, its accumulation is often observed in many neurodegenerative diseases, including MS foci, and its amount changes over time. In this regard, the values of magnetic susceptibility obtained using QSM can potentially become a convenient biomarker that reflects the latent activity and progression of MS, which, in turn, can influence the choice of therapy and the tactics of treating patients.

[Controlled arterial hypertension and blood-brain barrier damage in patients with age-related cerebral small vessel disease and cognitive impairments]. / Kontroliruemaya arterial'naya gipertenziya i povrezhdenie gematoentsefalicheskogo bar'era u bol'nykh s vozrastzavisimoi tserebral'noi mikroangiopatiei i kognitivnymi narusheniyami.

OBJECTIVE: To evaluate the relationship between blood pressure (BP) profile and blood-brain barrier (BBB) permeability in age-related cerebral microangiopathy (CMA) in patients with- and without controlled arterial hypertension (AH). MATERIAL AND METHODS: 24-hour ambulatory BP monitoring (ABPM), brain MRI, including T1-weighted dynamic contrast images, were performed in 53 patients with CMA (age 60.1±6.8, women 69.8%, controlled hypertension/normal BP 84.8%/15.2%) and 17 healthy volunteers. RESULTS: ABPM showed good control of AH with most of the assessed parameters associated with the severity of white matter hyperintensity (WMH). The permeability of the BBB in normal-appearing white matter (NAWM) and gray matter in patients with CMA was significantly higher than in the control group and was associated with ABPM parameters. The permeability of the BBB in WMH decreased with an increase in its severity. CONCLUSION: BBB permeability is a universal mechanism of NAWM and gray matter damage that supports the progression of WMH in CMA patients with controlled AH and without AH. The relationship of increased BBB permeability with slight deviations of ABPM can be explained by common mechanisms of their development due to endothelial dysfunction due to CMA and also points to the utility of more aggressive AH treatment. It is advisable to study the effect of antihypertensive and vascular drugs on BBB permeability with a view to their potential use in CMA.

Daily blood pressure profile and blood-brain barrier permeability in patients with cerebral small vessel disease.

Cerebral small vessel disease (CSVD) plays an important role in cognitive impairment, stroke, disability, and death. Hypertension is the main risk factor for CSVD. The use of antihypertensive therapy has not resulted in the expected decrease in CSVD complications, which may be related to the underestimation of significance of daily blood pressure profile for blood-brain barrier (BBB) permeability. 53 patients with CSVD of varying severity (mean age 60.08 ± 6.8 years, 69.8% women, subjects with treated long-standing hypertension vs. normotensive subjects - 84.8% vs. 15.2%) and 17 healthy volunteers underwent ambulatory blood pressure monitoring (ABPM) and MRI, including T1-weighted dynamic contrast-enhanced magnetic resonance imaging for assessing BBB permeability. Most of ABPM parameters in CSVD patients did not differ from controls, but were associated with the severity of white matter hyperintensity (WMH) and the total CSVD score. BBB permeability in normal-appearing white matter (NAWM) and grey matter (GM) was significantly higher in CSVD patients, and the severity of BBB permeability remained similar in patients with different stages of WMH. Among BBB permeability parameters, the area under the curve, corresponding to an increase in the contrast transit time in NAWM, had the greatest number of correlations with deviations of ABPM parameters. BBB permeability in CSVD is a universal mechanism of NAWM and GM damage associated with a slight increase in ABPM parameters. It is obvious that the treatment of hypertension in patients with not severe WMH should be more aggressive and carried out under the control of ABPM.

[Predictors and integrative index of severity of cognitive disorders in cerebral microangiopathy]. / Prediktory i integrativnyi pokazatel' tyazhesti kognitivnykh rasstroistv pri tserebral'noi mikroangiopatii.

OBJECTIVE: To search for sensitive predictors of cognitive impairment (CI) and an integrative index of their severity. MATERIAL AND METHODS: We assessed CI and diffusion-tensor MRI (DT-MRI) in the regions of interest (ROI) significant for CI in 74 patients (48 women, mean age 60.6±6.9 years) with cerebral small vessel disease (CSVD). The results of DT-MRI were used to construct a predictive model of CI using binary logistic regression and to calculate an integrative index of CI severity. RESULTS: According to the constructed model, the predictors of CI were axial diffusivity (AD) of posterior frontal periventricular normal-appearing white matter (pvNAWM), right middle cingulum bundle (CB) and mid-posterior corpus callosum (CC). ROC analysis showed strong model predictive power for CI in cSVD (AUC (95% CI): 0.845 (0.740-0.950)). The threshold value of the AD predictors model for CI in cSVD was 0.53 (sensitivity 84%, specificity 76%). AD predictors of CI showed significant correlations with white matter hyperintensities volume and MoCA scores. The presence of CI as measured by neuropsychological testing and regression equation solution was corresponded to individual AD predictors of patients exceeding the CI model's threshold. CONCLUSION: Disturbances in the AD of pvNAWM, right middle CB and mid-posterior CC associated with axonal damage are a predominant factor in the development of CI in CSVD. The predictors of CI and the integrative index of CI severity calculated on their basis can potentially be used as a tool for assessing the severity of CI and the effectiveness of treatment, as well as in clarifying the interaction between vascular and degenerative pathology and in developing measures for the prevention of CI in patients with MRI signs of cSVD.

[Resting state functional MRI in neurology and psychiatry]. / Funktsional'naya MRT pokoya v nevrologii i psikhiatrii.

Resting state functional magnetic resonance imaging (fMRI) is a neuroimaging technique based on analyzing spontaneous, low frequency fluctuations in the activity of brain areas by measuring by their MRI signal to investigate the functional architecture of the brain during rest. The use of resting state fMRI opens up possibilities for assessing brain functional relationships in both normal conditions and in different CNS pathologies in order to clarify the disturbed mechanisms of brain functioning and develop approaches for therapeutic non-invasive neuromodulation. Understanding the acquisition of data, the features of their preprocessing and analysis is very important for clinicians who use resting state fMRI in their studies, since it is neurologists, psychiatrists, and neurosurgeons who set research tasks and are the final consumers of the results. The article details the methodological features of obtaining and analyzing resting state fMRI data, the advantages and disadvantages of the method. The article is intended for a wide range of specialists using this method in their work or planning to include it in their research.

White matter hyperintensity in different migraine subtypes.

The diagnostic value of white matter hyperintensities (WMH) in different types of migraineare unknown. To evaluate the WMH pattern of different subtypes in migraine patients with no vascular risk factors. 92 migraine patients (73 females, mean age 34.6 ± 8.9; 61 episodic migraine, 31 chronic migraine, 36 migraine with aura, 56 migraine without aura) without vascular risk factors underwent brain MRI (3 T). We also included a matched healthy control group with no migraine (n = 24). The prevalence of WMH in different types of migraine was similar and ranged from 38.7 to 44.4%; the control group showed no WMH at all. Lesions were located within frontal, parietal and temporal lobes (in order of decreasing incidence) in juxtacortical and/or deep white matter. WMH appeared as round or slightly elongated foci with a median size of 2.5 mm [1.5; 3]. Total number, size and prevalence of WMH by lobes and white matter regions were similar between groups, and no interaction with age or sex was found. The number of lesions within the frontal lobe juxtacortical white matter correlated with the age of patients (r = 0.331, p = 0.001) and the duration since migraine onset (r = 0.264, p = 0.012). Patients with different migraine subtypes and without vascular risk factors are characterized by a similar pattern of WMH in the absence of subclinical infarctions or microbleedings. Therefore, WMH have no relevant prognostic value regarding the course of migraine and vascular complications. WMH pattern may be used to differentiate migraine as a primary disorder and other disorders with migraine-like headache and WMH.

[Salt sensitivity and osmotic fragility are newly specified risk factors for age-related cerebral microangiopathy]. / Sol'-chuvstvitel'nost' i osmorezistentnost' ­ faktory riska vozrast-zavisimoi tserebral'noi mikroangiopatii.

AIM/: To assess individual values of salt sensitivity and osmotic fragility on the patient's erythrocytes and evaluate predictive ability of these parameters in the development of cerebral small vessel disease (CSVD). MATERIAL AND METHODS: The study included 73 patients with CSVD (48 women, mean age 60.1±6.5 years) and 19 volunteers (14 women, mean age 56.9±5.4 years). Their erythrocytes were used for the measurement of salt-sensitivity by a modified salt blood test and of osmotic fragility by the classical osmotic fragility test. Binary logistic regression was used to assess the ability of salt-sensitivity and osmotic fragility to predict CSVD development. ROC analysis was used to find out the optimal threshold values of these predictors, their sensitivity and specificity. RESULTS: An increase in salt sensitivity (cut-off: 8.5 mm/h; sensitivity 64%, specificity 74%) and osmotic fragility (cut-off: 0.62 u.a.; sensitivity 52%, specificity 90%) or their simultaneous use (p of the model <0.000001, cut-off 0.62; sensitivity 88%, specificity 68%) are the independent predictors of CSVD. An increase in salt sensitivity and osmotic fragility is also independently associated with the acceleration of severity of white matter hyperintensities according to Fazekas stages (p=0.019 and 0.004, respectively). CONCLUSION: The possibility of prediction of CSVD according to an increase in salt sensitivity and osmotic fragility allows us to consider them as the risk factors of CSVD. The standardization of these tests for use in clinical practice is necessary to identify the risk group for CSVD and its individual prevention.

[Aneurysms and pathological tortuosity of the internal carotid and vertebral arteries in patients with dissection of these vessels: a results of long-term study]. / Anevrizmy i patologicheskaya izvitost' vnutrennikh sonnykh i pozvonochnykh arterii u bol'nykh s dissektsiei etikh sosudov: rezul'taty dolgosrochnogo issledovaniya.

OBJECTIVE: To study the frequency, angiographic and clinical features of aneurysms and tortuosity (T) in patients with internal carotid artery (ICA) and vertebral artery (VA) dissection. MATERIAL AND METHODS: Three hundred and twenty-seven patients (average age - 37.8±9.1 years, women - 57%) with ICA/VA dissection verified by neuroimaging were studied. Repeated neuroimaging in 2.4±3.3 years was performed in 254 patients. In one case, tortuous ICA fragment resected at the surgery complicated by dissection was histologically studied. RESULTS: ICA/VA aneurysms were found in 46 (14%) patients. At repeated neuroimaging aneurysms did not change (38%), increased (11%) or decreased in size (8%), were not detected (38%) or were detected for the first time (5%). Patients with aneurysms compared with those without aneurysms more often had multiple dissections (44% vs. 20%, p=0.001) and T (35% vs. 13%, p=0.001), but less frequently the artery lumen occlusion in the acute period (15% vs. 40%, p=0.001). T was found in 53 (16%) patients. Patients with T compared with patients without T were older (40.6±8.1 vs. 37.3±9.3 years, p=0.039), more often had aneurysms (30% vs. 11%, p=0.001) and recanalization of occlusion observed in the acute period (89% vs. 54%, p=0.006). Dissection more often occurred in tortuous than in non-tortuous artery (79% vs 21%, p=0.001). During 4.8±3.6 years of follow-up, TIA developed inone patient (2%) with an aneurysm. Histological examination of tortuous ICA fragment, which also contained a small aneurysm, revealed dysplastic changes. CONCLUSION: The association between aneurism and T in patients with ICA/VA dissection suggests their common basis - the arterial wall weakness due to dysplasia. Age-related changes are also important for T development. T is a risk factor for ICA/VA dissection. Aneurysms formed after ICA/VA dissection have a benign course.

[Clustering of diagnostic MRI signs of cerebral microangiopathy and its relationship with markers of inflammation and angiogenesis]. / Klasterizatsiya diagnosticheskikh MRT-priznakov tserebral'noi mikroangiopatii i ee svyaz' s markerami vospaleniya i angiogeneza.

OBJECTIVE: To perform cluster analysis of MRI signs of cerebral microangiopathy (small vessel disease, SVD) and to clarify the relationship between the isolated groups and circulating markers of inflammation and angiogenesis. MATERIAL AND METHODS: The identification of groups of MRI signs (MRI types) using cluster hierarchical agglomerative analysis and iterative algorithm of k-means and assessment of their relationship with serum concentrations of tumor necrosis factor-α (TNF-α), transforming growth factor-ß1 (TGF-ß1), vascular endothelial growth factor-A (VEGF-A), hypoxia-inducible factor 1-α (HIF1-α) determined by ELISA were performed in 96 patients with SVD (STRIVE, 2013) (65 women, average age 60.91±6.57 years). RESULTS: Cluster analysis of MRI signs identified two MRI types of SVD with Fazekas grade 3 of white matter hyperintensity (WMH). MRI type 1 (n=18; 6 women, mean age 59.1±6.8 years) and MRI type 2 (n=22, 15 f., mean age 63.5±6.2 years) did not differ by age, sex, severity of hypertension, presence of other risk factors. MRI type 1 had a statistically significantly more pronounced WMH in the periventricular regions, multiple lacunes and microbleeds, atrophy, severe cognitive impairment and gait disorders compared with MRI type 2. Its formation was associated with a decrease in VEGF-A level. MRI type 2 had the significantly more pronounced juxtacortical WMH, white matter lacunes, in the absence of microbleeds and atrophy, and less severe clinical manifestations compared with MRI type 1. Its formation was associated with an increase in TNF-α level. CONCLUSION: Clustering of diagnostic MRI signs into MRI types of SVD with significant differences in the severity of clinical manifestations suggests the pathogenetic heterogeneity of age-related SVD. The relationship of MRI types with circulating markers of different mechanisms of vascular wall and brain damage indicates the dominant role of depletion of angiogenesis in the formation of MRI type 1 and increased inflammation in the formation of MRI type 2. Further studies are needed to clarify the criteria and diagnostic value of differentiation of MRI types of SVD, and also their mechanisms with the definition of pathogenetically justified prevention and treatment of various forms of SVD.

[Intracerebral hemorrhage in the late period of internal carotid artery dissection]. / Vnutrimozgovye krovoizliianiia v pozdnem periode dissektsii vnutrennei sonnoi arterii.

Cervical artery dissection is the common cause of ischemic stroke in young and middle-age patients. According to our previous studies, dissection is related to arterial wall dysplastic changes, which in their turn are due to mitochondrial cytopathy. The authors describe three male patients who at the age of 53, 25 and 35 years underwent internal artery (ICA) dissection with occlusion of its lumen and subsequent recanalization in one of them. In 3.5 months, 13.5 years and 3 years respectively, patients developed intracerebral hemorrhage (IСH), which was not related to arterial hypertension, cerebral arterial aneurysms and anticoagulants. IСH were located on the side of ICA occluded after dissection (2 patients) or bilaterally in the territory of patent ICA (1 patient). Multivoxel 1H-MR spectroscopy performed in one patient on 40 and 48 days after ICH revealed a high lactate peak in the externally unchanged hemispheric white matter. It is assumed that mitochondrial cytopathy in patients with dissection may involve large as well as small intracerebral arteries (mitochondrial microangiopathy), which could be the cause of ICH.

[Predictors of acute cerebral embolic lesions during carotid artery stenting]. / Prediktory ostrykh tserebral'nykh émbolicheskikh povrezhdenii pri stentirovanii sonnoi arterii.

The authors carried out a prospective study aimed at revealing predictors of acute embolic lesions of cerebral vessels during angioplasty with stenting of the internal carotid artery. The study enrolled a total of 54 patients who between May 2015 and December 2018 underwent carotid angioplasty with stenting performed at the Department of Vascular and Endovascular Surgery of the Research Centre of Neurology. The procedure of internal carotid artery stenting may be accompanied by intraoperative acute embolic lesions. In order to reveal intraoperative acute embolic lesions of cerebral vessels all patients before and 24 hours after the intervention were subjected to diffusion-weighted magnetic resonance imaging. Thirty-six patients received classical carotid stents (Xact and Acculink) and 18 patients received Casper stents. The patients of both groups were comparable by 24 characteristics studied, including the incidence of intraoperative acute cerebral embolic lesions (18/36 for the classical stents and 10/18 for the Casper stent), which made it possible to unite them into one group in order to increase the power of the study. All acute embolic lesions detected by the diffusion-weighted magnetic resonance imaging (prior to stenting and 24 hours thereafter) were clinically, asymptomatic with no perioperative stroke observed. In order to reveal predictors of intraoperative acute embolic lesions of cerebral vessels we analysed 22 characteristics of the patients, with the obtained findings demonstrating the following signs: a low-intensity (below 20 dB) ultrasonographic signal reflected from fragments of an atherosclerotic plaque during ultrasound examination prior to stenting (p=0.001) - a sign strongly associated with acute embolic lesions (sensitivity - 75%, specificity - 92%); symptomatic stenosis according to the anamnestic data (p=0.02) - a sign significantly associated with acute embolic lesions; female gender (p=0.06) - a sign moderately associated with acute embolic lesions; a history previously endured (according to the anamnestic data) operations on coronary and/or carotid arteries (p=0.09) - a sign weakly associated with acute embolic lesions. Based on the obtained findings we proposed a prognostic scale to assess the risk of acute embolic lesions of cerebral vessels during internal carotid artery stenting. Knowing the factors associated with intraoperative acute embolic lesions will allow the endovascular surgeon to single out the patients at increased risk of acute embolic lesions.

[The role of arterial, venous blood and cerebrospinal fluid flow disturbances in forming cognitive impairment types in age-related cerebral microangiophathy]. / Rol' narushenii arterial'nogo, venoznogo krovotoka i likvorotoka v formirovanii kognitivnykh rasstroistv pri vozrastzavisimoi tserebral'noi mikroangiopatii.

BACKGROUND: Age-related cerebral microangiopathy (small vessel disease, SVD) is the main cause of vascular and mixed cognitive impairment (CI) with a complex neuropsychological profile. AIM: To investigate the role of arterial and venous blood flow and cerebrospinal fluid (CSF) flow, as well as their interrelation, in the forming of CI types in patients with SVD. MATERIAL AND METHODS: Fifty patients (31 f., mean age 61.2±6,2) with SVD (STRIVE, 2013), including 37 with mild CI and 13 with dementia, were examined. A type of CI was determined based on combination of standard deviations from normal results on memory and executive function tests: isolated dysexecutive (13) and predominantly dysexecutive (6), predominantly amnestic (12), mixed, equal impairment of EF and memory, (19). In the statistical analysis, groups of the isolated and predominantly dysexecutive types were merged according to the dominance of deviations in the EF into the dysexecutive type of CI (19). Phase contrast MRI (PhC-MRI) was used to assess characteristics of arterial and venous blood flow and CSF flow on different levels. Indexes of pulse and intracranial compliance and surface of the cerebral aqueduct were calculated. RESULTS: Patients with all CI types had a CSF flow systolic peak delay at the cervical level. Mixed and dysexecutive CI types as compared with predominantly amnestic type and control were defined by blood flow reduction in the sinus rectus, and mixed type by the additional decrease in its pulse wave width, blood flow reduction in an internal jugular artery and maximal blood flow velocity in the inner carotid artery, the increase in the intracranial compliance index and surface of the cerebral aqueduct. CONCLUSION: The neuropsychological CI type in SVD is defined by features of pathophysiological mechanisms conditioned on differences in blood flow and CSF flow impairment severity and formed hydrodynamic interaction between them. Differential features of CI types in SVD defined by PhC-MRI might become important predictive indicators of potential interaction between SVD and degeneration, improve understanding of risk factors, pathogenesis, prevention and treatment of age-related brain damage.

[Executive functions: fMRI of healthy volunteers during Stroop test and the serial count test]. / Upravliaiushchie funktsii mozga: funktsional'naia magnitno-rezonansnaia tomografiia s ispol'zovaniem testa Strupa i testa seriinogo scheta pro sebia u zdorovykh.

AIM: To assess executive function in healthy adults using fMRI. MATERIAL AND METHODS: An analysis of fMRI activation and functional connectivity during a serial count task (as a shifting function test) and color-word Stroop test (classical inhibition function test) was made for 12 healthy adults. RESULTS AND CONCLUSION: The executive control network and salience network activation was comparable in both tasks. Nevertheless, there were differences between two tests in functional connectivity of the dorsolateral prefrontal cortex (DLPFC) and the supplementary motor area (SMA) with other brain regions, that can be explained by the differences in the regulatory mechanisms of task performance. Stroop test assumes its automatic performance, and control of program realization is performed mainly by executive-control network. The connectivity between the two DLPFCs with the lower parietal lobules and with each other and inhibition by SMA connectivity with only the right hemisphere regions support this notion. Serial count task excludes the process of monotonous learning, that was confirmed by widespread SMA connections in the absence of connectivity of the DLPFC with executive control network regions. This connectivity pattern allows assuming the leading role of SMA in certain brain regions choice and switching their activity for providing attention and executive control of cognitive operations shift during task performance. These findings allow us to consider the serial count task as the relevant fMRI test for executive functions with the special focus on set shifting, also in patients with executive function deficits. Furthermore, SMA region mapping with the serial count test paradigm could be considered as a potential target for navigated transcranial magnetic stimulation (nTMS) in these patients.

[Cognitive disorders in the middle-aged population and cerebrovascular risk factors]. / Kognitivnye narusheniia u lits srednego vozrasta i faktory riska tserebrovaskuliarnykh zabolevanii.

AIM: To study the frequency of subjective and objective cognitive disorders in the middle-aged population and their associations with main and additional cerebrovascular risk factors. MATERIAL AND METHODS: The authors examined 169 men and 239 women aged 40-59 years. Medical history study, blood tests, electrocardiography, brachiocephalic and common femoral arteries scan, echocardiography, magnetic resonance imaging of the brain (MRI) were performed. Luria and Munsterberg tests were done to assess cognitive dysfunction. Affective disorders were assessed by the Hospital scale of anxiety and depression. RESULTS AND CONCLUSION: Absence of subjective (SCI) and/or objective (OCI) cognitive impairments was found in 26,5%; 10% had purely SCI, more than 35,7% of complaints were accompanied by deviations in neuropsychological test results (OCI+), over 25% had only OCI-. The average age of patients with OCI+ was higher than in the control group. In women, the frequency of SCI was twice as high and OCI less frequent as in men. Absence of cognitive impairment and SCI were observed more frequently in individuals with higher education. The prevalence of multiple white matter lesions (WML) in MRI was 36%. Multiple WML and atherosclerosis of major arteries were more common in OCI+ group (47%). Mild affective disorders were more frequent in the studied groups. Anxiety disorders were more common than depressive ones. The amount of patients with affective disorders was highest in OCI+. Therefore, SCI is a common phenomenon among people aged 40-60 years. The use of simple neuropsychological tests in screening examination allows to identify individuals who are most appropriate for active search for vascular risk factors. Anxiety and depressive disorders cause a significant proportion of SCI among middle-aged people and are an important additional target for therapeutic measures.

[Radiologically isolated syndrome as a possible preclinical stage of primary-progressive multiple sclerosis]. / Radiologicheski izolirovannyi sindrom - vozmozhnaia doklinicheskaia stadiia pervichno-progressiruiushchego rasseiannogo skleroza.

The article presents a clinical case-report of transformation of radiologically isolated syndrome (RIS) to primary-progressive multiple sclerosis (PPMS). It also provides a review of international and Russian data on the comparison of clinical and MRI characteristics of PPMS with relapsing-remitting multiple sclerosis and secondary-progressive multiple sclerosis and the review of the current data on the risks of transition of RIS to PPMS.