Task Switching After Cerebellar Damage.

The authors of this study investigated task switching following cerebellar damage. The study group consisted of 7 children and adolescents (M age = 13.8 years) who underwent surgical removal of a benign posterior fossa tumor. They were tested at a sufficient interval after surgery (M lag = 6.13 years) for restoration of normal cognitive skills and intelligence. Although all showed normal learning of the task compared with control participants, when rapid behavioral changes were required (short preparation time), they exhibited behavioral rigidity manifested by enhanced switching cost. These results are in line with another study on serial reaction time with the same patients (A. Berger et al., in press). They have important implications for our understanding of the cognitive sequelae of early cerebellar damage as well as the involvement of the cerebellum in task switching. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

In-vivo confocal scanning laser microscopy of the cerebral microcirculation

Confocal scanning laser microscopy (CSLM) was used to study the microcirculation of the brain neocortex in anaesthetized rats. After removal of the dura mater, implantation of a closed cranial window, and intravenous injection of fluorescein, three-dimensional reconstructions of cortical capillaries were performed down to a depth of 250 μm below the pial surface. Using a one-dimensional approach (single line scanning), erythrocyte (negative contrast in fluorescently labelled plasma) and leucocyte (labelled with rhodamine 6 G) velocity and supply rate in cortical capillaries were measured. The effect of CO₂-inhalation on capillary blood flow dynamics was studied. Capillaries were imaged continuously for up to 1 h without changes in flow or fluorescence pattern. However, by increasing the laser power 10–100-fold, aggregate formation was induced and capillaries were occluded, possibly due to damage to vascular endothelium. We conclude that CSLM can be used to study morphological and dynamic aspects of fluorescently labelled subsurface structures in organs of experimental animals.     

个性化钛合金颅骨修复体成形仿真

针对钛合金颅骨修复体的数字化制造，依据实际成形条件建立有限元模型，采用薄板成形数值模拟技术对颅骨修复体的成形过程进行仿真，从而事先预测可能出现的缺陷(拉裂、起皱与回弹等)，优化调整冲压工艺参数。实践表明，利用仿真结果指导实际制造过程，大大提高了修复体成形的一次成功率，可消除成形的不确定性，保证个性化制造的成形质量。     

侧颅底手术过程中脑及颅神经功能保护

手术是绝大部分侧颅底病变的首选治疗方式。因侧颅底解剖结构复杂,毗邻脑及重要血管神经,手术容易致死或致残,限制了该部位手术的实施。脑、后组颅神经、面神经、听力功能是该部位手术保护的重点,恰当处理功能保留和切除病变的关系、良好的外科操作技能以及合理使用介入、导航等新的辅助技术是侧颅底手术中实现器官功能保护的关键。     

Core neurocognitive functions in children treated for posterior fossa tumors.

Identifying cognitive deficits associated with pediatric brain tumors and their treatment is important in delineating the mechanisms of intellectual decline often associated with these diseases. The authors evaluated sustained attention, information processing speed, working memory, and IQ in 64 patients with posterior fossa tumors, including those treated with either: (a) surgery and cranial radiation (n = 32), and (b) surgery without radiation (n = 32). Ten patients treated for non-CNS solid tumors were included as a comparison group. The authors also examined the impact of relevant demographic and medical variables on neurocognitive outcome. The authors found that neither age at, nor time since, diagnosis predicted cognitive outcome in this sample. Further, sustained attention and working memory were largely intact and there were no differences between groups. Patients treated with cranial radiation demonstrated lowered short-form IQ and slow information processing speed: Patients treated with cranial radiation and who experienced postsurgical complications demonstrated the poorest performance. The authors consider information processing speed to be an excellent candidate mechanism in understanding the impact of cranial radiation on intellectual outcome. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

高功率半导体激光在38例颅脑外科手术中的应用

目的为了减少脑组织的损伤,更有效的切除肿瘤,发展微侵袭神经外科.也是神经显微外科手术成功的关键。方法应用高功率半导体激光器(805nm,30W)在38例颅内肿瘤和脊髓肿瘤患者中,成功地进行了激光手术治疗(气化或切割)。结果术后效果良好。还充分显示了805nm半导体激光在应用于显微镜下各类手术的入路,可非常有效地减少对肿瘤的牵拉。保证了神经显微外科手术的成功。     

Single-Shot 360-Degree Cranial Deformity Detection System Using Digital Image Correlation

In this paper, a single-shot 360-degree cranial deformity detection system using digital image correlation (DIC) is presented to quickly obtain and detect accurate 3D data of infants’ cranium. By introducing plane mirrors into a stereo 3D DIC measurement system, a multi-view 3D imaging model is established to convert 3D data from real and virtual perspectives into 360-degree 3D data of the tested infant cranium, achieving single-shot and panoramic 3D measurement. Experimental results showed that the performance and measurement accuracy of the proposed system can meet the requirements for cranial deformity detection, which provides a fast, accurate, and low-cost solution medically.     

颅内动脉瘤3D几何模型建立方法的研究

血流动力学的状态参数及其变化是认识动脉瘤的发生、发展和破裂以及风险预测的基础。提出了一种基于DSA图像的颅内动脉瘤的3D几何模型的建立方法,完成了动脉瘤3D形状的几何表达。该模型为进一步分析血流动力学因素的基础。     

Cranial Base Synchondrosis Lacks PTHrP-Expressing Column-Forming Chondrocytes

The cranial base contains a special type of growth plate termed the synchondrosis, which functions as the growth center of the skull. The synchondrosis is composed of bidirectional opposite-facing layers of resting, proliferating, and hypertrophic chondrocytes, and lacks the secondary ossification center. In long bones, the resting zone of the epiphyseal growth plate houses a population of parathyroid hormone-related protein (PTHrP)-expressing chondrocytes that contribute to the formation of columnar chondrocytes. Whether PTHrP⁺ chondrocytes in the synchondrosis possess similar functions remains undefined. Using Pthrp-mCherry knock-in mice, we found that PTHrP⁺ chondrocytes predominantly occupied the lateral wedge-shaped area of the synchondrosis, unlike those in the femoral growth plate that reside in the resting zone within the epiphysis. In vivo cell-lineage analyses using a tamoxifen-inducible Pthrp-creER line revealed that PTHrP⁺ chondrocytes failed to establish columnar chondrocytes in the synchondrosis. Therefore, PTHrP⁺ chondrocytes in the synchondrosis do not possess column-forming capabilities, unlike those in the resting zone of the long bone growth plate. These findings support the importance of the secondary ossification center within the long bone epiphysis in establishing the stem cell niche for PTHrP⁺ chondrocytes, the absence of which may explain the lack of column-forming capabilities of PTHrP⁺ chondrocytes in the cranial base synchondrosis.     

From Reparative Surgery to Regenerative Surgery: State of the Art of Porous Hydroxyapatite in Cranioplasty

Decompressive craniectomy is one of the most common neurosurgical procedures, usually performed after neuropathological disorders, such as traumatic brain injury (TBI), but also vascular accidents (strokes), erosive tumours, infections and other congenital abnormalities. This procedure is usually followed by the reconstruction of the cranial vault, which is also known as cranioplasty (CP). The gold-standard material for the reconstruction process is the autologous bone of the patient. However, this is not always a feasible option for all patients. Several heterologous materials have been created in the last decades to overcome such limitation. One of the most prominent materials that started to be used in CP is porous hydroxyapatite. PHA is a bioceramic material from the calcium phosphate family. It is already widely used in other medical specialties and only recently in neurosurgery. In this narrative review of the literature, we summarize the evidence on the use of PHA for cranial reconstruction, highlighting the clinical properties and limitations. We also explain how this material contributed to changing the concept of cranial reconstruction from reparative to regenerative surgery.