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Radiation treatment techniques are essential in complex management of selected neurooncological, neurovascular and functional brain pathology. Stereotactic radiotherapy provides sufficient damage to the target (tumor, AVM, functional structures) with minimal impact on surrounding brain tissue. Development of stereotactic methods with X-ray guidance lead to expansion of indications for irradiation of intracranial and extracranial lesions. This paper represents the first experience of treating patients with AVMs using CyberKnife system in Russia. The technique of stereotactic radiotherapy (SRT) and radiosurgery (SRS) is described in details, as well as indications for SRT and SRS in different regiment of fractionation, possibilities of planning systems, with additional emphasis on specific complications, radiation-induced reactions and capabilities of neurovisualization methods in evaluation of radiation-induced damage of brain tissue.

Recently the number of AVM resections in Burdenko Neurosurgical Institute has been increased dramatically. Aim of this study was to assess the results of open surgery in our clinic in modern neurosurgical era. Consecutive series if 160 patients with AVM treated using microsurgical technique since 2009 till 2011 was analyzed. Spetzler-Martin score distribution was: grade I--29 (18.1%) cases, grade II--84 (52.5%), grade III--38 (23.8%), grade IV--9 (5.6%). Patients with grade V AVMs were not operated. Treatment options included: AVM resection in 143 (89.4%) cases, embolization followed by resection in 15 (9.3%) and clipping of afferents in 2 (1.3%). Glasgow outcome scale score distribution was the following: V (good recovery)--70 (43.7%), IV (moderate disability)--71 (44.4%), III (severe disability)--16 (10%), II (vegetative state)--1 (0.6%) and I (death)--2 (1.3%). Microsurgery remains the primary option for radical treatment of cerebral AVMs. Careful selection of patients and planning of surgery are crucial for good outcomes.

A 16-year-old boy with arteriovenous malformation (AVM) of septum pellucidum in combination with left side persistent trigeminal artery (PTA) is described. Presentation of AVM included severe intracranial hemorrhage and the lesion was removed surgically. The case deserves interest for two reasons. 1) The observation demonstrates the possibility of increased pressure in the afferent arteries of AVM. It was illustrated by distinctive displacement of the zones of the hemodynamical balance around the circle of Willis. The raised pressure in conditions of shunting can be explained using principles of the constant shear stress in the vascular system. 2) The observation of the features of venous system that may be causative for PTA. These features included presence of the large anastomotic vein between petrosal and cavernous sinuses, enlargement of petrosal sinuses and shrinking of transverse sinus ipsilateral to PTA.

The paper presents two cases of high-surgical-risk deep arteriovenous malformations (AVM) concurrent with aneurysms of the middle portion of the anterior ciliary artery (a male aged 35 years and a female aged 24 years). In the former case, aneurysm and large AVM in the left visual tuber were causes of 4 hemorrhages. In the latter, AVM of subcortical nodes and internal capsule were responsible for single hemorrhage. The patients underwent intraoperative embolization of the anterior ciliary artery followed by its clipping. This allowed the authors to exclude aneurysm and to achieve obliteration of the bulk of AVM. Operation were performed under intraoperative guidance of motor and speech functions. Residual AVM were exposed to proton beam radiation. The outcomes of treatment were good. After 4 months of surgery, the male had no neurological disorders; in the female motor and speech disorders were associated with prior hemorrhage.

A comprehensive examination was made in 39 patients with arteriovenous malformations (AVM) of hippocampus. Prior to and following surgery, all the patients underwent neuropsychological study after A. R. Luriia (1962). Mnestic disorder was found to be the most common abnormality in patients with AVM at this site. Before surgery, they were detected in 34 of 39 patients, 11 of them having severe memory disorders with the traits of the Korsakoff's syndrome. These patients were found to have mixed posthemorrhagic lesion of the hippocampus, other portions of the temporal lobe and periventricular structures. Twenty nine patients were operated on, 14 of them had progressive mnestic disorder of the modally nonspecific type irrespective the side operated on. There were no postoperative Korsakoff's syndromes. There was no progression in memory defects in patients after surgery on the brain drastically changed after hemorrhage or removal of minor malformations. Before hemorrhage, epileptic paroxysms were observed in 2 of the 39 patients only in the presence of massive AVM obligatorily involving the temporal cortex. Following surgery, there were no new epileptic paroxysms and changes in the emotional status and motivations in the patients. Thus, the hippocampal formation is involved in the primary mechanisms of fixation, retention, reproduction of a memory trace. The participation of many structures of the brain is required to form an emotional status, motivation, and clinical manifestations of epileptic activity.

Clinical and neuropsychological studies of the outcomes of surgical treatment in patients with arteriovenous malformations (AVM) of the gyrus cinguli were conducted. Preoperative examination revealed predominantly memory disorders in 38 cases. Of them 5 cases had amnestic disturbances similar to those of the Korsakoff syndrome. Autonomic and epileptic seizures were not common. Thirty eight patients underwent surgery. Memory deterioration was recorded in 23 cases postoperatively. Three patients developed a "new" Korsakoff syndrome. The rate of deterioration of memory disorders showed a clear correlation with the extent of gyrus cinguli destruction and degree of corpus callosum integration to AVM nidus. The qualitative analysis of amnestic syndromes demonstrated that the majority of patients developed pre- and postoperative disorders of trace selectivity, the insight incontinence of the story essence accompanied by diminished critical attitude towards their condition. This pattern of defects was similar to the clinical features of the amnestic syndrome in patients with frontal lobe lesions. Combined damage of frontal lobes and their connections (with gyrus cinguli in this case) is of great importance in the formation of a clinical picture in man. The findings should be taken into consideration when surgical policy is to be analyzed.

To choose the optimal surgical treatment, the follow-ups of 25 patients with arteriovenous malformations (AVMs) concurrent with arterial aneurysms who had been surgically treated were considered. Twenty four patients experienced spontaneous subarachnoidal hemorrhage, 16 of them were repeated and multiple. The accurate diagnosis of the source of bleeding was associated with objective difficulties. With allowance for intraoperative findings. AVMs caused hemorrhage in 14 (58%) cases, aneurysms in 6 (25%). AVMs and aneurysms in 4 (17%). Thirteen (52%) patients were operated on AVMs and aneurysms in one or two steps, 5 had operations only on aneurysms, 7, on AVMs alone. Taking into account ruptures and higher sizes of aneurysms after AVM dissection, it is concluded that it is necessary to immediately exclude saccular bifurcating aneurysms irrespective of the cause of bleeding. Possible variants of policy decisions are dealt with, by taking into account the specific features of the location of AVMs and aneurysms-the sources of hemorrhage. One-stage surgical interventions into AVMs and aneurysms are recognized to be optimal.

A comprehensive clinical and neuropsychological study was made of 34 patients with thalamic arteriovenous malformations. In the thalamus. Memory disorders were a common abnormality (in 31 of 34 patients). They were modally nonspecific and depended on the site of arteriovenous malformations. With the prevalent ventricular pattern of hemorrhages, memory disorders were accompanied by disorientation and emotional and volitional impairments. Arteriovenous malformation was removed in 12 patients (on the left side in 7 patients and on the right in 5). After surgery there was virtually progression of memory defects in all patients. Speech disorders combining the specific features of lesions in various cortical regions were detected in 5 of 7 patients with left thalamic arteriovenous malformations.

The clinical and neuropsychological signs were studied in 32 patients with arteriovenous malformations of various site who had sustained hemorrhages into the cerebral ventricles. The studies allowed the authors to identify the neuropsychological syndrome which involved the following signs: disorientation, chiefly in time, marked inertia in various scopes of activities, emotional and volitional disorders, and dysmnesia. Memory defects were seen in all spheres of mnestic activity: there were abnormalities in the actualization of consolidated knowledge, modal non-specific memory disorders in the experiment, defects in memory for current events. The degree of defect severity was found to be directly proportional to that of prior hemorrhages. In the absence of hydrocephalus, the disorders were regressive. The authors discuss what topical belonging of the detected syndrome is and how it is related to the phase of consciousness restoration.

The article analyzes the clinical data of 48 patients with arteriovenous malformations of the thalamus, who were examined at the Burdenko Institute of Neurosurgery, AMS USSR, from 1970 to 1989. The experience in surgical treatment is based on 25 cases. The authors describe in detail the indications for surgical treatment, adequate surgical approaches, and the method for removal of the malformations. Neuropsychological and electrophysiological methods of examination of patients in dynamics were applied to evaluate the results of surgery.

The article analyses the clinical data in 56 patients with hippocampal arteriovenous malformations who underwent complex clinical examination in the course of the disease by means of neurological, neuropsychological, and electrophysiological methods. Cerebral angiography and computerized tomography were the main methods of topical diagnosis. Thirty-nine patients were subjected to total removal of the malformations. The authors substantiate the indications for surgical treatment. Adequate surgical approaches and the methods of removal of the malformations are described.

An anatomo-surgical classification of arteriovenous malformations of the posterior cranial fossa (PCF) is suggested, based on angiography and computer-aided tomography findings with due consideration for adequate surgical approaches to the defect. Conditions of blood supply and drainage are described with regard to localization of the malformation in the PCF structures. Analysis of the neurologic symptoms in PCF arteriovenous malformations permitted a conclusion on a comparatively rare correlation between the symptoms and the localization of the malformation in a certain PCF structure.

The work is based on analysis of the results of complex clinical examination of 70 patients (48 males and 22 females) treated at the Burdenko Institute of Neurosurgery, Academy of Medical Sciences of the USSR, for arteriovenous malformations in the posterior cranial fossa (AVM PCF). The patients' age ranged from 8 to 50 years. Various types of surgical interventions were performed on 26 patients. The authors suggest an anatomo-surgical principle of grouping AVM PCF, which is based on the findings of radiocontrast diagnostic methods. Problems of the clinical picture and topical diagnosis of AVM PCF are discussed. The indications for surgical treatment of AVM PCF, the surgical approaches to them, and the techniques of total extirpation (16 cases) are determined. The results of palliative operations (6 cases) are analysed. The microsurgical anatomy of anastomoses between AVM and PCF and their importance in surgery for these conditions are described.