[Application of robotized radiosurgical system CyberKnife for the treatment of neurosurgical patients].

Robotized system for radiosurgery CyberKnife (Accuray Inc., USA) is the first device dedicated and optimized for advanced irradiation during 1-7 fractions (i.e. radiosurgery and hypofractionation). CyberKnife is characterized by elaborate guidance system, high precision of dose delivery, possibility of conformal dose distributions with high gradient of target borderline dose which is most important in proximity of critical structures. The first CyberKnife system in Russia was installed in Burdenko Neurosurgery Institute. The paper presents 2-year experience of treating patients using CyberKnife. From April 2009 till October 2011 896 patients were treated using CyberKnife. Mean age was 48 years. Overall number of sessions was 2626. Radiosurgical procedures were performed in 21.8% of patients. 91% of cases were treated for intracranial lesions. Limited follow-up period in all kinds of pathology demonstrated results consistent with standard fractionation or radiosurgery. The rates of observed complications were also comparable with accepted techniques. CyberKnife system plays significant role in everyday activity of department of radiation therapy. In careful and thorough selection of patients it allows efficient and high-quality treatment of patients with neurosurgical diseases.

[CyberKnife stereotactic radiotherapy for mass lesions of the spinal cord and spine].

Introduction of a novel technology of stereotactic radiation treatment using linear accelerators, refining of systems for visualization and guidance provided rapid development of extracranial radiosurgery. Nowadays there is a possibility of precise stereotactic irradiation of lesions with different size and localization. One of the most actual and promising indications for radiosurgery are different primary and metastatic lesions and arteriovenous malformations of spinal cord and spine. Radiosurgery and hypofractionated radiotherapy with precise dose delivery during one or several sessions allow effective and safe treatment of neoplasms with any degree of radioresistance. This paper contains analysis of the first Russian experience of stereotactic radiation treatment of lesions of spinal cord and spine using robotized system CyberKnife (Accuray Inc., USA).

[Noninvasive magnetic resonance myelography in patients with lumbosacral intervertebral disk herniation].

For many decades X-ray myelography has remained one of the major diagnostic methods for spinal pathology. With the advent of computed tomography (CT), CT myelography using water-soluble contrast agents has been developed. Visualization of the subarachnoidal spaces of the spinal cord and dural sac without an intrathecal contrast agent has become possible with the emergence of magnetic resonance imaging (MRI). Its further development and improvement has brought to existence the new noninvasive technique MR myelography based on the suppression of a signal from the medulla and its enhancement from the cerebrospinal fluid-containing spaces. This paper compares routine X-ray myelography, CT myelography, and MR myelography used in the diagnosis of lumbosacral intervertebral disk herniation and assesses the informative value and benefits of MR myelography as a noninvasive diagnostic method for this pathology.

[Neuroradiological diagnostics of atherosclerotic lesions and kinking of the carotid arteries in determination of indications to surgical treatment].

Range of methods for diagnostics of extracranial arterial stenosis includes both untrasonic techniques (transcranial Doppler study, duplex sonography, which are not only screening methods, but also used in surgery as well) and high-tech imaging methods--spiral CT scans and MR angiography with visualization of structural changes in vascular wall, quantitative and functional assessment of blood flow in vessels. Aim of this study was to determine the effective of non-invasive diagnostic techniques--MR angiography (MRA), including phase-contrast MRA (PCMRA), and spiral CT angiography (SCTA) in identification and comprehensive assessment of stenosis of internal carotid artery and comparison of capabilities of these methods with gold standard--direct angiography.

[Complex neuroradiological diagnosis in case of atherosclerotic lesion of the carotid arteries].

The diagnostic arsenal for extracranial stenosis includes both ultrasound techniques, such as transcranial Doppler and duplex sonography, which are not only screening methods, but also are used at surgery, and high-tech neuroradiological techniques, such as spiral computed tomographic and magnetic resonance angiography, which can visualize structural changes in the vessel walls and qualitatively and functionally evaluate blood flow in the vascular bed. The purpose of this investigation was to determine the efficacy of non-invasive diagnostic methods, such as magnetic resonance angiography, including phase-contrast magnetic resonance angiography and spiral computed tomographic angiography, in the detection and comprehensive evaluation of stenoses and to compare the feasibilities of noninvasive procedures with the gold standard--selective angiography.

[Rare observation of hyperostotic cranial lesions in osteogenesis imperfecta].

A rare case of hyperostotic skull deformity in a patient with congenital bone defect--osteogenesis imperfecta--is described. In this case typical symptoms encountered in adults were observed: decreased body length caused by shortened extremities due to multiple pathological fractures in childhood, deformities of thorax, spine, facial bones and teeth, skull lesions with craniobasal and brainstem symptoms, bluish hue of sclera, hypoacusis etc.). In this patient non-typical abnormalities were found: visual deficit due to optic nerve atrophy caused by bilateral optic canal stenosis on the background of densitometrically proven hyperostotic skull base deformity.

[Linear accelerator-based stereotactic radiotherapy and radiosurgery in treatment of neurosurgical patients].

Radiation methods are essential in management of certain types of neurooncological, neurovascular and functional brain pathology. Application of stereotactic technique of irradiation allows sufficient damaging impact on target (tumor, AVM, functional structures) and maximal protection of surrounding brain tissues. Indications to radiation treatment of intracranial lesions are expanding with evolution of stereotactic methods. The paper deals with the first experience of linear accelerator-based treatment of patients with intracranial neurosurgical pathology in this country. Techniques of stereotactic radiotherapy (SRT) and radiosurgery (SRS), indications to SRS and SRT in different modes of fractioning are described in details. Additionally specific complications, radiation reactions and feasibility of neurovisualization in diagnosis of radiation-induced brain damage are discussed.

[Stereotactic radiotherapy and radiosurgery in treatment of patients with intracranial schwannomas].

Aim of this study is to assess the role of stereotactic radiosurgery (SRS) and radiotherapy (SRT) in management of cranial nerves schwannomas by analysis of tumor control, clinical response and variables affecting treatment outcomes. Between April 2005 and January 2009 patients with schwannomas of VIII (63), V (14) and caudal nerves (2) were treated in Burdenko Moscow Neurosurgical Institute using linear accelerator. Mean age was 49 years (13-82). In 42 cases radiation treatment was preceded by surgical resection. 13 patients had type I or II neurofibromatosis. Mean volume of the tumor was 3.9 cm3 (0.5-14.4 cm3) and 13.4 cm3 (2.8-41.3 cm3) for SRS and SRT, respectively. Mean SRS dose was 12 Gy (10.8-14.4 Gy) for vestibular schwannomas and 15 Gy (13.2-18 Gy) for schwannomas of other nerves. In hypofractionated SRT the dose of 35 Gy was delivered in 7 fractions or 30 Gy in 6 fractions. In cases of classical fractioning total dose of 50-60 Gy was divided into daily fractions of 1.8-2.0 Gy. Radiographic tumor control rate reached 97.5% at the last follow-up. 5 patients experienced trigeminal dysfunction, it was transient in 3 cases and persistent in 2. Permanent decline in House-Brackmann facial nerve scale developed in 2 of 79 patients. After treatment effective hearing (class I-II) was preserved in 7 of 9 patients (67%) who had same level of hearing before SRS. Linear accelerator-based stereotactic radiation treatment provides long-term tumor control associated with high rates of preservation of neurological functions. No further tumor surgery was necessary in 100% of cases with solitary tumors with a minimal follow-up of 5 years.

[Linear accelerator-based stereotactic radiotherapy in combined treatment of skull base chordomas].

Short-term results of postoperative stereotactic linear accelerator-based radiation treatment of 18 patients with cranial base chordomas are analyzed. Total dose was 70 Gy or more. Control of tumor growth confirmed by CT and/or MRI was achieved in 15 cases (83%). Only 1 patient had complication--visual deficit which resolved after 3 months. Control group consisted of 73 patients treated only surgically. 38% of cases in this group were recurrence-free. The study has demonstrated effectiveness of radiotherapy of skull base chordomas.

[Cerebrospinal fluid dynamics in chronic obstructive hydrocephalus before and after successful endoscopic third ventriculostomy].

OBJECTIVE: to describe cerebrospinal fluid dynamics in chronic obstructive hydrocephalus before and after successful endoscopic third ventriculostomy (ETV). MATERIALS AND METHODS: 8 patients (7-21 years old) with chronic obstructive hydrocephalus due to tectal plate glioma were investigated before and after successful ETV. Apart from clinical and MRI assessment ICP-monitoring (ICP0) and intraventricular infusion studies were performed as well as upright ICP (ICP90) was investigated preoperatively and on 1st and 7th postoperative days (POD). Dynamic changes were assessed using Wilcoxon matched pairs test. RESULTS: There were no complications. MRI demonstrated functional ventriculostomy and reduced ventricle size in all cases. At follow-up all ETV's were considered clinically successful. By the 7th POD ICP0 showed tendency to reduction (p = 0.07) and ICP90 reduced significantly (p = 0.02). Significant reduction of Rcsf was evident by the 1st POD (p = 0.03) and was maintained until the 7th POD (p = 0.02). Elastance coefficient and compliance (as measured during infusion study) didn't change significantly in relation to ETV. In all the 3 cases when computerized ICP monitoring was used reduction of ICP pulse amplitude (AMP), AMP/ICP slope and RAP was noted by the 7-th POD which most probably reflects reduction of intracranial elastance. CONCLUSION: Effect of ETV in chronic obstructive hydrocephalus cannot be explained exclusively by its influence on ICP0; clinical improvement can possibly be attributed also to normalization of ICP90 and Rcsf, reduction of intracranial elastance and increase of cerebral blood flow reserve capabilities. There may be a pathophysiological ground for ETV in obstructive hydrocephalus with normal ICP.

[X-ray diagnosis of hemangioblastomas of the posterior cranial fossa].

A series of observation covered four patients with hemangioblastomas of the posterior cranial fossa. The study analyzed the infomative value of CT, MRI (with and without contrast enhancement), vertebral angiography, MR angiography and perfusion CT in the diagnosis and differential diagnosis of hemangioblastomas of the posterior cranial fossa and tumors of another origin. Perfusion CT study (estimation of the relative cerebral blood volume) has indicated that hemangioblastomas in relation to the medulla is an increased perfusion area. The analysis of complex radiological study in patients with hemangioblastomas of the posterior cranial fossa has demonstrated that perfusion CT may be useful in differentiating hemangioblastomas from other contrasted neoplasms. Moreover, perfusion CT provides additional information on tumor hemodynamic changes.

[Magnetic resonance imaging of the orbital portion of the optic nerve at different stages of papilledema].

High-resolution magnetic resonance image makes it possible to examine the radiological anatomy of the orbital portion of the optic nerve in patients with papilledema. The longitudinal diameters of the orbital portion of the optic nerve and its subarachnoidal space were measured on coronal images just behind the eyeball, in the middle of the latter and the orbital apex, and at the orbital apex in 10 healthy volunteers and 20 patients with papilledema. In patients with papilledema, the diameter of the subarachnoidal space of the optic nerve was increased as compared with that in the control group. In its moderate form, that of the optic nerve was significantly increased as compared to the control group. In patients with severe papilledema and secondary atrophy, the diameter of the optic nerve just behind the eyeball was significantly less than that in patients with moderate papilledema. It may be suggested that elevated intracranial pressure leads to the dilated subarachnoidal space of the optic nerve. The clinical and X-ray signs of atrophy of the optic nerve are detectable in patients with severe papilledema and secondary atrophy.

[Basilar skull fractures: clinical and prognostic aspects]. / Perelomy osnovaniia cherepa: klinicheskie i prognosticheskie aspekty.

The incidence of basilar skull fractures and their clinical and prognostic aspects were studied in victims with varying severity of brain injury. Of 947 cases, 449 (46%) patients were diagnosed as having basilar skull fracture and 181 (18.6%) had basal spinal fluid leakage. The frequency of fractures and basal spinal fluid leakage increased in proportion to the severity of brain injury. The above 14-day history of spinal fluid leakage was an absolute indication for surgical fistula closure.

Unusual intraventricular herniation of the suprasellar arachnoid cyst and its successful endoscopic management.

A child with a benign intrinsic tectal tumor and obstructive hydrocephalus developed a huge intraventricular cystic lesion following insertion of a shunt, which was complicated by a subdural-subarachnoid bleeding. The lesion was identified to be an entrapped chiasmatic cistern, which disrupted the septum pellucidum in front of the third ventricle and filled gradually the anterior horn of the lateral ventricle. The condition was successfully treated endoscopically by fenestration of the cyst and a third ventriculostomy. Probable mechanisms of such unusual cyst formation and general management strategies in patients with obstructive hydrocephalus are discussed.

[Surgical treatment of meningiomas of the craniovertebral junction]. / Khirurgicheskoe lechenie meningiom kraniovertebral'nogo perekhoda.

The results of surgical treatment in 21 patients with meningiomas of the craniovertebral junction are presented. Main clinical diagnostic criteria in relation to the site of a tumor relative to the brain stem are considered. The basic surgical approaches used in the surgical treatment of meningiomas of the craniovertebral junction are described. These include posterior, median, posterolateral, transcondylar approaches. Surgical techniques to remove meningiomas having a matrix of varying areas were concretized, this is also done in relation to the consistency of a tumor. The outcomes of surgical treatment are analyzed. Possible postoperative complications and measures of their prevention and treatment are considered.

[Results of endoscopic ventriculostomy of the III ventricle in the treatment of occlusive hydrocephalus]. / Rezul'taty éndoskopicheskoi ventrikulostomii III zheludochka v lechenii okkliuzionnoi gidrotsefalii.

The paper presents data of a retrospective analysis of the outcomes of endoscopic ventriculostomy of the 3rd ventricle, obtained in a consecutive series of 120 patients aged 5 months to 58 years who had occlusive hydrocephalus and operated on at the Research Institute of Neurosurgery, Russian Academy of Medical Sciences, in 1995-2000. In most cases (n = 112), hydrocephalus was caused by a block at the level of the cerebral aqueduct. In more than 50% of the patients, different tumors were responsible for occlusion. In 96 (80%) cases, the operation led to the elimination of occlusion and to the regression of symptoms just after surgery. Complications were few and observed in 19 patients, ventriculitis (n = 7) and intracranial hemorrhages (n = 6) being most common. No death occurred. Seventy three patients were followed up for 1 month to 5 years (mean 1.5 years). Eliminated occlusion and steady-state remission were found in 64 (87.7%) cases. Improvement was strongly correlated with an increase in the reserve craniovertebral content capacity estimated by measuring the pulse amplitude of blood flow in the tentorial sinus in body position-changing tests. In 9 patients, the symptoms of hydrocephalus remained or recurred after short-term improvement. In 3 of them, this occurred with anatomically competent anastomoses between the 3rd ventricle and cisterns. In the other 6 cases, the obliteration and anatomic incompetence of ventriculostoma were responsible for a relapse. In 8 of the 9 patients, shunting had to be made subsequently in the period of 1 to 6 months. The paper also considers some biophysical aspects of cerebrospinal fluid circulation and discusses indications for endoscopy. It is concluded that endoscopic ventriculostomy of the 3rd ventricle is the method of choice in the treatment of patients with obstructive hydrocephalus.

[Delayed radiation-induced optic neuropathy in patients with tumors in the chiasmal-sellar area after radiation therapy]. / Otsrochennaia radiatsionnaia opticheskaia neiropatiia u bol'nykh s opukholiami kiazmal'no-selliarnoi oblasti posle luchevoi terapii.

Six clinical observations of a rare condition, delayed radiation-induced optic neuropathy (RON) are presented. RON developed in patients with brain tumors treated by radiotherapy and radiosurgery; in the majority of patients the condition developed during exposure to therapeutic doses; its incidence was 0.5% of the total number of patients treated by radiotherapy during this period. Asymmetrical chiasmal syndrome developed rapidly in all the patients. Clinical diagnosis of RON was confirmed by magnetic resonance tomography in all cases, and in one case by morphological analysis. Conservative therapy including hyperbaric oxygenation just stabilized the visual function. Remote period of observation was 42 months.

[A study of the spinal fluid flow by magnetic resonance imaging]. / Izuchenie likvorotoka na osnove magnitno-rezonansnoi tomografii.

The study was undertaken to examine the potentialities of new MRI techniques (MR-myelocysternoventriculography and phasic contrast-enhanced MRI with reference to a cardiac cycle) in visualizing the spinal fluid system and flow in different groups of neurosurgical patients. MR-myelocysternoventriculography was based on the sequences of SSFP-3D (Signa, GE, 1.5 T) and PSIF-3D (Magnetom 42SP, Siemens, 1.0 T). These regimens were applied to obtain highly T2*-weighed images. These techniques were used in 280 patients. Phasic contrast-enhanced MRI with reference to a cardiac cycle was performed in the axial (through the aqueduct of the cerebrum) and sagittal projects (CINE-2D mode, Signa GE). This technique was employed to study 30 patients and 5 healthy volunteers. MRI-cysternography based on SSFP-3D- and PSIF-3D sequences is recommended as the method of choice in evaluating the 3rd ventriculostoma and, in combination with spiral computed tomography, in detecting fistulas of the base of the skull. Phasic contrast-enhanced MRI with reference to a cardiac cycle yielded the values of spinal fluid flow through the aqueduct of the cerebrum in health: Vsyst max = 4.1 +/- 1.3 cm/sec; Vsyst mean = 2.5 +/- 1.4 cm/sec; Vdiast max = 3.4 +/- 1.5 cm/sec; Vdist mean = 2.5 +/- 1.7 cm/sec (N = 5). The prospect of the technique is to develop recommendations and to predict prognosis while making bypass surgery for ventriculostomas and cystostomas.

[A cryptococcal granuloma of the midbrain]. / Kriptokokkovaia granulema srednego mozga.

The paper describes the most infrequent case of cryptococcal granuloma of the midbrain in a HIV-negative female patient aged 41 years. The patient with midbrain lesion without signs of meningitis was found to have a bulky midbrain opercular formation that was regarded as a nodal glioma. The diagnosis of cryptococcal granuloma was established after removal of the formation (via occipito-transtentorial access with dissection of the lamina tecti) and pathomorphological examination. Microbiological studies verified the diagnosis. Despite the initiation of specific treatment with amphotericin B, the patient died on day 12 following surgery for cryptococcal meningoencephalitis.