Tethered cord syndrome: an updated review

Recurrent tethered cord: outcome and follow-up of 20 de-thetering for symptomatic spina bifida: choort study

OBJECTIVE

The objective of this study was to evaluate the prevalence of tethered cord among patients in the postoperative period of open and occult spina bifida. To identify warning signs for its early diagnosis, as well as outcomes after the new surgical approach.

METHODS

Retrospective study of patients followed at the Pediatric Neurosurgery Department of the Federal University of São Paulo with spinal dysraphism. Signs and symptoms indicating reoperation were collected, and postoperative results were classified as improved, unchanged, or worsened.

RESULTS

222 medical records of patients diagnosed with spinal dysraphism were evaluated. Symptomatic Tethered Cord Syndrome (STCS) was identified in 30 patients (13.51%), with clinical manifestations related to orthopedic deformities (66.7%), neurological deficits (56.7%), urological dysfunction (50%), and intestinal dysfunction (40%). 20 cases underwent surgery for tethered cord release. The mean age at the time of surgery was 7.7 ± 4.9 years, with 13 female patients (65%). In the postoperative evaluation, improvement in low back pain (90.9%), urological pattern, and urinary tract infection episodes (45.4%) were particularly noteworthy. 3 patients (33.3%) with constipation showed improvement, and one worsened (11.1%). Improvement in ambulation was seen in two cases (16.7%). Low back pain was the first symptom to improve after surgery, with an average time of 1.3 months, followed by changes in the urological pattern at 15.6 months. Improvement in constipation was observed in the first month in 2 cases (66.7%), positive changes in ambulation were observed around 7 months after surgery, and only one case showed improvement in clubfoot correction.

CONCLUSIONS

The prevalence of tethered cord recurrence after primary correction surgery for open or occult neural tube closure defects was similar to that found in the literature. The results were encouraging, with good postoperative evolution of patients, especially in the improvement of low back pain and urological symptoms.

Disparities in indications and outcomes reporting for pediatric tethered cord surgery: The need for a standardized outcome assessment tool

PURPOSE

Tethered cord syndrome (TCS) is characterized by abnormal attachment of the spinal cord neural elements to surrounding tissues. The most common symptoms include pain, motor or sensory dysfunction, and urologic deficits. Although TCS is common in children, there is a significant heterogeneity in outcomes reporting. We systematically reviewed surgical indications and postoperative outcomes to assess the need for a grading/classification system.

METHODS

PubMed and EMBASE searches identified pediatric TCS literature published between 1950 and 2023. Studies reporting surgical interventions, ≥ 6-month follow-up, and ≥ 5 patients were included.

RESULTS

Fifty-five studies representing 3798 patients were included. The most commonly reported non-urologic symptoms were nonspecific lower-extremity motor disturbances (36.4% of studies), lower-extremity/back pain (32.7%), nonspecific lower-extremity sensory disturbances (29.1%), gait abnormalities (29.1%), and nonspecific bowel dysfunction/fecal incontinence (25.5%). Urologic symptoms were most commonly reported as nonspecific complaints (40.0%). After detethering surgery, retethering was the most widely reported non-urologic outcome (40.0%), followed by other nonspecific findings: motor deficits (32.7%), lower-extremity/back/perianal pain (18.2%), gait/ambulation function (18.2%), sensory deficits (12.7%), and bowel deficits/fecal incontinence (12.7%). Commonly reported urologic outcomes included nonspecific bladder/urinary deficits (27.3%), bladder capacity (20.0%), bladder compliance (18.2%), urinary incontinence/enuresis/neurogenic bladder (18.2%), and nonspecific urodynamics/urodynamics score change (16.4%).

CONCLUSION

TCS surgical literature is highly variable regarding surgical indications and reporting of postsurgical outcomes. The lack of common data elements and consistent quantitative measures inhibits higher-level analysis. The development and validation of a standardized outcomes measurement tool-ideally encompassing both patient-reported outcome and objective measures-would significantly benefit future TCS research and surgical management.

Aberrant Dorsal Nerve Root as a Concomitant Cause of Spinal Cord Tethering Associated with a Dorsal Type Lipomyelomeningocele in a Child With Caudal Agenesis

ABSTRACT

Tethered cord syndrome is a neurological disorder closely associated with congenital spinal dysraphism. Aberrant dorsal nerve roots may be one of the possible and relatively rare tethering pathologies, especially in the complex form of occult spinal dysraphism such as caudal regression syndrome or split cord malformation. We report an illustrative case of caudal regression syndrome with spinal cord tethering due to a combination of a contiguous bundle of an aberrant dorsal nerve root, and a dorsal-type lipomyelomeningocele, with a thickened filum terminale treated with microneurosurgical untethering.

Current Global Research Trends of Tethered Cord Syndrome Surgery: A Scientometric and Visual Analysis

BACKGROUND

Since tethered cord syndrome (TCS) may lead to neurologic and motor dysfunction, surgeries often are applied to relieve the symptoms. The aim of the research was to explore the current global research trends of TCS surgery.

METHODS

In this article, articles on TCS surgery in the Web of Science Core Collection from 1980 to 2023 were searched. Research trends, countries, institutions, journals, authors, highly cited articles, and key words were analyzed using bibliometric methods. The literature co-citation network was mapped using VOSviewer, and research hotspots and trends were analyzed using CiteSpace.

RESULTS

A total of 432 publications were included. The number of publications and related research interest in the field of TCS surgery has increased globally year by year. The United States is the largest contributor (154 publications). The journal Childs Nervous System has the greatest number of publications (48 publications) and the most frequently cited journal is Neurosurgery (973 citations). In network visualization, the institution with the greatest contribution is University of California System (16 publications). Lee JY and Wang KC are the authors with the greatest number of publications (8 publications), and the most frequently cited author is Klekamp J (268 citations). Neurogenic bladder and spina bifida may be the next hot spot in this field.

CONCLUSIONS

This study will help researchers to identify the mainstream research directions and the latest hotspots in the field of TCS surgery and provide a reference for further research.

Tethered spinal cord tension assessed via ultrasound elastography in computational and intraoperative human studies

BACKGROUND

Tension in the spinal cord is a trademark of tethered cord syndrome. Unfortunately, existing tests cannot quantify tension across the bulk of the cord, making the diagnostic evaluation of stretch ambiguous. A potential non-destructive metric for spinal cord tension is ultrasound-derived shear wave velocity (SWV). The velocity is sensitive to tissue elasticity and boundary conditions including strain. We use the term Ultrasound Tensography to describe the acoustic evaluation of tension with SWV.

METHODS

Our solution Tethered cord Assessment with Ultrasound Tensography (TAUT) was utilized in three sub-studies: finite element simulations, a cadaveric benchtop validation, and a neurosurgical case series. The simulation computed SWV for given tensile forces. The cadaveric model with induced tension validated the SWV-tension relationship. Lastly, SWV was measured intraoperatively in patients diagnosed with tethered cords who underwent treatment (spinal column shortening). The surgery alleviates tension by decreasing the vertebral column length.

RESULTS

Here we observe a strong linear relationship between tension and squared SWV across the preclinical sub-studies. Higher tension induces faster shear waves in the simulation (R2 = 0.984) and cadaveric (R2 = 0.951) models. The SWV decreases in all neurosurgical procedures (p < 0.001). Moreover, TAUT has a c-statistic of 0.962 (0.92-1.00), detecting all tethered cords.

CONCLUSIONS

This study presents a physical, clinical metric of spinal cord tension. Strong agreement among computational, cadaveric, and clinical studies demonstrates the utility of ultrasound-induced SWV for quantitative intraoperative feedback. This technology is positioned to enhance tethered cord diagnosis, treatment, and postoperative monitoring as it differentiates stretched from healthy cords.

Diagnosis and Management of Tethered Cord Syndrome

Tethered cord syndrome is a condition in which the spinal cord is tethered by pathological structures such as a tight filum terminale, intradural lipomas with or without a connecting extradural component, intradural fibrous adhesions, diastematomyelia, and neural placode adhesions following closure of a myelomeningocele.It usually occurs in childhood and adolescence as the spine grows in length, but it can also develop in adulthood. Symptoms of tethered cord syndrome are slowly progressive and varied. Incorrect diagnosis and inappropriate treatment may be provided if the physician lacks knowledge and understanding of this disease.This chapter aims to describe the pathophysiology, syndromes, diagnostic imaging, surgical treatment, and prognosis of tethered cord syndrome to enhance the understanding of this condition.

Ultrasound-Guided Prospective Screening for Spinal Dysraphism in Offspring of Mothers With Pregestational Diabetes: A Pilot Study

AIM

Determine the utility of prospective spinal ultrasound in infants of mothers with pregestational diabetes (PGDM) for the diagnosis of closed spinal dysraphism (SDs).

METHODS

This prospective observational pilot study was completed at a tertiary care center between May 1, 2020 and December 30, 2022. Infants born to mothers with PGDM and with normal spinal physical examinations were included. A total of 25 mother-infant dyads were enrolled in the study and prospectively screened with spinal ultrasound. The study was registered on ClinicalTrials.gov (Identifier-NCT05033275).

RESULTS

Twenty-five spinal ultrasounds were performed over the course of this study with three (8%) resulting in abnormal findings that required further imaging. Follow-up with magnetic resonance imaging found one case of tethered cord syndrome.

CONCLUSION

Prospective screening in infants of mothers with PGDM found one case of tethered cord syndrome. This finding suggests that risk stratified screening of mothers with diabetes might be a reasonable approach to care.

Ventral anchoring of the conus medullaris: a new surgical technique preventing the radiographic recurrence of retethering after surgery for tethered spinal cord

OBJECTIVE

Retethering is not an unusual operation for a congenital lumbosacral dysraphic spinal lesion. The present study aimed to assess a new surgical technique for preventing retethering.

SURGICAL TECHNIQUE

After untethering the spinal cord, the pia mater or scar tissue at the caudal end of the conus medullaris is anchored to the ventral dura mater loosely using 8-0 thread, and the dura mater is closed directly. This technique is called ventral anchoring.

RESULTS

Ventral anchoring was performed in 15 patients (aged 5 to 37 years old, average age: 12.1 years old) between 2014 and 2021. All but one patient showed improvement or stabilization of the preoperative symptoms. No complication directly related to the procedure was observed. Postoperative MRI demonstrated that the dorsal subarachnoid space was restored in 14 patients but was undetectable or absent in three patients on follow-up MRI. No patients have experienced a recurrence of the tethered cord syndrome during the follow-up period.

CONCLUSION

Ventral anchoring is effective for restoring the dorsal subarachnoid space after untethering the spinal cord. This preliminary study suggested that ventral anchoring has the potential to prevent the postoperative radiographic recurrence of tethered spinal cord in patients with a congenital lumbosacral dysraphic spinal lesion.

Potential higher risk of tethered spinal cord in children after prenatal surgery for myelomeningocele: A systematic review and meta-analysis

INTRODUCTION

We performed a systematic review and meta-analysis on the incidence of secondary tethered spinal cord (TSC) between prenatal and postnatal closure in patients with MMC. The objectives was to understand the incidence of secondary TSC after prenatal surgery for MMC compared to postnatal surgery for MMC.

MATERIAL AND METHODS

On May 4, 2023, a systematic search was conducted in Medline, Embase, and the Cochrane Library to gather relevant data. Primary studies focusing on repair type, lesion level, and TSC were included, while non-English or non-Dutch reports, case reports, conference abstracts, editorials, letters, comments, and animal studies were excluded. Two reviewers assessed the included studies for bias risk, following PRISMA guidelines. TSC frequency in MMC closure types was determined, and the relationship between TSC occurrence and closure technique was analyzed using relative risk and Fisher's exact test. Subgroup analysis revealed relative risk differences based on study designs and follow-up periods. A total of ten studies, involving 2,724 patients, were assessed. Among them, 2,293 patients underwent postnatal closure, while 431 received prenatal closure for the MMC defect. In the prenatal closure group, TSC occurred in 21.6% (n = 93), compared to 18.8% (n = 432) in the postnatal closure group. The relative risk (RR) of TSC in patients with prenatal MMC closure versus postnatal MMC closure was 1.145 (95%CI 0.939 to 1.398). Fisher's exact test indicated a statistically non-significant association (p = 0.106) between TSC and closure technique. When considering only RCT and controlled cohort studies, the overall RR for TSC was 1.308 (95%CI 1.007 to 1.698) with a non-significant association (p = .053). For studies focusing on children up until early puberty (maximum 12 years follow-up), the RR for tethering was 1.104 (95%CI 0.876 to 1.391), with a non-significant association (p = 0.409).

CONCLUSION AND DISCUSSION

This review found no significant increase in relative risk of TSC between prenatal and postnatal closure in MMC patients, but a trend of increased TSC in the prenatal group. More long-term data on TSC after fetal closure is needed for better counseling and outcomes in MMC.

Onabotulinum Toxin A Intradetrusor Injections in Children with Neurogenic Lower Urinary Tract Dysfunction: Long-Term Histological Effects on the Bladder Wall

BACKGROUND

In the last twenty-five years, Onabotulinum Toxin A (BTX-A) has gained increasing popularity for neurogenic lower urinary tract dysfunction (NLUTD) treatment. To maintain its efficacy, repeated BTX-A intradetrusor injections are required over time, with unknown effects on the bladder wall in children. The aim of this paper is to report long-term effects on the bladder wall in children treated with BTX-A.

METHODS

Children with NLUTD not responsive to anticholinergics were treated with BTX-A, according to our protocol, with bladder wall control using endoscopic cold-cup biopsy. Specimens were evaluated considering edema, chronic inflammation, and fibrosis.

RESULTS

Of the 230 patients treated from 1997 to 2022, we considered only specimens obtained in patients who had received ≥5 treatments (36 children), considered as the threshold to evaluate clinical effectiveness on long-term treatment with BTX-A. Most of them had congenital NLUTD (25 patients) and detrusor overactivity (27 patients). In all, increased edema and chronic inflammation with reduced fibrosis over time was reported; these data were not statistically significant. No difference was observed between patients with congenital and acquired diseases.

CONCLUSIONS

Repeated intradetrusor BTX-A injections are not related to significant histological alterations in children, similarly with adults, and repeated injections could be considered safe.

Dekyphosis operation combined with limited osteotomy to treat the symptomatic adult tethered cord syndrome with complicated malformations: A case report

RATIONALE

Tethered cord syndrome (TCS) represents a spectrum of neurological symptoms that are caused by constant or intermittent axial traction of the terminal cone of the spinal cord due to abnormal positioning. It is uncommon for abnormal structures of TCS to be accompanied by split cord malformation, thoracic spinal stenosis, and other spinal cord diseases.

PATIENT CONCERNS

A 45-year-old male patient visited our hospital due to severe lower back pain, extensive left lower limb muscle weakness, and intermittent claudication.

DIAGNOSES

TCS combined with stenosis of the thoracic canal, split cord malformation, and kyphosis deformity.

INTERVENTIONS

The patient underwent Dekyphosis operation combined with limited osteotomy symptoms.

OUTCOMES

The patient felt the right lower limb improved after surgery. At 4-month follow-up, a radiological examination showed adequate decompression of the spinal cord and a good internal fixation position. Overall, the patient's clinical symptoms significantly improved.

CONCLUSION

This is a rare case of TCS combined with thoracic disc herniation and bony mediastinum. A more conservative invasive surgical approach was elected and markedly improved the patient's symptoms. Additional clinical cases are needed to confirm the stability and feasibility of this surgical approach.

Spinal cord anomalies in children with anorectal malformations: a retrospective cohort study

PURPOSE

First, to assess the number of spinal cord anomalies (SCA), specifically tethered spinal cord (TSC) in patients with anorectal malformations (ARM), identified with spinal cord imaging (i.e. spinal cord US and/or MRI). Second, to report outcomes after TSC treatment.

METHODS

A retrospective mono-center study was performed. All ARM patients born between January 2000 and December 2021 were included. Screening for SCA consisted of spinal cord US and/or MRI. Radiology reports were scored on presence of SCA. Data were presented with descriptive statistics.

RESULTS

In total, 254 patients were eligible for inclusion, of whom 234 (92.1%) underwent spinal cord imaging. In total, 52 (22.2%) patients had a SCA, diagnosed with US (n = 20, 38.5%), MRI (n = 10, 19.2%), or both US and MRI (n = 22, 42.3%), of whom 12 (23.5%) with simple, 27 (52.7%) intermediate, and 12 (23.5%) complex ARM types. TSC was identified in 19 patients (8.1%), of whom 4 (21.1%) underwent uncomplicated neurosurgical intervention.

CONCLUSIONS

SCA were present in 22% of ARM patients both in simple, as well as more complex ARM types. TSC was present in 19 patients with SCA, of whom 4 underwent uncomplicated neurosurgical intervention. Therefore, screening for SCA seems to be important for all ARM patients, regardless of ARM type.

LEVEL OF EVIDENCE

Level III.

Electrodiagnostic findings of retethering in children with spinal dysraphism

PURPOSE

Retethering of the cord can occur after the initial untethering surgery. Typical neurological manifestations indicative of cord tethering are often difficult to determine in pediatric patients. Patients who had a primary untethering operation are likely to present with some degree of neurological deficits from a previous tethering event, and urodynamic studies (UDSs) and spine images are frequently abnormal. Therefore, more objective tools to detect retethering are needed. This study sought to delineate the characteristics of EDS of retethering, and therefore, could support the diagnosis of retethering.

METHODS

Among 692 subjects who had an untethering operation, data from 93 subjects who had been suspected of retethering clinically were retrospectively extracted. The subjects were divided into two groups, a retethered group, and a non-progression group, according to whether or not surgical interventions had been performed. Two consecutive EDSs, clinical findings, spine magnetic resonance imaging scans, and UDSs before the development of new tethering symptoms were reviewed and compared.

RESULTS

In the electromyography (EMG) study, the appearance of abnormal spontaneous activity (ASA) in new muscles was prominent in the retethered group (p < 0.01). The loss of ASA was more pronounced in the non-progression group (p < 0.01). Specificity and sensitivity of EMG for retethering were 80.4 and 56.5%, respectively. In the nerve conduction study, the two groups did not show differences. The size of fibrillation potential was not different between the groups.

CONCLUSIONS

To provide support for a clinician's decision on retethering, EDS could be an advantageous tool with high specificity when the results are compared to previous EDS results. Routine follow-up EDS post-operatively is recommended as a baseline for comparison at the time when retethering is clinically suspected.

Diagnostic Utility of 3D Gradient-Echo MR Imaging Sequences through the Filum Compared with Spin-Echo T1 in Children with Concern for Tethered Cord

BACKGROUND AND PURPOSE

Fatty intrathecal lesions are a cause of tethered cord, and detection of these on spinal MR imaging is paramount. Conventional T1 FSE sequences are the mainstay of detecting fatty elements; however, 3D gradient-echo MR images, volumetric interpolated breath-hold examination/liver acquisition with volume acceleration (VIBE/LAVA), are popular, given the increased motion resistance. We sought to evaluate the diagnostic accuracy of VIBE/LAVA compared with T1 FSE for detection of fatty intrathecal lesions.

MATERIALS AND METHODS

In this retrospective, institutional review board-approved study, 479 consecutive pediatric spine MRIs obtained to evaluate cord tethering between January 2016 and April 2022 were reviewed. Inclusion criteria were patients who were 20 years of age or younger who underwent spine MRIs containing both axial T1 FSE and VIBE/LAVA sequences of the lumbar spine. The presence or absence of fatty intrathecal lesions was recorded for each sequence. If fatty intrathecal lesions were present, anterior-posterior and transverse dimensions were recorded. VIBE/LAVA and T1 FSE sequences were evaluated on 2 separate occasions (VIBE/LAVAs first followed by T1 FSE several weeks later) to minimize bias. Basic descriptive statistics compared fatty intrathecal lesion sizes on T1 FSEs and VIBE/LAVAs. Receiver operating characteristic curves were used to determine minimal fatty intrathecal lesion size detectable by VIBE/LAVA.

RESULTS

Sixty-six patients were included, with 22 having fatty intrathecal lesions (mean age, 7.2 years). T1 FSE sequences revealed fatty intrathecal lesions in 21/22 cases (95%); however, fatty intrathecal lesions on VIBE/LAVA were detected in 12/22 patients (55%). Mean anterior-posterior and transverse dimensions of fatty intrathecal lesions measured larger on T1 FSE compared with VIBE/LAVA sequences (5.4 × 5.0 mm versus 1.5 × 1.6 mm, respectively; P values = .039 anterior-posterior; .027 transverse).

CONCLUSIONS

While T1 3D gradient-echo MR images may have decreased the acquisition time and are more motion-resistant than conventional T1 FSE sequences, they are less sensitive and may miss small fatty intrathecal lesions.

Utilizing pre- and postoperative radiological parameters to predict surgical outcomes following untethering for tethered cord syndrome in a pediatric population

OBJECTIVE

Tethered cord syndrome (TCS) can lead to significant downstream neurological deficits including gait deterioration, incontinence, and often unexplained chronic low-back pain. Surgical intervention may relieve symptoms, but there are no defined radiological parameters associated with surgical outcomes and functional status. The authors aimed to define pre- and postoperative radiological parameters for assessing surgical outcomes in TCS.

METHODS

The authors performed a single-center retrospective review of all pediatric patients treated for TCS between 2016 and 2021. Patient baseline characteristics and operative metrics included age, sex, level of conus, level of procedure, tethering pathology, symptoms at presentation, complications, improvement of symptoms, and reoperation rate. MRI measurements included pre- and postoperative anterior canal distance (ACD) and bending angle (BA).

RESULTS

Thirty-three pediatric patients were identified who underwent untethering of the spinal cord and had pre- and postoperative MRI between 2016 and 2021. The mean patient age was 5.64 ± 5.33 years. Twenty patients (60.60%) were female. Regarding the site of untethering, 31 procedures (93.93%) were performed at the lumbosacral region and 2 (6.06%) were performed at the thoracolumbar region. The conus medullaris was found above L3 in 21.21% of patients. Postoperatively, 18.18% of patients experienced complications, 48.48% showed improvement in their symptoms, and 48.48% were equivocal or had persistent symptoms. The mean preoperative ACD0 (measured from the posterior vertebral body margin [middle] to the anterior margin of the conus medullaris) was 6.15 ± 3.18 mm, the postoperative ACD0 was 2.25 ± 2.72 mm, and the average change in ACD0 was -0.90 ± 1.31 mm. The mean preoperative BA was 26.00° ± 11.56°, the mean postoperative BA was 15.92° ± 9.81°, and the average change in BA was -10.08° ± 8.80°. An optimal cutoff value for preoperative BA to predict reoperation in pediatric patients with complex TCS undergoing surgery was ≥ 31.70° (area under the curve = 0.83).

CONCLUSIONS

In surgically treated patients with TCS, certain preoperative radiological parameters may be important in predicting postoperative surgical outcomes; these parameters can be evaluated and reported to indicate patients at high risk for complications. Further prospective multicenter research is warranted to offer robust evidence of association of patient outcomes with preoperative radiological parameters in TCS.

Prenatal assessment and pregnancy outcomes of foetal low-lying conus medullaris using 3D ultrasound

OBJECTIVES

This study aims to follow up on low-lying conus medullaris (CM) cases and explore the correlation between the CM location and the final prognosis.  METHODS: We retrospectively collected 37 cases diagnosed with low-lying CM during pregnancy in the Peking University First Hospital from January 2019 to December 2020. The location of CM was confirmed by 3D ultrasonography, and clinical data, including postnatal outcomes, were recorded. When the conus medullaris was below L3 (excluding L3), it was diagnosed as low-lying conus medullaris, regardless of gestational age. The short-term postnatal outcome included assessment of symptoms and signs of motor and sensory neuron dysfunction.

RESULTS

The average gestational weeks of low-lying diagnosis was between 23 and 24 weeks. Among 37 cases, nine (24.3%) were complicated with spine dysraphism (3 cases of open spina bifida, 6 cases of tethered cord syndrome). Apart from 7 cases of pregnancy termination, the remaining 30 live births had a good prognosis in the short term, though 5 out of 6 cases of tethered cord syndrome underwent surgical release. The mean location of cases of open spinal dysraphism (n = 3) and those of closed dysraphism/tethered cord syndrome (n = 6) was at Lumber vertebra 5 (L5) and between L5 and Sacral vertebra 1 (S1), respectively, which showed statistical significance compared with the postnatally normal group. When we set Lumber 4.25 as the cut-off value to predict the diagnosis of spine dysraphism (mainly involving open spinal dysraphism and closed spinal dysraphism/tethered cord syndrome), the sensitivity was 66.7. At the same time, the specificity was 96%, along with the area under the curve (AUC) at 0.877.

CONCLUSION

The second trimester finding of low CM is associated with spinal defects, mainly open spinal dysraphism and closed spinal dysraphism/tethered cord syndrome. Careful assessment of the fetal spine should be considered especially when the location of CM is lower than L4.

Does early tethered cord release in occult spinal dysraphism improve urological outcomes? A systematic review

Introduction

Occult spinal dysraphism involves a wide range of congenital anomalies, e.g., lipoma, Lipomeningomyelocele, congenital dermal sinus, etc. Occult spinal dysraphism also may present with a wide spectrum of clinical manifestations and radiological findings, i.e., it ranges from asymptomatic patients that are accidentally discovered to low lying conus with neurological, skeletal and urological manifestations. Even though neurosurgeons are well-aware of neurological presentations that indicate surgical intervention in children with occult spinal dysraphism, urological symptoms may present some controversy in management. This review aims to discuss urological outcomes of detethering as regarding time of intervention, improvement of the urological symptoms after detethering, and the role of urodynamics preoperatively and during follow-up.

Methodology

An online search of the literature was done including studies in English language from 1990 to January 2022. Included studies were analytical with well conducted descriptive nature of acceptable quality (at least level 3 evidence). Patient characteristics included both male and female children and adolescents, up to 19 years old who presented with clinical and/or radiological evidence of tethering of the spinal cord. Most studies that were included had availability of urodynamics. A total of 15 studies were included involving 633 patients. Meningomyelocele (MMC) and other spina bifida operta cases are excluded.

Results

Results of all studies were collected and mean age of studies was gathered and plotted on a chart in relation to urological outcome and urodynamic improvement. Most results favored early detethering; however, many factors were found to affect the inverse proportion curve of age with clinical improvement or urodynamics. For example, studies that included secondary tethered cord showed poorer results than results that included primary tethered cord only, preoperative severity of urological symptoms (more severe symptoms were associated with irreversible poor outcomes), and preoperative urodynamic parameters.

Conclusion

The management of tethered cord syndrome and occult spinal dysraphism remains controversial. There is lack of class 1 evidence regarding tethered cord release surgery in occult spinal dysraphism. Heterogenicity of pathology, symptomatology and radiology make the randomization of such sample size difficult. The outcomes of surgical detethering are therefore multifactorial. A large sample of prospective randomized controlled studies addressing each factor, e.g., age, severity of symptoms, preoperative urodynamic parameters, is recommended in order to evaluate the impact of each factor on outcome.

Spinal manifestations of Ehlers-Danlos syndrome: a scoping review

OBJECTIVE

Since its initial description, the definition of Ehlers-Danlos syndrome (EDS) has notably changed. At present, it broadly refers to disorders of the connective tissue that are heritable and have similar features including joint hypermobility, dermal dysplasia, and vascular as well as internal organ fragility. There has been no comprehensive review of spinal manifestations of EDS in the recent literature. That has led to controversies in management protocols of this so-called orphan disease.

METHODS

The authors used the latest version of the EDS classification from 2017, in which 13 subtypes were recognized. EDS has 19 different causal genes, mainly associated with collagen synthesis. Of these, 5 subtypes have associated spinal manifestations.

RESULTS

Some of the spinal pathologies associated with EDS include Chiari malformation, craniocervical instability, kyphoscoliosis, segmental instability and kyphosis, spontaneous CSF leaks, Tarlov cyst syndrome, tethered cord, and problems associated with wound healing. Here, the authors briefly discuss the demographics, etiology, pathophysiology, clinical features, management strategies, and directions for further research for each of these manifestations.

CONCLUSIONS

EDS belongs to the group of orphan diseases, with the total patient population being below 200,000. Further research on spinal manifestations of EDS is the need of the hour to establish clinical practice guidelines and close the significant knowledge gaps that currently exist.

Reduced complication rate with simultaneous detethering and spinal deformity correction surgery compared to staged surgeries in patients with early onset scoliosis

PURPOSE

In patients with early onset scoliosis (EOS) and intraspinal anomalies, surgery may be necessary for both the tethered spinal cord (TSC) and spinal deformity. The purpose of this study was to determine if there is a difference in complications when TSC release and surgery for spinal deformity correction (SDC) are performed separately compared simultaneously.

METHODS

EOS patients with TSC who underwent detethering and SDC surgeries were identified through a multicenter registry. Patients were stratified into two groups. The simultaneous cohort consisted of patients receiving both detethering and SDC surgeries in a single anesthetic event on the same day, and the staged cohort consisted of patients undergoing detethering and SDC on two separate occasions. Postoperative complications up to 180 days for either surgery were assessed.

RESULTS

Twenty five (65.8%) patients were staged and 13 (34.2%) underwent a simultaneous approach. Percent curve correction following SDC surgery did not significantly differ between the groups (p = 0.36). Within 90 days postoperatively, 16 complications in 11 patients (44.0%) occurred in the staged group, whereas no complications occurred in the simultaneous cohort (p = 0.006). From 90-days to 180-days postoperatively, 4 additional complications in 3 patients (12.0%) occurred in the staged group, with no complications reported in the same timeframe for the simultaneous cohort.

CONCLUSION

To our knowledge, this is the largest multicenter comparative study to date, and it suggests that a simultaneous approach can be performed safely for EOS patients undergoing detethering and SDC surgeries, with a potentially lower risk profile than the traditional staged approach to these pathologies.

LEVEL OF EVIDENCE

Level III.

Importance of Electrodiagnostic Testing Prior to a Tethered Cord Release in a Patient with Overlapping Symptoms of Charcot-Marie-Tooth Disease

Charcot-Marie-Tooth (CMT) disease is the most common inherited neuromuscular disorder causing a symmetric, slowly progressive distal neuropathy of the legs and arms. Tethered cord syndrome (TCS) encompasses a constellation of neurological, gastrointestinal, musculoskeletal, and urinary abnormalities resulting from spinal cord traction. The signs and symptoms of CMT and TCS may be very similar. Electrodiagnostic (EDX) studies are crucial in differentiating between these two conditions. We describe a 20-year-old woman with a history of low back pain, right leg tingling, and difficulty in walking. She experienced bowel and urinary incontinence 11 years earlier as well as back pain, in-toeing gait, and difficulties with balance and coordination. Urodynamic studies and cervical, thoracic, and lumbar magnetic resonance imaging (MRI) were normal, with the latter demonstrating the tip of the conus medullaris in the normal position at the L1-2 interspace and the filum terminale demonstrating no thickening or fatty infiltration. Despite the absence of radiological evidence of TCS, she underwent a tethered cord release (TCR) with improvement of the pain postoperatively. Two years later, the back pain recurred with increasing pain, paresthesia, and weakness of the lower extremities with frequent trip and fall episodes. EDX studies of the lower extremities were requested. Clinical findings included weakness of flexion and extension of the toes as well as dorsiflexors of the ankles bilaterally. The knee and ankle reflexes were absent bilaterally. EDX testing of the lower extremities were non-diagnostic due to loss of sensory and compound muscle action potentials. EDX studies of the upper extremities suggested a demyelinating polyneuropathy, most likely CMT disease. Genetic studies subsequently confirmed CMT type 1A (CMT1A) disease. Ensuing EDX studies on the patient's father and brother also suggested CMT1A disease. Physicians should be aware of the overlapping signs and symptoms of CMT disease and TCS. Performing comprehensive EDX studies prior to a TCR particularly in cases when a lumbar MRI is negative may prove valuable in identifying cases of CMT disease with subsequent confirmation by genetic testing.

Novel use of nonpenetrating titanium clips for pediatric primary spinal dural closure: A technical note

BACKGROUND

Dural closure is an important part of any pediatric spinal procedure with intradural pathology to prevent post-operative cerebrospinal fluid (CSF) egress and associated complications. Utilization of nonpenetrating titanium clips is one closure option that may have technical advantages such as ease of use and amenability to a narrow surgical corridor. No data exist on the efficacy of these clips for pediatric spinal dural closure.

METHODS

A single surgeon case series of 152 pediatric patients underwent procedures involving lumbar durotomy with subsequent dural closure using the AnastoClip® nonpenetrating titanium clip closure system. Rates of infection and cerebrospinal fluid leak were measured during the follow-up period.

RESULTS

A total of 152 pediatric patients (mean age: 6.25 ± 5.85 years, 50.7 % female) underwent intradural surgery with clip closure. The mean follow-up time was 57.0 ± 28.5 months. All patients were initially indicated for procedures involving spinal durotomy, with a majority being isolated tethered cord release (84.2 %). Others required tethered cord release and excision of a lipomyelomeningocele, spinal meningioma or arachnoid cyst (15.8 %). Post operative CSF leak occurred in two (1.32 %) patients at 11 and 18 days. Only one (0.66 %) patient was diagnosed with an infection, which was in a separate patient from those that had CSF leaks.

CONCLUSION

The remarkably low incidence of post-operative CSF leak and infection with nonpenetrating titanium clips suggests a strong safety and efficacy profile for this form of dural closure in a pediatric cohort. Further research evaluating this technique is required to fully demonstrate its acceptability as a cost-effective alternative to traditional suture-based closure.

Assessment of MRI and US Screening for Tethered Cord Syndrome in Patients Diagnosed With Esophageal Atresia/Tracheoesophageal Fistula

INTRODUCTION

Infants with esophageal atresia and/or tracheoesophageal fistula (EA/TEF) undergo screening for tethered cord syndrome (TCS) via ultrasound and magnetic resonance imaging. Existing literature lacks data to guide optimal timing of screening and magnetic resonance imaging (MRI) is often delayed until 3-6 mo of age, when it is frequently forgotten. Detethering surgery has a high rate of success in patients with TCS and is often performed prophylactically due to potential irreversible deficits. This study aims to improve screening procedure for infants with EA/TEF.

METHODS

A retrospective chart review was done of all EA/TEF patients treated over 6 y (n = 79). The study examined how often each imaging modality was performed and identified a TCS lesion, as well as age of screening/surgical intervention.

RESULTS

Screening for TCS was done with MRI 58% of the time and US 15% of the time. However, 38% of patients did not undergo any screening. Out of the patients with TCS on MRI (n = 19, 41.3%), 73.7% had neurosurgery. Of patients who underwent US (n = 12), nine patients also had MRI later: two reported TCS lesions and subsequently had neurosurgery. Surgical infection rates and complications were 0/14.

CONCLUSIONS

MRI demonstrated a higher rate of detecting TCS lesions than US, and patients with TCS frequently had detethering. Patients with ≥3 VACTERL or vertebral anomalies had a higher incidence of TCS on MRI. Patients with vertebral anomalies reported false negative ultrasounds in two cases, suggesting the potential superiority of MRI screening in this subgroup. A third of children did not undergo any imaging and this will require a process improvement.

Filum terminale transection in pediatric tethered cord syndrome: a single center, population-based, cohort study of 95 cases

Purpose

The purpose of this study was to evaluate outcome following surgical transection of filum terminale (FT) in symptomatic and asymptomatic pediatric patients with radiological findings consistent with tethered cord syndrome (TCS).

Methods

Patients < 17 years who underwent untethering surgery between 2007 and 2018 were screened for eligibility. Those who had undergone primary transection of the FT, and had preoperative radiological findings of fatty filum, thickened FT, or low-lying conus, below the pedicles of L2, were included. The cohort was divided into symptomatic and asymptomatic depending on clinical presentation. Surgical complications and functional outcome was recorded.

Results

In total, 95 patients were included, of whom 62 were symptomatic. In symptomatic patients, the main indications for radiological evaluation were scoliosis (29%) and motor symptoms (19%). In asymptomatic patients, skin stigmata (76%) were the most common finding. Fatty or thick FT was the most common radiographic finding, seen in 61% of symptomatic and 79% of asymptomatic cases. All patients underwent transection of the FT and were followed for a median of 1.8 years. A postoperative complication occurred in 12%, all Ibanez type Ib and managed without invasive treatment. For the symptomatic cohort, significant improvement was seen for both urodynamic assessment (48% improved, p = 0.002) and sensorimotor function (42% improved, p < 0.001).

Conclusions

Neurological improvement or halted deterioration was seen in the majority of symptomatic cases. Asymptomatic patients did not experience any severe complications. Filum transection should be offered to symptomatic and asymptomatic patients upon diagnosis of fatty filum, thickened FT, or low-lying conus.

Filum Terminale: A Comprehensive Review with Anatomical, Pathological, and Surgical Considerations

The conus medullaris is the distal tapering end of the spinal cord, and the filum terminale (FT) is regarded as a bundle of non-functional fibrous tissue; therefore, some scholars call it the spinal ligament, while others describe the human FT as "remnants of the spinal cord." It was later found that in the human spinal cord, the FT is composed of an intradural segment and an epidural segment, and the end of the FT is connected to the coccyx periosteum. Because some nerve tissue is also found in the FT, as research progresses, FT may have the potential for transplantation. A lack of exhaustive overviews on the FT in the present literature prompted us to conduct this review. Considering that a current comprehensive review seemed to be the need of the hour, herein, we attempted to summarize previous research and theories on the FT, elucidate its anatomy, and understand its pathological involvement in various diseases.

Spinal cord detethering without laminectomy or laminotomy

Background:

Tethered cord syndrome occurs when there is abnormal tension on the distal spinal cord, which limits its elevation as patients grow. This results in stretching of the neural elements and microvasculature, resulting in both direct and ischemic injury.[7] Animal studies suggest that impairment of oxidative metabolic pathways may contribute to neuronal injury.[7] Associated conditions include myelomeningocele, lipomyelomeningocele, intraspinal lipomas, diastematomyelia, thickened/fatty filum terminale, and trauma.[2] Tethering may be asymptomatic or result in a variety of symptoms including lower extremity weakness/sensory deficits, bowel/bladder dysfunction, scoliosis, pes cavus, and back/leg pain.[6] Early surgical intervention has been shown to improve outcomes and may be performed prophylactically or to prevent symptom progression.[1,3] More specifically, retrospective studies demonstrate that surgical intervention in patients under the age of 2 years is associated with improved outcomes.[5] In some cases, detethering may result in clinical improvement.[3]

Case Description:

We present a case of a 6-month-old male with a low-lying conus medullaris, lumbar syrinx, mildly abnormal urodynamic studies, and asymmetric utilization of his lower extremities observed during the evaluation of a Y-shaped gluteal cleft. He underwent elective spinal cord detethering via the safe and effective, minimally invasive technique described in the video.

The patient’s parents gave informed consent for treatment and video recording. Institutional review board approval was deemed unnecessary.

Conclusion:

Given the variety of surgical techniques used for cord detethering, this video may assist other surgeons in developing techniques that require little to no compromise of the developing bony spinal column while achieving sufficient release of the spinal cord.[4]

Intradural view of the spinal cord and dura after three-column osteotomy: illustrative case

BACKGROUND

A three-column osteotomy results in dural buckling, which may appear concerning upon intraoperative visualization because it may appear that the neural elements may also be buckled. The authors presented an intraoperative view after intentional durotomy of the neural elements and the relaxed state of the dura after three-column osteotomy.

OBSERVATIONS

A 52-year-old woman with adult tethered cord syndrome and previous untethering presented with worsening leg pain and stiffness, urinary incontinence, and unbalanced gait. Magnetic resonance imaging demonstrated an arachnoid web at T6 and spinal cord tethering. Spinal column shortening via three-column osteotomy was performed with concomitant intradural excision of the arachnoid web. Dural buckling was observed intraoperatively after spinal column shortening. After the durotomy, the spinal cord was visualized without kinking or buckling.

LESSONS

Dural buckling after spinal column shortening of 15 mm via three-column osteotomy at T6 did not result in concomitant buckling of the underlying neural elements.

Absent sural responses in tethered cord syndrome

Context: Tethered cord syndrome is a progressive condition usually diagnosed early in life, and leads to a diversity of manifestations including neurologic, urologic, and orthopedic dysfunction.Findings: We report two cases of tethered cord syndrome associated with a unilaterally absent sural sensory response on nerve conduction studies while other causes of this finding being excluded.Conclusion/clinical relevance: We believe that this finding is caused by a selective injury of sensory fibers at the level or distal to the dorsal root ganglia.

Effect of untethering on occult tethered cord syndrome: a systematic review

BACKGROUND AND OBJECTIVES

Despite the evident clinical, neurological, orthopedic, and urodynamic dysfunctions, neuroanatomic imaging is normal in patients with occult tethered cord syndrome (OTCS). Therefore, the diagnosis of OTCS can be very complex. In this regard, this systematic review aimed to determine the main clinical features (i.e. neurological, musculoskeletal, and urological abnormalities) and improvement rates of these symptoms in patients with OTCS after the section of the filum terminale (SFT).

MATERIALS AND METHODS

All the papers published in three electronic databases, namely Google Scholar, PubMed, and Web of Science, were searched for the purposes of this study. The searching process started on 15 October and lasted until 9 November 2020. Eventually, 10 reports were found about the clinical outcomes of SFT for the management of the OTCS.

RESULTS

The included studies were carried out on a total of 234 patients with OTCS, all of whom had undergone SFT. Evaluation of urologic symptoms revealed that 40-100% of patients with OTCS suffered from urinary instability. Moreover, its improvement rate after SFT was estimated at 59-100%. Evaluation of neurological symptoms indicated that 25-69% of patients with OTCS suffered from back/leg pain, And its improvement rate, the symptoms of back/leg pain of all patients were resolved or improved after SFT. Lower extremity weakness was found in 9-40% of patients with OTCS which was resolved or improved after SFT in about 25-100% of patients. Nevertheless, surgical indications for occult tight filum terminale syndrome remain controversial.

CONCLUSION

Although it seems that the SFT in OTCS patients is promising in treating neurologic, orthopedic and urological symptoms, usage of surgical untethering for patients with OTCS is a controversial issue. Clinical evaluation and urodynamic testing can be used to identify patients with OTCS. However, a multidisciplinary diagnostic work-up is strongly recommended for every child with OTCS.

Intrathecal baclofen therapy for severe spasticity in an adult with tethered cord syndrome: a case report

Background

Patients with tethered cord syndrome often suffer severe spasticity. To the best of our knowledge, intrathecal baclofen (ITB) therapy in a patient with tethered cord syndrome has not been reported previously. We describe a case in which ITB therapy was useful for treating severe spasticity in an adult with tethered cord syndrome.

Case presentation

We present the case of a 50-year-old Japanese woman with tethered cord syndrome and related conditions suffering from severe spasticity and pain in the lower limbs. She was born with a lumbosacral myelomeningocele, which was closed in the neonatal period. For 4–5 years before this presentation, spasticity in the lower limbs had been exacerbated without any obvious cause. She received rehabilitation and pharmacotherapy from a local doctor, but symptoms were unimproved, and her previous doctor referred her to this department. A test with 50 μg of intrathecally delivered baclofen showed total relief of spasticity and pain, so a pump was implanted for continuous baclofen delivery. During 24 months of follow-up, spasticity has remained under excellent control with baclofen at 38.5–41.0 μg/day.

Conclusions

ITB therapy proved extremely effective in this adult with severe spasticity from tethered code syndrome.

Surgical pathway proposal for severe paralytic scoliosis in adolescents with myelomeningocele

PURPOSE

The increased life expectancy of patients with myelomeningocele led to the necessity of new management for addressing complex spine deformities with severe pelvic obliquity. Tethered cord release (TCR) and spinal fusion were described as treatment options. However, nowadays, the surgical strategy is not well defined and high rates of mechanical failures and complications are reported. Our aim was to propose a new two-stage surgical pathway to treat a selected group of severe myelomeningocele scoliosis.

METHODS

This is a retrospective series of myelomeningocele scoliosis in paralytic adolescent patients treated with concurrent TCR and posterior spinal fusion (PSF), followed by delayed anterior fusion (ASF) through minimally invasive lateral approach. Inclusion criteria were as follows: evolutive scoliosis in tethered cord syndrome and paraplegia, main curve >70°, pelvic obliquity >20°, and age between 10 and 18 years. Clinical, surgical, and radiographic parameters were evaluated preoperatively and at a mean follow-up (FU) of 2.8 years.

RESULTS

Six patients out of 58 met the inclusion criteria and were included in the study (mean age 12.3 years old). The mean curve and pelvic obliquity correction were 68.8% and 82%, respectively. No loss of correction was recorded at FU. One case of cerebrospinal fluid leakage requiring revision surgery was recorded.

CONCLUSION

To the best of our knowledge, this is the first study proposing a two-stage surgical pathway for severe MMC spinopelvic deformity treatment. Concurrent TCR and PSF with delayed minimally invasive ASF permitted to minimize complications providing good fusion rates without loss of correction and implant failure.

Posterior Vertebral Column Subtraction Osteotomy for Recurrent Tethered Cord Syndrome: A Multicenter, Retrospective Analysis

BACKGROUND

Few have explored the safety and efficacy of posterior vertebral column subtraction osteotomy (PVCSO) to treat tethered cord syndrome (TCS).

OBJECTIVE

To evaluate surgical outcomes after PVCSO in adults with TCS caused by lipomyelomeningocele, who had undergone a previous detethering procedure(s) that ultimately failed.

METHODS

This is a multicenter, retrospective analysis of a prospectively collected cohort. Patients were prospectively enrolled and treated with PVCSO at 2 institutions between January 1, 2011 and December 31, 2018. Inclusion criteria were age ≥18 yr, TCS caused by lipomyelomeningocele, previous detethering surgery, and recurrent symptom progression of less than 2-yr duration. All patients undergoing surgery with a 1-yr minimum follow-up were evaluated.

RESULTS

A total of 20 patients (mean age: 36 yr; sex: 15F/5M) met inclusion criteria and were evaluated. At follow-up (mean: 23.3 ± 7.4 mo), symptomatic improvement/resolution was seen in 93% of patients with leg pain, 84% in back pain, 80% in sensory abnormalities, 80% in motor deficits, 55% in bowel incontinence, and 50% in urinary incontinence. Oswestry Disability Index improved from a preoperative mean of 57.7 to 36.6 at last follow-up (P < .01). Mean spinal column height reduction was 23.4 ± 2.7 mm. Four complications occurred: intraoperative durotomy (no reoperation), wound infection, instrumentation failure requiring revision, and new sensory abnormality.

CONCLUSION

This is the largest study to date assessing the safety and efficacy of PVCSO in adults with TCS caused by lipomyelomeningocele and prior failed detethering. We found PVCSO to be an excellent extradural approach that may afford definitive treatment in this particularly challenging population.

Successful Treatment of Chronic Back and Leg Pain With Lower Than Usual Placement of High-Frequency Spinal Cord Stimulation in a Patient With Uncorrected Tethered Cord: Case Report

BACKGROUND AND IMPORTANCE

Tethered cord syndrome (TCS) often leads to severe back and leg pain. The typical treatment to stall disease progression is untethering surgery, but this is not always effective for pain. Spinal cord stimulation (SCS) is an efficacious treatment for neuropathic pain. However, it has seldom been utilized in TCS cases. Moreover, with cord elongation, ideal paddle placement is not certain.

CLINICAL PRESENTATION

We present the case of a 77-yr-old male with severe chronic lower-back and lower-extremity pain. Magnetic resonance imaging (MRI) showed severe lumbar spine degenerative changes, along with a previously undiagnosed spina bifida and conus medullaris termination at L5. We felt that SCS would be the best treatment avenue for his chief complaint of pain. Due to cord elongation, we trialed lower placement of the high-frequency (HF)-SCS system at T11-T12, which led to 80% improvement in pain symptoms within 1 wk and ability to walk for the first time in a year. At his first follow-up appointment, the patient endorsed 80% to 90% relief of his lower-back and bilateral lower-extremity pain, which improved to 100% relief at 12 mo at last visit.

CONCLUSION

Only 4 other reports were identified in the literature utilizing SCS in TCS cases. Our case adds to the limited body of literature that SCS is an effective therapy for pain in TCS and degenerative spine disease. Only 2 other reports employed lower than usual lead placement. Our case demonstrates that lead placement may need to be changed to accommodate the elongated cord.

Functional outcome after cord detethering in fecally incontinent patients with anorectal malformations

PURPOSE

Tethered cord (TC) occurs in 36% of patients with anorectal malformations (ARMs), for whom the benefit of detethering surgery remains unclear regarding bowel and/or bladder function. This study aimed to examine whether cord detethering could improve fecal and urinary incontinence in these patients.

METHODS

This was a retrospective study of TC patients (>3 years old) with fecal incontinence and ARMs, who underwent detethering surgery between 2016 and 2020 and were followed up for at least 6 months.

RESULTS

Of the 27 included patients, 55% had sacral ratios between 0.4 and 0.7, and in 37% it was < 0.4; the remaining 8% was over 0.7; 52% suffered from colonic hypermotility. After detethering surgery, partial fecal continence was achieved in five patients (18%); total fecal continence, in ten patients (37%); 12 (44%) remained fecally incontinent. Partial urinary continence was obtained in four cases (14%), and the number of patients with total urinary continence rose from 7 (25%) to 15 (55%). Lower extremity symptoms were also improved in 72% of the cases. Patients with colonic hypomotility were found to have a better functional outcome than those with colonic hypermotility (69% vs. 43%, respectively).

CONCLUSION

Our study demonstrated that detethering surgery led to remarkably improved bowel and bladder control in ARM patients with fecal incontinence, which, surprisingly, was not associated with sacral ratio.

Association between filum terminale internum length and pain in Cavalier King Charles spaniels with and without syringomyelia

Background

Lumbar syringomyelia (SM), lumbosacral pain, and more caudal spinal cord termination are reported in Cavalier King Charles spaniels (CKCS). Data are lacking on the clinical relevance of alterations in their spinal cord terminal structures.

Objectives

To compare spinal cord termination level and filum terminale internum length (FTIL) with presence of lumbar SM and clinical signs in CKCS.

Animals

Forty‐eight CKCS.

Methods

In this prospective study, pain was quantified using owner and clinician assessments. Vertebral level of spinal cord and dural sac termination, presence of SM, and FTIL were determined from sagittal magnetic resonance imaging (MRI) sequences. Kappa and intraclass correlation (ICC) analyses determined interobserver reliability. The MRI findings were compared to owner and clinician‐reported pain quantification.

Results

Interobserver reliability was good for spinal cord and dural sac termination (kappa = 0.61 and 0.64, respectively) and excellent for FTIL (ICC: 92% agreement). The spinal cord terminated at 6th lumbar vertebra in 1, 7th lumbar vertebra in 31, and the sacrum in 15 dogs, and termination level was associated with lumbar SM (P = .002) but not clinical signs. Mean FTIL was 2.9 ± 1.08 mm; it was associated with owner‐reported pain (P = .033) and spinal palpation scores (P = .023). Painful CKCS without SM had shorter FTIL compared to normal CKCS and painful CKCS with SM (P = .02).

Conclusions

Painful CKCS without SM have decreased distance between the termination of the spinal cord and dural sac, suggesting a shorter FTIL. More caudal spinal cord termination is associated with development of lumbar SM.

A Simplified Approach to Myelomeningocele Defect Repair

BACKGROUND

Repair of the soft tissue defect in myelomeningoceles remains challenging. The literature currently lacks a systematic approach, reporting high rates of complications. We present outcomes from the largest series to date and describe a simplified approach that minimizes morbidity and streamlines decision making.

METHODS

Patients 1 year or younger who underwent myelomeningocele repair between 2008 and 2018 were reviewed. Flap types were categorized by tissue composition. Complications were dichotomized into early and late (<30 days and >30 days postoperative, respectively). Logistic regression was used to measure the impact of flap tissue composition and skin closure technique on odds of postoperative complications.

RESULTS

Ninety-seven patients met inclusion criteria. Reoperation was required in only 3 (3.0%) patients-1 for wound dehiscence and 2 for surgical site infections. Zero cases of tethered cord or cerebrospinal fluid leak occurred. The most common minor complications were early wound complications (n = 18, 18.6%) and early infection (n = 5, 5.2%). Fascia-only flaps and muscle + other tissue flaps were not associated with higher odds of complications compared with muscle-only flaps (odds ratio [OR], 2.13; 95% confidence interval [CI], 0.53-8.50, P = 0.29; OR = 2.87, 95% CI 0.66-12.51, P = 0.16, respectively). Rhomboid flaps for skin closure were associated with higher odds of complications (OR, 4.47; 95% CI, 1.00-19.97; P = 0.05).

CONCLUSIONS

Our approach to myelomeningocele repair demonstrated no cases of secondary tethered cord or cerebrospinal fluid leak, and reoperative rates were extremely low. Because complications were unrelated to flap type, we recommend a simplified approach using any tissue type for dural coverage and 2-layer primary closure of the skin.

Utility of CISS imaging in the management of tethered cord syndrome

OBJECTIVE

To compare the utility of constructive interference in steady-state (CISS) sequence over T2-weighted (T2W) sequence in the accurate delineation of the tethering element on magnetic resonance (MR) imaging in patients of tethered cord syndrome (TCS) and correlation with intraoperative findings.

METHODS

MR findings of fifty-six consecutive patients with operative findings of TCS were studied. The intraoperative findings of all patients were studied and compared with the preoperative imaging findings on T2W imaging and CISS images.

RESULTS

CISS images provided more information than T2W imaging. The overall sensitivity of CISS in MR evaluation of patients with TCS was higher (99.17%) as compared with the T2W sequence (71.48%) especially in the detection of precise position/extent of tethered cord, assessment of filum terminale thickening, detection of a fibrous spur in cases of split cord malformation, detection of dorsal dermal sinus, and evaluation of its precise extent and ramifications. The area under the ROC curve was higher with CISS (0.99) than with T2W sequence (0.85) which reflects its good predictive value as a screening test. This information was useful to the operating surgeon.

CONCLUSION

CISS sequence for imaging TCS can help enhance the overall surgical outcome of the patients ensuring completeness of the surgery. CISS should be routinely performed in the work-up of patients with tethered cord syndrome.

MRI characteristics of the fetal tethered spinal cord: a comparative study

Purpose: To compare fetuses and children with confirmed tethered cord syndrome to age-matched controls to provide a reference for prenatally identifying tethered spinal cord and to identify salient points on MRI for diagnosis.Materials and Methods: This retrospective study enrolled 13 fetuses and 20 children with tethered cord syndrome, and age-matched counterparts were included as controls. The MRI features including concomitant malformations, position of the conus medullaris, and thickened filum terminale of the two patient groups were evaluated and compared. Levels of the conus medullaris were discriminated between patients and an equivalent number of controls.Results: Various concomitant malformations manifested on the MRI of all patients, and there were differences between the two patient groups. Significant differences of the level of the conus medullaris were found between the fetal and child patients (U, 26.50; Z, -3.87; p < 0.001) and between the normal fetus and child controls (U, 23.50; Z, -4.13; p < 0.001). The position of the conus medullaris was visibly lower in the patient groups than in the control groups. No significant difference in the diameters of the filum terminale was found between the fetal and child patients (p = 0.67).Conclusions: The current study's results indicate that tethered spinal cord syndrome can be diagnosed in utero with MRI combined with several characteristics, particularly the position of the conus medullaris. Special attention should be paid to the gestational age of the fetus because normal changes in spinal cord position occur with gestational development.

Comparison of inherited neural tube defects in companion animals and livestock

Neural tube defects (NTDs) are congenital malformations resulting from the improper or incomplete closure of the neural tube during embryonic development. A number of similar malformations of the protective coverings surrounding the central nervous system are also often included under this umbrella term, which may not strictly fit this definition. A range of NTD phenotypes exist and have been reported in humans and a wide range of domestic and livestock species. In the veterinary literature, these include cases of anencephaly, encephalocele, dermoid sinus, spina bifida, and craniorachischisis. While environmental factors have a role, genetic predisposition may account for a significant part of the risk of NTDs in these animal cases. Studies of laboratory model species (fish, birds, amphibians, and rodents) have been instrumental in improving our understanding of the neurulation process. In mice, over 200 genes that may be involved in this process have been identified and variant phenotypes investigated. Like laboratory mouse models, domestic animals and livestock species display a wide range of NTD phenotypes. They remain, however, a largely underutilized population and could complement already established laboratory models. Here we review reports of NTDs in companion animals and livestock, and compare these to other animal species and human cases. We aim to highlight the potential of nonlaboratory animal models for mutation discovery as well as general insights into the mechanisms of neurulation and the development of NTDs.

Assessing the previously repaired patient with an anorectal malformation who is not doing well

In this review, the care of children with a previously repaired anorectal malformation is explored. We know that the surgical care of children with anorectal malformations is complex; however, despite an increased understanding of the congenital anomaly and significant technical advances in the operative repair, many of these children continue to have poor functional outcomes. In this article we focus on the common surgical complications, discuss typical presentations, consider appropriate investigations, and review the risks and benefits of revisional surgery in those patients that are 'not doing well' following their primary reconstruction.

Filum Terminale Lipoma with Herniated Intervertebral Disc Treated with Traditional Korean Medicine: A Case Report

Filum terminale lipoma is an inherited lumbosacral abnormality that can cause tethered cord syndrome. This report describes an unusual case of lumbago and sciatica, pain suspected to be caused by a filum terminale lipoma where a herniated intervertebral disc had occurred. The patient was hospitalized for 43 days and received integrative Korean medicine treatment, including acupuncture, pharmacopuncture, Chuna therapy, cupping therapy, physiotherapy and herbal medicine. Treatment effectiveness was assessed using the numerical rating scale, Oswestry Disability Index, European Quality of Life 5-Dimensions, and patient symptoms. After inpatient treatment, the pain the patient suffered was significantly reduced, and the evaluation indices scores reflected this. Integrative Korean remedies may be an effective option for lower back pain and lower extremity symptoms which are caused by filum terminale lipoma where a herniated intervertebral disc has occurred. Additional clinical research is required to support this observation.

Multidisciplinary Management of Tethered Spinal Cord Syndrome in Children: Operationalizing an Outpatient Patient-Centered Workflow

Introduction

Multidisciplinary care for patients with tethered spinal cord syndrome (TCS) is valuable in ensuring comprehensive evaluation, timely follow-up, optimal functional outcome, and patient-centered care. The family-centered focus aims to minimize patient and parental burdens associated with care coordination. We present our first-year institutional experience in operationalizing a multidisciplinary, patient-centered, pediatric tethered cord clinic (TCC) to manage routine, long-term surgical follow-up for children with non-myelomeningocele-related tethered spinal cords.

Methods

TCC is composed of three surgical services: orthopedic surgery, neurosurgery, urology. A retrospective chart review of patients seen in the TCC from January 2019 to January 2020 was conducted. Patients enrolled in the clinic were intended for long-term follow-up. Demographic and outcome variables were collected.

Results

Fifty-nine patients were seen in TCC. Types of tethered spinal cords amongst these patients were the following: fatty filum (62.7%), dermal sinus tract (15.2%), meningocele manqué (8.4%), lipomyelomeningocele (6.7%), low lying conus medullaris (5.1%), and sacral arachnoid cyst (1.7%). Age at diagnosis was 1.31 ± 2.21 (median: 0.25 years) and at follow-up was 9.0 ± 5.18 years (median: 8 years). A total of 50.9% of patients were female, and 93.2% had a prior untethering procedure. Of all patients, 6.8% have no surgical intervention and continue to be monitored conservatively for evidence of decline. All three services evaluated 84.8% of patients during the same clinic session, while 15.3% of patients were seen by two of the services, and 20.3% of patients were able to schedule related imaging or diagnostic testing during the same visit.

Conclusion

We describe successful implementation of a multidisciplinary pediatric TCC and document the first year of experience. The TCC streamlines care, decreases burden on families, and reduces those lost to follow-up. Complex disease pathologies, even when clinically stable, require long-term follow-up with multiple subspecialties and benefit from multidisciplinary clinics.

A Novel Case of Tethered Cord in a Five-Month-Old Male With Pallister-Killian Syndrome

A five-month-old male presented with an incidentally found low-lying conus medullaris on ultrasound and subsequent MRI demonstrating its position at L4. Pre-operative examination findings included mild, global hypotonia and a coccygeal dimple without bladder or bowel abnormalities or spasticity. The patient underwent spinal cord untethering with a section of filum terminale and was discharged without complication following his procedure. Follow-up at one year revealed continued baseline hypotonia without further neurosurgical needs. This is the first reported case of tethered cord syndrome described in a patient with Pallister-Killian syndrome managed successfully with neurosurgical intervention.

Anatomic factors predict urinary continence in patient with anorectal malformation

It has been described that patients with more complex anorectal malformations (ARM), lower sacral ratios and spinal anomalies have poorer rates of fecal and urinary continence. While the ARM subtype has been shown to be an independent predictor of fecal continence, it is not well understood how each of these anatomic factors impact urinary continence. The purpose of this study was to identify anatomic factors associated with urinary continence in children born with ARM. We performed a retrospective review of a large prospectively collected database of children with ARM. Inclusion criteria included diagnosis of ARM, age >4 years, available lateral sacral ratio measurement and presence of spinal MRI. Any child with incomplete or absent continence data was excluded. Continence was defined as voiding per urethra volitionally, dry between voids and ≤1 urinary accident per week. Bivariable tests of association and log-binomial regression models were used to examine association between anatomic factors and urinary continence. A total of 434 patients were included in the study. 57.8% (n = 251) were male. Median age was 8.4 years (IQR 6.0-12.3). With regards to severity of ARM, 20.3% (n = 88) were complex, 23.3% (n = 101) were moderate and 56.5% (n = 245) were simple. Lateral sacral ratio included 11.1% (n = 48) that were <0.4, 36.2% (n = 157) 0.4-0.7 and 52.8% (n = 229) > 0.7. Spine status was found to be myelomeningocele in 4.4% (n = 19), low conus or tethered cord in 34.8% (n = 151) and normal or fatty filum in 60.8% (n = 264). Overall 62.2% were continent. ARM severity, lateral sacral ratio and spine status were each independent predictors of urinary continence on univariate and multivariable analysis. We conclude that in children born with ARM, the severity of ARM, lateral sacral ratio and spine status each independently predict urinary continence. These results allow us to better understand these complex patients and their ability to develop urinary continence. This is crucial in enabling proper patient and family counseling and thus, setting appropriate expectations.

The incidence and effect of tethered cord release for tethered cord syndrome in patients with myelomeningocele: a population-based study

OBJECTIVE

The goal of this study was to establish an incidence and assess the effect of tethered cord release for tethered cord syndrome in patients with myelomeningocele.

METHODS

The study population was based on the Western Denmark Myelomeningocele Database, which contains all patients born with myelomeningocele in western Denmark since 1970. The study population was cross-referenced in 2015 with a database for surgical procedures containing all surgical procedures performed in the central Denmark region since 1996. Patients alive between 1996 and 2015 were identified. Incidences was calculated and presented for year of age. File reviews were conducted for all patients who underwent the procedure. Follow-up was divided into short-term and long-term follow-up.

RESULTS

One hundred sixty-six patients were alive during various time periods between 1996 and 2015. Of these, 45 patients underwent the procedure. Seven underwent reoperation. The median age for the procedure was 12 years and the highest incidence was found at 15 years of age. Incidence was bimodal with highest incidence in children and adolescents. The most common indications were progressive spine deformity (40%), deteriorating ambulation (38%), and deteriorating neurogenic bladder and/or bowel dysfunction (32%). The mean short-term follow-up was 4.7 months and the mean long-term follow-up was 72.6 months. Postoperatively, the majority had improved (27%) or stabilized (27%) at short-term follow-up. At long-term follow-up, most patients were stable (27%) or had deteriorated (24%). For both follow-up terms there was a loss of approximately one-third of all patients. Complications occurred in 17% of the procedures.

CONCLUSIONS

In this population-based study, tethered cord release has the highest incidence in children and adolescents. The beneficial effect of the procedure seems to be short term. Due to the uncertainty of a long-term effect of the procedure in patients with myelomeningocele and the registered complications, the authors suggest that this surgical indication should be reserved for well-selected patients.

Secondary tethered cord syndrome in adult patients: retethering rates, long-term clinical outcome, and the effect of intraoperative neuromonitoring

BACKGROUND

The strategy for surgical treatment of tethered cord syndrome in pediatric patients is well established but still bares challenges for adult patients. This retrospective study was performed to assess the surgical outcome of adult patients with a secondary tethered cord syndrome and to evaluate the benefit of intraoperative neuromonitoring.

METHODS

Clinical charts of 32 consecutive adult patients who underwent in total 38 surgical untethering procedures at our facility between 2008 and 2018 were retrospectively analyzed. Epidemiological data, MRI scans, and postoperative results were evaluated.

RESULTS

The retethering rate in our patient cohort was 16%. Main complaints were maximal pain (82%), bladder dysfunction (79%), paresthesia (68%), and weakness in the lower extremities (68%). Forty-eight months after surgery, patients' symptoms generally improved, with an average level of pain of 19.1% (95% CI, 5.7-32.5%), paresthesia 28.7% (95% CI, 12.6-44.8%), weakness in the lower extremities 27.7% (95% CI, 11.1-44.4%), and bladder dysfunction 60.2% (95% CI, 41.6-78.7%). The use of neuromonitoring appears to have a positive impact on patient weakness (OR = 0.07; 95% CI, 0.01-0.68) and paresthesia (OR = 0.03; 95% CI, 0.00-2.18). This benefit is less clear for the retethering rate (OR = 0.45; 95% CI, 0.06-3.26) or the overall clinical outcome (OR = 0.70; 95% CI, 0.14-3.45). The presence of a preoperative Chiari syndrome, syringomyelia, or scoliosis had no relevant influence on the retethering rate.

CONCLUSIONS

Our data confirms that untethering surgery in adult patients is relatively safe and has a reasonable chance of clinical improvement of pain, paresthesia, and weakness in the lower extremities. The use of intraoperative monitoring has a positive influence on the improvement of preoperative paralysis.

Surgical volume of simple tethered spinal cord releases: review of a large pediatric neurosurgical service experience

OBJECTIVE

The aim of this study was to retrospectively review, from a single busy pediatric neurosurgical service, a consecutive series of patients who had undergone surgery for a simple tethered spinal cord, which was defined by a thickened or fatty filum terminale with a normal conus. The hope was to contribute to benchmark data regarding the expected frequency of surgery for this condition.

METHODS

The authors reviewed the electronic medical records of every patient with diagnosed simple tethered spinal cord, defined on spinal MRI as a thickened (> 2 mm in diameter) or fatty filum terminale, and who had undergone primary filum section at Boston Children's Hospital between 2005 and 2011.

RESULTS

A total of 208 patients met the study inclusion criteria. At the time of surgery, patients ranged in age from 0.4 to 19.8 years. One hundred forty-four (69%) patients were symptomatic with one or more of the following: bowel/bladder dysfunction, 94 (45%); neurological dysfunction, 49 (24%); scoliosis, 44 (21%); or back pain, 44 (21%). Sixty-four (31%) patients were asymptomatic and were operated on prophylactically when filum pathology was discovered during the course of a workup for clinical syndromes such as anorectal anomalies and/or suspicious cutaneous lesions. No patients in this series were operated on if they had normal MRI studies, defined as a conus tip no lower than L3 and no distal tethering lesion visualized. Over the study period, approximately 1000 major surgical cases were performed in the department every year, only 30 of which were simple detethering procedures, representing well under 5% of the service's operative volume and approximately 5 cases per surgeon per year. Clinical follow-up, available at a postoperative interval of 6.6 ± 3.8 years, demonstrated that approximately 80% of patients symptomatic with bowel or bladder involvement or neurological dysfunction had improvement or relief of their symptoms and that none of the patients treated prophylactically experienced new-onset symptoms that could be related to spinal tethering.

CONCLUSIONS

Simple detethering procedures were relatively uncommon in an active, well-established pediatric neurosurgical service and represented less than 5% of the service's total case volume per year with an average of 5 cases per surgeon per year. No patients with normal MRI studies were operated on during the study period.

Retethering after transection of a tight filum terminale, postoperative MRI may help to identify patients at risk

PURPOSE

Retethering after transection of a tight filum terminale (TFT) deemed to be a rare and usually only years after initial surgery occurring complication. Possible perioperative factors that might influence the retethering rate or help to allow a prognostic risk assessment are still poorly investigated. The aim of this study was to analyze our patient cohort who underwent a TFT transection by assessing clinical outcome, retethering rate, and pre- and postoperative MRI studies.

METHODS

All consecutive patients undergoing transection of a TFT from January 2011 to December 2018 were evaluated. Inclusion criteria were defined as exclusive TFT intervention and a minimum follow up period of 1 year. Epidemiological data, treatment modalities, complication characteristics, and MRI studies were recorded and analyzed.

RESULTS

A total of 58 patients met our inclusion criteria. The retethering rate in our patient cohort was 5.2% (3/58); one of the three patients developed two episodes of a retethering. Patients with an unchanged conus level, no improvement in the syringomyelia, and an unchanged thickness of the spinal cord postoperatively seem to have a significant higher risk to develop a retethering episode in the follow-up.

CONCLUSION

Retethering after transection of the filum terminale did occur more often than expected. Certain existing factors on the routine postoperative MR images may help to identify patients with an increased likelihood to develop a retethering episode. These results may contribute to improve the follow-up for patients after transection of a TFT and may facilitate adequate treatment.