Foreign body reactions causing spinal cord tethering: a case-based update

Background  

Patients operated on for myelomeningocele (MMC) and lipomeningocele (LMC) can suffer from late functional worsening that, in many cases, is due to spinal cord tethering by the post-repair scarring process.     

Amniotic band syndrome with tethering of the spinal cord: a case-based update

Background  

Amniotic band syndrome consists of a wide spectrum of clinical manifestations attributed to entanglement and disruption of different developing parts of the embryo. Multiple asymmetric encephalocele and anencephaly have previously been reported with amniotic band syndrome. Tethering of the spinal cord secondary to amniotic band constriction is exceedingly rare, and this is the second reported case in the literature.     

Urodynamic studies on the untethering of spinal lipoma in the children]

We performed conus untethering on 44 children with spinal lipoma. In this retrospective study, we studied urological examinations obtained in 36 consecutive patients. Urological examinations were ultrasonography of bladder and kidney, voiding cystourethrography (VCG), and urodynamic cystometry. In those of them, 6 patients had already had urinary dysfunction at preoperative stage, but 4 patients' spinal lipoma was one complication of cloaca exstrophy and 2 patients' spinal lipoma after repairment of their myelomeningocele. In the remaining 30 cases, 18 patients (60.0%) as the group 1 did not have urinary dysfunction and abnormality in any urological examinations. Another 7 patients (23.3%) as group 2 also did not have urinary dysfunction, but abnormal vesicoureteral reflux (VUR) was found out in their VCG examination. At postoperative stage, abnormal VUR resolved or improved in all these 7 cases, but one of them showed transient urinary retention. Two patients of 18 in the group 1 had to require clean intermittent self-catheterization at postoperative stage. These observations confirmed that children with spinal lipoma were more likely to present with urological findings, and so it was imperative that a diagnosis be made and treatment be instituted as early as possible.     

Effects of tethering on regional spinal cord blood flow and sensory-evoked potentials in growing cats

The spinal cords of 2-week-old kittens were tethered by fixing the end of the filum terminale to the lower sacrum, to study the effects of tethering and untethering on regional spinal cord blood flow (rSCBF), sensory-evoked potentials (SEPs) and clinical features. Progressive sensorimotor deficits and incontinence were observed in all the tethered cats. Cord tethering induced a reduction of rSCBF in the distal spinal cord close to the tethering (L 3) by 32% of the normal flow 2 weeks after tethering and by 67% 10 weeks after tethering. Untethering of the cord resulted in an increase of rSCBF, restoring it to the normal level in the group untethered 2 weeks after tethering, but rSCBF did not increase in the group untethered 8 weeks after tethering. The changes in SEPs were observed whenever rSCBF was below 14 ml/100 g per minute. Suppression of the early components of SEPs was observed 2 weeks after tethering and the components were progressively altered in amplitude and latency during the experimental period. It is assumed that early untethering can improve the spinal cord blood flow as well as the function of the cord.     

Management of multiple tethering in spinal dysraphism

Introduction

The most challenging component of spinal dysraphism is cord tethering. Tethering can occur due to single or multiple lesions within the same patient. It is imperative to aggressively identify and release all the tethering lesions in order to provide maximum benefit to the patient. With increasing number of tethering lesions, the clinical profile and outcome show significant differences, and this difference is significantly more when more than two tethering lesions coexist in the same patient.

Material and methods

Out of the 248 patients of spinal dysraphism who underwent surgical management at Sanjay Gandhi Institute of Medical Sciences, Lucknow, India, between 1997 and 2007, 160 were included in the study. Patients were classified into two groups based on the number of tethering lesions. The first group (Group A) comprised cases of spinal dysraphism with tethering demonstrable at one or two sites. The second group (Group B) comprised patients with radiological or intraoperative evidence of multiple tethering lesions (more than two).

Results

There were 119/160 patients in Group A, while 41/160 patients were in Group B (with more than two sites of tethering). The preoperative neurological examination revealed significant differences between the two study groups. The clinical profile and the surgical outcomes have shown significant differences in the two study groups. These differences are statistically significant.

Conclusion

We strongly believe that the mere presence or absence of tethering is not a sufficient documentation to predict its effect on the cases of spinal dysraphism. Tethering is a complex entity that needs to be further classified in terms of the number of tethering lesions, which significantly affect the pre- and postoperative status of the patients. We would like to suggest the term “Spina Bifida Multiplex” for the cases where more than two lesions are found to be responsible for tethering.     

Nocturnal penile tumescence studies in spinal cord injured males

Traditional methods of evaluating sexual function in disabled individuals using neurological examinations, interviews, and psychological screening has been well established. A patient's ability to have erections and ejaculations are recorded through interviews with the patient and his partner. Therefore, to obtain a more objective view of the patient's sexual function, we used a nocturnal penile tumescence monitor in 12 tetraplegics and 12 paraplegics. Patients were interviewed for sexual histories before and after the injury. Their penile size was monitored during sleeping time using two strain gauges attached to each end of the penile shaft. The bridge output from these strain gauges was amplified to a single channel recorder. The spontaneous increase of penile circumference and its duration was recorded. The result showed that: tetraplegics had a greater increase of penile size and longer duration of erection than paraplegics, there is no correlation between incompleteness of spinal lesion and erection, there is no correlation between the presence of bulbocavernosus reflex and erection, and there is no correlation between sex dreams and erections.     

脊髓继发性损伤的实验与临床研究

脊髓伤分原发伤与继发伤，一部分脊髓伤，解剖上未横断，伤后当时无截瘫，但由于继发血液循环障碍，出现脊髓缺血、出血、中心性坏死。使脊髓内重要结构产生继发性的不可逆性损害，导致完全截瘫的不良后果。本文报道犬、大白鼠的实验性脊髓伤早期病理改变，并从２３例继发性脊髓伤的分析，探讨脊髓继发性损伤的发生机理。实验提示早期应用钙通道阻断剂尼维地平，有利于改善脊髓缺血引起的继发性脊髓损害。     

Experimental studies on spinal cord injuries in the last fifteen years

Abstract

Experimental studies on spinal cord (SC) injuries published from 1975 to 1989 in some of the most widely circulating neurosurgical journals were reviewed. The relatively large number of animal species utilized as well as the intensely variable dynamic or static methods employed to induce SC injury represent elements of confusion more than objective necessities in this field of research. In fact, the objective of SC injury research should be to solve the problem of severe SC injuries by either preventing and/or repairing SC damage, rather than looking for modalities to provoke a large spectrum of SC injuries with the result of establishing a correlation between for example, the clinical picture and trauma magnitude. It should be time to study all variables and treatments mainly in only one experimental model. The rat with a permanent paraplegia should represent such a model; the abdominal aorta occlusion for 45 minutes, distal to the renal arteries in rabbits should be the experimental model of choice for ischaemia. If a significant result, such as reversing permanent paraplegia, were obtained in rats, it would be logical to repeat the study in higher mammals and if successful' in humans. For the last decade of this century it is necessary to further study all the mechanisms implied in secondary SC damage as well as to attempt to repair definitive SC damage by using grafts and enhancing the potential regenerative ability of the SC with known and new growth factors. Presently, methylprednisolone, dexametasone, thiopental, naloxone, and hypothermia seem to have some clinical potentials that require studies in humans.     

Experimental studies on permeability of tracers into the spinal cord

For investigation of the intramedullary penetration of metrizamide, the intramedullary movements of fluorescein, Evans Blue, Horseradish peroxidase (HRP) and ionic lanthanum in the normal cord and experimental syringomyelia of rats were studied. Syringomyelia was induced by injection of kaolin suspension into the cisterna magna. Subsequently HRP or ionic lanthanum was perfused into the subarachnoid space and its distribution was examined by electron microscopy. In normal rats, HRP mainly became localised in the basement membrane between the pia mater and glial cells and only a few vesicles migrated into the extracellular spaces (ECS) between glial cells. Ionic lanthanum, however, migrated deep into the ECS. In rats with experimental syringomyelia many vesicles of HRP migrated deep into the ECS of glial cells and the white matter. These findings indicated that the ECS of the marginal glia and the neuropil constitute part of a pathway through which metrizamide migrates into the intramedullary cavity.     

Facilitating transparency in spinal cord injury studies using data standards and ontologies简

<正>Extract Progress in developing robust therapies for spinal cord injury(SCI),traumatic brain injury(TBI)and peripheral nerve injury has been slow.A great deal has been learned over the past 30 years regarding both the intrinsic factors and the environmental factors that regulate axon growth,but this large body of information has not yet resulted in clinically available therapeutics.This therapeutic bottleneck has many root causes,but a consensus     

Lampreys as an animal model in regeneration studies after spinal cord injury

Spinal cord injuries are an important sanitary and economical problem for the society. In mammals, including humans, a traumatic injury to the spinal cord leads to a loss of motor and sensorial function, which is irreversible due to the low regenerative ability of the central nervous system. In contrast to mammals, functional recovery occurs spontaneously after a complete spinal cord transection in lampreys. Functional recovery occurs because in these animals about 50% of the reticulospinal axons regenerate after injury and also because of the occurrence of processes of reorganization and plasticity of the spinal circuits. In this review, we first analyze the characteristics and regeneration ability of lampreys as compared to mammals. Then, we compile the knowledge about the process of recovery after a spinal cord injury acquired in studies using the lampreys as animal model and finally we provide some general perspectives about the molecular processes implicated in regeneration that can be investigated in a very advantageous way in this animal model and which knowledge could allow to develop new therapies for patients suffering spinal cord injury.     

Experimental studies on spinal cord injuries in the last fifteen years.

Experimental studies on spinal cord (SC) injuries published from 1975 to 1989 in some of the most widely circulating neurosurgical journals were reviewed. The relatively large number of animal species utilized as well as the intensely variable dynamic or static methods employed to induce SC injury represent elements of confusion more than objective necessities in this field of research. In fact, the objective of SC injury research should be to solve the problem of severe SC injuries by either preventing and/or repairing SC damage, rather than looking for modalities to provoke a large spectrum of SC injuries with the result of establishing a correlation between for example, the clinical picture and trauma magnitude. It should be time to study all variables and treatments mainly in only one experimental model. The rat with a permanent paraplegia should represent such a model; the abdominal aorta occlusion for 45 minutes, distal to the renal arteries in rabbits should be the experimental model of choice for ischaemia. If a significant result, such as reversing permanent paraplegia, were obtained in rats, it would be logical to repeat the study in higher mammals and if successful, in humans. For the last decade of this century it is necessary to further study all the mechanisms implied in secondary SC damage as well as to attempt to repair definitive SC damage by using grafts and enhancing the potential regenerative ability of the SC with known and new growth factors. Presently, methylprednisolone, dexametasone, thiopental, naloxone, and hypothermia seem to have some clinical potentials that require studies in humans.     

Spinal cord tethering by aberrant nerve root in myelomeningocele: case report

Introduction  A 2,796-gram male baby was born at 40 weeks gestation by vaginal delivery. Soon after, he was admitted at our department for treatment of a dorsal appendage. Results and discussion  Magnetic resonance (MR) imaging showed a low-position spinal cord, skin-covered myelomeningocele, syringomyelia, and a tethered cord. Resection of the caudal appendage and tethering tissue was performed 22 days after birth under electrophysiological monitoring. Histopathological examination of the caudal appendage that was covered with skin revealed the presence of spinal cord tissue and peripheral nerve tissue. The string-like tethering tissue that extended from the spinal cord to the caudalis was a nerve root, and there was fiberization of the caudalis. The syringomyelia was improved at postoperative MR imaging. To our knowledge, there is no report of a similar case in the literature. We report rare combination of myelomeningocele and spinal cord tethering by aberrant nerve root with thoracic syringomyelia.     

Modeling chronic cervical spinal cord injury in aged rats for cell therapy studies

With an expanding elderly population, an increasing number of older adults will experience spinal cord injury (SCI) and might be candidates for cell-based therapies, yet there is a paucity of research in this age group. The objective of the present study was to analyze how aged rats tolerate behavioral testing, surgical procedures, post-operative complications, intra-spinal cell transplantation and immunosuppression, and to examine the effectiveness of human iPSC-derived Neural Progenitor Cells (IMR90-hiPSC-NPCs) in a model of SCI. We performed behavioral tests in rats before and after inducing cervical hemi-contusions at C4 level with a fourth-generation Ohio State University Injury Device. Four weeks later, we injected IMR90-hiPSC-NPCs in animals that were immunosuppressed by daily cyclosporine injection. Four weeks after injection we analyzed locomotor behavior and mortality, and histologically assessed the survival of transplanted human NPCs. As rats aged, their success at completing behavioral tests decreased. In addition, we observed high mortality rates during behavioral training (41.2%), after cervical injury (63.2%) and after cell injection (50%). Histological analysis revealed that injected cells survived and remained at and around the grafted site and did not cause tumors. No locomotor improvement was observed in animals four weeks after IMR90-hiPSC-NPC transplantation. Our results show that elderly rats are highly vulnerable to interventions, and thus large groups of animals must be initially established to study the potential efficacy of cell-based therapies in age-related chronic myelopathies.