[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.

[Treatment and prevention of cognitive dysfunction in patients with arterial hypertension and atherosclerosis: results of a randomized double-blind placebo-controlled trial of cerebrolysin]. / Lechenie i preduprezhdenie rasstroistv poznavatel'noi funktsii u bol'nykh arterial'noi gipertoniei i aterosklerozom: rezul'taty randomizirovannogo dvoinogo slepogo platsebo-kontroliruemogo issledovaniia tserebrolizina.

AIM: To assess therapeutic and prophylactic effect of large-dose cerebrolysin (15 ml/day for 28 days) in hypertensive and atherosclerotic patients with cognitive disorders. MATERIAL AND METHODS: Cerebrolysin was given annually (15 ml/day for 28 days) for 2 years to 42 patients in a randomized double-blind placebo-controlled study. The effect was stated by clinical status, neuropsychological and neurophysiological data. RESULTS: In mild disturbances of cognitive functions in patients with arterial hypertension and atherosclerosis courses of cerebrolysin with one-year interval produce stable improvement of subjective status, productivity of memory, attention and thinking which persist for at least a year after the course. The clinical data agree with positive trend in neurophysiological parameters of cognitive component of the response of evoked potentials P-300. CONCLUSION: A course of 28-day annual treatment with cerebrolysin (15 ml/day) of patients with mild defects of cognitive functions stabilizes the process, leads to regression of cognitive disorders predicting vascular dementia.

Disorders of higher mental function due to single infarctions in the thalamus and in the area of the thalamofrontal tracts.

Nine patients (five female and four male, mean age 58 years) with small infarcts in the thalamus (TH) or in the region of the thalamofrontal tracts and producing acute mental disturbances which in the acute phase of insult consisted of dementia in seven cases and mild cognitive disturbances in two cases. The complex of mental changes was similar to that seen in "frontal syndrome" and was characterized largely by lack of spontaneity, adynamia, disorientation, loss of attention and memory, slowing of all mental processes, and lack of criticality and adequacy. Accompanying focal neurological symptoms were mild in seven patients and moderate or pronounced in two. In five patients, the severity of mental disturbances decreased with time. Computer tomography demonstrated small infarcts in the anterior or medial parts of the TH in seven patients and in the posteromedial parts of the anterior limb of the internal capsule, i.e., the thalamofrontal tracts, in two cases. In five cases, infarcts were located in the dominant hemisphere, with lesions in the non-dominant hemisphere in three and in both hemispheres in one. The positions of all foci corresponded to structures traversed by pathways connecting the TH and the lower part of the reticular formation to the frontal lobes. It is suggested that disconnection of these pathways leads to cognitive lesions or dementia because of functional inactivation of the frontal cortex.

[Disorders of higher mental functions in localization of separate infarctions in the optic thalamus and in the region of thalamo-frontal tracts]. / Narushenie vysshikh psikhicheskikh funktsii pri lokalizatsii odinochnykh infarktov v zritel'nom bugre i v oblasti talamofrontal'nykh putei.

The paper presents 9 patients (5 women, 4 men, average age 58 years) with small infarctions located in either thalamus (T) or in the region of thalamofrontal ways. Such infarctions resulted in acute development of mental disorders which corresponded to dementia in 7 cases and to slight cognitive disorders in 2 cases. The complex of mental disorders resembled one in "Frontal Syndrome" and was characterised mainly by aspontaneity, adynamia, hypersomnia, disorientation, memory impairment, attention deficit, delay of all mental processes, lack of criticism and adequacy. Accompanying focal neurologic symptoms were slight in 7 patients, moderate or pronounced in 2 cases. In 5 patients the manifestation of mental disorders decreased gradually. Computer tomography revealed small infarctions in anterior or medial areas of T in 7 cases, and in thalamofrontal routes in 2 patients. Infarctions were located in dominant hemisphere of brain in 5 patients, in nondominant one--in 3 cases, in both hemispheres--in one patient. Location of all the foci corresponded to the structures through which the routes passed and connected T and reticular formation localized lower with frontal lobes of brain. It was suggested that separation of these routes resulted in cognitive disorders or dementia because of functional inactivation of the cortex of frontal lobes of brain.

[In vivo diagnosis of Creutzfeldt-Jakob disease]. / Prizhiznennaia diagnostika bolezni Kreitzfel'dta-Iakoba.

The paper presents the data concerning usage of some original method of vital laboratory diagnostics of Creutzfeldt-Jacob disease that belongs to the group of prionic diseases. The method consisted in the inoculation of inoculative culture of rat Gasser ganglion's neurinoma by biologic materials investigated (serum and clot of blood) with the following passivation and investigation of the contaminated culture by means of both morphologic and electron microscopic methods. As an example of vital verificated case the wide pathomorphologic analysis of the biopsy sample of brain was presented. Besides, the efficiency of the investigation of cognitive evoked potentials (P300) together with EEG was also demonstrated as the method of objectification of the development of dementia in this disease.

[Lifetime diagnosis of prion transmissive encephalopathies]. / Prizhiznennaia diagnostika prionovykh transmissivnykh éntsefalopatii.

An original method for life-time diagnosis of Greutzfeldt-Jakob's disease, a neurodegenerative disease belonging to transmissive spongiform encephalopathies, is proposed. It consists in inoculation of the examined biological materials (blood serum and clot) into a continuous culture of the rat Gasser's node neurinoma, followed by passages and study of the inoculated culture by morphological methods and electron microscopy.