Translational Neuroscience and Clinics

Aims and Scope Translational Neuroscience and Clinics is an open access journal publishing articles focusing on information derived from human experimentation so as to optimise the communication between basic and clinical neuroscience.Articles deal with a wide range of topics including physiological,medical。

Biodegradable mineralized collagen plug for the reconstruction of craniotomy burr‐holes:A report of three cases

Objectives: In this case report, we describe the design, fabrication and clinical outcomes of a novel bioresorbable, mineralized collagen burr‐hole plug for the reconstruction of craniotomy burr‐holes. Methods: Mineralized collagen burr‐hole plugs were fabricated via a biomimetic mineralization process. The biomimetic mineralized collagen has a similar chemical composition and microstructure to natural bone tissue, thereby possessing good biocompatibility and osteoconductivity. The mineralized collagen burr‐hole plugs were implanted into three patients, and clinical outcomes were evaluated at one‐year follow‐ups. Results: All bone defects healed very well using the mineralized collagen burr‐hole plugs, and there were no adverse reactions at the surgical sites. Conclusions: The clinical outcomes indicated that the mineralized collagen was effective for reconstructing burr‐holes in the skull after craniotomy.

A review of EEG-based brain-computer interface systems design

A brain-computer interface(BCI) system can recognize the mental activities pattern by computer algorithms to control the external devices. Electroencephalogram(EEG) is one of the most common used approach for BCI due to the convenience and non-invasive implement. Therefore, more and more BCIs have been designed for the disabled people that suffer from stroke or spinal cord injury to help them for rehabilitation and life. We introduce the common BCI paradigms, the signal processing, and feature extraction methods. Then, we survey the different combined modes of hybrids BCIs and review the design of the synchronous/asynchronous BCIs.Finally, the shared control methods are discussed.

Antiparkinsonian treatment for depression in Parkinson's disease: Are selective serotonin reuptake inhibitors recommended?

Depression is a frequent comorbid syndrome in Parkinson's disease. It is a difficult symptom to manage, as patients continuously receive antiparkinsonian medication and may also have to be treated for the amelioration of the side-effects of antiparkinsonian therapy. The first-line treatment for depression in Parkinson's disease is the use of selective serotonin reuptake inhibitors(SSRIs). The clinical efficacy of these medications in patients with Parkinson's disease is questionable. In fact, based on their mechanism of action, which requires at least a functional serotonergic system, it is predicted that SSRIs will have lower efficacy in patients with Parkinson's disease. Here, we consider the mechanism of action of SSRIs in the context of Parkinson's disease by investigating the fall in the levels of serotonergic markers and the inhibitory outcomes of antiparkinsonian treatment on serotonergic nerve activity. Because certain classes of antidepressant drugs are widely available, it is necessary to perform translational research to address different strategies used to manage depression in Parkinson's disease.

An association between the location of white matter changes and the behavioral and psychological symptoms of dementia in Alzheimer's disease patients

Objective:The frontal lobe may be involved in circuits associated with depression,apathy,aggression,and other psychiatric symptoms.Although white matter changes(WMC)are related to the severity of behavioral and psychological symptoms of dementia(BPSD)in patients with Alzheimer’s disease(AD),it is unclear which part of the WMC may play the most important role in BPSD.This study was designed to investigate the relationship between the location of WMC and the severity of BPSD in AD patients.Methods:Among patients diagnosed with Alzheimer’s disease between 2009 and2014,387 patients were retrospectively reviewed after those with pre‐existing organic brain syndrome,psychiatric diseases,or toxic‐metabolic encephalopathy were excluded.Patients’demographic and laboratory data,WMC measured with brain computed tomography and scored using the age‐related white matter changes(ARWMC)scale,and neuropsychological tests,including the cognitive abilities screening instrument(CASI),the Mini‐Mental State Examination(MMSE),the clinical dementia rating scale with sum‐box(CDR‐SB),and the neuropsychiatric inventory(NPI)were analyzed.Results:There was no significant difference in the NPI between patients with and without a history of stroke,hypertension,and diabetes.No significant difference in the NPI was identified between different sexes or different Apolipoprotein E(APOE)alleles.The NPI score was significantly correlated with the duration of education(r=–0.4515,P=0.0172),CASI(r=–0.2915,P<0.0001),MMSE(r=–0.8476,P<0.0001),and CDR‐SB(r=2.2839,P<0.0001).WMC in the right frontal lobe showed a significant difference in NPI in comparison to those without WMC(P=0.0255).After adjusting for age,duration of education,and CASI,WMC in the right frontal lobe remained significantly associated with the NPI score(β=3.8934,P=0.042).Conclusions:WMC involving the right frontal lobe may play an important role in the BPSD in AD patients during their dementia diagnosis.Further studies are necessary to confirm whether controlling the risk factors of WMC can slow the progression of BPSD.

Application of multimodal image fusion technology in brain tumor surgical procedure

Objective: To construct brain tumors and their surrounding anatomical structures through the method of registration, fusion and, three-dimensional(3D) reconstruction based on multimodal image data and to provide the visual information of tumor, skull,brain, and vessels for preoperative evaluation, surgical planning, and function protection.Methods: The image data of computed tomography(CT) and magnetic resonance imaging(MRI) were collected from fifteen patients with confirmed brain tumors.We reconstructed brain tumors and their surrounding anatomical structures using Neuro Tech software. Results: The whole 3D structures including tumor, brain surface, skull, and vessels were successfully reconstructed based on the CT and MRI images. Reconstruction image clearly shows the tumor size, location, shape, and the anatomical relationship of tumor and surrounding structures. We can hide any reconstructed images such as skull,brain tissue, blood vessles, or tumors. We also can adjust the color of reconstructed images and rotate images to observe the structures from any direction. Reconstruction of brain and skull can be semi transparent to display the deep structure; reconstruction of the structures can be axial, coronal, and sagittal cutting to show relationship among tumor and surrounding structures. The reconstructed 3D structures clearly depicted the tumor features, such as size, location, and shape, and provided visual information of the spatial relationship among its surrounding structures. Conclusions: The method of registration, fusion, and 3D reconstruction based on multimodal images to provide the visual information is feasible and practical. The reconstructed 3D structures are useful for preoperative assessment, incision design,the choice of surgical approach, tumor resection, and functional protection.

Skull repair materials applied in cranioplasty: History and progress

The skull provides protection and mechanical support, and acts as a container for the brain and its accessory organs. Some defects in the skull can fatally threaten human life.Many efforts have been taken to repair defects in the skull, among which cranioplasty is the most prominent technique. To repair the injury, numerous natural and artificial materials have been adopted by neurosurgeons. Many cranioprostheses have been tried in the past decades, from autoplast to bioceramics. Neurosurgeons have been evaluating their advantages and shortages through clinical practice. Among those prostheses, surgeons gradually prefer bionic ones due to their marvelous osteoconductivity,osteoinductivity, biocompatibility, and biodegradability. Autogeneic bone has been widely recognized as the "gold standard" for renovating large-sized bone defects. However, the access to this technique is restricted by limited availability and complications associated with its use. Many metal and polymeric materials with mechanical characteristics analogous to natural bones were consequently applied to cranioplasty. But most of them were unsatisfactory concerning osteoconductiion and biodegradability owe to their intrinsic properties. With the microstructures almost identical to natural bones, mineralized collagen has biological performance nearly identical to autogeneic bone, such as osteoconduction. Implants made of mineralized collagen can integrate themselves into the newly formed bones through a process called "creeping substitution". In this review, the authors retrospect the evolution of skull repair material applied in cranioplasty. The ultimate skull repair material should have microstructure and bioactive qualities that enable osteogenesis induction and intramembranous ossification.

Repairing skull defects in children with nano-hap/collagen composites: A clinical report of thirteen cases

Objective:To evaluate the clinical results of repairing skull defects with biomimetic bone(nano-hap/collagen composites,NHACs)in children.Methods:Thirteen children with skull defects were treated with NHACs in our hospital.The NHACs molded with the help of a 3D printer were used in the operations.Results:All 13 operations were successful,and patients recovered without infection.Only one patient suffered from subcutaneous hydrops post-operation.The implanted NHACs remained fixed well after 1 year,and their CT HU values raised gradually.Skull shapes of children developed normally.Recovery of neurological and cognitive function was significant.Conclusions:NHAC,chosen to repair skull defects in children,can coexist with normal skull and reduce the negative effects on growth and development.NHAC could be a good choice for children with skull defects.

Neural matrix and its role in preoperative evaluation of partial epilepsy

The network characteristic of the central neural system has been widely accepted as a basic fabric form. However,the matrix characteristics of neural network are still not fully understood. If we ignore the matrix characteristics of the neural networks and just pay close attention to its connection mode,we are likely to fall into the theory of mechanical reductionism. This can lead to a problem in representing consciousness in a disadvantageous situation. It can also be a barrier to further improving the global workspace theory. Incomplete elucidation of the mechanisms of consciousness representation can also affect the assessment of the surgical outcome of partial epilepsy with conscious injury. Therefore,this paper reviews the epistemological development of neuroscience. We will initially describe the matrix characteristics of the neural system and their significance to the information processing mechanism,and further explore the role of neural matrix in identifying cases of partial epilepsy with little effect on the resection of the lesion.

Application of intraoperative O-arm-assisted real-time navigation technique for spinal fixation

This study explored the combined use of the O-arm and real-time navigation during spinal fixation. The clinical data for 60 patients undergoing spinal fixation, at Beijing Tsinghua Chang Gung Hospital between May 5, 2015 and May 1, 2017, were retrospectively analyzed. Pre-, intra-, and postoperative imaging findings were assessed. The patients were classified into the occipitocervical fusion(32 cases) and thoracic/lumbar/sacral spine fixation(28 cases, including 6 cases of percutaneous pedicle screw) groups. Lesion resections were performed microscopically. An O-arm, combined with real-time navigation, was used to assess spinal fixation. Efficacy was evaluated using operative times, X-ray times, screw positioning, and complications. Within the occipitocervical fusion group, 182 screws were placed in the cervical spine and 96 in the occipital bone. However, 6 screws penetrated the bone cortex and were adjacent to the vertebral arteries, based on O-arm three-dimensional imaging; therefore, the precision rate was 96.7%. Within the thoracic/lumbar/sacral spine fixation group, 148 pedicle screws were implanted, with 4 initially outside the vertebral body,yielding a precision rate of 97.3%. Ten percutaneous pedicle screws were implanted and well positioned. O-arm scans were performed 3 times/patient, with an average of 20–30 min/time. Screw implantation times were 5–7 min(cervical spine), 8–10 min(thoracic spine), and 6–8 min(lumbar spine). Intraoperative O-arm scans, combined with real-time navigation technology, allow real-time observation of screw angles and depths, improving the accuracy and safety of posterior screw fixations and reducing the radiation dose and frequency experienced by patients and surgeons.

Using nerve segment insert grafting to reconstruct neural pathways of brain-derived paralysis

Since 1992,task groups have used free nerve auto grafts to bridge partially transected nerves from the dominant area of the normal cerebral cortex to nerves that innervate spastic muscles from a diseased cerebral cortex,using transplanting sutures to alleviate the muscle spasm of cerebral palsy caused by different diseases. This has facilitated rebuilding of some of its neurological function. In this study,80 such patients were followed up,including 20 patients with traumatic brain injury,32 patients with stroke,and 28 pediatric patients with cerebral palsy. After postoperative follow-up of 3 to 21 years,the efficacy rate of this operation was 100% and the excellent and good spasm relief rate was 82.5%.

Surgical complications secondary to decompressive craniectomy for patients with severe head trauma

Decompressive craniectomy(DC)is a surgical method for managing highly elevated intracranial increased pressure(ICP)resulted from severe head trauma.This procedure is able to reduce the ICP rapidly and effectively.However,it may lead to kinds of secondary complications,which would cause patient’s severe neurological dysfunction or even death.In this paper,we reviewed the literatures about surgical complications secondary to DC,and tried to bring up suggestions on surgical techniques aiming to prevention and treatment of these complications.

Mechanisms and major sites of distal catheter migration in ventriculoperitoneal shunting maneuvers: A review article

A ventriculoperitoneal shunt(VPS) is a medical device used to deflect cerebrospinal fluid from cerebral ventricles to the peritoneal cavity. Since 1908, ventriculoperitoneal shunts have been considered the best option in hydrocephalus management. Manifestation related to VPS may arise anywhere whilst tunneling the VPS from the ventricle to the peritoneal cavity, but complications associated with the distal catheter are especially common and a leading cause of revision surgeries. Among the many complications associated with peritoneal shunts, migration of the catheter into other parts of the body is still common. Scrotal migration mainly takes place in children aged 4 days to 5 years. Patent processus vaginalis, formation of an inguinal hernia, and increased intraabdominal pressure are leading risk factors associated with migration of the peritoneal catheter into the scrotum. Thoracic migration of peritoneal catheters predominantly occurs in adult patients. Important mechanisms in thoracic migration include(1) iatrogenic perforation of the external or internal jugular veins by the surgeon during tunneling and(2) gradual destruction of the venous structures by the catheter due to routine extension and flexion of the neck. After entering the vessel, negative intrathoracic pressure combined with positive intraabdominal pressure aids migration into the thoracic cavity. Sharp tips or shunt types contribute to intraabdominal migration and perforation.

Comparison of different microsurgery methods for trigeminal neuralgia

Objective: To study the influence of different microsurgical methods on surgical outcomes and complications, and to improve the surgical outcomes for trigeminal neuralgia. Methods: The clinical data of 109 patients with trigeminal neuralgia, who were treated with microsurgery, were analyzed retrospectively. All patients were divided into 3 groups according to surgical modality: the trigeminal neuralgia decompression group(TND group, 19 patients), the TND and rhizotomy group(rhizotomy group,55 patients), and the TND and selective lesioning group(lesioning group, 35 patients).The mid-term and short-term effects of microsurgery, and the occurrences of complications, were compared between the 3 groups. Results: There were no statistical differences in the frequency of complications between the 3 groups(P > 0.05). Eighty-four patients were followed up for 6 to 33 months. The rate of pain disappearance was found to be 94.4% in the TND group, and 100% in both the rhizotomy and lesioning groups; thus, no significant differences were found between these 3 groups(P > 0.05). Additionally, 50% of the patients in the rhizotomy group and 3.6% of the patients in the lesioning group had facial numbness while no patients were affected with facial numbness in the TND group, and the differences between these 3 groups were significant(P < 0.05). Conclusions: Microsurgery is effective and safe for trigeminal neuralgia. The use of TND, in combination with selective lesioning, ensures therapeutic efficacy and improves the quality of life in postoperative patients.

Stereoelectroencephalography-guided radiofrequency thermocoagulation(SEEG-guided RF-TC) in patients with drug-resistant focal epilepsy

For some patients with drug-resistant focal epilepsy, we usually select conventional surgical resection, which has brought better outcomes. However, others are not eligible for a conventional open surgical resection of the epileptogenic zone because of the proximity of a functional area or the implication of a larger epileptogenic network. Initially, stereoelectroencephalography(SEEG) exploration was a method of electroencephalography recording that was used in the presurgical evaluation of epileptic patients with complex epilepsy. Later, intracerebral electrodes used for SEEG were applied to produce radio frequency thermocoagulation(RF-TC) in epileptic patients. SEEG-guided RF-TC has produced some promising results, especially in the last dacade. Now, it has become popular as a palliative treatment to reduce seizure frequency in patients with drug-resistant focal epilepsy. This article presents a review of SEEG-guided RF-TC.

Progress in the research and development of nerve conduits

The reconstruction after peripheral nerve damage, especially for long‐segment nerve defects, remains a clinical challenge. Autologous nerve graft transplantation is an efficient method for the repair of peripheral nerve defects, but the involved com‐plications and shortcomings have greatly limited the clinical efficacy of treatments offered to patients with nerve defects. Thus, there is an urgent need to develop new therapeutic strategies and explore alternatives to autologous nerve transplantation in clinical practice, based on the knowledge of the peripheral nerve regeneration mechanism and biological histocompatibility principles. With significant advances in the research and application of nerve conduits, they have been used to repair peripheral nerve injury for several decades. In this paper, the study background of nerve conduits, their applications in clinic, status of conduit material research and construction of tissue‐engineered artificial nerves were reviewed.

Severe remote cerebellar hemorrhage with intracerebral hemorrhage after burr-hole evacuation for chronic subdural hematoma

Since remote cerebellar hemorrhage, with intracerebral hemorrhage after supratentorial neurosurgery, is rare, its pathophysiology remains elusive. Here, we report a 64-year-old man who had severe bilateral symmetric remote cerebellar hemorrhage with frontal lobe hemorrhage following burr-hole evacuation for supratentorial chronic subdural hematoma. Computed tomography venography showed undeveloped left internal jugular vein and sigmoid sinus. He received 3 weeks of conservative treatment and fully recovered. Overdrainage of cerebrospinal fluid and head rotation with undeveloped internal jugular vein may have resulted in this complication. This case is the first case in the literature with this event sequence and has some significance for revealing the mechanism of remote cerebellar hemorrhage occurrence after other supratentorial surgeries.

Transplantation of neural progenitor cells differentiated from adipose tissue-derived stem cells for treatment of sciatic nerve injury

Objectives: Currently, the clinical repair of sciatic nerve injury remains difficult.Previous studies have confirmed that transplantation of adipose tissue-derived stem cells promotes nerve regeneration and restoration at peripheral nerve injury sites. Methods: In this study, adipose tissue-derived stem cells were induced to differentiate into neural progenitor cells, transfected with a green fluorescent protein-containing lentivirus, and then transplanted into the lesions of rats with sciatic nerve compression injury. Results: Fluorescence microscopy revealed that the transplanted cells survived,migrated, and differentiated in rats. At two weeks post-operation, a large number of transplanted cells had migrated to the injured lesions; at six weeks post-operation, transplanted cells were visible around the injured nerve and several cells were observed to express a Schwann cell marker. Sciatic function index and electrophysiological outcomes of the transplantation group were better than those of the control group. Cell transplantation promoted the recovery of motor nerve conduction velocity and compound muscle action potential amplitude, and reduced gastrocnemius muscle atrophy.Conclusions: Our experimental findings indicate that neural progenitor cells,differentiated from adipose tissue-derived stem cells, are potential seed stem cells that can be transplanted into lesions to treat sciatic nerve injury. This provides a theoretical basis for their use in clinical applications.

A newly developed open-end intracranial hematoma drainage tube

Objective: To design a new open-end intracranial hematoma drainage tube for clinical application. Methods: The newly developed device consists of two parts: the plunger and barrel.On one side, the barrel is bullet shaped with an opening tip. The plunger is located in the middle cavity of the tube barrel and extended out at the open-end. It was designed for strengthening the tube barrel and for convenience in performing the drainage procedure. It can be used by inserting the drainage tube into the lesion and pulling out the plunger, whereby blood will forcefully rise up inside the barrel, providing a satisfactory outcome. It is made for effusion drainage purposes. During the procedure, the drainage tip is placed at the deepest part of the intracranial hematoma to completely drain the blood. Moreover, the plunger fits tightly in the tube, preventing leakage during the operation. With the use of the device, brain can be separated. In addition, the device can help reduce the risk of cerebral damage because of the small operating area. The barrel sidewall has matching opening holes bilaterally and equally for exchanging substances between the inner and outer parts.The overlapping ratio in each horizontal pair is around 1/3–1/2. Each pair on the opposite side will form a different pressure. Thus, the opening holes will not easily get blocked with blood clot. Results: Blood and accumulated liquid from the deepest part of the intracranial hematoma can be directly drawn through the drainage tube without damaging a large area. The tube does not get blocked easily and allows for complete removal of the hematoma. Conclusions: The device is asuitable instrument for clinical application.

Changes of synaptic structures associated with learning, memory and diseases

Synaptic plasticity is widely believed to be the cellular basis of learning and memory. It is influenced by various factors including development, sensory experiences, and brain disorders. Long-term synaptic plasticity is accompanied by protein synthesis and trafficking, leading to structural changes of the synapse. In this review, we focus on the synaptic structural plasticity, which has mainly been studied with in vivo two-photon laser scanning microscopy. We also discuss how a special type of synapses, the multi-contact synapses(including those formed by multi-synaptic boutons and multi-synaptic spines),are associated with experience and learning.