[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.

[Effects of bilateral deep brain stimulation in the subthalamic nucleus using two methods of target structure verification]. / Dinamika motornykh simptomov bolezni Parkinsona na fone khronicheskoi dvustoronnei élektrostimuliatsii subtalamicheskogo iadra s ispol'zovaniem dvukh metodik verifikatsii struktury misheni.

AIM: To evaluate the efficacy of deep brain stimulation in the subthalamic nucleus (DBS STN) in patients with Parkinson's disease (PD) using different methods of targeting according to the dynamics of motor symptoms of PD. MATERIAL AND METHODS: The study involved 90 patients treated with DBS STN. In 30 cases intraoperative microelectrode recording (MER) was used. MER was not performed in 30 patients of the comparison group. The control group consisted of 30 patients with PD who received conservative treatment. Hoehn and Yahr scale, Tinetti Balance and Mobility Scale (TBMS), Unified Parkinson's Disease Rating Scale (UPDRS), Parkinson's Disease Quality of Life-39 Scoring System (РDQ-39), Schwab & England ADL Scale were used. Levodopa equivalent daily dose (LEDD, 2010) was calculated for each patient. RESULTS AND CONCLUSION: The effect of DBS STN using intraoperative microelectrode recording on the main motor symptoms, motor complications, walking as well as indicators of quality of life and daily activities was shown. In both DBS STN groups, there was a significant reduction in the LEDD and marked improvement of the control of motor symptoms of PD. A significant reduction in the severity of motor fluctuations (50%) and drug-induced dyskinesia (51%) was observed. Quality of life and daily activity in off-medication condition were significantly improved in both DBS STN groups of patients, irrespective of the method of target planning (75-100%), compared with the control group.

[Dynamics of functional MRI and speech function in patients after resection of frontal and temporal lobe tumors]. / Dinamika funktsional'noi MRT i rechevoi funktsii u bol'nykh posle udaleniia vnutrimozgovykh opukholei lobnoi i visochnoi dolei mozga.

RATIONALE: There are no studies on application of functional MRI (fMRI) for long-term monitoring of the condition of patients after resection of frontal and temporal lobe tumors. PURPOSE: The study purpose was to correlate, using fMRI, reorganization of the speech system and dynamics of speech disorders in patients with left hemisphere gliomas before surgery and in the early and late postoperative periods. MATERIAL AND METHODS: A total of 20 patients with left hemisphere gliomas were dynamically monitored using fMRI and comprehensive neuropsychological testing. The tumor was located in the frontal lobe in 12 patients and in the temporal lobe in 8 patients. Fifteen patients underwent primary surgery; 5 patients had repeated surgery. Sixteen patients had WHO Grade II and Grade III gliomas; the others had WHO Grade IV gliomas. Nineteen patients were examined preoperatively; 20 patients were examined at different times after surgery. Speech functions were assessed by a Luria's test; the dominant hand was determined using the Annette questionnaire; a family history of left-handedness was investigated. Functional MRI was performed on an HDtx 3.0 T scanner using BrainWavePA 2.0, Z software for fMRI data processing program for all calculations >7, p<0.001. RESULTS: In patients with extensive tumors and recurrent tumors, activation of right-sided homologues of the speech areas cold be detected even before surgery; but in most patients, the activation was detected 3 months or more after surgery. Therefore, reorganization of the speech system took time. Activation of right-sided homologues of the speech areas remained in all patients for up to a year. Simultaneous activation of right-sided homologues of both speech areas, the Broca's and Wernicke's areas, was detected more often in patients with frontal lobe tumors than in those with temporal lobe tumors. No additional activation foci in the left hemisphere were found at the thresholds used to process fMRI data. Recovery of the speech function, to a certain degree, occurred in all patients, but no clear correlation with fMRI data was found. CONCLUSION: Complex fMRI and neuropsychological studies in 20 patients after resection of frontal and temporal lobe tumors revealed individual features of speech system reorganization within one year follow-up. Probably, activation of right-sided homologues of the speech areas in the presence of left hemisphere tumors depends not only on the severity of speech disorder but also reflects individual involvement of the right hemisphere in enabling speech function. This is confirmed by right-sided activation, according to the fMRI data, in right-sided patients without aphasia and, conversely, the lack of activation of right-sided homologues of the speech areas in several patients with severe postoperative speech disorders during the entire follow-up period.

[A clinical and neuropsychological study of patients before and after resection of third ventricle colloid cysts]. / Kliniko-neĭropsikhologicheskie issledovaniia bol'nykh do i posle udaleniia kolloidnykh kist tret'ego zheludochka.

The literature lacks studies of cognitive impairments in large groups of patients after resection of third ventricle colloid cysts. AIM: To evaluate cognitive impairments in patients before and after resection of third ventricle colloid cysts. MATERIAL AND METHODS: We performed a clinical and neuropsychological study of 52 patients with third ventricle colloid cysts using the Luria method (1962). Forty three patients were examined before and after cyst resection in the early postoperative period (three patients in this group were also examined in a long-term period of 3-7 months after surgery). Forty one patients were operated on using the transcallosal approach, and two patients were operated on using the subtentorial-supracerebellar transchoroidal approach. The other patients were examined only before or after surgery. The patients' age ranged from 14 to 61 years; the mean age was 33.8 years; the median age was 29 years. RESULTS: On examination before surgery, cognitive impairments were minimal in 5 patients without clear signs of hydrocephalus. Impairments of memory and dynamic praxis, mild spatial disorders, and psychological inertia were observed in other patients with hydrocephalus. There was no significant difference in the state of cognitive functions between patients with and without stagnation in the fundus. On examination on day 3-6 after transcallosal surgery, several groups of patients were identified. Eight patients had an improvement in cognitive functions, which might be related to postoperative resolution of hydrocephalus. In 15 patients, changes in mnestic functions were insignificant. This group consisted of the youngest patients with a median age of 24 years. Korsakoff syndrome and disorientation were detected in 5 patients. This was the oldest age group, with a median age of 48 years. In other 13 patients, aggravation of mnestic disorders was moderate. Similar memory impairments were detected in the case of the subtentorial-supracerebellar approach. Memory disorders progressively regressed in all patients. CONCLUSION: Postoperative memory impairment of a varying degree was found in 21 out of 43 patients, with adhesions between the cyst capsule and fornix being observed only in 5 patients. In this case, no injury to the fornix was intraoperatively observed. We discuss the role of the age factor, cyst size, and technical surgical difficulties in the pathogenesis of memory disorders in the absence of injury to the calvarium during colloid cyst resection.

[Syndrome dopamine dysregulation and deep brain stimulation of the subthalamic nucleus in Parkinson's disease]. / Sindrom dofaminovoi dizreguliatsii i khronicheskaia stimuliatsiia subtalamicheskogo iadra pri bolezni Parkinsona.

AIM: Dopamine dysregulation syndrome (DDS) is a complication of the dopaminergic therapy in Parkinson's disease (PD); it is manifested as a compulsive medication use and may have negative impact on patients' social, psychological, and physical functioning. An effect of deep brain stimulation in the subthalamic nucleus (DBS STN) on DDS is not fully understood. Therefore, the degree of DDS during DBS STN in PD patients was evaluated in the study. MATERIAL AND METHODS: The main group included 15 patients with DDS symptoms in the preoperative period. The comparison group consisted of 15 patients without DDS symptoms and the control group consisted of 15 patients who did not undergo surgery. RESULTS AND CONCLUSION: The severity of motor disturbances in the surgery groups has decreased significantly (by 45%). Motor complications during DBS STN in patients with DDS have decreased by 50%; a decrease in the reduction of doses of dopaminergic preparations was noted as well.

[The structure of activation of the language zone in patients with intracerebral tumors according to fMRI with respect to tumor location and the functional asymmetry profile].

MATERIAL AND METHODS: A total of 50 patients were examined prior to surgical resection of intracranial tumors of the temporal and frontal lobes. Left-sided tumors were observed in 33 patients and right-sided tumors were observed in 17 patients. The functional asymmetry profile was determined using self-assessment, the Annet questionnaire, and the dichotic listening task. Twelve patients were left-handers or retrained left-handers and the remaining 38 patients were right-handers. FMRI examination was carried out on a 3.0 T SignaHDxt magnetic resonance tomograph (GE). The standard language block design paradigm was used in the study. We used the following tests: 1) recitation of months in reverse order; 2) generation of nouns according to the initial letters shown on the screen (K, M, L, N, P, C); 3) generation of verbs according to simple actions shown on the screen; 4) producing sentences using nouns shown on the screen; 5) listening to text through headphones. Data were processed using the standard BrainWave PA software (General Electric). Z-test was used in the range from 6 to 9. In all the studies, p<0.001. Statistical data processing included the nonparametric Spearman's test to determine the correlation between lateralization of the detected activation zone under speech load and tumor location (tumor is adjacent to the language zone, invades the language zone, or is located far from the language zone), as well as left- or right-handedness. RESULTS: Among 16 patients (right-handers and 2 left-handers) the activation of language zones was observed only on the left side; in one left-handed patient, Broca's area was detected only on the right side. In other patients (including right-handers with right-sided tumors), lateralization of language zones was different, including bilateral. Statistical processing revealed that bilateral activation of both Broca's and Wernicke's areas was more frequently observed in left-handers. Broca's area was more frequently detected on the left side in the presence of a distant tumor, while this trend did not apply for Wernicke's area. CONCLUSION: Localization of activation of Broca's area is more dependent on tumor location, while it depends on personal characteristics of an individual in the case of Wernicke's area.

[Pharmacotherapy accompanied by deep brain stimulation of the subthalamic nucleus in patients with Parkinson's disease]. / Medikamentoznaia terapiia na fone élektrostimuliatsii subtalamicheskogo iadra u patsientov s bolezn'iu Parkinsona.

AIM: To analyze pharmacotherapy accompanied by deep brain stimulation of the subthalamic nucleus. MATERIAL AND METHODS: The study included 54 patients, who underwent bilateral STN DBS from 2003 to 2012. The severity of motor disturbances, activities of daily living and complications of dopaminergic therapy were estimated in accordance with II, III and IV parts of the Unified Parkinson's Disease Rating Scale (UPDRS) before operation and one, three and four years after it. L-dopa equivalent daily dose (LEDD) was assessed along with an analysis of the pharmacotherapy in whole. RESULTS AND CONCLUSION: By the end of the 1st year, the severity of motor disturbances in OFF-period decreased by 52.3% and remained stable for 3 years (51.8%), a slight increase of severity of motor disturbances was observed later, however it didn't reach the pre-operative level. The severity of motor fluctuations and drug-induced dyskinesia fell by 64.9%, 70.7% and 42.7% by the end of the first, third and fourth year of observation. The maximal decrease in LEDD was reached by the end of the 1st year and accounted for 57.7%; by the end of the third and fourth years it was 52.4% and 38.2%, respectively. During the 1st year, 16.7% of patients didn't take levodopa. The dose of pure levodopa decreased by the end of the 1st year by 64.6%, and by 56.7% and 43.7% by the end of the 3rd and 4th years, respectively. Monotherapy by an agonist of dopamine receptors (ADR) was received by 12.9% of patients, thus the share of ADR as part of the combined therapy increased in the postoperative period from 24.1% to 35.2%.