[Interposition and transposition techniques of vascular decompression for hemifacial spasm]. / Interpozitsionnaya i transpozitsionnaya metodiki vaskulyarnoi dekompressii pri gemifatsial'nom spazme.

OBJECTIVE: To analyze the vessels compressing facial nerve root exit zone and efficacy of interposition and transposition techniques of vascular decompression for hemifacial spasm. MATERIAL AND METHODS: Vascular compression was evaluated in 110 patients. Implant interposition between vessels and nerve was performed in 52 cases, transposition of arteries without contact between implants and nerve - in 58 patients. RESULTS: Compressing vessels were anterior (44), posterior (61) inferior cerebellar, vertebral (28) arteries and veins (4). Multiple compressing vessels were found in 27 cases. Premeatal meningioma and jugular schwannoma were accompanied by vascular compression in 2 cases. Immediate regression of symptoms was observed in 104 patients, partial regression - in 6 patients. Transient facial paresis (4) and impaired hearing (5) were noted after implant interposition. Redo vascular decompression was performed in one case. CONCLUSION: The most common compressing vessels were cerebellar arteries, vertebral artery and veins. Transposition of arteries is highly effective technique with low incidence of VII-VII nerve dysfunction but relatively slow regression of symptoms.

[Anterior transpetrosal (Kawase) approach for petroclival meningioma with trigeminal neuralgia: case report and literature review]. / Perednii transpiramidnyi dostup (dostup Kawase) pri petroklival'noi meningiome s trigeminal'noi nevralgiei: opisanie klinicheskogo nablyudeniya i obzor literatury.

The authors present a patient with petroclival meningioma complicated by trigeminal neuralgia. Resection of tumor via anterior transpetrosal approach with microvascular decompression of the trigeminal nerve was performed. A 48-year-old female patient presented with left-sided (V1-V2) trigeminal neuralgia. Magnetic resonance imaging revealed a tumor 33´27´25 mm with a base adjacent to the top of petrous part of the left temporal bone, tentorium cerebelli and clivus. Intraoperative examination revealed true petroclival meningioma extending to trigeminal notch of petrous part of temporal bone. There was additional compression of trigeminal nerve by caudal branch of superior cerebellar artery. Total resection of tumor was followed by disappearance of vascular compression of trigeminal nerve and regression of trigeminal neuralgia. Anterior transpetrosal approach provides early devascularization and resection of true petroclival meningioma, as well as wide imaging of anterolateral surface of the brainstem, identification of neurovascular conflict and vascular decompression.

[Etiopathogenetic substantiation of surgical treatment of neurogenic pain syndromes]. / Etiopatogeneticheskoe obosnovanie khirurgicheskogo lecheniya neirogennykh bolevykh sindromov.

The purpose of the study was to improve classification of neurogenic (neuropathic) pain syndromes. This will make it possible to define the indications for appropriate analgesic surgery for each type of drug-resistant neurogenic pain syndrome. Incorrect management of neurogenic pain syndromes is usually associated with underestimation of pathogenetic prerequisites for its occurrence. Differentiation of compression, deafferentation and mixed neurogenic pain syndromes makes it possible to determine appropriate surgery and avoid tactical errors. Moreover, this approach allows you to save patients from unreasonable long-standing suffering. Patients with chronic pain syndromes often become disabled, sometimes in the prime of life, and isolated from society and family. Therefore, treatment of chronic pain is currently an urgent problem.

[Dysfunctions and anatomical relationships of cranial nerves in epidermoids of the cerebellopontine angle]. / Disfunktsii i anatomicheskie vzaimootnosheniya kranial'nykh nervov pri epidermoidakh mostomozzhechkovogo ugla.

OBJECTIVE: To evaluate the correlation of neurological symptoms with anatomical relationships of cranial nerves, lesions and vessels in patients with epidermoids of the cerebellopontine angle. MATERIAL AND METHODS: We analyzed neurological symptoms, magnetic resonance data, intraoperative findings and postoperative functional outcomes in 25 patients (14 females and 11 males aged 22-77 years) with epidermoids of the cerebellopontine angle. RESULTS: Cranial nerve dysfunctions were noted in 15 patients. Involvement of cochlear (n=9) and trigeminal (9 cases including 4 ones with sensory impairment and 5 patients with neuralgia) nerves was the most common. There were 10 patients with ataxia, hemiparesis and seizures without cranial nerve dysfunction. In 15 patients, epidermoids spread to supratentorial space and contralateral cerebellopontine angle. Lesion-induced brainstem compression was found in 22 cases. Cranial nerves and cerebellar arteries were partially or completely enclosed by lesion in all cases. Severe compression and dislocation of the nerve root entry/exit zone were found in all cases. One patient with trigeminal neuralgia had vascular compression of trigeminal nerve caused by superior cerebellar artery. Total resection was achieved in 16 patients. Small capsule remnants were left on vessels, nerves or brainstem in 9 patients. Postoperative complete or partial restoration of cranial nerve functions was noted in 11 cases. Deterioration of preoperative neurological deficit in 4 patients and postoperative neurological symptoms de novo in 3 patients were temporary. CONCLUSION: Cranial nerve dysfunctions are caused by compression of the nerve root entry/exit zones by epidermoids of the cerebellopontine angle. Surgical intervention is effective in alleviating symptoms of cranial neuropathy and brainstem compression. Vascular decompression should be performed in patients with trigeminal neuralgia.

[Trigeminal radiculopathy in vestibular schwannomas]. / Trigeminal'naya radikulopatiya pri vestibulyarnykh shvannomakh.

OBJECTIVE: To evaluate the correlation of trigeminal radiculopathy with anatomical relationships of trigeminal nerve root, brainstem, tumors and vessels in patients with vestibular schwannomas. MATERIAL AND METHODS: A retrospective analysis included 153 patients (106 females and 47 males aged 22-82 years) with vestibular schwannomas who underwent surgery via retromastoid approach. Preoperative trigeminal radiculopathy (facial pain and sensory disturbances) was examined after microsurgical resection. Brainstem compression was analyzed by comparison of transverse size of contralateral to vestibular schwannoma half of brainstem and ipsilateral side. RESULTS: Tumor-induced brainstem and trigeminal nerve compression was found in 115 cases. Sixty-four of these patients had trigeminal radiculopathy symptoms. Degree of brainstem compression was significantly higher in trigeminal radiculopathy group. Facial hypoesthesia was found in 61patients, trigeminal neuralgia - in 5 cases, neuropathic pain - in 3 patients. Thirty-seven patients without brainstem compression had no trigeminal nerve involvement. One patient had trigeminal neuralgia following compression by superior cerebellar artery. Total resection with brainstem and trigeminal nerve decompression were performed in all cases. Isolated or combined compression of trigeminal nerve root was noted in 9 patients with trigeminal neuralgia and neuropathic pain, in 2 with facial numbness and in 2 patients without trigeminal symptoms. In case of trigeminal neuralgia following compression by superior cerebellar artery, vascular decompression was performed only in patients with facial pain and numbness. Facial pain completely resolved in all patients. Complete or partial sensory restoration was noted in 25 cases. No facial sensory disorders were noted in 26 cases, transient sensory deterioration - in 10 patients. CONCLUSION: Trigeminal radiculopathy is caused by severe brainstem compression following vestibular schwannomas and usually results sensory disturbances and rarely facial pain. The impact of tumor on trigeminal nerve root and brainstem trigeminal pathways can be accompanied by vascular compression by superior cerebellar artery. Regression of trigeminal radiculopathy symptoms after resection of vestibular schwannoma is caused by decompression of trigeminal nerve root and brainstem. In case of concomitant neurovascular syndrome, vascular decompression is indicated.

[Trigeminal nerve lipoma presenting with trigeminal neuralgia: case report and literature review]. / Lipoma koreshka troinichnogo nerva, proyavlyayushchayasya trigeminal'noi nevralgiei: opisanie klinicheskogo nablyudeniya i obzor literatury.

Cerebellopontine angle lipomas are benign mass lesions and rarely result trigeminal neuralgia. A 61-year-old male with right-sided trigeminal neuralgia in V2 and V3 divisions without sensory disturbances is reported in the article. MRI revealed mass lesion 11´11´4 mm on the lateral pontine surface spreading to the right trigeminal nerve root entry zone. No signs of neurovascular compression were found. Microsurgical exploration of the cerebellopontine angle showed a fatty mass adherent to the brainstem with incorporation of inferior part of trigeminal nerve root. Fatty tissue resection was followed by partial sensory trigeminal rhizotomy. Histological examination identified lipoma. Postoperative MRI showed small residual tissue with minimal ischemic area near trigeminal nerve root entry zone. Mild hypoesthesia within V2 and V3 trigeminal branches occurred after surgery. Trigeminal neuralgia completely resolved, and medications were discontinued. This clinical case and literature review clearly demonstrated successful elimination of trigeminal neuralgia in patients with cerebellopontine angle lipoma after resection of mass lesion and partial trigeminal rhizotomy.

[Anatomical rationale for surgical treatment of trigeminal neuralgia combined with cerebellopontine angle tumors]. / Anatomicheskoe obosnovanie khirurgicheskogo lecheniia trigeminal'noi nevralgii, sochetaiushcheisia s opukholiami mostomozzhechkovogo ugla.

Trigeminal neuralgia (TN) can be combined with tumors of the cerebellopontine angle (CPA). The optimal surgical management in these cases depends on the anatomical relationship of the trigeminal nerve root (TNR) with tumors and vessels. The purpose of this study is to evaluate variants of the anatomical relationship between the TNR and the surrounding structures as well as to analyze the results of using various surgical techniques for treatment of TN in CPA tumors. MATERIAL AND METHODS: We performed a retrospective analysis of 51 patients (38 females and 13 males aged 22 to 77 years) with TN and ipsilateral CPA tumors. Space-occupying lesions were represented by 29 meningiomas of the petrous apex, 11 epidermoids, 9 vestibular schwannomas, 1 hemangioma, and 1 cavernoma. RESULTS: Intraoperatively, we identified 6 types of the anatomical relationships among the TNR, tumors, and CPA vessels: type I - the TNR is completely surrounded by the tumor (4 epidermoids); type II - the tumor compresses and displaces the TNR (21 meningiomas, 4 schwannomas, and 6 epidermoids); type III - the tumor occurs inside the TNR (1 cavernoma); type IV - the tumor together with the vessel compresses the TNR (3 meningiomas and 1 epidermoid); type V - the tumor displaces the TNR towards the vessel (5 meningiomas and 5 schwannomas); type VI - the tumor does not contact the TNR that is compressed by the vessel (1 hemangioma). Preoperative MRI and intraoperative findings revealed compression and deformity of the brain stem at the TNR entry level in all but two patients. Vascular compression of the TNR (usually by the superior cerebellar artery) was found in 15 of 51 patients. Microvascular decompression (MVD) was performed using various techniques: interposition of implants between vessels and the TNR, transposition of the compressing vessels from the TNR, or transposition of the nerve root. In all patients, except 1, pain syndrome regressed immediately after tumor removal and MVD. In 1 case, the pain syndrome did not regress after total removal of epidermoid and MVD, and TN was resolved by percutaneous radiofrequency rhizotomy. Long-term postoperative follow-up results showed complete elimination of TN in all cases; there were no persistent neurological complications and postoperative mortality. CONCLUSION: TN may result from direct compression and deformation of the TNR and brain stem by CPA tumors. In some cases, the cause of TN is combined compression of the TNR by the tumor and vessels. Assessment of the neurovascular relationships requires detailed examination of the entire TNR after tumor removal. In the case of vascular compression of the TNR, various MVD techniques can be used for treatment of TN.

[Assessing retinal photosensitivity in patients with central vision impairment using a portable perimeter (a preliminary report)]. / Issledovanie svetochuvstvitel'nosti setchatki pri narushenii tsentral'nogo zreniia s pomoshch'iu portativnogo perimetra (predvaritel'noe soobshchenie).

INTRODUCTION: The problem of reliably performing perimetry in people with impaired central vision who are unable to keep the gaze on the fixation point during the examination is yet to be resolved. PURPOSE: To develop a perimetry method for patients with impaired central vision using a portative perimeter based on a virtual reality device (p-VRD). MATERIAL AND METHODS: The study included 16 eyes (19 patients) without central vision (maximum visual acuity was from lateral light projection to 20/400). Each eye was examined in 3 ways and 3 groups were organized: 1st (control) - automatic static perimeter; 2nd (control) - Goldmann kinetic perimeter; 3-rd (experimental) - portable automatic static perimeter based on a virtual reality device (p-VRD). Patients of the experimental group used their sense of deep proprioception to keep the gaze on the screen center: putting p-VRD on, they were asked to lift a finger opposite their face on the eye level so that their line of sight went through the centre of the device's screen. RESULTS: Perimetry results in the 1st group were found to be unreliable due to frequent fixation loss. The contours of central scotoma could be determined in perimetry results of the 2nd and 3rd groups while achieving good comparability between the two respective methods (conformity coefficient K=73.7%). CONCLUSION: It is possible to assess light sensitivity of the eyes without central vision by performing perimetry with p-VRD. Satisfactory gaze fixation on the central zone of p-VRD screen is possible thanks to the human's sense of deep proprioception - the nonvisual sense of the exact location of the limbs.

[Surgical treatment of epilepsy in patients with mediobasal temporal cavernous malformations]. / Khirurgicheskoe lechenie épilepsii u patsientov s mediobazal'nymi visochnymi kavernoznymi mal'formatsiiami.

OBJECTIVE: Epilepsy is a frequent clinical manifestation of cavernous malformations (CMs) of the mediobasal temporal region (MBTR). Surgical removal of CMs is an excellent technique for treating associated epilepsy and may range from pure lesionectomy to tailored resection of the temporal lobe. PURPOSE: The study purpose was to determine the optimal surgical management for epilepsy in patients with CMs of the MBTR. MATERIAL AND METHODS: We retrospectively analyzed the clinical data, neuroimaging findings, surgical techniques, and surgical outcomes in 11 patients with epilepsy and CMs of the MBTR. All patients underwent video-electroencephalography, magnetic resonance imaging, and computed tomography in the pre- and postoperative periods. Nine patients underwent preoperative implantation of foramen ovale electrodes. In all cases, surgery was accompanied by electrocorticography (ECoG). RESULTS: CMs were located in the anterior MBTR in 7 cases, anterior and middle thirds of the MBTR in 1 case, middle third in 2 cases, and middle and posterior thirds in 1 case. In 8 patients, preoperative monitoring revealed a seizure onset area in the MBTR. These patients underwent cavernomectomy with ECoG-guided resection of the hemosiderin ring and adjacent tissue using the pterional (4 cases) or supracerebellar transtentorial approach (4). In 3 cases, anterior temporal lobectomy with cavernomectomy was additionally used due to spreading of pathological activity to the lateral temporal neocortex. Seizure control after surgery was excellent in 7 patients (class 1 ILAE) and good in 4 (class 2 ILAE). CONCLUSION: Surgery in patients with epilepsy caused by CMs of the MBTR should be performed based on non-invasive and invasive presurgical evaluation. If the seizure onset area is located in the MBTR, lesionectomy with ECoG-guided resection of the adjacent temporal cortical areas can be performed using the pterional or supracerebellar transtentorial approach. Lateral spread of epileptic activity requires cavernomectomy and anterior temporal lobectomy.

[New visual field testing possibilities (a preliminary report)]. / Novye vozmozhnosti issledovaniia polia zreniia (predvaritel'noe soobshchenie).

There are currently no portable mobile perimeters that allow visual field testing outside ophthalmologist's examination rooms. PURPOSE: To develop a mobile perimetry technique based on use of a virtual reality headset (VR). MATERIAL AND METHODS: The study involved 26 patients (30 eyes) with II-III stage primary open-angle glaucoma (POAG) with compensated IOP. Perimetry was performed for each patient twice - on Humphrey analyzer (test 30-2, 76 points) and employing similar strategy on a perimeter integrated into VR headset (Total Vision, Russia). Visual field testing was performed with an interval from 1 hour to 3 days. The results were comparatively analyzed. RESULTS AND CONCLUSION: Patients tolerated the examination well. Comparative analysis of preliminary perimetry results obtained with both methods showed high degree of identity, so the results were concluded to be comparable. By visually isolating the wearer, VR headset achieves elimination of distractions and stable light conditions for visual field testing. The headset-perimeter is compact, mobile, easily transportable, can be used in the work of visiting medical teams and for examination at home.

[An aneurysm of the medial posterior choroidal artery: a case report and a literature review]. / Anevrizma medial'noi zadnei vorsinchatoi arterii: opisanie klinicheskogo nabliudeniia i obzor literatury.

INTRODUCTION: Aneurysms of the medial posterior choroidal artery are very rare. To date, only 5 cases have been reported. The article presents a case of successful surgical treatment of an aneurysm of the medial posterior choroidal artery and a literature review. CLINICAL CASE: A 57-year-old male was admitted to the Center 1 month after a massive subarachnoid hemorrhage. CT angiography revealed an aneurysm of the right posterior medial choroidal artery in the perimesencephalic cistern and resolved hemorrhage. TREATMENT: The paramedian supracerebellar transtentorial approach to the lateral surface of the midbrain was used. The posterior cerebral artery was identified in the perimesencephalic cistern, and the medial posterior choroidal artery aneurysm was isolated and successfully clipped, with the parent artery being preserved. Postoperative CT and MRI scans revealed a small asymptomatic ischemic lesion in the tectal region on the right. The patient was discharged without any neurological symptoms 10 days after surgery. CONCLUSION: Medial posterior choroidal artery aneurysms can be clipped using the paramedian supracerebellar transtentorial approach.

[Propranolol Impairs Memory Reconsolidation at Single and Multiple Paired with Tone Painful Electrocutaneous Stimulations].

In the current paper there were used two methods for assessment of the propranolol effect on reactivated memory at reconsolidation phase--a classical pavlovian conditioning and the two-ways escape reflex. The difference between these two models was that in the first case a tone was paired with electrocutaneous painful stimulation only once, while in the second case it was applied multiply. Reminding was produced in the first case by placing the animals into the same context, whereas in the second case by application of the same amount of pairings of conditional and unconditional stimuli as it was used at the first day of learning. Propranolol reduced intensity of freezing reaction on 25% from the baseline at the classical conditioning approach and practically led to disappearance of memory and complete regress of the two-ways escape reflex. There was suggested on existence of the possible different mechanisms of noradrenergic blockade on memory loss at the stage of its reconsolidation in the used models of learning.

[Does Impulsivity Affect a Long-term and Working Memory in rats?].

In the present paper usingthe method of delay discounting three groups of animals were discovered: a) those that at choice between immediate weak and delayed strong rewards have chosen an immediate reinforcement (high impulsive rats); b) those that were able to inhibit its own behavior and get the delayed reinforcement (low impulsive rats); and c) the rats with both types of reactions. In the water maze the different groups of rats did find a hidden platform for different time, swum various distance and with different speed. The differences however were significant only at overall comparison (for all days and trials) of the above mentioned parameters of the water maze learning. ANOVAs Group x Days, Group x Trials, and Groups x Days x Trials interactions were insignificant. The data obtained indicate that the difference between groups was appeared evidently due to the difference in general motor activity, rather than difference in their cognitive abilities assessed by reference and working memory tasks.

[Impulsive Choice Improves the Cue Memory at an 8-arms Radial Maze Learning in Rats].

At the process of learning in an 8-arm radial maze the impulsive animals found the reinforced arms and ate the pellets faster, than self-control and ambivalent rats. They committed less working memory errors at the cue memory task, though there was no difference in the rate of learning and a number of errors of reference memory in animals of different groups. During reversion learning at the change of reinforced arms on unre- inforced, and vice versa, the impulsive animals spent less time to enter into the reinforced arms compared to other groups. They had fewer errors of cue working and reference memory, but the rate of learning was the same as in other groups. The date obtained indicate that in the impulsive rats in comparison with the other groups of animals are stronger the general motor activity and better the working memory.

[Trigeminal neuralgia and hemifacial spasm associated with vertebrobasilar artery tortuosity].

BACKGROUND: The tortuous vertebrobasilar artery (TVBA) often causes neurovascular conflicts in patients with trigeminal neuralgia (TN) and hemifacial spasm (HFS). Implementation of microvascular decompression (MVD) in these circumstances is hindered due to stiffness of the enlarged and dilated arteries and is often accompanied by poor outcomes. The surgical strategy in cases of trigeminal neuralgia and hemifacial spasm associated with the TVBA should be clarified in order to achieve good outcomes. MATERIAL AND METHODS: MVD was performed in 268 TN patients and 71 HFS patients. The TVBA as a compressing vessel was identified in 30 cases (11 cases of TN, 18 cases of HFS, and 1 patient with painful tic convulsif). All patients underwent MVD and a retrospective analysis of clinical outcomes. RESULTS: Compression caused by the vertebral artery was found in all HFS patients and 4 TN patients, and compression caused by the basilar artery was observed in 7 TN cases. Additional compression of the cranial nerve root entry/exit zone by cerebellar vessels was observed in 21 cases. The TVBA was mobilized by dissection of arachnoid adhesions between the vessel and the brainstem and retracted laterally. Then, the TVBA was retracted from the brainstem to the caudorostral direction. These manipulations resulted is "spontaneous" decompression of the cranial nerves without placing prostheses between the artery and the nerve root entry/exit zone. In all cases (except two), the displaced TVBA was fixed between the enlarged artery and brainstem using pieces of the patient's muscle and adipose tissues, followed by application of fibrin glue. A cylindrical silicone prosthesis was used in 1 case. In another case, the TVBA was retracted using a fascial loop fixed to the dura mater of the petrous pyramid by means of a suture. After application of MVD, TN and HFS symptoms completely regressed. There were several transient complications and 2 cases of permanent hearing loss. No clinical symptom recurrence was observed. CONCLUSION: MVD is the most effective surgical treatment of TN and HFS caused by the TVBA. The TVBA should be retracted from the brainstem without placing prostheses in the nerve root entry/exit zone.

[The paramedian supracerebellar transtentorial approach to the mediobasal temporal region]. / Paramediannyi supratserebellyarnyi transtentorial'nyi dostup k mediobazal'nomu otdelu visochnoi doli.

UNLABELLED: The mediobasal temporal region (MTR) is located near the brain stem and surrounded by the eloquent neurovascular structures. The supracerebellar transtentorial approach (STA) is safe access to the posterior MTR structures, however its use for resection of anterior MTR lesions still remains controversial. The article describes the technique and outcome of surgery for different MTR structures using STA. MATERIAL AND METHODS: The paramedian STA was used in 18 patients (13 females and 5 males) for 7 years. Ten patients presented with glial MTR tumors, 3 patients with cavernomas, 2 patients with arteriovenous malformations (AVMs), 2 patients with intraventricular meningiomas, and 1 patient with mesial temporal sclerosis. The patient age ranged from 19 to 57 years. In 10 cases, lesions were localized on the left. Epilepsy was the leading symptom in 14 cases. Patients underwent preoperative high-resolution MRI, electroencephalography video monitoring before and after surgery, intraoperative corticography (if necessary), and postoperative CT and MRI. RESULTS: Lesions were located in the anterior third of MTR in 5 patients, in the anterior and middle thirds in 2 patients, in the middle third in 5 patients, in the middle and posterior thirds in 2 patients, in the posterior third in 1 patient, in the anterior, middle, and posterior thirds in 1 patient, and in the ventricular triangle area in 2 patients. In all patients with intraventricular tumors, AVMs, and cavernous malformations and in 8 patients with glial MTR tumors, the lesions were totally resected. Two patients with intracerebral tumors underwent subtotal resection. A patient with intractable epilepsy and mesial temporal sclerosis underwent resection of the anterior two-thirds of the hippocampus and parahippocampal gyrus and, partially, amygdala using intraoperative corticography. There was no surgical mortality; 2 patients developed a transient neurological deficit, and 1 patient had a cerebellar hematoma that was successfully removed during surgery. CONCLUSION: STA enables resection of lesions localized in all parts of the MTR, without damage to the surrounding nerve and vascular structures.

[Giant partially thrombosed aneurysm of the vertebral artery: a case report and literature review]. / Gigantskaia chastichno trombirovannaia anevrizma pozvonochnoi arterii: opisanie klinicheskogo nabliudeniia i obzor literatury.

INTRODUCTION: Giant partially thrombosed aneurysms of the vertebral artery are recalcitrant to treatment by microsurgical trapping and thrombectomy. Application of endovascular interventions is limited due to substantial brainstem compression and cranial nerve neuropathy. Combined endovascular exclusion and microsurgical excision provides an approach to treatment of these lesions. CLINICAL CASE: A 48-year-old female patient presented with progressive complaints of ataxia, diplopia in left lateral gaze, and dysphagia. Imaging studies (CT, MRI, angiography) revealed a giant partially thrombosed aneurysm of the right vertebral artery and pronounced brainstem compression. TREATMENT: The initial phase of treatment involved endovascular occlusion of the vertebral artery and aneurysm trapping that did not lead to changes in the postoperative patient's neurological status. MRI demonstrated complete aneurysm thrombosis and a weak TOF signal in the vertebral artery near the proximal aneurysm neck region. Because of persistent brainstem compression, the patient underwent right suboccipital craniectomy and hemilaminectomy of the CI arch for aneurysm excision one week after endovascular occlusion. After isolating the aneurysmal sac, the vertebral artery was transected, and two small branches extending from the aneurysm neck to the brainstem were also coagulated and transected, followed by aneurysm excision. Numerous vasa vasorum in the wall of the proximal vertebral artery and aneurysm neck were coagulated to stop bleeding. After surgery, the patient developed neurological symptoms (right leg ataxia and dysphagia worsening) due to lateral medullary infarction (confirmed by MRI) that presumably resulted from coagulation of two small perforating branches coming from the aneurysm neck to the brainstem. Recovery of the patient's neurological functions was observed during conservative treatment. The patient was discharged with mild right leg ataxia and preoperative left-sided abducens paresis. CONCLUSION: Medulla oblongata compression associated with a giant thrombosed aneurysm of the vertebral artery can be eliminated by endovascular trapping followed by surgical excision of the aneurysm. Preserving the vasa vasorum feeding the brainstem is crucial for prevention of ischemic complications.

[Animal Models of Depression: Behavior as the Basis for Methodology, Assessment Criteria and Classifications].

Analysis of the current state modeling of depression in animals is presented. Criteria and classification systems of the existing models are considered as well as approaches to the assessment of model validity. Though numerous approaches to modeling of depressive states based on disturbances of both motivational and emotional brain mechanisms have been elaborated, no satisfactory model of stable depression state has been developed yet. However, the diversity of existing models is quite positive since it allows performing targeted studies of selected neurobiological mechanisms and laws of depressive state development, as well as to investigate mechanisms of action and predict pharmacological profiles of potential antidepressants.

[Stress reactivity and stress-resilience in the pathogenesis of depressive disorders: involvement of epigenetic mechanisms].

The data of epigenetic studies of stress reactivity and resilience in the pathogenesis of depression in experimental animals and humans subjected to stress at different periods of life are analyzed. Specific chromatin modifications, first of all histone acetylation and methylation, are controlling expression of definite genes in distinct brain structures. Epigenetic modulation of particular genes related to development of pro-depressive or antidepressive stress response are discussed (5HT transporter and receptors, corticotropin releasing hormone, glucocorticoid and their receptors, BDNF and other neurotrophic factors).

[Role of glycogen synthase kinase-3 in mechanisms of learning and memory].

In the current paper a review of the role of GSK-3b in mechanisms of learning and memory is presented. A regulation of GSK-3 by phosphorylation of serine and tyrosine sites and through Wnt signaling pathway by disruption of axin-ß-catenin complex is described. The data on participation of GSK-3b in regulation of NMDA-dependent long-term depression and potentiation, and the possible mechanisms of enzyme's influence through NMDA receptors and AMPA endocytosis are shown. A role of GSK-3b in development of Alzheimer's disease through inhibition of Wnt signaling parthway by beta-amyloid resulting in a strengthening of GSK-3b activity with further hyperphosphorylation of tay and formation of the neurofibrillary complexes are also considered. Behaviour of animals with knockout and overexpression of GSK-3b gene and effects of GSK-3 inhibitors in different behavioural models are also described.