Wei Liu and Jian-Guo Zhang
Gamma Knife irradiation–induced histopathological changes in the trigeminal nerves of rhesus monkeys
Zhe-Feng Zhao, Li-Zhuang Yang, Chuan-Lu Jiang, Yong-Ri Zheng, and Jin-Wei Zhang
The authors' goal was to observe histopathological changes in the trigeminal nerve after Gamma Knife surgery (GKS) in rhesus monkeys, and to investigate the radiobiological mechanism of GKS for primary trigeminal neuralgia. The nerve length–dosage effect of irradiation is also discussed.
One of 5 rhesus monkeys randomly served as a control, and the other 4 monkeys were randomly administered a target radiation dose of 60, 70, 80, or 100 Gy (a different dose in each animal). The size of the collimator was 4 mm, and the target point was the trigeminal nerve root. In each experimental monkey, one side was exposed to single-target-point irradiation, and the contralateral side was exposed to double-target-point irradiation. After 6 months, the trigeminal nerve root was examined using light microscopy, transmission electron microscopy, and immunohistochemistry.
At each radiation dose, the damage to the nerve tissue by single-target-point irradiation was identical to that caused by double-target-point irradiation. In the trigeminal nerve tissues of the monkeys irradiated with 60 and 70 Gy, there was limited nerve demyelination and degeneration, fragmentation, or loss of axons. In the trigeminal nerve tissue of the monkey irradiated with 80 Gy, the nerve tissue showed a disordered structure. In the trigeminal nerve tissue of the monkey irradiated with 100 Gy, there was severe derangement in the structure of the nerve tissue, and extensive demyelination, fragmentation, and loss of axons.
The target doses of 60 and 70 Gy have very little impact on the structure of the trigeminal nerve. Irradiation at 80 Gy can cause partial degeneration and loss of axons and demyelination. A 100-Gy dose can cause some necrosis of neurons. Comparing the single-target-point with the double-target-point irradiation, the extent of damage to the nerve tissue is identical, and no difference in the nerve length–dosage effect was found.
Reng-Jye Lee, Chih-Feng Chen, Shih-Wei Hsu, Chun-Chung Lui, and Yeh-Lin Kuo
✓ Endovascular therapy for dural carotid cavernous fistulas (CCFs) is generally accepted to be safe and effective. The authors report a rare complication of hemorrhage and subsequent venous infarcts of the pons and cerebellum after transvenous embolization.
This 41-year-old man presented with a severe left frontal headache, congestion of the left conjunctiva, blurred vision, and photophobia. Cerebral angiography demonstrated a right dural CCF. The patient underwent transvenous embolization of the cavernous sinus but had the initial complication of cerebellar hemorrhage. One month later, he developed progressive dizziness, ataxia, and right-sided weakness. Magnetic resonance imaging revealed severe cerebellar and pontine edema. The cause was a residual fistula combined with delayed occlusion of the inferior petrosal sinus. The fistula was obliterated after repeated embolizations. The patient's symptoms gradually resolved, and there was no evidence of recurrence during the 4-year follow-up period.
Incomplete transvenous embolization of a dural CCF can result in life-threatening vascular complications due to redistribution of shunt flow. Early recognition of redistributed drainage and preventive placement of coils at the origin of draining veins during the procedure could avert this rare complication.
Yang Lin, Feng Li, Wenjian Chen, Heng Zeng, Anmin Chen, and Wei Xiong
This study evaluated the efficacy and safety of mini-open anterior debridement and lumbar interbody fusion in combination with posterior percutaneous fixation for single-level lumbar pyogenic spondylodiscitis.
This is a retrospective study. Twenty-two patients with single-level lumbar pyogenic spondylodiscitis underwent mini-open anterior debridement and lumbar interbody fusion in combination with posterior percutaneous fixation via a modified anterior lumbar interbody fusion (ALIF) approach. Patients underwent follow-up for 24 to 38 months. Clinical data, etiological examinations, operative time, intraoperative blood loss, American Spinal Injury Association (ASIA) grade, Japanese Orthopaedic Association (JOA) lumbar function score, visual analog scale (VAS) score, Oswestry Disability Index (ODI), postoperative complications, and the bony fusion rate were recorded.
The mean operative time was 181.1 ± 22.6 minutes (range 155–240 minutes). The mean intraoperative blood loss was 173.2 ± 70.1 ml (range 100–400 ml). Infection was found in lumbar vertebrae L2–3, L3–4, and L4–5 in 2, 6, and 14 patients, respectively. Bacterial cultures were positive in 15 patients, including 4 with Staphylococcus aureus, 6 with Staphylococcus epidermidis, 4 with Streptococcus, and 1 with Escherichia coli. Postoperative complications included urinary retention, constipation, and numbness in the thigh in 5, 3, and 2 patients, respectively. Compared with before surgery, the VAS scores and ODI were significantly lower at the final follow-up, the JOA scores were significantly higher, and the ASIA grades had improved. All patients achieved good intervertebral bony fusion.
Mini-open anterior debridement and lumbar interbody fusion in combination with posterior percutaneous fixation via a modified ALIF approach results in little surgical trauma and intraoperative blood loss, acceptable postoperative complications, and is effective and safe for the treatment of single-level lumbar pyogenic spondylodiscitis. This approach could be an alternative to the conventional open surgery.
Chen Wang, Xiao-Jun Yuan, Ma-Wei Jiang, and Li-Feng Wang
The purpose of this study was to explore the clinical features and outcome of medulloblastoma in Chinese children. The authors analyze the reasons that treatment is abandoned and attempt to provide evidence-based recommendations for improving the prognosis of medulloblastoma in this population.
A total of 67 pediatric cases of newly diagnosed medulloblastoma were included in this study. All of the children were treated at Xinhua Hospital between January 2007 and June 2013. The authors retrospectively analyzed the clinical data, treatment modalities, and outcome. The male-to-female ratio was 2:1, and the patients’ median age at diagnosis was 51.96 months (range 3.96–168.24 months). The median duration of follow-up was 32 months (range 3–70 months).
At the most recent follow-up date, 31 patients (46%) were alive, 30 (45%) had died, and 6 (9%) had been lost to follow-up. The estimated 3-year overall survival and progression-free survival, based on Kaplan-Meier analysis, were 55.1% ± 6.4% and 45.6% ± 6.7%, respectively. Univariate analysis showed that standard-risk group (p = 0.009), postoperative radiotherapy (RT) combined with chemotherapy (p < 0.001), older age (≥ 3 years) at diagnosis (p = 0.010), gross-total resection (p = 0.012), annual family income higher than $3000 (p = 0.033), and living in urban areas (p = 0.008) were favorable prognostic factors. Multivariate analysis revealed that postoperative RT combined with chemotherapy was an independent prognostic factor (p < 0.001). The treatment abandonment rate in this cohort was 31% (21 of 67 cases).
There was a large gap between the outcome of medulloblastoma in Chinese children and the outcome in Western children. Based on our data, treatment abandonment was the major cause of therapeutic failure. Parents’ misunderstanding of medulloblastoma played a major role in abandonment, followed by financial and transportation difficulties. Establishment of multidisciplinary treatment teams could improve the prognosis of medulloblastoma in Chinese children.
Chun-Wei Yu, Kuan-Ting Chen, Yu-Lan Liu, Yi-Chiao Hsieh, Dun-Wei Huang, Yi-Feng Lee, Tsui-Jung Chien, and Dueng-Yuan Hueng
Yen-Po Cheng, Chien-Min Chen, Shao-Wei Feng, and Dueng-Yuan Hueng
Shao-Wei Feng, Huey-Kang Sytwu, and Dueng-Yuan Hueng
Hsuan-Kan Chang, Tun-Wei Hsu, Johnson Ku, Jason Ku, Jau-Ching Wu, Jiing-Feng Lirng, and Shih-Ming Hsu
Good bone quality is the key to avoiding osteoporotic fragility fractures and poor outcomes after lumbar instrumentation and fusion surgery. Although dual-energy x-ray absorptiometry (DEXA) screening is the current standard for evaluating osteoporosis, many patients lack DEXA measurements before undergoing lumbar spine surgery. The present study aimed to investigate the utility of using simple quantitative parameters generated with novel synthetic MRI to evaluate bone quality, as well as the correlations of these parameters with DEXA measurements.
This prospective study enrolled patients with symptomatic lumbar degenerative disease who underwent DEXA and conventional and synthetic MRI. The quantitative parameters generated with synthetic MRI were T1 map, T2 map, T1 intensity, proton density (PD), and vertebral bone quality (VBQ) score, and these parameters were correlated with T-score of the lumbar spine.
There were 62 patients and 238 lumbar segments eligible for analysis. PD and VBQ score moderately correlated with T-score of the lumbar spine (r = −0.565 and −0.651, respectively; both p < 0.001). T1 intensity correlated fairly well with T-score (r = −0.411, p < 0.001). T1 and T2 correlated poorly with T-score. Receiver operating characteristic curve analysis demonstrated area under the curve values of 0.808 and 0.794 for detecting osteopenia/osteoporosis (T-score ≤ −1.0) and osteoporosis (T-score ≤ −2.5) with PD (both p < 0.001).
PD and T1 intensity values generated with synthetic MRI demonstrated significant correlation with T-score. PD has excellent ability for predicting osteoporosis and osteopenia.
Guo-jie Hu, Yu-gong Feng, Wen-peng Lu, Huan-ting Li, Hong-wei Xie, and Shi-fang Li
Therapeutic neovascularization is a promising strategy for treating patients after an ischemic stroke; however, single-factor therapy has limitations. Stromal cell-derived factor 1 (SDF-1) and vascular endothelial growth factor (VEGF) proteins synergistically promote angiogenesis. In this study, the authors assessed the effect of combined gene therapy with VEGF165 and SDF-1 in a rat model of cerebral infarction.
An adenoviral vector expressing VEGF165 and SDF-1 connected via an internal ribosome entry site was constructed (Ad-VEGF165-SDF-1). A rat model of middle cerebral artery occlusion (MCAO) was established; either Ad-VEGF165-SDF-1 or control adenovirus Ad-LacZ was stereotactically microinjected into the lateral ventricle of 80 rats 24 hours after MCAO. Coexpression and distribution of VEGF165 and SDF-1 were examined by reverse-transcription polymerase chain reaction, Western blotting, and immunofluorescence. The neurological severity score of each rat was measured on Days 3, 7, 14, 21, and 28 after MCAO. Angiogenesis and vascular remodeling were evaluated via bromodeoxyuridine and CD34 immunofluorescence labeling. Relative cerebral infarction volumes were determined by T2-weighted MRI and triphenyltetrazolium chloride staining. Cerebral blood flow, relative cerebral blood volume, and relative mean transmit time were assessed using perfusion-weighted MRI.
The Ad-VEGF165-SDF-1 vector mediated coexpression of VEGF165 and SDF-1 in multiple sites around the ischemic core, including the cortex, corpus striatum, and hippocampal granular layer. Coexpression of VEGF165 and SDF-1 improved neural function, reduced cerebral infarction volume, increased microvascular density and promoted angiogenesis in the ischemic penumbra, and improved cerebral blood flow and perfusion.
Combined VEGF165 and SDF-1 gene therapy represents a potential strategy for improving vascular remodeling and recovery of neural function after cerebral infarction.