Magnetic implants in the tongue for assistive technologies: Tests of migration; oromotor function; and tissue response in miniature pigs

ObjectiveUncertain biological consequences of titanium-magnet (Ti-mag) tongue implants constrain application of the Tongue Drive System (TDS), a brain-tongue-computer interface for individuals with severe physical impairment. Here we describe oromotor function and tongue tissue response following Ti-Mag implantation and explantation in the miniature pig, an animal model with a tongue similar in size to humans.DesignA 1.8 × 6.2 mm Ti-mag tracer was implanted into the anterior tongue in five Yucatan minipigs. X-rays were taken immediately and >six days after implantation to evaluate tracer migration. In three minipigs, the tracer was explanted >16 days after implantation. Twenty-five days post-explantation, tongue tissue was harvested and processed for histological and immunohistochemical (IHC) markers of healing. In two minipigs tissue markers of healing were evaluated post-mortem following >12 days implantation. Drink cycle rate (DCR) was characterized to determine the impact of procedures on oromotor function.ResultsNeither implantation (N = 5) nor explantation (N = 3) changed DCR. X-rays revealed minimal tracer migration (N = 4, 0–4 mm). By histology and IHC a robust capsule was present two weeks post-implantation with limited fibrosis. Explantation produced localized fibrosis and limited muscle remodeling.ConclusionsThese findings suggest the safety of Ti-mag anterior tongue implants for assistive technologies in humans.     

儿童椎管内硬脊膜外蛛网膜囊肿的外科治疗

目的 探讨儿童椎管内硬脊膜外蛛网膜囊肿的临床特点及其诊治.方法 回顾性分析2001年1月至2009年8月我科收治的4例儿童椎管内硬脊膜外蛛网膜囊肿.其中颈胸段1例,胸腰段3例.临床表现3例患儿出现运动障碍,1例有感觉障碍,1例有小便失禁,1例有根痛表现.4例患儿均采用外科手术治疗,其中2例囊肿节段小于3个椎体的采用椎板切除+囊肿切除术,2例囊肿节段大于3个椎体的采用椎板成形+囊肿切除术.结果 4例患儿术后均恢复良好,除1例患儿术后随访1年下肢仍有轻度乏力外,其余临床症状均消失,恢复学习.随访1～9年均未见囊肿复发,复查脊柱三维CT未见脊柱畸形的发生.结论 儿童椎管内硬脊膜外蛛网膜囊肿是一种少见疾病,外科手术治疗能获得满意的结果,椎板成形术能够减少囊肿节段过长的患儿术后脊柱畸形的发生.

Abstract：

Objective To review the clinical features and surgical treatment of spinal extradural arachnoid cysts (SEACs) in children. Methods Four children with SEAC from were admitted to our department between January,2001 to August,2009. One SEAC was located at the cervicothoracic spine whereas the other three were found in the thoracolumbar spines. All cases were treated by surgery.Two children underwent the laminectomy for resection of the SEAC, which occupied less than 3 segments. SEAC, spreading more than 3 segments in the remaining cases, were treated by laminoplasty and en bloc resection. Results Postoperatively, the children had good recovery and resumed school. Followup of 1 to 9 years revealed no recurrences. The three-dimensional CT spine did not demonstrate any spine deformity in follow-up study. Conclusions SEACs in children are rarely reported in the literature. Excision of the SEAC result in a favorable outcome. The larninoplasty can reduce spinal deformity in patients with the long segment SEAC.     

Small Nogo-66-binding peptide promotes neurite outgrowth through RhoA inhibition after spinal cord injury

Abortive regeneration in the adult mammalian central nervous system (CNS) is partially mediated through CNS myelin proteins, among which Nogo-A plays an important role. Nogo-66, which is located at the C-terminus of Nogo-A, inhibits axonal regrowth through the Nogo-66/NgR signalling pathway. In this study, two small peptides were tested in a neurite outgrowth assay and spinal cord injury (SCI) model to examine the effects of these molecules on the inhibition of Nogo-66/NgR signalling. PepIV was selected from a phage display peptide library as a Nogo-66 binding molecule. And PepII was synthesized as a potential NgR antagonist. The results indicated that PepIV and PepII decrease the mRNA levels of the small GTPase RhoA and partially neutralize CNS myelin inhibition to cultured cerebellar granule cells (CGCs). Moreover, treatment with both peptides was propitious to maintaining residual axons after SCI, thereby promoting regeneration and locomotion recovery. Because RhoA plays a role in stabilizing the cytoskeleton in growth cones and axons, enhanced neurite outgrowth might reflect a decrease in RhoA expression through PepIV and PepII treatment. Moreover, PepIV induced lower RhoA mRNA expression compared with PepII. Therefore, PepIV could block Nogo-66/NgR signalling and reduce RhoA mRNA level, and then contribute to neuronal survival and axonal regrowth after SCI, showing its ability to reverse CNS myelin inhibition to regeneration. Furthermore, selected small peptide might cover some unknown active sites on CNS myelin proteins, which could be potential targets for improving neurite outgrowth after injury.     

Healing of painful intervertebral discs: implications for physiotherapy

Abstract

Background: Population studies show close associations between intervertebral disc degeneration and back pain, with structural changes such as annulus tears being most closely related to pain. However, little effort has been made to link back pain to disc injury in individual patients, or to treat the disc injury in a similar way to a ligament or tendon sprain.

Objectives: To re-interpret the scientific literature in order to provide a rationale for physical therapy treatments that aim to promote ‘disc healing’.

Major Findings: Intervertebral discs deteriorate over many years, from the nucleus outwards, to an extent that is influenced by genetic inheritance, metabolite transport, and mechanical loading. Additionally, surgically-removed ‘painful’ human discs usually show an active inflammatory process proceeding from the outside-in. There is growing evidence that the ligamentous outer annulus can be re-innervated, and sensitized to pain by inflammatory-like responses to injury, and from displaced nucleus pulposus. Animal studies confirm that effective disc healing occurs only in the outer annulus and endplate, where cell density and metabolite transport are greatest. Identifying discogenic pain is not easy, but techniques are available. Healing of the disc periphery has the potential to relieve pain, by reducing inflammation and restoring function.

Conclusion: Physical therapies should aim to promote healing in the disc periphery, by stimulating cells, boosting metabolite transport, discouraging adhesion formation, and preventing re-injury. Such an approach, which can be applied through information sessions and classes, has the potential to bring about pain relief to large numbers of back pain sufferers through self-treatment.     

Effects of methyl prednisolone,dimethyl sulphoxide and naloxone in experimental spinal cord injuries in rats

The effects of methyl prednisolone (MPD), dimethyl sulphoxide (DMSO), and naloxone were examined in 38 albino rats after making an impact spinal cord injury on the midthoracic segments with a modified Allen’s weight dropping trauma method. Somatosensorial evoked potentials (SEPs) were recorded before and 12 h and 14 d after the injury from epidurally inserted electrodes on the parietal cortex with sciatic nerve stimulations. Lower extremity, motor functions of the animals were also examined. It may be concluded that in this study model, DMSO has a moderate effect which can be demonstrated clinically and through SEPs. Naloxone has no effect on the clinical outcome but causes reasonable improvement electro-physiologically.     

Prognostic factors in traumatic atlanto-occipital dislocation

Traumatic atlanto-occipital dislocation (AOD) is an ominous injury with high mortality and morbidity in trauma patients. Improved survival has been observed with advancements in pre-hospital and hospital care. Furthermore, high quality imaging studies are accessible at most trauma centers; these are crucial for prompt diagnosis of AOD. The objective of this study is to perform a comprehensive literature review of traumatic AOD, with specific emphasis on identifying prognostic factors for survival. A review of the literature was performed using the Medline database for all traumatic atlanto-occipital articles published between March 1959 and June 2015; 141 patients from 60 total studies met eligibility criteria for study inclusion. A binary logistic regression model was utilized to identify prognostic factors. The analysis assessed age, sex, spinal cord injury (SCI), traumatic brain injury (TBI), polytrauma injury (PI), and Traynelis AOD Classification. Only TBI was statistically significantly associated with death (OR 8.05 p < 0.05); SCI did not reach statistical significance for predicting mortality in AOD patients (OR 1.25 p > 0.05). Age, sex, PI, and Traynelis AOD Classification did not meet significance to predict mortality in AOD patients. We found that patients with TBI are eight times more likely to die than patients without TBI. A high degree of suspicion for AOD during pre-hospital care, as well as, prompt diagnosis and management in the trauma center play a key role in the treatment of this devastating injury. The relationship between survival and factors such as TBI and SCI should be further explored.