[Neuroprotection in epilepsy].

Brain damage and neuronal loss caused by traumatic brain injury, ischemic stroke, and symptomatic status epilepticus can lead to severe long-term consequences, such as impairment in learning and memory and cognitive functions, and development of chronic epilepsy. This can be the result of morphologic and functional changes underlying temporal lobe epilepsy. Epilepsy patients have increased risk of status epilepticus. It is a life-threatening condition when seizures last for more than 30 min and trigger processes leading to neuronal apoptosis and necrosis in various parts of brain. Administration of neuroprotective drugs preventing these pathologic processes could improve the prognosis for such patients. However despite of active research of neuroprotective drugs, the effective ways to prevent brain damage resulting from prolonged seizures are yet to be found. Studies of neuroprotective properties of classic and novel anticonvulsant drugs showed that most of them do not have the sufficient neuroprotective effect and are not able to prevent epileptogenesis. Thus the studies of other potential neuroprotective drugs seem to be promising.

[The new MRI pulse sequence: experience in emergency neuroradiology].

The new pulse sequence (PS) has been obtained on MRI tomography Ellipse, B=0,15 and Biospec 70/30, B=7 T. The new pulse images of the brain combine features of FLAIR and its sensitivity to magnetic field heterogeneity. We named its PS as the T2 Fluid Attenuation Gradient Echo (T2 FLAGE). The T2 FLAGE characteristics of tissue contrast as well as its efficacy in detection of ICH have been assessed in 57 patients with acute stroke and in 16 experimental rats. The analysis of tissue contrast of lesions and normal brain structure has revealed the greater visibility of T2 FLAGE images compared to FLAIR. At the same time, the images sensitivity of magnetic field heterogeneity is retained. The ROC-analysis has shown that T2 FLAGE images are more effective in differential diagnosis of stroke type compared to FLAIR.

[An experimental model of focal brain ischemia in rats based on the endovascular microsurgery].

An endovascular model of focal brain ischemia in rats with controlled duration of reperfusion of 1h has been studied. The reliability of experimental model for localization and volume of ischemic lesion (basal ganglia, hippocampus, parietal-temporal regions; the volume of lesion focus on MRI T2-weighted image (T2-WI) in the first day after brain ischemia 146.4 +/- 44.7 mm3) has been worked out. We conducted the clinical monitoring including assessment of neurological deficit, behavioral tests and performed MRI of the brain on 1st, 5th and 10-17th days after the occlusion of middle cerebral artery (MCA), including regimes of diffusion-weighted image (DWI) and T2-WI, and carried out a histological study of the brain. The regress of neurological deficit was seen on the 14th day after surgery. Behavioral tests revealed the reduction of movement activity of animals in the case group 7 days after the MCA occlusion. Compared to the first day after surgery, the decrease of volume lesion focus on DWI and T2-WI was observed on the 5th day (p < 0.05) as well, with the following decrease to the 10-14th days. The histological picture in the lesion foci corresponded to the brain infarction on the 5th and 14th days after surgery.

[Comparative assessment of MR-semiotics of acutest intracerebral hematomas in low- and extra high-field frequency magnetic resonance tomography].

An objective of the study was to compare sensitivity of low- and extra high-field frequency magnetic resonance (MR) tomography of acutest intracerebral hematomas (ICH) and to assess differences between symptoms in obtained images. A study was conducted using experimental ICH in rats (n=6). Hematomas were formed by two injections of autologic blood into the brain. MR-devices "Bio Spec 70/30" with magnetic field strength of 7 T and "Ellipse-150" with magnetic field strength of 0,15 T were used in the study. MR-tomography was carried out 3-5 h after the injections. Both MR-devices revealed the presence of pathological lesion in all animals. Extra highfield frequency MR-tomography showed the specific signs of ICH caused by the paramagnetic effect of deoxyhemoglobin in T2 and T2*-weighted images (WI) and low frequency MR-tomography - in T2*-WI only. The comparable sensitivity of low- and extra high-field frequency MR-devices in acutest ICH was established.

[MRI morphometry of the brain ventricles in patients with attention-deficit hyperactivity disorder].

Twenty seven right-handed subjects aged 7-30 years with the attention deficit/hyperactivity disorder (ADHD) were exposed to standard MRI examination. From them, 14 were younger than 13 years old. The volumes of lateral ventricles were measured using T1-weighted MR-images of the sagittal brain sections to within 3 mm3. External head radii were measured additionally to normalize ventricle volumes. All patients passed complex neuropsychological testing. Memory and functions of visual, auditory, tactile and spatial recognition, motor and speech spheres were examined. Test results were evaluated by the degree of disorders with reference to corresponding brain structures on a 10-point scale. Absence of disorders corresponded to 0 points and maximum intensity of was scored as 10. Disorder scores were summed up for each of hemispheres, the first area (cortical structures), and all structures. Neuropsychological testing revealed disorders, predominantly, in the frontal area, hippocampus and reticular formation. Neuropsychological deficit was minimally related to the disturbances in post-central and parietal cortical areas. Statistical analysis revealed significant positive correlation between normalized volume of the left lateral ventricle and neuropsychological disorder score (r = 0.5127, p = 0.0063) for the whole group studied. The correlation between the normalized volume of the left lateral ventricle with the disorder score related to the left hemisphere was more significant (r = 0.6303, p = 0.0004). At the same time, a correlation of the ventricle volume and the dysfunction of the cortical structures was revealed (r = 0.5071, p = 0.0069) in subjects younger than 13 years old. The study corroborated interrelation between the volume of ventricles and linear head dimensions (r = = 0.5759, p = 0.0017) which was more pronounced in younger subjects (r = 0.6833, p = 0.01).

[MRI semiotics features of experimental acute intracerebral hematomas].

The aim of this study was to assess the possibility of revealing intracerebral hematomas (ICH), using MRI, within the first hours after onset and to determine their MRI semiotics features. Thirty animals with experimental ICH were studied. A method of two-stage introduction of autologous blood was used to develop ICH as human spontaneous intracranial hematomas. Within 3-5h after blood introduction to the rat brain. The control MRI was performed in the 3rd and 7th days after blood injections. ICH were definitely identified in the first MRI scans. The MRI semiotics features of acute ICH and their transformations were assessed. The high sensitivity of MRI to ICH as well as the uniform manifestations in all animals were shown. In conclusion, the method has high specificity for acute ICH detection.

[Estimation of localization and dipole moment of alpha- and theta-rhythm sources by cluster analysis in healthy subjects and schizophrenics].

In 12 healthy subjects and 9 schizophrenic patients in the background conditions (with eyes closed) EEG was recorded from 16 standard derivations (10-20 system) during 3 min. The record underwent the spectral analysis detecting alpha- and theta-frequency bands. After the preliminary narrow band filtration for the main frequencies the sources of the spontaneous rhythms were localized. The data on localization for all healthy subjects and patients were summarized. The K-means clustering was used for identification of the sources clusters which were revealed in occipital and parietal lobes and limbic cortex for alpha-rhythm and also in frontal, temporal and parietal regions, limbic cortex and hippocampus for theta-rhythm. In schizophrenic patients in comparison with healthy subjects there was revealed significant increase of the numbers of dipole sources of alpha-rhythm in the clusters localized in limbic cortex and hippocampus. For theta-rhythm there was significant increase of the dipole moment of the sources in the clusters localized in the temporal and frontal cortices and hippocampus in patients in comparison with the norm.