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A new method, resting-state fMRI, has been proposed recentlfor studying basic sensory, emotional, and cognitive processes inhealthy and neurologically affected subjects. It allows assessingspontaneous co-activation of different CNS regions in rest onthe basis of temporal characteristics of neuronal activity ofanatomically separated brain regions. On resting-state fMRIstudies, the existence of stable and functionally linked restingstatebrain networks was shown, that is important in the contextof basic mechanisms of neurological disorders. We performed afirst resting-state fMRI study in Russia in the group of 10 healthysubjects and revealed a clear default mode network patternwhich was consistent with data in published papers. Examiningof integrative system of functionally interacting brain regionswith the use of resting-state fMRI can provide new insights intolarge-scale neuronal communication within the human brain.

For the assessment of factors promoting progression of atherosclerosis of the carotid arteries (CA), we performed a detailed clinical-laboratory and instrumental comparison of the two groups of patients – with asymptomatic CA stenosis and with ischemic stroke resulted from stenosis of the CA. Progression of atherosclerotic damage of the CA was shown to be related with the following factors: а) severity of hemorheologic changes (including iatrogenic resistance to antiagregating drugs); b) presence of endothelial dysfunction; c) increase of the level of immunohistochemical markers of angiogenesis (molecules of intercellular adhesion sICAM21 and sРЕCAM21); d) the state of central hemodynamics and cerebral perfusion. The obtained data help to individualize medical and prophylactic procedures, select a group of patients with the high risk of ischemic stroke and clarify indications to reconstructive angioneurosurgical operations.

In this study, most characteristic clinical and neuroimaging features of different subtypes of ischemic stroke (IS), such as different evolution rates during an acute period of the disease, weredetermined. Despite the lack of differences in the final size of thelesion, more frequent hemorrhagic transformation and theregress of ischemic penumbra in patients with cardioembolicstroke during the first week may be regarded as the evidence of earlier recovery process in this subtype of IS. The obtained dataallowed elaborating an algorithm of application of different MRIregimens for brain visualization in the context of examinationand treatment of patients with acute IS.

One of the most important inherited neurodegenerative disorders,Huntingtons disease (HD), is characterized by cerebral atrophy,the features of which need to be clarified. MRI morphometryallows assessing quantitatively the atrophy of different brainregions, and this method may be regarded as a potential biomarkerof neurodegeneration. We used whole-brain voxel-based morphometry(VBM) and region-of-interest (ROI) morphometry in24 patients with HD, 10 preclinical HD gene carriers and 9 controls.On whole-brain VBM patients had significantly lower greymatter in the caudate, the putamen, and the pre- and postcentralgyri bilaterally compared to controls, while on ROI morphometrythe grey matter volume decrease in patients was seen in the caudate,the putamen and the pallidum bilaterally. In clinically unaffectedgene carriers the pallidum, the putamen, and the pre-andpostcentral gyri bilaterally were larger and the left pallidum wassmaller compared to controls. We found more pronounced atrophyof a dominant hemisphere in patients and gene carriers, aswell as negative correlation between basal ganglia and corticalstructures volumes and the mutation severity, motor and cognitiveimpairment.

Strategic trend in the treatment of acute stroke resulted from thrombosis or embolization of intracerebral arteries is reperfusion of the blood flow in the ischemic area thrombolysis. The modern methods of neuroimaging (CT and MR-angiography, diffusion and perfusion-weighted MRI, CT perfusion) play an important role in the thrombolysis decision making, as they allow to visualize the occlusion of the artery causing acute stroke, recanalization of the artery due to thrombolytic therapy,as well as the dynamics of the blood flow and metabolism in the respective brain regions. The presented clinical examples demonstrate the high efficacy of the thrombolytic treatment in acute ischemic stroke under the condition of absolute compliance with the inclusion and exclusion criteria to this therapy. The treatment of patients with acute stroke should be guided by the principles of evidence-based medicine and rely on adequate diagnostic algorithm of neuroimaging methods.

Modern high-field MRI and multispiral CT machines enable notonly exploring structural changes in the central nervous system(CNS) but also evaluating cerebral blood flow, cerebral metabolicprocesses, and functional status of various brain regions. In thisarticle, we review state-of-the-art neuroimaging techniques suchas diffusion tensor imaging, susceptibility-weighted imaging,functional MRI, and MRI morphometry.The article provides abrief description of the physical principles of these techniques aswell as their application in research and clinical practice.

Cognitive impairments are an important medical and socialproblem associated with a high prevalence of this disease in thepopulation. 46% of patients develop dementia within 5 years afterthe diagnosis of mild cognitive impairments (MCIs). Voxelbasedmorphometry (VBM) is a modern neuroimaging techniquewell-proven in studying dementia. VBM in a combinationwith neuropsychological examination of patients enables clarifyingthe genesis of mild cognitive impairments (MCIs) and predictingfurther development of the disease as early as the initialstage of the pathology.

Balos concentric sclerosis is a monophase demyelinating diseasecharacterized by alternating rings of demyelinated and myelinatedaxons, and it is most frequently diagnosed by magneticresonance imaging. At the present time Balos sclerosis is discussedin case of MRI detection of two or more concentric areasof demyelination, one or more ring of that is enhanced by thecontrast. For 100-year period of the study there are 4 main theoryof pathogenesis of Balos sclerosis: theory of concentric demyelination,theory of distal oligodendrocytopathy, colloid theoryand theory of astrocytopathy. None of the theories includes alldetails of the disease. One of the details is concentric lesionsin monophasic Balo sclerosis and in Balo-like syndromes inchronic demyelinating disorders.In case of Balos sclerosis andBalo-like syndromes probability of resistant to immunosuppressivtherapy is very high. So glucocorticosteroid therapy must beinitiated right after concentric demyelination determination onMRI. In case of ineffectiveness of glucocorticosteroid therapyplasmapheresis and cytostatic therapy could be applied.

Motor recovery after ischemic stroke is associated with the neuralnetworks reorganization. fMRI studies of these networks inpatients with mild motor deficit showed that activation patterncan be used for the prognosis of functional recovery. However,characteristics and clinical relevance of activation patterns inpatients with severe to moderate motor deficit, its effective functioningin patients with different severity of primary sensorimotorsystem components (corticospinal tract [CST] and primarysensorimotor [SM] cortex) injury were not investigated. Twentyfivechronic hemispheric ischemic stroke patients were studied(13 males, 12 females; median age 38.05.9 years). Dependingon the severity of hand motor impairment and functional outcomethe patients were divided into 3 groups. All patients underwent1.5 T fMRI (Siemens Avanto) with passive block paradigmof paretic index finger movement (1 Hz frequency). Statisticmaps of group activation showed significant differences ingroups with different functional outcome: the more severe wasmotor deficit, the less SM activation volume size in injuredhemisphere was seen, and activation cluster center movedtowards non-primary motor cortex. The association between theactivation volume of SM and structural integrity of CST, assessedby fractional anisotropy index was revealed. Statistic maps ofindividual activation showed SM activation in injured hemispherein 38% patients with unfavourable (severe paresis, plegia)and moderate recovery with different physiologic lateralization,that is typical for the group with good recovery (mild and moderateparesis). These data do not allow us to consider the activationpattern as a marker of motor recovery and prognostic factorin patients with severe and moderate motor deficit. Our resultsshowed that sensorimotor networks formation and functioningdiffer depending on the CST sparing, and its effective work ispossible in certain degree CST integrity.

We described two patients (female, 47 years and male, 42 years)with mitochondrial encephalomyopathy, lactic acidosis andstroke-like episodes (MELAS). Diagnosis was confirmed bygenetic study (A3243G mitochondrial DNA mutation wasfound), muscle biopsy and elevated lactate level in the blood.Clinical picture of stroke-like episodes was presented by symptomsof mainly involvement of the posterior brain area (fluentand amnestic aphasia, hemianopia, paresis, ataxia), as well as byheadache and epileptic seizures. In the first patient stroke-likeepisodes recurred but their symptoms almost completelyregressed with time. The second patient had severe residualneurological deficit. Other clinical manifestations includedhearing loss, memory deterioration, cardiomyopathy, fatigueand type 1 diabetes mellitus. MRI in acute period of stroke-likeepisodes found cortical lesions mainly in the posterior parts ofthe brain. They completely disappeared in the first case, butpersisted in the second patient. The differential diagnosis ofstroke-like episodes and ischemic stroke and approaches totreatment are discussed.

The fMRI study of 7 healthy volunteers was performed to evaluatethe neuron networks of sensorimotor system during activeand passive movements of the left and right index fingers. Whileperforming all the tasks, the predominant activation of primarysensorimotor, premotor, supplementary motor areas, secondarysensory zones were shown on the contralateral side, as well asipsilateral cerebellar activation. It was demonstrated that brainactivation areas in both types of paradigm were corresponding,as well as the activation clusters size, amplitude and voxel coordinates,with the maximum values in the primary motor and sensorycortex. These results allow recommending the paradigm ofpassive index finger movements in given rate for the evaluation ofsensorimotor system in patients with movement disorders.

Resting-state functional magnetic resonance imaging (rs-fMRI)enables evaluation of low-frequency oscillations (0.010.1 Hz)of the BOLD-signal, which are related to changes in the hemodynamicsparameters, thereby making possible to determineindirectly the spontaneous neuronal activity of various areas ofthe brain at rest . We conducted an rs-fMRI study in groups ofhealthy volunteers and patients with Parkinsons disease (PD).Out of the spectrum of resting neural networks of the brain, thebrains default mode network (DMN) was selected, and changesin the neuronal activity pattern of the network in PD patientswere evaluated. Compared to the norm, PD was found to becharacterized by a decrease in the activity of the right inferior parietallobe (i.e. in the area incorporated into DMN and involvedin visual-spatial perception) and, on the contrary, an increase inthe spontaneous neuronal activity of DMN in the medial segmentsof the right superior frontal gyrus, right and left angulargyri, and anterosuperior and posteroinferior parts of the left andright precuneus. The detected changes in the neuronal activity,regarded as a manifestation of the neuroplasticity phenomenon,may potentially serve as biomarkers of a neurodegenerative processin PD.

Hemostatic and hemorheological dysregulations are the typicalpathological conditions in stroke. Thorough dynamic examinationsof hemostasis, platelet aggregation, kinetics of erythrocyteaggregation/disaggregation along with clinical and neuroimagingfeatures and functional outcome were conducted in ischemicstroke patients who underwent i.v. thrombolysis or did not receivedrtPA. Increased strength of erythrocyte aggregates (SEA)was associated with better functional outcome, and that correlationwas stronger in patients treated with i.v. thrombolysis. Increased SEA was also associated with regression of ischemiclesion on DWI-MRI on Day 3 day in patients treated with i.v.thrombolysis.

Assessment of cerebral perfusion and collateral circulation inpatients with carotid stenosis might have prognostic value foreffective blood flow restoration after carotid revascularization.To evaluate the changes of cerebral perfusion we studied 41patients with moderate and severe carotid stenosis before andafter surgical or endovascular treatment. Perfusion CT at thelevel of basal ganglia was performed in 17 patients with moderate(5069%) and 24 patients with severe (7099%) carotidstenosis for 3 times: before intervention (transluminal angioplastywith stenting or carotid endarterectomy), 3 to 7 days and 1 to3 months after treatment. Additionally, single CT perfusionstudy was done in 39 patients without carotid stenosis (controlgroup). We found that surgical recanalization of internal carotidartery may aid restoring cerebral blood flow characteristics in theMCA area to the levels similar to those in control group (namely,decrease of MTT and CBV and increase of CBF). However, inanterior and posterior watershed zones, which are known to bethe most vulnerable by chronic hypoperfusion, blood flow normalizationwas seen only in patients with complete circle ofWillis and with moderate carotid stenosis.Thus, prognostic factorsfor inadequate blood flow restoration in patients withcarotid artery stenosis after revascularization include severestenosis (70%) and incomplete circle of Willis.

Since the early 1990s, fMRI has come to dominate the brainmapping field due to its relatively low invasiveness, absence ofradiation exposure, and relatively wide availability. It measuresthe hemodynamic response related to neural activity in the brain(BOLD-effect). During planning fMRI experiment it is importantto take into account equipment (MRI scan, devices for thestimuli presentation), experimental design and post processing.The last one includes several important steps, such as realignment,co-registration, normalization, smoothing. NowadaysfMRI is widely used not only in research field, especially forcognitive studies, but in clinical practice. However investigatorshould always remember some limitations and controversies,especially in patients with various nosological forms. It is alsoimportant to draw many specialists in experiment and its interpretation neuroradiologists, MR-physicists, clinicians, psychologists,etc. while fMRI is multidisciplinary methodic.

Its a traditional belief among neuroscientists that the speechfunction is located in some strictly definite areas of the left hemisphere:Brocas area in the rear part of the lower frontal gyrus(Brodmann area 44, or BA44), and Wernickes area in the rearpart of the upper temporal gyrus (BA22). However, data collectedwith the contemporary neurovisual research methods, in particular,with functional magnetic resonance imaging (fMRI),disprove the localizationist theory of speech. With the speciallydesigned speech task (paradigm) consisted of sentence readingand sentence continuation tests, we researched distribution ofspeech neuron network in healthy people and its reorganizationin patients with different types of aphasia. After processing ofcontrol sample data, we noticed activation of classic speech areas(Brocas and Wernickes) and their right hemisphere homologies.However, the amount of activations was predominant in theleft hemisphere. We also noticed bilateral activity in lower partsof pre-central (BA4) and post-central (BA1) gyri, in cerebellumhemispheres and in visual cortex (BA1718). In stroke patientsactivation in Brocas and Wernickes areas depended on a lesionlocation. Activation wasnt registered in case of damage of correspondingregion, but it was migrated on perilesional area. Werevealed new regions of activity at patients with aphasia, includingupper parietal gyrus (BA7), angular and over-marginal gyri(BA3940). Aforementioned activations were disclosed both inleft and right hemispheres. The research shows that the speechparadigm used demonstrates functioning of speech system in theoptimal way. The received data will increase understanding ofbrain structures involved in process of speech and their importancefor recovery of damaged speech functions.

Transcranial magnetic stimulation (TMS) is method of brainneurons stimulation by alternating magnetic field and measuringmotor-evoked potentials (MEPs) with electromyography monitoring.Recently, some new technologies were introduced, basedon classical TMS, which allowed noninvasive brain mapping ofcortical motor areas. Navigation transcranial magnetic stimulation(nTMS, NBS eXimia Nexstim) is one of them. In this articlewe describe our experience of m. abductor pollicis brevismotor area mapping in 29 healthy volunteers. Basic parametersof TMS were measured: MEP amplitude (408.49216.36 uV),latency (22.380.97 ms), passive motor threshold(40.084.68% for the left hemisphere, 48.719.16% for theright hemisphere). Maps of cortical areas were builded.

Functional magnetic resonance imaging (fMRI) is widelyapplicable for sensorimotor cortex mapping in human. Themost challenging fMRI task for researchers is the assessment oflocomotion. The aim of our study was to design of a passivemotor fMRI paradigm for assess supraspinal control of the skillof walking in normal subjects and in patients with motor neurologicdeficit after ischemic stroke. We conducted fMRI intwo groups of human subjects: first group 19 healthy subjects(10 females and 9 males, mean age = 38 [31,5; 60] years), secondgroup 18 ischemic stroke patients in early recovery period(first 6 months) (6 females, 12 males, mean age = 55,5[45,5; 64,5] years) with severe and moderate (mean Fugl-Meyer scale score = 22 [15; 28]).The protocol consisted ofblocked-design paradigm: plantar stimulation by imitation ofslow walking vs rest. Individual and group activation patternswere analyzed using statistical package SPM5. A significantactivation (pcorrect0.05 at cluster level) in first group wasobserved in the primary and secondary sensorimotor cortex,premotor and dorsolateral prefrontal cortex, in insula. Due tolesion localization second group was subdivided into corticalsubcotrical(CS) and subcortical (S) subgroups. In CS subgroupthere was reduce of activation size, more prominent inthe affected hemisphere, whereas in S subgroup the extensionof activation regions in both hemispheres was revealed, comparingto group 1. It was demonstrated that our passive motorfMRI paradigm of walking imitation with the use of plantarload imitator Korvit can be used to localize the ensorimotorbrain areas involved in locomotion in both healthy people andpatients. Concerning stroke patients, such an approach canhelp in understanding the mechanisms of supraspinal controlof the skill walking and optimal rehabilitation strategy.

We describe a 53 year old patient with the left internal carotid artery (ICA) dissection, which developed after the resection of tortuous part of ICA. The first clinical manifestations of dissection were the left lower cranial nerve palsies (dysphagia, dysphonia, disorder of tongue movement), in two days left frontotemporal headache appeared and in two weeks patient developed ischemic stroke in the territory of the left middle cerebral artery. Diagnosis of ICA dissection was confirmed by CT-angiography and duplex ultrasound. Morphological study of resected ICA found two small arteries beginning from ICA, small aneurismatic dilatation of the ICA wall and evidence of fibromuscular dysplasia. In two months, swallowing significantly improved and right hemiparesis partly regressed. Clinical and morphological data suggest that fibromuscular dysplasia was the cause of dissection and ischemia of the lower cranial nerves was the cause of their palsies. Blood supply of the lower cranial nerves was not from the external carotid artery, as usually, but from the ICA. Its dissection led to the interruption of the nutrient arteries and as the result to nerve ischemia.

Cerebral amyloid angiopathy (CAA) is characterized by -amyloid deposition in cortical and leptomeningeal arteries of small and medium size that disturbs normal structure of arterial wall. CAA is one of the often causes of peripheral intracerebral hemorrhages and cognitive impairment in old patients. We describe male patient, 52 years with CAA. Clinical picture was characterized by recurrent cortical-subcortical (lobar) hemorrhages, cognitive impairment of subcortiical type and epileptic seizures. MRI revealed superficial posthemorrhagic lesions. Gradient-echo MRI found small multiple asymptomatic hemorrhages in cerebral cortex and subcortical matter. Repeatgradientecho MRI carried out monthes revealed new clinically asymptomatic hemorrhages. Arterial hypertension as a cause of intracerebral hemorrhage was excluded on the base of atypical location of hemorrhage (superficial, but not deep). CAA diagnosis was made according to international Boston criteria: multiple lobar, cortical-subcortical hemorrhages not connected with other definite cause of intracerebral hemorrhage. Gradient-echo MRI is of a great importance in diagnosis of CAA, as it discovers small cortical and superficial hemorrhages, none detected by standard MRI regimes.

The aim of this study was a comparison of diagnostic efficacy of non contrast enhanced MR-angiography (MRA) and CT-angiography (CTA) with digital subtraction angiography (DSA) in patients with atherosclerotic lesions of internal carotid arteries. We examined 70 patients with stenosis of carotid arteries. A stenosis degree of more than 50% (assessed by DSA) was considered as hemodynamically significant. Besides neurological survey the examination of extracranial arteries was performed, whichincluded MRA, CTA and DSA. In each case we analysed a plane on which a degree of a stenosis was assessed as maximum. To characterize each modality we evaluated sensitivity, specificity and positive predictive value. A coincidence rate for CTA and DSA was 95%, for MRA and DSA 89%. We can conclude that CTA and MRA can be use for an appropriate evaluation of stenosis of interna carotid arteries.

We present clinical and morphological study of intracranial dissection of carotid artery and its branches led to massive brain infarct in practically health 23-year old female patient. Clinical picture was presented with sudden development of right sided hemiplegia, aphasia and left sided headache. Magnetic resonance image and ultrasound study showed increasing occlusion of the left intracranial internal carotid artery (ICA), middle (MCA) and anterior cerebral artery (ACA). On 11 day of disease lethal exit occurred. Autopsy study showed that the lumen of ICA, ACA and MCA was filled with a dense dark-red mass suggested to be intra-arterial thrombi. However microscopic study demonstrated that this mass was the hemorrhage in the arterial wall (intramural hematoma) which completely occluded its lumen. At the different levels of extraand intracranial arteries microscopy revealed pronounced dysplastic changes in the arterial wall (fibromuscular dysplasia), which were the main cause predisposed to arterial wall dissection and development of intramural hematoma. Presented observation demonstrates that dissection with intramural hematoma formation may be the cause of intracranial occlusion. On differential diagnosis with thrombosis one should take into consideration the absence of clinical and laboratory thrombophylic manifestations as well as atherosclerotic changes in cerebral arteries in patient with artery dissec- tion.

A pseudo-tumoral course of multiple sclerosis is very rare. In the paper, a morphologically confirmed case of multiple sclerosis with a pseudo-tumoral course is described. A radiation treatment (because of a misdiagnosis of cerebral tumor) resulted in radio-necrosis of the cerebral tissue. Presented are the experience of treatment of this patient, differential diagnosis and efficacy of the long-term hormone therapy.

To analyze potential of different MRI methods in the quantitativeassessment of brain lesions after ischemic stroke, 19 patients(mean age 38.96.2 years) with hemiparesis of various severityresulted from supratentorial ischemic stroke (612 months priorthe examination) were studied. A relationship was establishedbetween such parameters as fractional anisotropy (FA), apparentdiffusion coefficient (ADC), size of the brain lesion, and severityof motor deficit. The FA and ADC values obtained in the corticospinaltract (CST) projection allow them to be considered asindicators of the degree of the CST post-ischemic damage predictingmotor deficit. FA was found to be the most reproducibleindicator of the CST structural integrity. FA threshold values(index, %) for unfavorable outcome of the motor functionrestoration were determined as follows: 50% for posterior limb ofinternal capsule, 42% for cerebral peduncle, and 65% for ponsvarolii. High sensitivity and specificity of the obtained parametersprovides ground for their use in identifying patients withpoor prognosis for the motor function restoration.

Primary blepharospasm (BS) is one of most frequent forms offocal dystonia characterized by excessive involuntary eye closure.Pathophysiology of primary BS remains obscure. The purposeof this study: to determine changes of the cerebral gray mattervolume that may be pathogenically important in primary BS.We examined 23 right-handed patients with primary BS (6 malesand 17 females) and 16 healthy age- and sex-matched individualswho underwent voxel-based morphometry (VOM) amethod of assessment of fine regional quantitative changes ofgray matter volume. In 15 patients VOM studies were performedtwice, before and one month after injections of botulinum toxintype A (BTA). Compared to controls, BS patients were characterizedby the decrease in gray matter volume in the head of theright caudate nucleus, anterior and posterior lobes of the rightcerebellar hemisphere, and the right fusiform gurus. Multiplefactoranalysis did not show relationships between gray matterchanges and age of patients, age at the debut of BS, and durationof the disease or BTA treatment. On repeat examination afterlocal BTA injections in the circular orbicular muscles (aimed atreducing dystonic spasms in BS patients), the increase in graymatter volume in both fusiform gyri, the opercular parts of theleft Rolandic gyrus, the right middle and the left inferior temporalgyri, the left inferior frontal gyrus, and the left cingular gyruswas observed. The obtained data demonstrate the presence ofstructural brain changes in primary BS, confirming a significantrole of the striatum and the cerebellum in pathophysiology ofthis form of focal dystonia.