Tethered cord syndrome: overview of diagnosis and treatment

This article covers the basis of tethered cord syndrome as a stretch-induced spinal cord disorder, including pathophysiology, signs and symptoms, imaging diagnosis, indication for surgical treatment, and surgical procedures. Anomalies that cause mechanical spinal cord tethering are listed, and the surgical untethering technique for each anomaly is described.     

儿童脊髓脂肪瘤的分型与疗效探讨(附211例分析)

目的探讨儿童脊髓脂肪瘤手术年龄、病理解剖类型与预后的关系。方法回顾性分析211例儿童脊髓脂肪瘤的临床资料,以手术年龄、手术前后直肠膀胱功能评分和运动功能评价、术中解剖分型、脊髓松解程度进行综合评估。结果各病理解剖类型组中(除髓内型外),术前不同膀胱直肠功能评分的平均年龄之间具有显著差异(P<0.05)。手术能保持原有正常功能,术后直肠膀胱功能总体改善率48.3%、加重率0.97%,运动改善率43.2%、加重率0.96%。依脊髓松解程度分为可分离型和不可分离型,复合型42例(100%)和膨出型13例(32.5%)为不可分离型。结论病儿症状随年龄增长加重,说明早期手术必要性,手术具有稳定和改善症状作用,对不可分离型不可盲目再次手术。     

Inappropriate surgical interventions for midline fusion defects cause secondary tethered cord symptoms: implications for natural history report of four cases

Introduction

The causes of tethered spinal cord are various. In order to release the tethering effect of these malformations, the surgical interventions must include removal of all tethering components, reconstruction of the neural tube and sectioning of tight filum terminale as well.

Cases

The cases reported in this paper have had an operation many years before for various developmental defects. After a certain period of time (5–10?years) of the first operation, the patients reapplied to the hospital with various symptoms of spinal cord tethering, either vertical or horizontal.

Discussion

At surgical intervention, it was noted that inappropriate surgical procedures caused retethering of the spinal cord in all patients. Postoperative period of all patients were uneventful. All patients declared relief in their symptoms. We would like to draw attention that untreated (or inappropriately treated) midline developmental defects will invariably cause syndrome of tethered cord. Consequently, prophylactic surgical untethering must be applied to all patients with developmental midline defects as soon as possible.

Conclusion

It looks that tethered cord symptoms invariably appear as enough negative influence accumulates as the time passes. Elapsed time may vary but unpleasant end result invariably arrives. While these cases with tethered spinal cord develop progressive neurological symptoms, prophylactic and appropriate surgical intervention should be considered as early as possible. There is no acceptable rationale to wait for the appearance of tethered cord syndrome symptoms to perform surgical untethering of the spinal cord because of the probability of irreversibility of the symptoms (incontinence of urine in particular) of tethered spinal cord syndrome.     

显微手术治疗脂肪瘤型脊髓栓系综合征的疗效分析(附611例报告)

目的 通过对611例脂肪瘤型脊髓栓系综合征临床数据分析评价其显微外科治疗的疗效.方法 患者均行神经系统和MRI检查,并经显微外科手术治疗.手术前后相应地应用尿动力学、神经电生理等检查手段.术后疗效根据Hoffman功能性分级、Kirollos术中松解分级、尿动力学和神经电生理等结果进行评定.结果 根据Hoffman功能性分级:术后无症状87例(14.2％),轻度289例(47.3％),中度214例(35.1％),重度21例(3.4％).按Kirollos术中松解分级评定方法:587例(96.0％)达到Ⅰ级,16例(2.6％)达到Ⅱ级,8例(1.3％)为Ⅲ级.尿动力学检查在术前和术后差异有统计学意义.神经电生理检查在术前和术后差异有统计学意义.结论 显微外科手术治疗脂肪瘤型脊髓栓系综合征可获得较好的疗效,尿动力学以及神经电生理的临床应用可以提高疗效.     

Surgical treatment of syringomyelia associated with spinal dysraphism

Clinical and radiological features of syringomyelia in 15 patients with spinal dysraphism are reported. There were 8 patients with occult spinal dysraphism (lumbosacral lipoma) and 7 with spina bifida aperta (meningomyelocele). Syringomyelia with spinal dysraphism can be radiologically divided into two types according to the dysraphic state. The syrinx in the patients with occult spinal dysraphism occurred immediately rostral to the lipoma and was localized to the lower thoracic to lumbar levels, while in the meningomyelocele patients the syrinx extended from the cervical to the thoracic level. Large syrinx formation was recognized in 1 of the 7 occult spinal dysraphism cases and 3 of the 8 meningomyelocele cases. For syringomyelia with occult spinal dysraphism, 4 patients underwent syringo-subarachnoid shunting (S-S shunt, 2 cases) or syringostomy (2 cases) during an untethering operation. In the case of meningomyelocele, S-S shunts were placed in 2 patients. Collapse of the syrinx was achieved in all 6 patients who underwent S-S shunting or syringostomy. Decreased size of the syrinx was also noted in 3 occult spinal dysraphism patients who underwent untethering operations alone. In conclusion, a large syrinx in the case of spinal dysraphism should be surgically treated. S-S shunting is effective in both types of syringomyelia. Foramen magnum decompression may be an alternative method of surgical treatment for syringomyelia in patients with meningomyelocele.     

Secondary tethered cord syndrome in spinal dysraphism

Secondary tethered cord syndrome following initial repair for spinal dysraphism is an important area of interest. In this study, 32 cases with spinal dysraphism in the lumbosacral region were enrolled, in whom radical repair with autologous material had been carried out in the early stage soon after birth. During the follow-up period of up to 19 years 10 months, surgery was considered to be indicated in 2 of the 8 lipomeningocele cases and in 6 of the 24 meningocele and meningomyelocele cases, because of the presence of tethered cord syndrome 4–19 years after the primary operation. In all 8 of these cases, MR imaging demonstrated tethered spinal cord in the form of low conus medullaris. In 6 of the 8 operated cases surgery was followed by improvement of the spinal neurological deterioration. According to our experience, early untethering for secondary tethered cord syndrome is essential. In addition, since the complications of Silastic duraplasty at untethering were all minor and the operative outcome was satisfactory, the use of silicone rubber sheeting as a dural substitute might be recommended to prevent adhesion of the spinal cord. Received: 10 May 1999 Revised: 1 October 1999     

腰骶部脂肪瘤型脊髓栓系的手术治疗

目的 探讨脂肪瘤型脂肪脊髓脊膜膨出的病理改变以及如何手术去除病灶,彻底解除脊髓栓系,最大限度地恢复脊髓正常解剖结构.方法 手术治疗脂肪瘤型脂肪脊髓脊膜膨出73例,年龄1.5个月～18岁,临床症状有疼痛、大小便失禁及(或)双下肢功能障碍.手术切除皮下和椎管内脊髓外的脂肪瘤,脊髓内的脂肪瘤部分切除,将脊髓从两侧硬脊膜上剪开并分离,切断病变终丝.结果 随访67例,时间1-5年.术前有症状的患儿,术后多有不同程度改善,5例术后症状一过性加重;无症状者术后仍然无症状.结论 只有充分认识脂肪瘤型脂肪脊髓脊膜膨出的病理改变,才能最大限度地切除脂肪瘤,真正解除脊髓栓系,恢复神经功能.

Abstract：

Objective To study the pathological changes of lipomas of conus medullaris and the appropriate surgical treatment for removing such lipomas for optimal reconstruction of normal spinal cord anatomy.Methods The clinical data of 73 patients ( aged from 1.5 months to 18 years) who underwent surgical removal of lipoma of conus medullaris from January 2005 to July 2009 were collected.The neurological symptoms included pain, urine and stool incontinence, and bilateral lower limb dysfunction.The surgical procedures consisted of excision of subcutaneous and intradural extramedullary lipoma, partial excision of intramedullary lipoma, detachment of the spinal cord from the dural membrane, relief of tethered spinal cord, and excision of the affected filum terminale.Results The main pathological changes in patients with lipoma of the conus medullaris were ventral deviation of the spinal cord caused by compression from dorsal lipoma, traction on the spinal cord from attachment of intradural lipoma and subcutaneous lipoma, increased tight fit between the spinal cord and the dural membrane on both sides, and degeneration of the filum terminale.Sixty - seven patients were followed - up from 1 to 5 years.The improvement after surgery varied among the symptomatic patients.Five patients had transient deterioration of symptoms after surgery.All asymptomatic patients remained asymptomatic.Conclusion Only through thorough understanding of the pathology of lipoma of conus medullaris, we could optimally excise the lipoma, untether the spinal cord, reconstruct the normal anatomy of the spinal cord and rehabilitate neurological function.     

Syringomyelia and tethered cord in children

Introduction

The presence of syringomyelia varies in patients with different forms of dysraphism; from 21 % to 67 %. Only around 60 % of patients with syringomyelia is likely to experience symptoms related to it.

Pathophysiology

Many theories have been outlined for the creation of syringomyelia. The one most applicable to tethered cord dictates that tensile radial stress may create a syrinx in a previously normal cord tissue and transiently lower pressure may draw in interstitial fluid, causing the syrinx to enlarge if fluid exit is inhibited. In addition, arachnoiditis increases flow resistance in the spinal subarachnoid space, altering temporal CSF pulse pressure dynamics, which promotes entry of CSF in to the spinal cord.

Clinical presentation

There is a significant overlap between the symptoms that are due to tethered cord and syringomyelia, both in newly presenting patients with coexisting syringomyelia, and in previously treated patients who during follow-up present recurrent symptoms and a new syringomyelia cavity.

Treatment

The treatment of patients with tethered cord and syringomyelia is directed towards untethering the cord from its most caudal region upwards and restoring spinal anatomy with reestablishment of unobstructed CSF flow in the subarachnoid space. Only if complete untethering has been ensured and syringomyelia deteriorates, then surgical treatment can be directed against the syrinx. In patients with spinal dysraphism and coexisting hydrocephalus, radiological presentation of new syringomyelia or deterioration of previously known syringomyelia may signify shunt obstruction “until proven otherwise”.

Conclusion

In most occasions, satisfactory cord untethering addresses the development of syringomyelia.     

Factors in neurological deterioration and role of surgical treatment in lumbosacral spinal lipoma

The purpose of this study was to determine factors that might be involved in neurological deterioration and the role of surgical treatment in patients with lumbosacral spinal lipoma. Pre- and postoperative courses of 34 patients were retrospectively analyzed. The age at surgery ranged from 1 month to 47 years. The records of preoperative neurological status indicated that older patients had more severe deficits, while all 8 asymptomatic patients were under 5 years of age. Motor deficits were noted in 9 patients, in 7 of whom the lipoma extended cranially beyond the L5 level. Transitional-type lipomas were accompanied by more severe deficits (asymptomatic 1, symptomatic 17) than other types (asymptomatic 7, symptomatic 9). Postoperative follow-up periods ranged from 5 months to 13 years. During these periods, 7 of the 8 asymptomatic patients remained neurologically intact. Nine of the 26 symptomatic patients improved. Age, extension of the lipoma in the spinal canal and type of lipoma will influence the preoperative neurological status of the patients. Early untethering surgery is recommended in patients with large lipomas extending beyond the L5 level. Received: 24 August 1998 Revised: 19 July 1999     

The lumbosacral angle does not reflect progressive tethered cord syndrome in children with spinal dysraphism

Purpose  

Our goal was to validate the hypothesis that the lumbosacral angle (LSA) increases in children with spinal dysraphism who present with progressive symptoms and signs of tethered cord syndrome (TCS), and if so, to determine for which different types and/or levels the LSA would be a valid indicator of progressive TCS. Moreover, we studied the influence of surgical untethering and eventual retethering on the LSA.     

Paraplegia as initial manifestation of tethered spinal cord. Case report]

Tethered spinal cord (TSC) is a rare disorder; it occurs when the conus medularis is anchored to the base of the vertebral canal by thickened filum terminale cysts, lipoma and spinal dysraphia. This disorder may cause paraplegia, sensory and sphincter disturbance. We report a twenty-two months-old girl presenting with paraplegia. TSC diagnostic was confirmed by myelotomography. The patient was submitted to surgical relief of tethered filum terminale.     

脊髓发育不良的外科病理解剖学研究

目的研究脊髓发育不良的临床病理解剖学。方法依据112例术前病史、体检、影像学、尿流和肛肠动力学、排尿性膀胱尿道造影(VCUG)、EMG检查评价并行脊髓手术治疗。术中观察脊髓形态学改变并留取组织学标本。结果按照椎管内病变及其脊髓病理解剖改变将其分为终丝拴系、脊髓粘连、脊髓脂肪瘤、囊性占位、脊髓纵裂、静态病变六型及若干亚型。结论脊髓发育不良主要为一进行性加重的动态病理过程,其脊髓神经损害的病理解剖学基础是椎管内病变及其脊髓、神经根的形态学改变,应尽早诊断和椎管内手术治疗以改善预后。     

脂肪瘤型脊髓栓系综合征的手术技巧

目的 探讨脂肪瘤型脊髓栓系综合征的手术治疗技巧. 方法 自2003年至2006年,我科共收治33例脂肪瘤型脊髓栓系患者,均在电生理监测下切除脂肪瘤,显微手术分离粘连、松解脊髓,以无损伤不可吸收缝线(Prolene线,5-0)连续缝合硬脊膜,一期行硬脊膜重建;翻转腰背部筋膜行先天性缺损修补与加固. 结果 29例患者切口一期愈合:4例患者出现脂肪坏死导致皮下积液,其中2例患者出现脑脊液漏,经缝合及引流后治愈.随访1～3年,28例患者临床症状有显著改善,5例患者虽无改善亦无神经系统症状加重;复查均无再栓系形成. 结论 脂肪瘤型脊髓栓系综合征早期电生理监测下行栓系松解术,同时行硬脊膜的修补与重建,对于预防术后再栓系至关重要.     

The role of flexible hollow core carbon dioxide lasers in resection of lumbar intraspinal lipomas

Purpose

The authors assess the role of flexible hollow core CO₂ laser system (Omniguide system) in resection of intraspinal lipomas.

Methods

Eight patients with intraspinal lipomas were operated using an Omniguide laser system over a 22-month period. The age range varied between 6?months and 16?years. All of them had lipoma of the conus medullaris associated with lumbar subcutaneous lipoma. Two of these had previous surgery with resection of the subcutaneous part of the lipoma; in one of them, a partial resection of the conus medullaris lipoma had also been performed. In six, there were no obvious motor or sensory deficits whereas two had gross neurologic deficits, with the deficits occurring in one after the previous decompression. Resection of the conus lipoma, untethering of the spinal cord, and reconstruction of the decompressed conus was performed in all aided with Omniguide laser system. The power settings of the laser system ranged from 4 to 8?W.

Results

Subtotal to near-total resection was achieved in all. None of the patients developed any new motor or sensory deficits. Three had postoperative CSF leaks which initially required reoperation with graft resuturing and subsequently placement of lumboperitoneal shunt. One child with preexisting neurologic deficits improved in power over the next 12?months.

Conclusion

Flexible CO₂ laser system was precise and convenient in decompressing the conus lipomas and untethering of the cord in lumbar spinal lipomas.     

Spinal lipoma misinterpreted as a meningomyelocele on antenatal MRI scan in a baby girl

INTRODUCTION: Antenatal screening for spina bifida with ultrasound and MR imaging is increasingly used. CASE REPORT: A baby girl's antenatal MRI examination showed features originally interpreted as a lumbar meningomyelocele. Repeat MRI examination soon after birth showed features of a spinal lipoma (lipomeningomyelocele). This was excised surgically and complete spinal cord untethering was achieved. CONCLUSION: As antenatal MR scanning is increasingly used, and fetal surgery is becoming more prominent, the correct interpretation of such images is crucial. We present a rare case of a misleading antenatal radiological diagnosis of spina bifida, which would have had severe implications if termination of the pregnancy or intra-uterine surgical repair had been considered.     

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.     

Neuropraxia of the cervical spinal cord following cervical spinal cord trauma: a report of five patients

Neuropraxia of the cervical spinal cord is a rare condition which is almost exclusively reported in American football players following cervical hyperextension or hyperflexion trauma. In this entity-neurological symptoms of both arms and legs for a period of up to 15 minutes are observed with complete recovery. We report the characteristics of five patients not involved in contact sport activities with a neuropraxia of the spinal cord following cervical trauma. In four of the five patients, this syndrome was associated with a cervical canal stenosis. Surgical decompression was performed in two patients with progressive neurological symptoms after an initial period of recovery. The cases illustrates that although neuropraxia of the spinal cord is usually seen in athletes, also other persons may be at risk for developing this condition, especially when a preexisting spinal stenosis is present. Patients who experienced neuropraxia of the spinal cord should thus be evaluated carefully for the presence of cervical spinal cord abnormalities.     

Is meningocele really an isolated lesion?

OBJECT: We designed this study to elucidate the associated occult spinal lesions in patients with simple dorsal meningocele. METHODS: The study population was comprised of two groups. Group I comprised newly diagnosed patients with dorsal spinal meningocele, and group II comprised patients who had had surgery for meningocele and presented with progressive neurological deficits. Magnetic resonance imaging (MRI) scans of the whole spinal column were done. The associated spinal cord malformations were also treated at the same operation. There were 14 boys and 8 girls, with an age range from birth to 4 years (mean 3.9 months), in group I. Of 20 patients (90%) with associated spinal lesions, 6 had more than one lesion, excluding hydromyelia. Group II was made up of 6 patients who had been previously operated on for a meningocele and who presented with tethered cord syndrome. These were 4 boys and 2 girls, who ranged in age from 4 to 10 years (mean 6 years). RESULTS: The level of the conus terminalis was lower than L3 in all patients. The other findings on MRI, besides low conus, were as follows: tight filum, split cord malformation, epidermoid, dorsal lipoma and hydromyelia. CONCLUSIONS: Meningocele frequently camouflages a second, occult, spinal lesion. MRI of the whole spinal column should be performed. An intradural exploration performed with a microneurosurgical technique is needed to detect the fibrous bands that may lead to spinal cord tethering and to release the entrapped nerve roots. The other associated spinal anomalies should be operated on during the same operation.     

Superficial cerebral and spinal haemosiderosis caused by secondary tethered cord syndrome after resection of a spinal lymphoma

Superficial haemosiderosis results from chronic subarachnoid haemorrhage during which haemosiderin is deposited in the leptomeninges around the brain, spinal cord and cranial nerves. We describe an exceptional case of superficial haemosiderosis characterised by two special aspects. (1) The cause was a secondary tethered cord syndrome due to dural adhesions which had developed 8 years after resection of a thoracic lymphoma and (2) an explorative neurosurgical procedure with complete untethering caused normalisation of the cerebrospinal fluid and stopped disease progression.     

Surgical technique and outcome in cervical and thoracic myelomeningocoele surgery.

Cervical and thoracic myelomeningocoeles differ from common lumbosacral myelomeningocoeles in many respects. We review the surgical technique and outcome achieved for a series of six infants who underwent surgery for cervical or thoracic myelomeningocoele. Five patients, who had intradural exploration and microsurgical untethering of the spinal cord, were neurologically stable on follow-up. The other patient, who had a simple subcutaneous resection of the sac without release of the intradural tethering bands, was re-operated on 16 months later, with progressive neurological symptoms due to cord tethering. Following re-exploration and microsurgical untethering of the spinal cord, the neurological deficits significantly improved. We suggest that the surgical technique in these lesions should include careful intradural exploration and microsurgical release of the spinal cord by meticulous resection of all tethering bands. This enables postoperative neurological improvement and possible prevention of future neurological deficits due to cord tethering.