[Intracellular pH measurement in glioblastoma cells: the possibilities of phosphorus-31 MR spectroscopy]. / Izmerenie vnutrikletochnogo vodorodnogo pokazatelya glioblastom: vozmozhnosti fosfornoi magnitno-rezonansnoi spektroskopii.

OBJECTIVE: To analyze intracellular pH measurement with phosphorus-31 MR spectroscopy in glioblastoma cells and to compare these data with intracellular pH in healthy volunteers. MATERIAL AND METHODS: There were 10 patients aged 41 - 67 years with supratentorial glioblastomas. Intracellular pH in glioblastoma cells was compared with pH in healthy persons. RESULTS: We found a tendency to increased intracellular pH in glioblastoma cells in comparison with pH in intact brain tissue. CONCLUSION: Intracellular pH in brain tissue can be used as a potential marker of early abnormalities which could not be detected by conventional MRI. Moreover, these data may be valuable to estimate the efficacy of chemotherapy. The study was supported by Russian Science Foundation (grant No. 18-15-00337).

[Individual preoperative 3D modeling of vascular brain pathology]. / Individual'noe predoperatsionnoe 3D-modelirovanie sosudistoi patologii golovnogo mozga.

The possibility of segmenting three-dimensional objects by DICOM-series is well known and available both on specialized workstations and on personal computers. The technique, however, is relatively rarely used in clinical practice, and we believe that the benefits of preoperative preparation using segmented 3D models are underestimated. The article is devoted to our experience in using segmentation of anatomical structures based on CT and MRI for preoperative preparation for surgical operations performed in neurosurgical departments on patients with vascular pathology. The paper discusses the types and possibilities of segmentation, provides some examples describing the clinical use of the technique.

[Phosphorus (P) magnetic resonance spectroscopy for evaluation of brain tissue metabolism and measuring non-invasive pH. A study involving 23 volunteers. Part I]. / Fosfornaia (R) MR-spektroskopiia v otsenke énergeticheskogo metabolizma mozgovoi tkani i neinvazivnom izmerenii pH. Issledovanie 23 dobrovol'tsev. Chast' I.

Evaluation of brain metabolism is an important part in examination of brain lesions. Phosphorus magnetic resonance spectroscopy opens up great opportunities for studying the energy metabolism and allows noninvasive examination of metabolic processes occurring both in healthy and in pathologic brain tissue by obtaining a spectrum of phosphorus-containing metabolites involved in the turnover of cell membrane phospholipids. The technique presented in this paper was used to conduct 31P MR spectroscopy and to estimate the ratio between the peaks of the main metabolites and intracellular pH of the healthy brain tissue of 23 volunteers in the age group under 30 years old in clinical settings. Based on the recorded stable phosphorus spectra of metabolites of the healthy brain tissue, the value of intracellular pH (6.963±0.044) and the ratio of the main PME/PDE peaks (1.17±0.20) were calculated. The database was created to subsequently analyze the metabolic changes in brain tissue spectra in norm and in pathology, as well as the intracellular pH variations that have diagnostic and prognostic value.

[fMRI study of the dominant hemisphere for language in patients with brain tumor].

THE AIM OF THE STUDY: Paper describes a study of language lateralization of patients with brain tumors, measured by preoperative functional magnetic resonance imaging (fMRI) and comparison results with tumor histology and profile of functional asymmetry. METHODS: During the study 21 patient underwent fMRI scan. 15 patients had a tumor in the left and 6 in the right hemisphere. Tumors were localized mainly in the frontal, temporal and fronto-temporal regions. Histological diagnosis in 8 cases was malignant Grade IV, in 13 cases--Grade I-III. fMRI study was perfomed on scanner "Signa Exite" with a field strength of 1.5 As speech test reciting the months of the year in reverse order was used. fMRI scan results were compared with the profile of functional asymmetry, which was received with the results of questionnaire Annette and dichotic listening test. RESULTS: Broca's area was found in 7 cases in the left hemisphere, 6 had a tumor Grade I-III. And one patient with glioblastoma had a tumor of the right hemisphere. Broca's area in the right hemisphere was found in 3 patients (2 patients with left sided tumor, and one with right-sided tumor). One patient with left-sided tumor had mild motor aphasia. Bilateral activation in both hemispheres of the brain was observed in 6 patients. All of them had tumor Grade II-III of the left hemisphere. Signs of left-handedness were revealed only in half of these patients. Broca's area was not found in 4 cases. All of them had large malignant tumors Grade IV. One patient couldn't handle program of the research. CONCLUSIONS: Results of fMRI scans, questionnaire Annette and dichotic listening test frequently were not the same, which is significant. Bilateral activation in speech-loads may be a reflection of brain plasticity in cases of long-growing tumors. Thus it's important to consider the full range of clinical data in studying the problem of the dominant hemisphere for language.

[Neurodegenerative process in multiple sclerosis and a possible neuroprotective effect of ß-interferon 1a (avonex)].

To evaluate clinical perspectives of proton multi-voxel magnetic-resonance spectroscopy (PMMRS) for monitoring the severity of multiple sclerosis (MS) and neurodegenerative process, we studied the changes of the NAA/Cr ratio in the brain tissue of patients with MS and calculated the correlations between this parameter and the clinical state of patients. Based on these results, we studied the potential neuroprotective effect of ß-interferon 1a (avonex) for intramuscular injection in patients with remitting MS. Twenty-six patients with remitting MS were enrolled in the study. The study of anamnesis, neurological examination using EDSS, neuropsychological testing and dynamic MRI using PMMRS were performed. The NAA/Cr ratio was decreased in patients compared to controls. An analysis of the NAA/Cr ratio after one year revealed the significant decrease of this parameter. The negative correlation between the NAA/Cr ratio in the brain tissue and the level of neurological and cognitive deficits was noted. The analysis of existing treatment of MS with ß-interferon 1a for intramuscular injection revealed the neuroprotective stabilizing effect during one year of treatment that is probably associated with the effect of this drug on the neurodegenerative process in MS.

[The neurodegenerative process in multiple sclerosis and the possible neuroprotective effect of treatment with Β-interferon 1a (avonex)].

The aim of the study was to investigate the change of NAA/Cr ratio in the brain parenchyma in patients with MS with the help of protonic multivoxel magnetic resonance spectroscopy (PMMRS) and to detect the correlation between this factor and clinical status of the patients. The study was also performed in order to investigate whether this method can be potentially used for monitoring of the severity of the disease and severity of the neurodegenerative process. On the basis of this knowledge potential neuroprotective effect of the interferon beta 1a (IFN Β1а) i.m. (avonex) was investigated. Twenty six patients with relapsing-remitting multiple sclerosis (RRMS) were included in the study. The procedures included examination of the history of the disease, neurological examination, EDSS, neuropsychological tests, dynamic MRI with PMMRS. The decrease of the NAA/Cr ratio in patients with RRMS compared to healthy controls was detected. The dynamic control in a year revealed the decrease NAA/Cr in patients with MS. Negative association was revealed between NAA/Cr in the brain and the level of neurological and cognitive deficit. The analysis of the 1 year therapy with IFN Β1а i.m. revealed neuroprotective effect which can be related to the possible positive effect of the drug on the neurodegenaration process.

[Early results of irradiation of intracranial meningiomas using CyberKnife].

Meningiomas are frequently diagnosed intracranial lesions which cannot be resected radically in the majority of cases. Traditional radiotherapeutical techniques allow control of tumor growth in such situations. CyberKnife system may be used for radiosurgery and in sight hypofractionation. During 27 months 231 patient with intracranial meningiomas of different localization was treated in department for radiation therapy of Burdenko Neurosurgical Institute using CyberKnife system (Accuray Inc., USA). Mean age was 53 years. 55% of patients underwent previous surgical treatment, and diagnosis of meningioma was histologically verified. In 231 patient 374 targets were irradiated. Mean volume of irradiation reached 15.8 cm3 (range - 0.73-108.5 cm3). In 89% of cases hypofractionated therapy was used, in 10.1% we performed radiosurgery. Catamnestic data were available in 80 patients. Mean follow-up period was 11.6 months (6-27 months). Control of tumor growth was established in 100% of cases with WHO grade I tumors, in 66.7% of WHO grade II tumors and 60% in WHO grade III tumors. Deterioration after radiation treatment was observed in 16% of cases of 75 with control of tumor growth. In 8 cases worsening was due to radiation-induced reactions verified by MRI studies. Radiosurgical and hypofractionated treatment of meningiomas using CyberKnife is actual and highly-effective technique. Further investigations are needed to determine optimal standards of hypofractionated radiotherapy of meningiomas.

[CyberKnife stereotactic radiosurgery in the treatment of patients with trigeminal neuralgia].

Trigeminal neuralgia (TN) is a disabling disease with severe impairment of quality of life and everyday activity of patients. Range of treatment modalities is wide and includes conservative therapy, surgical methods and stereotactic radiosurgery (SRS). SRS is a minimally invasive technique which provides good results and minimal rate of complications. High geometrical and clinical precision of frameless SRS using CyberKnife system allows its application in TN when high dose is delivered to a small volume. The given paper focuses on the first Russian experience of frameless SRS of TN using robotized system CyberKnife. Since April 2009 till June 2011 4 patients with TN were treated in department for radiation therapy of Burdenko Neurosurgical Institute using CyberKnife system. Mean age was 63 years. Mean and maximal target dose reached 70 and 90 Gy, respectively. Data of catamnestic clinical examination were available in all 4 patients. Follow-up period reached 8 months. Response to treatment was observed in all cases. In 2 (50%) patients full effect was reached while in the rest only partial effect was present. No complications were encountered. Effectiveness and safety of SRS using CyberKnife system is comparable with framed SRS.

[Syndrome of cerebral hyperperfusion after carotid endarterectomy].

UNLABELLED: The aim of this study was to assess the role of different modalities in early diagnosis of cerebral hyperperfusion syndrome (CHPS) following carotid endarterectomy, as well as to develop effective treatment protocol for abovementioned complication. MATERIAL AND METHODS: Study group consisted of 61 patient who underwent uni- or bilateral carotid endarterectomy (CEA). Diagnostic modalities included transcranial Doppler study (TCD), cerebral oximetry, perfusion CT scanning and neuropsychological evaluation. STUDY RESULTS: We demonstrated that both bilateral carotid stenosis and stroke were independent predictive factors for CHPS at early postoperative period. "Classical" two-fold increase of cerebral blood flow in ipsilateral CMA was seen in 15% patients only. According to our data, predictive TCD-value was 1.48 increase of CBF. The most informative tool for early CHPS diagnosis was perfusion CT scans: preoperative mean transit time asymmetry in temporal areas (in the group of patients with unilateral carotid stenosis) correlated with CHPS development. Effective medical treatment for CHPS was achieved with Ca2+ channel antagonists use, that enabled us to prevent evolution of "mild" clinical appearance of CHPS into status epilepticus or intracerebral hemorrhage. CONCLUSION: Modern diagnostic modalities that assess brain perfusion can (with certain rate of accuracy) predict CHPS development even preoperatively. Early therapy of this complication with Ca2+ antagonists can usually control it.

[Intraosseous cranioorbital hemangiomas].

The authors describe 2 cases of primary intraosseous cavernous hemangioma (PICH). PICH are extremely rare tumors that represent less than 1% of all tumors of the bone. Only 20% of them involve skull. In both cases clinical findings were presented by proptosis, oculomotor disorders and chronic daily headaches. Surgery is the most recommended method of treatment. The best surgical management is gross total resection within intact tissue. In both cases tumor was removed completely.

[The role of susceptibility-weighted MRI in detection of ruptured aneurysm in multiple aneurysms].

Since 2008 till 2010 years 22 patients with multiple aneurysms were examined in Burdenko Neurosurgical Institute (Moscow, Russia). The series included 13 female and 9 male patients, age ranged from 28 to 62 years (mean 45 years). 68 aneurysms of different localization were discovered in these 22 patients. We also analyzed results of examination of 2 patients with solitary aneurysms in which SW-MRI was performed to confirm or exclude the fact of hemorrhage due to rupture of the aneurysm. All patients were operated microsurgically. SW-MRI is effective technique for identification of source of hemorrhage in patients with multiple aneurysms thus allowing selection of correct tactics of management. Information value of the method declines with increase of time after hemorrhage (over 2 years). SW-MRI enables verification of the fact of hemorrhage due to aneurysm in disputable cases (minimal non-specific clinical presentation, absence of hemorrhage verification).

[Multiple echinococcosis of brain, heart and kidneys].

The authors report a rare case of multiple echinococcosis (brain, heart and kidneys). Neuronavigation, intraoperative ultrasound scanning have allowed to plan exact and non-traumatic access to the cysts. Microsurgical technique and intraoperative neurophysiological monitoring provided removal of seven cysts without their rupture from the left parietooccipital and right parietal area with good postoperative functional result. Serologic analysis of antibodies with antigens of echinococci and histological research confirmed the diagnosis of cystic echinococcosis.

[FMRI-EEG estimation of cerebral reactivity to motor tasks in patients with brain tumors].

fMRI (1.5 or 3 T) and EEG studies with estimation of reactive responses on motor task (by right or left hand) were performed in 9 patients with tumors localized in frontal lobe of the brain. Results of this investigation were compared with results of the similar study in 12 healthy persons. It was shown that in cases of the brain pathology disorders of functional specialization and increase of diffuse component of reactivity was observed, fMRI-responses had been characterized the more intact reactions than reactive changes of EEG parameters. This specificity was described in cases of afferent loads in damaged hemisphere. Peculiarity of including different spectral bands in forming of EEG responses on motor tasks and changes of fMRI-answer depend on degree of cerebral decompensation, reflected in the of baseline EEG reorganization and degree of motor defect. Predominantly an increase of EEG coherence in delta-band with the predominance of reaction in the damaged hemisphere in cases of addressing any afferent load was observed in patients with severe cerebral decompensation and reflect dominant character of pathological focus forming. This data indicate on the more including of the deep brain structures in process of reactivity in patients compared with healthy persons and confirmed by fMRI-data.

[Linear accelerator-based stereotactic radiation treatment of patients with medial middle fossa meningiomas].

Medial middle fossa meningiomas are challenging for neurosurgical treatment. Invasion of cranial nerves and vessels leads to high risk of complications after removal of such meningiomas. Currently methods of conformal stereotactic radiation treatment are applied wider and wider for the discussed lesions. During a 3.5-year period 80 patients with medial middle fossa meningiomas were treated in Burdenko Moscow Neurosurgical Institute using linear accelerator "Novalis". In 31 case radiation treatment was preceded by surgical resection. In majority of patients symptoms included cranial nerve dysfunction: oculomotor disturbances in 62.5%, trigeminal impairment--in 37.5%, visual deficit--in 43.8%, facial nerve palsy--in 1.25%. 74 patients underwent radiotherapy with classical fractioning, 2--in hypofractionated mode and 4 received radiosurgery. In cases of classical fractioning mean marginal dose reached 46.3 Gy during 28-33 fractions, in hypofractioning (7 fractions)--31.5 Gy, in radiosurgery--16.25 Gy. Mean follow-up period was 18.4 months (6-42 months). Control of tumor growth was achieved in 97.5% of cases (78 patients): in 42 (52.5%) lesion shrinked, in 36 (45%) stabilization was observed. Clinical examination revealed improvement of visual function in 15 patients (18%) and deterioration in 2 (2.5%). No new neuropathies were found. Stereotactic radiation treatment is the method of choice for medial anterior and middle fossa meningiomas due to effective control of tumor progression and minimal rate of complications.

[Microsurgical treatment of large and giant aneurysms of the internal carotid artery: analysis of application of intravascular blood aspiration technique and future perspectives].

The article discusses results of surgical treatment of 82 patients with large and giant cerebral aneurysms operated in Burdenko Neurosurgical Institute (Moscow, Russia) during the recent 14 years. Special attention was given to benefits of intravascular blood aspiration (IBA) technique. This technique was proven to be very effective, allowing to clip the aneurysm in 87.8% of cases with good recovery in 41.5% and with moderate disability in 39%. Postoperative mortality was 4.9% (4 patients). The authors suggested original surgical classification of large and giant aneurysms. IBA was ineffective in cases of giant partially thrombosed aneurysms with sclerotic walls and giant aneurysms with very wide neck. These aneurysms require other surgical procedures such as embolization of ICA followed by extraintracranial bypass or high-flow bypass.

[Complex MR-diagnosis of brain abscesses]. / Kompleksnaia MR-diagnostika abstsessov golovnogo mozga.

Early diagnosis of brain inflammatory lesion is a basic factor in choosing treatment policy. The paper investigates the use and informative value of diffuse-weighed magnetic resonance imaging in the differential diagnosis of brain abscesses and processes of another origin. It also considers the application of MR spectroscopy and perfusion MRI to obtain additional information on an inflammatory processes. A series of observations covered 10 patients with brain abscesses at different sites. Diffusion-weighed image (DWI) revealed a drastic increase in a MR signal from the central abscess portions (a pyonecrotic area), which is suggestive of decreased diffusion of water molecules. The measured diffusion ratios (MDRs) were significantly lower in the central abscess area (p < 0.005) than those in the capsule and white matter of the brain at all values of the diffuse factor b (500, 1000 sec/mm2); the capsule was better visualized at the DWI at b = 500 sec/mm2. In addition, MDRs were significantly different within the annular contrasting area of abscesses and glioblastomas, in the abscess/tissue capsule, and edema (p < 0.01). Proton spectroscopy of the central abscess area (pus) revealed succinate, acetate, alanine, peaks of lactate and amino acid. Perfusion MR study (bolus contrasting and estimation of the tissue parameters rCBV and MTT) has indicated that the central abscess in relation to the medulla is a decreased perfusion area; perfusion in the abscess capsule is close to that in the medulla in its characteristics, but medullary time in this area is shorter than that in brain tissues; perifocal edema is also characterized by hypoperfusion. The analysis of complex MRI study in patients with brain abscesses has demonstrated that diffuse-weighed MRI enhances diagnostic specificity, diagnoses the development of a pyonecrotic abscess center at early stages of capsule formation; MR spectroscopy is an additional method of differential diagnosis of brain abscess and processes of another nature whereas perfusion MRI provides additional information on medullary hemodynamic changes.

[Proton magnetic resonance spectroscopy in diagnostics of tumorous and nontumorous lesions in brain]. / Protonnaia magnitno-rezonansnaia spektroskopiia v diagnostike opukholevykh i neopukholevykh porazhenii golovnogo mozga.

Whether proton magnetic resonance spectroscopy (1H-MRS) can be used in the diagnosis of tumorous and nontumorous lesions of the brain was studied. The results of studies were analyzed in 80 patients, including 54 patients with brain tumors (astrocytomas and meningiomas), 20 with nontumorous lesions of the brain, and 6 apparently healthy individuals (controls). The nontumorous lesions of the brain involved cerebral circulatory disorders as ischemia (n = 14) and postradiation changes (n = 6). The studies were performed on a 1.5-T Signa-Horizont magnetic resonance tomograph by using the PROBE/SV programme package. The peak ratios of the following metabolites: N-acetylaspartate (NAA), choline (Cho), creatine, lactate (Lac), lipids (Lip) were examined in the spectra obtained. The spectra of astrocytomas showed a reduced peak of NAA, an elevated peak Cho; there was an increase in the peak of Lac along with higher tumor malignancy stage. The spectra of meningiomas presented a high peak of Cho along with a noticeable reduction in the peaks of other metabolites, the peak of NAA was not visualized. In ischemic lesion of the brain, the peak of Lac appeared within the first hours when the peaks of other metabolites were unchanged. A rise in the peak of Lac and a reduction in that of other metabolites were detectable with time. In radiation-induced lesions, the spectrum displayed a high peak of Lac and the peak of Lip appeared with virtually complete reduction in the peaks of other metabolites. 1H-MRS should be considered as an axillary technique used in combination with routine MRI in the diagnosis of various lesions of the brain, which can estimate chemical compositions, time-course of metabolic changes in the study tissue.