Although radiosurgery-induced transformation of vestibular schwannoma (VS) into malignant peripheral nerve sheath tumor (MPNST) is being widely discussed, little attention is paid to the spontaneous transition of these tumors. Although the pathogenesis of this phenomenon remains uncertain, growing number of reported cases might call to notice them. We present a case of a 29-year-old woman who suffered right-sided hearing loss which remained untreated for 4.5 years. Magnetic resonance imaging revealed a right cerebellopontine tumor and the patient underwent tumor removal through retrosigmoid approach. Pathologically, the tumor was benign acoustic schwannoma with increased Ki-67 8%–10%. The tumor relapsed only 6 months later and was removed again-this time it was malignant peripheral nerve sheath tumor MPNST. The patient was treated with stereotactic radiotherapy, but despite that tumor growth was observed again and she underwent the third operation. Later on, tumor progression was noted with multiple intraaxial metastases and patient died 17 months after the diagnosis of MPNST had been confirmed. This is a seventh documented case of spontaneous transformation of VS into MPNST, which is clinically important for recording.

Одним из частых послеоперационных осложне-ний хирургического лечения опухолей задней че-репной ямки (ЗЧЯ) и мостомозжечкового угла (ММУ) является поражение лицевого нерва [1]. Данный вариант невропатии лицевого нерва сопро- Цель -оценка роли ботулинического токсина типа А в остром периоде поражения лицевого нерва после нейрохирурги-ческих операций. Материал и методы. Обследованы 55 пациентов с острым парезом мимических мышц, наступившим после поражения лицевого нерва при операции на задней черепной ямке и мостомозжечковом узле. 1-ю группу составили 35 больных (средний возраст 48,14±1,26 года), которым вводился ботулинический токсин типа А (ксеомин) в дозировке 2-3 ЕД на точку в мускулатуру здоровой половины лица. Во 2-ю группу (сравнения) вошли 20 больных (средний возраст 49,85±1,4 года), которым назначалось стандартное реабилитационное лечение данной патологии. Оценка эффективности лечения проводилась с использованием шкал Хауса-Брэкманна, Yanagihara System, FDI (Facial Disability Index) и шкалы Sunnybrook Facial Grading Scale (SFG). Результаты. До начала лечения у больных обеих групп наблюдалась тяжелая дис-функция по шкале Хауса-Брэкманна. Через 1 мес после начала лечения у пациентов, получавших ботулинический токсин типа А, отмечалось значимое улучшение по всем шкалам (р<0,05), тогда как в группе сравнения отмечено улучшение функции лицевого нерва лишь к 3-му месяцу реабилитационного лечения (р<0,05). Через 1 год после оперативного лече-ния у пациентов, не получавших ботулотоксин, количество синкинезий было на 46% больше, чем в 1-й группе (р=0,019), а через 2 года -на 91% (р<0,001). Выводы. Применение ботулинического токсина типа А является целесообразным при остром поражении лицевого нерва и должно быть включено в комплексное лечение данной категории больных. Aim. To evaluate the role of botulinum toxin type A in the acute phase of facial nerve injury after neurosurgical surgery. Materials and methods. The study involved 55 patients with acute facial muscle paresis caused by facial nerve injury during surgery on the posterior cranial fossa and cerebello-pontine angle (CPA). The first group consisted of 35 patients (mean age, 48.14±1.26 years) who were administered botulinum toxin type A (xeomin) at a dose of 2-3 U per point in muscles of the intact side of the face. The control group included 20 patients (mean age, 49.85±1.4 years) who underwent standard rehabilitation treatment of this pathology. The treatment efficacy was evaluated using the House-Brackmann Scale, the Yanagihara facial grading system, the Facial Disability Index (FDI), and the Sunnybrook Facial Grading (SFG) Scale. Results. Before treatment, patients of both groups experienced severe dysfunction according to the House-Brackmann Scale. A month after the botulinium toxin type A therapy had been started, a significant improvement in the group of patients who received botulinum toxin was observed at all scales (p<0.05), whereas improvement in the facial nerve function in the second group was observed only by the 3 rd month of rehabilitation t...

Purpose. To develop a methodology for assessing the degree of cerebrovascular insufficiency in patients with moyamoya angiopathy (AMM) based on measurement of cerebral blood flow (CBF) and determination the presence of arterial transit artifact (ATA) using MR method of arterial spin labeling (ASL).Materials and methods. The study included 47 patients with AMM who underwent 148 MR studies in PCASL mode (296 hemispheres), of which 47 (94 hemispheres) were done before surgical treatment. On received perfusion maps 7 areas of interest (ROI) were manually set in the gray and white matter of the brain using “Fusion” technique outside the ATA zones. The CBF values at the central point of the ATA were estimated. In the preoperative stage, 47 patients underwent direct angiography to assess the stage of the disease according to Suzuki, the presence and severity of leptomeningeal and transdural collaterals and MR angiography to assess the stage of the disease according to Houkin and the level of ICA stenosis. Statistical processing included univariate analysis of variance (ANOVA) and chi-square test (IBM SPSS Statistics 23).Results. ATA was detected in 77% of studies (69% of hemispheres). The average minimum CBF in ATA was 120.2 ± 21.1 ml/min/ 100 g at the lower bound of the confidence interval of 117.43 ml/min / 100 g. The average maximum CBF in ATA was 234.9. Depending on the CBF values in the MCA territory and the presence of ATA, 4 degrees of perfusion deficiency were identified: degree 0 (CBF = 64.5 ± 16.2 ml/min / 100 g, without ATA) corresponded to the stage of “compensation” of cerebral blood flow, degree 1 (CBF = 61.5 ± 16.6 ml/min/ 100 g, with ATA) – “subcompensation”, degree 2 (CBF = 26.5 ± 7.2 ml/min/100 g, with ATA) – “initial decompensation”, degree 3 (CBF = 16.0 ± 4.7 ml/min / 100 g, without ATA) – “decompensation”. The highlighted degrees statistically significantly differed among themselves in all ROIs (p < 0.0001). More severe perfusion deficiency corresponded to the more developed stages of AMM according to Suzuki and Houkin, proximal stenosis of the ICA (p < 0.0001), and more severe neurological deficit (p < 0.02). The occurrence of ATA reliably reflected the presence of leptomeningeal collaterals (p < 0.001).Conclusions. The proposed method for assessing patterns of ASL perfusion has a good agreement with the stage of the disease, the presence of sources of collateral circulation, the severity of neurological deficit and can be used to assess cerebrovascular insufficiency in patients with AMM.

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