Diffusion abnormalities on intraoperative magnetic resonance imaging as an early predictor for the risk of posterior fossa syndrome

Background

Posterior fossa syndrome (PFS) is an important complication of posterior fossa surgery in children. The pathophysiology of this condition remains unclear, but there is evidence implicating surgical injury of the proximal efferent cerebellar pathway (pECP) and the cerebellar vermis to PFS. We aimed to evaluate if diffusion abnormalities involving these structures on the final intraoperative MRI can predict the development of PFS.

Methods

Diffusion-weighted imaging from 31 posterior fossa resections were anonymized and evaluated for abnormalities involving the dentate nucleus, superior cerebellar peduncle, and the mesencephalic tegmentum forming the pECP, vermis, and middle cerebellar peduncle. The case notes were independently evaluated for evidence of PFS.

Results

The diffusion imaging in 28 cases was of optimal quality for evaluation. Diffusion abnormalities were identified in 10 cases, 7 of which involved the pECP. Retrospective evaluation revealed evidence of PFS in 6 cases. There was a significant association between abnormalities involving pECP structures (P = .001) and development of PFS. Bilateral involvement of pECP (P = .006) was a highly specific risk factor for predicting the development of PFS. Diffusion abnormality of the inferior vermis was significantly associated with PFS (P = .001) but may not represent a risk factor in isolation.

Conclusion

This study demonstrates the feasibility of identifying children at risk for developing PFS at the earliest stage post tumor resection and thus adds to the growing evidence base on its pathophysiology.     

Local Control of Brain Metastasis: Treatment Outcome of Focal Brain Treatments in Relation to Subtypes

Purpose

To investigate treatment options for local control of metastasis in the brain, we compared focal brain treatment (FBT) with or without whole brain radiotherapy (WBRT) vs. WBRT alone, for breast cancer patients with tumor relapse in the brain. We also evaluated treatment outcomes according to the subtypes.

Methods

We conducted a retrospective review of breast cancer patients with brain metastasis after primary surgery. All patients received at least one local treatment for brain metastasis. Surgery or stereotactic radiosurgery was categorized as FBT. Patients were divided into two groups: the FBT group received FBT±WBRT, whereas the non-FBT group received WBRT alone. Subtypes were defined as follows: hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative, HR-positive/HER2-positive, HR-negative/HER2-positive, and triple-negative (TN). We examined the overall survival after brain metastasis (OSBM), brain metastasis-specific survival (BMSS), and brain metastasis-specific progression-free survival (BMPFS).

Results

A total of 116 patients were identified. After a median follow-up of 50.9 months, the median OSBM was 11.5 months (95% confidence interval, 9.0-14.1 months). The FBT group showed significantly superior OSBM and BMSS. However, FBT was not an independent prognostic factor for OSBM and BMSS on multivariate analyses. In contrast, multivariate analyses showed that patients who underwent surgery had improved BMPFS, indicating local control of metastasis in the brain. FBT resulted in better BMPFS in patients with HR-negative/HER2-positive cancer or the TN subtype.

Conclusion

We found that patients who underwent surgery experienced improved local control of brain metastasis, regardless of its extent. Furthermore, FBT showed positive results and could be considered for better local control of brain metastasis in patients with aggressive subtypes such as HER2-positive and TN.     

超早期颅骨修补术对皮瓣分离时间及术中出血量的影响

目的探讨超早期（去骨瓣减速压术后6N内）颅骨修补术对皮瓣分离时间及出术中血量的影响。方法选取自2010年3月至2011年3月收治的行超早期颅骨修补术25例颅骨缺损患者为超早期修补组。选择同期去骨瓣减压术后3月以上行颅骨修补术颅骨缺损患者18例为对照组。对比分析两组患者的术中出血量、术中皮瓣分离时间的差异。结果超早期颅骨修补组患者的皮瓣分离时间[（12．9±7．2）min]较对照组[（30．1±10．8）min]明显缩短（P〈0．01）,而术中出血量[（226．3±40．3）m1]较对照组[（381．5±58．9）ml]明显减少（P〈0．01）。术后3月、6月患者均来院复查头颅cT,所有患者均未见脑积水、感染、硬膜下积液、头皮愈合不良等并发症。结论在严格选择适应症的前提下,超早期颅骨修补术有利于减少术中出血,缩短皮瓣分离时间,且其并发症发生率并未升高。     

颞下入路在中后颅窝肿瘤手术中的应用

目的探讨颞下入路显微手术治疗中后颅窝肿瘤的效果。方法采用颞下入路显微手术切除中后颅窝肿瘤20例,其中神经鞘瘤7例,海绵状血管瘤2例,脑膜瘤11例。结果肿瘤全切除15例,次全切除3例,大部切除2例。19例Labbe静脉处理未处理,1例切断。术后出现复视2例、面瘫1例、动眼神经麻痹1例、偏瘫1例、延髓麻痹1例。结论颞下入路显微手术是中后颅窝肿瘤理想的治疗方法。     

Outcomes of vagal nerve stimulation in a pediatric population: A single center experience

ObjectiveTo evaluate the efficacy of vagus nerve stimulation (VNS) in pediatric patients with medically refractory epilepsy.MethodWe reviewed the medical records of 252 consecutive patients who underwent VNS implantation at a single center over a 5-year period. Patients with complete 6- and 12-month follow-up data were included. Analysis was also done across various subgroups including gender, age at implantation, seizure type, abnormal MRI findings pre-implantation, number of medications at baseline, history of SE, and duration of epilepsy.ResultsComplete follow-up data were available for 69 patients. Median seizure reduction for these patients was 50% (Q1: 0%; Q3: 73%) at 6 months and 40% (Q1: −25%; Q3: 75%) at 12 months. When stratified by baseline seizure frequency, there was a significant reduction from baseline of 61% at 6 months and 69% at 12 months for patients in the high-baseline frequency group. There were no significant reductions at month 6 or 12 months for the lower-baseline frequency group. Adverse events were reported in 40.6% (28 out of 69 patients). Six patients had the VNS removed for reasons including lack of efficacy and side effects and were excluded from the study group.ConclusionVNS provides significant seizure reduction, in particular in pediatric patients with a higher baseline seizure frequency.     

Organized Hematoma Developed after Suboccipital Craniectomy

An organized hematoma shows a heterogeneous signal intensity on T1‐and T2‐weighted images on MR imaging, reflecting variable stages of hemorrhage. Although rather nonspecific, precontrast CT images of an organized hematoma demonstrate inhomogeneous hyperdense mass with or without calcification. We report a case of an organized hematoma in a 44‐year‐old man, which developed 5 years after decompressive suboccipital craniectomy following acute cerebellar infarction. To our best knowledge, there has been no report describing organized hematoma in the suboccipital craniectomy site. Computed tomography and magnetic resonance imaging findings of the organized hematoma are shown and discussed. We believe that recognition of the characteristic imaging findings of the organized hematoma as well as consideration of the history of surgery or anticoagulation treatment assists in its correct diagnosis enabling an inappropriate surgery to be avoided.     

Evaluating initial spine trauma response: Injury time to trauma center in PA,USA

Historical perceptions regarding the severity of traumatic spinal cord injury has led to considerable disparity in triage to tertiary care centers. This article retrospectively reviews a large regional trauma database to analyze whether the diagnosis of spinal trauma affected patient transfer timing and patterns. The Pennsylvania Trauma database was retrospectively reviewed. All acute trauma patient entries for level I and II centers were categorized for diagnosis, mechanism, and location of injury, analyzing transportation modality and its influence on time of arrival. A total of 1162 trauma patients were identified (1014 blunt injuries, 135 penetrating injuries and 12 other) with a mean transport time of 3.9 hours and a majority of patients arriving within 7 hours (>75%). Spine trauma patients had the longest mean arrival time (5.2 hours) compared to blunt trauma (4.2 hours), cranial neurologic injuries (4.35 hours), and penetrating injuries (2.13 hours, p < 0.0001). There was a statistically significant correlation between earlier arrivals and both cranial trauma (p = 0.0085) and penetrating trauma (p < 0.0001). The fastest modality was a fire rescue (0.93 hours) or police (0.63 hours) vehicle with Philadelphia County (1.1 hour) having the quickest arrival times. Most trauma patients arrived to a specialty center within 7 hours of injury. However subsets analysis revealed that spine trauma patients had the greatest transit times. Present research trials for spinal cord injuries suggest earlier intervention may lead to improved recovery. Therefore, it is important to focus on improvement of the transportation triage system for traumatic spinal patients.     

Diffusion tensor imaging for anatomical localization of cranial nerves and cranial nerve nuclei in pontine lesions: Initial experiences with 3T-MRI

With continuous refinement of neurosurgical techniques and higher resolution in neuroimaging, the management of pontine lesions is constantly improving. Among pontine structures with vital functions that are at risk of being damaged by surgical manipulation, cranial nerves (CN) and cranial nerve nuclei (CNN) such as CN V, VI, and VII are critical. Pre-operative localization of the intrapontine course of CN and CNN should be beneficial for surgical outcomes. Our objective was to accurately localize CN and CNN in patients with intra-axial lesions in the pons using diffusion tensor imaging (DTI) and estimate its input in surgical planning for avoiding unintended loss of their function during surgery. DTI of the pons obtained pre-operatively on a 3 Tesla MR scanner was analyzed prospectively for the accurate localization of CN and CNN V, VI and VII in seven patients with intra-axial lesions in the pons. Anatomical sections in the pons were used to estimate abnormalities on color-coded fractional anisotropy maps. Imaging abnormalities were correlated with CN symptoms before and after surgery. The course of CN and the area of CNN were identified using DTI pre- and post-operatively. Clinical associations between post-operative improvements and the corresponding CN area of the pons were demonstrated. Our results suggest that pre- and post-operative DTI allows identification of key anatomical structures in the pons and enables estimation of their involvement by pathology. It may predict clinical outcome and help us to better understand the involvement of the intrinsic anatomy by pathological processes.     

后颅窝颅手术应用不同冲洗液预防感染研究简

目的比较应用不同浓度庆大霉素冲洗液及甲硝唑冲洗液预防后颅窝开颅手术颅内感染的差异。方法采用前瞻性、随机对照分析方法,对2012年1月到2013年3月海军总医院神经外科收治的119例后颅窝开颅手术患者进行随机分组,分成4组,分别为生理盐水对照组30例,甲硝唑组29例,生理盐水＋庆大霉素8万U组30例,生理盐水＋庆大霉素16万U组30例。每组患者年龄范围、手术暴露时间及冲洗液总量,术前术后静脉应用抗菌素预防感染方法相同的情况下比较各组术后发热、细菌培养及术后颅内感染情况。结果生理盐水对照组发生感染7例（23．33％）,甲硝唑组发生感染6例（20．69％）,生理盐水＋庆大霉素8万U组发生感染1例（3．33％）,生理盐水＋庆大霉素16万U组发生感染1例（3．33％）。结论生理盐水＋庆大霉素8万U组及生理盐水＋庆大霉素16万u组冲洗液预防术后颅内感染明显好于生理盐水对照组及甲硝唑组（P〈0．05）,生理盐水＋庆大霉素8万U组与生理盐水＋庆大霉素16万U组无明显差别（P〉0．05）。