Treatment of the Occult Tethered Spinal Cord for Neuropathic Bladder: Results of Sectioning the Filum Terminale

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.

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.

Comparison of the electrophysiological characteristics of tight filum terminale and tethered cord syndrome

PURPOSE

This study aims to characterize tight filum terminale (TFT) in motor evoked potential (MEP) testing by comparing TFT patients with both tethered cord syndrome (TCS) patients and healthy subjects.

METHODS

Fifty TFT patients, 18 TCS patients, and 35 healthy volunteers participated in this study. We recorded MEPs following transcranial magnetic stimulation from the bilateral abductor hallucis muscles as well as compound muscle action potentials and F-waves evoked by electrical stimulation of the tibial nerve from the bilateral abductor pollicis brevis muscles. The peripheral conduction time (PCT) was calculated from the latency of the compound action potential and F-wave. Furthermore, the central motor conduction time (CMCT) was calculated by subtracting PCT from MEP latency.

RESULTS

TFT and TCS patients had a significantly longer MEP latency than healthy subjects. PCT in TFT patients was significantly longer than those in TCS patients or healthy subjects. Using the cutoff values for PCT, we were able to diagnose patients with TFT patients with a sensitivity of 72.0% and a specificity of 91.4%.

CONCLUSION

Prolonged PCT in the MEP test may be a useful indicator for TFT and suggests that MEP may be used as an adjunct diagnostic tool for TFT.

A systematic review and meta-analysis of minimally invasive surgery in children with occult tethered cord syndrome

BACKGROUND

At present, the surgical treatment of occult tethered cord syndrome (OTCS) in children is mostly two types of minimally invasive surgery: filum terminalis laxity or filum terminalectomy. The clinical efficacy and safety of minimally invasive treatment and conservative treatment are still unclear. Therefore, this study will use the advantages of systematic review and meta-analysis to evaluate the objectivity, and explore the effect of minimally invasive surgery on children with occult tethered cord syndrome.

METHODS

A computer search was used to search PubMed, Embase, CNKI, Wanfang Database and other literature search websites about the randomized controlled trials (RCTs) of minimally invasive surgery in children with occult tethered cord syndrome and spinal lipoma. Professional journals were manually searched to avoid omissions. The search keywords were: occult myelolipoma, occult tethered cord syndrome, surgical treatment of tethered cord syndrome, occult tethered cord syndrome.

RESULTS

A total of 6 relevant literatures that could be used for meta-analysis were selected. A total of 425 subjects were included in the article, of which 132 were treated conservatively and 293 were treated surgically. The heterogeneity detection test statistics of the included studies were Chi² (Chi-squared test) =8.18, df (degree of freedom) =5, I²=39%<50%, Z=2.53, and the homogeneity of the included studies was good. The number of unimproved cases under conservative treatment was 40, accounting for 30.30%; the number of unimproved cases under surgical treatment was 33, accounting for 11.26%, and the total unimproved rate of the two groups accounted for 17.17%. The unimproved rate of the experimental group was significantly lower than that of the control group, and the difference was statistically significant (P=0.01). The results of bias analysis showed that there was no significant bias in the literature included in this study.

DISCUSSION

Meta-analysis results confirmed that minimally invasive surgery has a significant effect on the treatment of occult children with tethered cord syndrome. However, due to the small sample size of the included literature, further evaluation of the treatment risk is required.

Preoperative Videourodynamic Study Is Helpful in Predicting Long-term Postoperative Voiding Function in Asymptomatic Patients With Closed Spinal Dysraphism

Purpose

Controversy exists regarding the role preoperative urodynamic study for asymptomatic closed spinal dysraphism as it has failed to reveal the benefit in surgical decision and expectation of urological outcomes. We explore the relationship between preoperative videourodynamic study and postoperative urological outcomes after toilet training completed, focusing on their capability of spontaneous voiding.

Methods

We retrospectively reviewed the data of 181 patients who underwent preventive spinal cord untethering and followed at least till the completion of toilet training. Before untethering, patients underwent preoperative videourodynamic study. Postoperative voiding function was evaluated in 3 phases: (1) till postoperative 6 months, (2) till the completion of toilet training, and (3) 2 years after toilet training. Changing distribution of emptying pattern at each period was described. Also, relevance to preoperative urodynamic parameters on spontaneous voiding and urinary continence after toilet training was assessed.

Results

Spinal lipoma and low lying conus were found in 145 (80%) and 128 patients (70.7%), respectively. Spontaneous voiding was found in 125 (69.1%), 164 (90.6%), and 162 patients (89.5%) at postoperative 6 months, till the toilet training, and 2 years after toilet training, respectively. Videourodynamics helped to clarify the presence of vesicourethral synergy. This was correlated with spontaneous voiding at postoperative 6 months and better urinary continence after 2 years of toilet training.

Conclusions

Eventual spontaneous voiding was achieved till toilet training in 90% patients following preventive untethering. Those showing preoperative vesicourethral synergy was associated with faster achievement of spontaneous voiding and better urinary continence when they enter elementary school.

Sacral nerve stimulator success after filum section for refractory dysfunctional voiding

INTRODUCTION

Filum section (FS) has been used to treat tethered cord syndrome (on MRI or occult) in pediatric patients with refractory dysfunctional voiding (DV). While controversial, some groups have previously reported significant improvement in patients' symptoms after FS, even in the presence of a normal preoperative spinal MRI. Until recently, it was our practice to refer patients with DV to pediatric neurosurgery for evaluation, MRI, and possible FS.

OBJECTIVES

We report our experience with sacral nerve stimulator (SNS) placement for pediatric patients with refractory DV after failed FS with the primary outcome being complications and explantations. The secondary outcome being change in quality of life.

STUDY DESIGN

We retrospectively reviewed all consecutive patients <18 years old who underwent second stage SNS placement after FS at our institution between November 2012 and December 2019. We abstracted rate of 2nd stage implantation, complication, and explantation. We also collected age-appropriate preoperative and postoperative 15-question quality of life questionnaires (PedsQL™). The PedsQL scores ranged 0-100, higher numbers correlating with higher quality of life. A paired t-test was used for statistical analysis.

RESULTS

Overall, 23 children proceeded to the second stage SNS due to persistent symptoms following FS. Median age at SNS implantation was 10.3 years (IQR 7.5-11.8 years), and 13 were female (56.5%). There were no intraoperative complications. Median follow-up was 2.8 years (IQR 1.1-3.7 years). One patient had the SNS removed due to a need for MRI, one for resolution of symptoms, and 4 patients underwent lead revision for lead fracture and return of symptoms (17.4%). All 15 patients who completed both preoperative and postoperative PedsQL reported significantly improved overall scores after SNS (Figure). Median scores improved from 61.7 to 86.7 (p < 0.0001).

DISCUSSION

Symptom relief in the child with refractory DV using SNS is not new. However, we sought to review our results in those with previous FS for tethered cord syndrome. While our study is limited by its small size, we assessed both surgical and patient-reported outcomes. Our patients' marked improvement in quality of life is similar to that of other reported pediatric SNS cohorts.

CONCLUSION

SNS placement after FS is feasible, safe, and can result in significant improvement in overall quality of life. Given these findings, we have changed our practice to offer SNS in patients with refractory DV with a normal lumbosacral spinal MRI. For those with MRI abnormalities, we seek neurosurgical evaluation for FS (if deemed necessary) prior to considering SNS.

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.

A critical analysis of surgery for occult tethered cord syndrome

INTRODUCTION

Tethered cord syndrome (TCS) is an amalgamation of neurological, urological, orthopedic, and dermatologic signs and symptoms with radiographic evidence of a thickened filum and low-lying conus. Surgical sectioning of the filum and disconnection of any tethering entities such as dermal sinus tracts or lipomas has been shown to improve outcomes. The manifestation of TCS symptoms in the absence of a low-lying conus has been referred to as occult tethered cord syndrome (OTCS) and is much less well reviewed in the literature. To date, there has only been one randomized controlled trial examining the effect of intervention in OTCS; therefore, contemporary data is often elicited from limited cohorts.

OBJECTIVE

To perform a comprehensive literature review of management in OTCS and evaluate treatment response rates to sectioning of the filum terminale.

RESULTS

Seventeen papers met inclusion criteria for our review. Sample sizes ranged from 8 to 60 children, and results were mixed, often dependent on study design, definition of typical OTCS symptoms, and follow-up intervals. Symptomatic improvement was observed in > 50% of patients for all but one study; however, the recurrence rates were highly variable.

CONCLUSION

The data regarding the efficacy of surgical treatment in OTCS is mixed and merits more rigorous scientific examination with strict and clear parameters regarding symptomatic operationalization and follow-up time points to monitor for TCS recurrence.

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.

Features of the Filum Terminale in Tethered Cord Syndrome with Focus on Pathology

Objective

Filum transection is one of the most commonly performed operative procedure in pediatric neurosurgery. However, the clinical and pathological features as well as the surgical indication are not well-established. This study aimed to analyze the characteristics of patients who underwent transection of the filum during the last 10 years in a single institute.

Methods

A total of 82 patients underwent transection of the filum during the period. As a general rule, we performed the transection in patients who are symptomatic or have abnormality in the urologic or neuromuscular evaluations. There were exceptions as asymptomatic patients who only fit the definition of thickened filum (width greater than 2.0 mm or conus level below L3 vertebral body) were operated by parent’s wish or surgeon’s preference according to radiological findings, etc.

Results

Seventy-six out of 82 patients had fibrous tissue in the pathologic specimen of filum. Interestingly, patients who had glial cells were more correlated with no preoperative syrinx, and no progression of syrinx even for those who did have syrinx initially. Also, larger percentage of symptomatic patients had peripheral nerve twigs than asymptomatic patients. No difference in conus level or thickness of filum was found between patients with or without preoperative syrinx. Significantly more patients with syrinx (56%) were chosen to be operated without any symptom or abnormality in study i.e., solely based on radiological findings than those without syrinx (21%). The surgical outcome for syrinx was favorable, as all but one patient had either improved or static syrinx. The exceptional case had increase in size due to the upward displacement of the proximal end of the cut filum.

Conclusion

This study evaluated the pathological, clinical, radiological features of patients who underwent transection of the filum. Interesting correlations between pathological findings and clinical features were found. Excellent outcome regarding preoperative syrinx was also shown.

Pediatric tethered cord release: an epidemiological and postoperative complication analysis

Background

Tethered cord release (TCR) is a common procedure in pediatric neurosurgery. Despite a reputation for being relatively safe, the risk factors for postoperative complications are poorly understood.

Methods

In this study, the American College of Surgeons-National Surgical Quality Improvement Program Pediatric Database (ACS-NSQIP-P) was reviewed to identify the demographics, risk factors, and 30-day postoperative complications for tethered cord release using univariate and multivariate analysis. A detailed analysis of reasons for readmission and reoperation was also performed.

Results

Three thousand and six hundred eighty-two pediatric patients were studied. Males undergoing TCR were younger (5.6 vs. 6.1 years) and had a higher rate of pre-operative comorbidities but lower 30-day complication rate versus females. Patients who later developed complications were more likely to require a microscope intraoperatively, had longer operative times, and worse preoperative American Society of Anesthesiologists (ASA) class.

Conclusions

Despite being a relatively safe procedure, TCR in the pediatric population carries a finite risk of complications. In this large, international database study, males were found to have a greater number of risk factors prior to TCR, while females exhibit a higher risk of developing postoperative complications. This paper provides a large sample size of multi institutional pediatric patients undergoing TCR and may serve as a contemporary "snapshot" for future studies.

A review of the disagreements in the prevalence and treatment of the tethered cord syndromes with chiari-1 malformations

Background

The tethered cord syndrome (TCS) accompanying Chiari-1 (CM-1) malformations and the occult tethered cord syndrome (OTCS) syndrome accompanying the low lying cerebellar tonsil (LLCT) syndrome may be treated with sectioning of the filum terminale (SFT).

Methods

Utilizing PubMed, we reviewed the neurosurgical literature to determine how frequently spinal neurosurgeons diagnosed the TCS (e.g., conus terminating below the normal L1-L2 disc level) on lumbar magnetic resonance (MR) studies in patients with CM-1 malformations [e.g. tonsils >5-12 mm below the foramen magnum (FM) warranting SFT]. In addition, we assessed how frequently spinal neurosurgeons encountered the OTCS (e.g., conus normally located at L1-L2 on MR) accompanying the LLCT (e.g., tonsils herniated <5 mm below the FM) also requiring SFT.

Results

According to the neurosurgical literature, the incidence of TCS accompanying CM-1 requiring SFT ranged from 2.2% to < 6%, and up to 14%. Few studies additionally highly correlated the OCTS accompanying the LLCT syndrome warranting SFT.

Conclusions

Given the differences in the literature, more studies are needed to assess the risks (complications) vs. benefits (improved neurological outcomes) of SFT surgery for TCS with CM-1 and SFT for OCTS with LLCT.

Impact of magnetic resonance imaging and urodynamic studies on the management of sacrococcygeal dimples

OBJECTIVE Sacrococcygeal dimples in neonates and infants are of uncertain pathological import. Previously they were believed to be rarely associated with intraspinal anomalies. Recent studies using MRI, however, revealed that 6%-7% of pediatric cases of sacrococcygeal dimples were associated with anatomical tethered spinal cord (TSC). Because the prevalence of tethered cord syndrome is still unclear, there is no consensus among pediatric neurosurgeons on the management of children with sacrococcygeal dimples. The authors performed an analysis of MRI and urodynamic studies to validate their management strategy for pediatric cases of sacrococcygeal dimples. METHODS A total of 103 Japanese children (49 male and 54 female, median age 4 months, range 8 days-83 months) with sacrococcygeal dimples who were referred to the Division of Pediatric Neurosurgery between 2013 and 2015 were included in this study. The lumbosacral region of all the patients was investigated using MRI. Anatomical TSC was defined as a condition in which the caudal end of the conus medullaris is lower than the inferior border of the L2-3 intervertebral disc. Patients with minor spinal anomalies (e.g., anatomical TSC, filum lipoma, thickened filum, or filar cyst) underwent further urodynamic studies to ascertain the presence of neurogenic bladder (NGB). In this study, the presence of NGB without anatomical TSC but with other minor spinal anomalies was defined as "functional TSC." The prevalence of anatomical and functional TSC was investigated. The association of the following cutaneous findings with spinal anomalies was also assessed: 1) depth of the dimple, 2) deviation of the gluteal fold, and 3) other skin abnormalities (e.g., discoloration, angioma, or abnormal hair). RESULTS The children were classified into 4 groups: Group 1, patients with anatomical TSC; Group 2, patients with functional TSC; Group 3, patients without anatomical or functional TSC but with other minor spinal anomalies; and Group 4, patients with no spinal anomaly. There were 6 patients (5.8%) in Group 1, 8 patients (7.8%) in Group 2, 10 patients (9.7%) in Group 3, and 79 patients (76.7%) in Group 4. Twenty-four patients (23.3%; Groups 1, 2, and 3) showed MRI abnormalities, including filum lipoma (14 cases), filar cysts (5 cases), thickened filum (2 cases), and anatomical TSC without other spinal anomalies (3 cases). Untethering of the spinal cord was indicated for 14 patients (13.6%; Groups 1 and 2) with anatomical and functional TSCs. Preoperative NGB was found in 12 patients and improved postoperatively in 7 (58.3%). None of the associated lumbosacral skin findings predicted the presence of underlying spinal anomalies. CONCLUSIONS The prevalence of tethered cord syndrome among children with sacrococcygeal dimples was, for the first time, revealed to be higher than previously thought. MRI and supplemental urodynamic studies may be indicated for children with sacrococcygeal dimples to identify patients with symptomatic TSC.

Evaluation and management of tethered cord syndrome in occult spinal dysraphism: Recommendations from the international children's continence society

AIMS

As awareness and frequency of tethered spinal cord (TSC) related to occult spinal dysraphism (OSD) has increased with magnetic resonance imaging (MRI), variability exists in its evaluation and management. Due to no published level I data, we summarize the current International Children's Continence Society (ICCS) recommendations for diagnosis and treatment of OSD.

METHODS

Guidelines were formulated based on analysis of pertinent literature and consensus among authors. This document was vetted by the multidisciplinary members of the ICCS via its website before submission for peer review publication.

RESULTS

The more frequent diagnosis of OSD is associated with increased operative intervention. Spinal cord untethering (SCU) has a highly variable risk profile, largely dependent on the specific form of OSD. Progressive neurological deterioration attributed to "tethered cord" may occur, with or without surgery, in selected forms of OSD whereas other cohorts do well.

CONCLUSION

Infants with classic cutaneous markers of OSD, with progressive neurologic, skeletal, and/or urologic findings, present no diagnostic or therapeutic dilemma: they routinely undergo MRI and SCU. Conversely, in asymptomatic patients or those with fixed, minor abnormalities, the risk profile of these OSD cohorts should be carefully considered before SCU is performed. Irrespective of whether or not SCU is performed, patients at risk for progression should be followed carefully throughout childhood and adolescence by a multidisciplinary team.

Histopathology of the filum terminale in children with and without tethered cord syndrome with attention to the elastic tissue within the filum

PURPOSE

To compare histologically transected fila from pediatric patients with tethered cord syndrome (TCS), with and without a low conus, with controls, focusing on collagenous and elastic tissue.

METHODS

Thirty fila from patients with TCS, including 5 where minimal cautery was used prior to filum section, were compared with fila from 27 pediatric cadavers without TCS (controls). Sections of fila were stained with H&E, Masson trichrome and Verhoeff von Gieson elastic stains, and 7 with Gordon and Sweet's reticulin stain.

RESULTS

Fila from controls showed loose fibrous connective tissue (FCT) with thin and evenly dispersed elastic fibers (EFs). Reticulin fibers (RFs) were seen in blood vessel walls and nerve twigs. Fat was identified microscopically in 2 fila. All fila from patients with TCS had dense FCT. The EFs were in normal numbers in 17, and focally or diffusely decreased in 13. All 25 patients where the fila were cauterized during resection had thick and coiled EFs. Coiling was not seen when minimal cautery was applied. RFs were seen in blood vessel walls and nerve twigs. Fat was identified in 19 patients. Findings were similar, whether the conus termination was normal or low.

CONCLUSION

The fila of all patients with TCS, whether or not the conus was low, showed abnormal FCT. EFs were decreased in 48 % of patients; however, there were thick and coiled EFs in all patients. Coiling of EFs, initially thought to be an abnormality in patients, is considered most likely to be a result of cautery (i.e., artifactual/iatrogenic coiling).

The natural history and management of patients with congenital deficits associated with lumbosacral lipomas

INTRODUCTION

Many patients with lumbosacral lipoma are asymptomatic; however, a significant proportion will have neurological deficits present at birth. Implication of these deficits with respect to natural history and management are not well understood.

METHODS

A retrospective review of all infants with lumbosacral lipoma seen at BCCH between 1997 and 2013 was carried out. The study population was stratified on the presence of a congenital, non-progressive deficit and subdivided on treatment approach. The subsequent developments of deficits resulting in untethering procedures were recorded.

RESULTS

Of the 44 infants in this study, 24 patients had no neurologic deficit while 20 patients had a fixed, non-progressive deficit evident at birth. Ten of 24 patients without a neurological deficit at birth underwent a prophylactic untethering with 3 eventually requiring repeat untethering after, on average, 62.7 months. Eleven of 14 asymptomatic, monitored patients required untethering for clinical deterioration. Two required a second untethering procedure after 48.7 months. Ten of 20 infants with congenital deficits present at birth underwent prophylactic untethering, and 4 required further surgery after 124 months. Ten patients underwent observation with 8 eventually requiring surgery. Two required repeat untethered after 154 months. The complication rates and operative burden for patients are similar whether prophylactic or delayed surgery is performed.

CONCLUSION

The presence of congenital neurologic deficit does not affect the likelihood of deterioration in patients managed expectantly; prophylactic detethering of these patients did not prevent delayed neurologic deterioration. Comparing the need for repeat surgery in prophylactically untethered patients with initial untethering of patients operated upon at the time of deterioration, prophylactic untethering may confer a benefit with respect to subsequent symptomatic tethering if complication rates are low. However, in a setting with multidisciplinary follow-up, a period of observation for patients and intervention when patients become symptomatic is an acceptable approach for patients with or without congenital deficits.

Filum Section for Urinary Incontinence in Children with Occult Tethered Cord Syndrome: A Randomized, Controlled Pilot Study

PURPOSE

Occult tethered cord syndrome, in which there is normal neuroanatomic imaging despite clinical and urodynamic evidence of neuropathic bladder behavior, is controversial. Several uncontrolled series describe improvement in bladder function following section of the filum terminale. We performed a pilot randomized, controlled study comparing medical treatment to surgical section of the filum plus medical treatment in children with occult tethered cord syndrome.

MATERIALS AND METHODS

Children refractory to standard medical management for 1 year or more with normal conus position on magnetic resonance imaging and abnormal urodynamics were randomized. Exclusion criteria included any neurological conditions, spinal dysraphism, bladder outlet obstruction and an atonic bladder. Patients were assessed at randomization and 1 year later with a standardized urodynamic score, the validated PEMQOL (Pediatric Enuresis Module on Quality of Life™) scale, and a validated bowel and bladder dysfunction score.

RESULTS

After 8 years we accrued 21 patients. The bowel and bladder dysfunction score improved in the surgical and medical arms (20% and 24%) and the urodynamic score improved slightly (6% and 4%, respectively). The PEMQOL Child and Family Impact Scales improved modestly in both groups. All differences were nonsignificant. Interim analysis indicated that more than 700 patients in each arm would be required to demonstrate a statistical difference with respect to urodynamic score based on our preliminary data.

CONCLUSIONS

There appears to be no objective difference in urological outcome between medical management plus or minus filum section for patients with occult tethered cord syndrome. These data challenge the existence of the concept of occult tethered cord syndrome, in which bowel and bladder dysfunction score is attributed to tethering by the filum despite a normally located conus.

Incidental findings on brain and spine imaging in children

In recent years, the utilization of diagnostic imaging of the brain and spine in children has increased dramatically, leading to a corresponding increase in the detection of incidental findings of the central nervous system. Patients with unexpected findings on imaging are often referred for subspecialty evaluation. Even with rational use of diagnostic imaging and subspecialty consultation, the diagnostic process will always generate unexpected findings that must be explained and managed. Familiarity with the most common findings that are discovered incidentally on diagnostic imaging of the brain and spine will assist the pediatrician in providing counseling to families and in making recommendations in conjunction with a neurosurgeon, when needed, regarding additional treatments and prognosis.

Utility of urodynamics in the management of asymptomatic tethered cord in children

BACKGROUND

We have noted a recent increase in neurosurgical requests at our institution for urodynamics (UDS) prior to release of asymptomatic tethered cord. Our aim was to determine how preoperative UDS results are used in the clinical management of asymptomatic tethered cord.

METHODS

A retrospective review was performed of 120 patients diagnosed with primary tethered cord from 2007 to 2010. Inclusion criteria included MRI diagnosis of tethered cord and UDS performed by three pediatric urologists. Excluded were any neurologic or urologic dysfunction or associated syndromes, as well as other significant comorbidities.

RESULTS

Thirty-eight patients (female 26; male 12), mean age of 3 years (0.2-16.3) were diagnosed with an asymptomatic tethered cord. The majority of the patients had normal preoperative renal ultrasounds. Thirty-one (82 %) of the children had normal baseline UDS, yet twenty-one (68 %) of these patients still underwent neurosurgical intervention. Of the 27 patients untethered, 15 patients (55 %) had follow-up UDS performed. Three patients had improved UDS parameters and one had worsening UDS parameters, including high PVR and DSD. Of the seven patients with abnormal baseline UDS, all had normal renal ultrasound findings and had no other significant differences in presentation from the patients with normal UDS.

CONCLUSION

In children with asymptomatic tethered cord, abnormal preoperative UDS may prompt intervention, while normal UDS do not appear to prevent intervention. There is no significant correlation between abnormal preoperative UDS and abnormal preoperative imaging. Further study is needed to evaluate the utility of this procedure in the preoperative setting in this asymptomatic patient population.

Early identification of tethered cord syndrome: a clinical challenge

Tethered cord syndrome (TCS) is a progressive clinical condition that arises from excessive spinal cord tension. The clinical signs and symptoms of TCS may be cutaneous, neurologic, musculoskeletal, genitourinary, and/or gastrointestinal. Patients also may be asymptomatic, which does not exclude the diagnosis of TCS. Although the exact etiology is unknown, early identification and lifelong surveillance or surgical treatment is an essential component of patient management. In this article we review the pathophysiology, various etiologies, clinical presentation, and long-term sequelae of TCS. This information will help pediatric nurse practitioners identify TCS early and anticipate the patient's needs and management requirements.

Filum terminale lipomas: imaging prevalence, natural history, and conus position

OBJECT

Filum terminale lipomas (FTLs) are being identified with increasing frequency due to the increasing utilization of MRI. Although an FTL may be associated with tethered cord syndrome (TCS), in many cases FTLs are diagnosed incidentally in patients without any symptoms of TCS. The natural history of FTLs is not well defined.

METHODS

The authors searched the clinical and imaging records at a single institution over a 14-year interval to identify patients with FTLs. For patients with an FTL, the clinical records were reviewed for indication for imaging, presenting symptoms, perceived need for surgery, and clinical outcome. A natural history analysis was performed using all patients with more than 6 months of clinical follow-up.

RESULTS

A total of 436 patients with FTL were identified. There were 217 males and 219 females. Of these patients, 282 (65%) were adults and 154 (35%) were children. Symptoms of TCS were present in 22 patients (5%). Fifty-two patients underwent surgery for FTL (12%). Sixty-four patients (15%) had a low-lying conus and 21 (5%) had a syrinx. The natural history analysis included 249 patients with a mean follow-up time of 3.5 years. In the follow-up period, only 1 patient developed new symptoms.

CONCLUSIONS

Filum terminale lipomas are a common incidental finding on spinal MRI, and most patients present without associated symptoms. The untreated natural history is generally benign for asymptomatic patients.

Clinical significance of imaging and histological characteristics of filum terminale in tethered cord syndrome

OBJECT

The pathophysiology of tethered cord syndrome (TCS) is uncertain; however, it has been suggested that fibrous and fatty elements within the filum terminale (FT) play a role. The objective of this study was to describe the radiological and histological features of the FT in TCS and determine if there are associations between those features and clinical outcomes, complications, and urodynamics.

METHODS

In this retrospective study, histological, MRI, and clinical data obtained in 293 patients with TCS who underwent FT transection were reviewed and analyzed in a multivariate analysis.

RESULTS

The median patient age was 4.9 years (range 0.3-64.3 years). On MRI, a fatty filum was present in 65% of patients and a thickened filum (> 2 mm) was seen in 45%. Histologically, the FT contained prominent fibrous tissue in 95%, nerve twigs in 79%, adipose tissue in 59%, and vascular tissue in 36%. Histological features associated with a thickened filum on MR images were adipose tissue (OR 3.5, p < 0.001), nerve twigs (OR 2.2, p = 0.028), and vascular tissue (OR 0.5, p = 0.025). Adipose tissue was associated with a conus level below the L2-3 disc space (OR 2.3, p = 0.031) and with a fatty filum on imaging (OR 9.8, p < 0.001). Nerve twigs were associated with abnormal urodynamics (OR 10.9, p = 0.049). The only variable predictive of clinical improvement was conus level; patients with conus levels caudal to L-2 were less likely to improve postoperatively (OR 0.3, p = 0.042).

CONCLUSIONS

Fibrous tissue was ubiquitous and may be important in the pathophysiology of TCS. Nerve twigs and adipose tissue were associated with abnormal urodynamics and low-lying coni, respectively. Although the majority of patients clinically improved, patients with normal conus levels had significantly better outcomes.

Occult tethered cord syndrome: a review

BACKGROUND

Tethered cord syndrome is a well-defined condition, the management of which is fairly uniform. In contrast, occult tethered cord syndrome is a recently defined entity, where the management is still controversial. The pathophysiology is unclear and may be conceptually incongruent with current understanding of typical tethered cord syndrome. Presentation, investigation, and management of this condition are reviewed, and current understanding is presented.

PURPOSE

The aim of this study is to review the presentation, pathophysiology, investigation, and management of occult tethered cord syndrome.

METHODS

Literature review.

RESULTS

Patients with occult tethered cord syndrome presents predominantly with urologic symptoms. Adult and pediatric patients vary slightly in their presentation with a higher incidence of pain in the former and incontinence in the latter. Operative management for these patients is associated with consistent improvement in urologic function in particular, although surgery is also associated with risk of worsening symptoms. The natural history of untreated patients is unknown.

CONCLUSIONS

As occult tethered cord syndrome becomes increasingly recognized, it is important to be aware of the potential benefits of operative intervention for appropriately selected patients. Given that the natural history of this entity remains unknown, a clinical trial is currently underway that may assist in defining the role for operative management in treating this condition.

Management of urological dysfunction in pediatric patients with spinal dysraphism: review of the literature

An intact, fully functional spine is the result of a complex sequence of embryological events involving both nervous and musculoskeletal system precursors. Deviations from this highly ordered system can result in congenital abnormalities ranging from clinically insignificant cosmetic changes to CNS malformations that are incompatible with life. Closure of the neural tube, which is believed to be the embryological event gone awry in these cases, is complete by just 28 days' gestation, often before pregnancy is detected. Although progress has been made to help prevent neural tube defects in the children of those attempting to conceive, these congenital deformities unfortunately continue to affect a startling number of infants worldwide each year. Furthermore, the precise mechanisms governing closure of the neural tube and how they might be interrupted remain elusive. What is known is that there are a large number of individuals who must deal with congenital spine dysraphism and the clinical sequelae on a daily basis. Bladder and urinary dysfunction are frequently encountered, and urological care is a critical, often neglected, component in the lifelong multidisciplinary approach to treatment. Although many treatment strategies have been devised, a need remains for evidence-based interventions, analysis of quality of life, and preemptive education of both caregivers and patients as they grow older. Pediatric neurosurgeons in particular have the unique opportunity to address these issues, often in the first few days of life and throughout pre- and postoperative evaluation. With proper management instituted at birth, many patients could potentially delay or avoid the potential urological complications resulting from congenital neurogenic bladder.

Radiographic and clinical outcome of syringomyelia in patients treated for tethered cord syndrome without other significant imaging abnormalities

OBJECT

The surgical management of patients with symptoms of tethered cord syndrome (TCS) who lack significant radiographic abnormalities is controversial. One potential MRI marker for TCS is a spinal cord syrinx or syringomyelia. Alternatively, a syrinx may be a benign and incidental finding. In this report the authors evaluated a highly selected cohort of patients with symptoms of TCS with minimal radiographic abnormalities other than syringomyelia. They analyzed clinical and radiographic outcomes after tethered cord release (TCR).

METHODS

A retrospective review of data from 16 children who met the study inclusion criteria was performed. All patients had been surgically treated at Riley Hospital for Children in Indianapolis, Indiana, between 2006 and 2011. All children had clinical symptoms of TCS as well as available pre- and postoperative MRI data.

RESULTS

The most common presentation (12 [75%] of 16 patients) was urinary dysfunction, defined as symptoms of urgency or incontinence with abnormal urodynamic studies. Clinical follow-up data were available in 11 of these 12 patients. All 11 had improvement in symptoms at an average follow-up of 17 months. Seven (87.5%) of 8 patients presenting with back or leg pain had improvement. Three patients had progressive scoliosis; 2 had stabilization of the curve or mild improvement, and 1 patient had worsening deformity. Radiographic follow-up data were obtained an average of 14.5 months after surgery. Twelve patients (75%) had stable syringomyelia after TCR. Four patients showed improvement, with 2 having complete radiographic resolution.

CONCLUSIONS

Highly selected patients with symptoms of TCS did very well clinically. Patients with abnormal urodynamic studies, pain, and gait disturbances showed a high rate of symptomatic improvement. However, a smaller percentage of patients had radiographic improvement of the syrinx. Therefore, the authors suggest that the decision to perform TCR should be based on clinical symptoms in this population. Symptomatic improvement was not necessarily related to radiographic resolution of the syrinx.

Use of prone position magnetic resonance imaging for detecting the terminal filum in patients with occult tethered cord syndrome

Object

The pathophysiology of occult tethered cord syndrome (OTCS) with no anatomical evidence of a caudally shifted conus and a normal terminal filum is hard to understand. Therefore, the diagnosis of OTCS is often difficult. The authors hypothesized that the posterior displacement of the terminal filum may become prominent in patients with OCTS who are in a prone position if filum inelasticity exists, and they investigated prone-position MRI findings.

Methods

Fourteen patients with OTCS and 12 control individuals were examined using T2-weighted axial MRI with the patients in a prone position on a flat table. On each axial view, the distance between the posterior and anterior ends of the subarachnoid space (A), the distance between the posterior end of the subarachnoid space and the terminal filum (B), the distance between the posterior end of the subarachnoid space and the dorsal-most nerve among the cauda equina (C), and the distance between the posterior end of the subarachnoid space and the ventral-most nerve (D) were measured. The location ratios of the terminal filum, the dorsal-most nerve, and the ventral-most nerve were calculated by the ratio of A to B (defined as TF = B/A), A to C (defined as DN = C/A), and A to D (defined as VN = D/A), respectively. Patients underwent sectioning of the terminal filum with the aid of a surgical microscope. The low-back pain Japanese Orthopaedic Association score was obtained before surgery and at the final follow-up visit.

Results

On prone-position axial MRI, the terminal filum was separated from the cauda equina and was shifted caudally to posterior in the subarachnoid space in all patients with OTCS. The locations of the caudal cauda equina shifted to ventral in the subarachnoid space. The TF values in the OTCS group were significantly lower than those in the control group at the L3–4 (p = 0.023), L-4 (p = 0.030), L4–5 (p = 0.002), and L-5 (p < 0.001) levels. In contrast, the DN values in the OTCS group were significantly higher than those of the control group at the L-2 (p = 0.003), L2–3 (p = 0.002), L-3 (p < 0.001), L3–4 (p < 0.001), L-4 (p = 0.007), L4–5 (p = 0.003), and S-1 (p = 0.014) levels, and the VN values in the OTCS group were also significantly higher than those of the control group at the L2–3 (p = 0.022), L-3 (p = 0.027), L3–4 (p = 0.002), L-4 (p = 0.011), L4–5 (p = 0.019), and L5–S1 (p = 0.040) levels. Sections were collected during surgery for histological evaluation, and a decreased elasticity within the terminal filum was suggested. Improvements in the Japanese Orthopaedic Association score were observed at the final follow-up in all patients.

Conclusions

The authors' new method of using the prone position for MRI shows that the terminal filum is located significantly posterior and the cauda equina is located anterior in patients with OTCS, suggesting a difference in elasticity between the terminal filum and cauda equina.

Improved symptoms and lifestyle more than 20 years after untethering surgery for primary tethered cord syndrome

AIMS

Evaluation of the long-term effectiveness of untethering surgery on social adaptations to urinary symptoms at the time of the survey.

METHODS

Postoperative analysis of the current activities of daily life implemented as a postal questionnaire survey. Completed questionnaires were returned by 33 of 52 patients with primary tethered cord syndrome (p-TCS) who had undergone untethering surgery more than 20 years ago, including 10 patients with tight filum terminale (TFT) and 23 with cauda equina adhesion syndrome (CEAS).

RESULTS

Long-term follow-up surveys in patients with p-TCS after untethering surgery indicated excellent effects on lower urinary tract symptoms in 9 of 10 patients with TFT, and the progression of symptoms tended to improve or halted in over half of the 23 patients with CEAS. However, one patient with TFT in whom new symptoms of voiding difficulty appeared immediately after surgery and 7 with CEAS showed deterioration of urinary and/or bowel symptoms. Eighteen patients complained of some symptoms caused by lower urinary tract dysfunction after untethering surgery in terms of difficulty in activities of daily life. With the exception of one female p-TCS patient with short stature and low body weight, all data of physical status, as well as educational level, employment, occupational category and marriage statistics were within the normal respective ranges taken from the Japanese census.

CONCLUSIONS

Postoperative long-term follow-up survey in patients with p-TCS indicated significant improvement of urological symptoms. However, 55% of patients had some lower urinary tract dysfunction that affected their activities in daily life.

Retethering of sectioned fibrolipomatous filum terminale in an adult: case report and review of the literature

BACKGROUND CONTEXT

Recurrent tethering of the spinal cord is a rare late complication after sectioning of a fibrolipomatous filum terminale that has only been reported in two pediatric cases.

PURPOSE

To report adult-onset recurrent tethering of the spinal cord after surgical sectioning of a fibrolipomatous filum terminale and review the literature in an attempt to identify similar cases.

STUDY DESIGN/SETTING

The study was designed to be a case report and literature review.

METHODS

A 21-year-old woman with a history of previous surgical repair for a tethered spinal cord secondary to a fibrolipomatous filum terminale presented with low back and right lower extremity pain, urinary frequency, and fecal incontinence. Progressive bladder and sphincter dysfunction was confirmed on urodynamic testing. Lumbar spine magnetic resonance imaging demonstrated a low-lying and dorsally positioned conus medullaris.

RESULTS

The patient underwent neurosurgical exploration of the previous site of sectioning with rerelease of the proximal fatty filum stump from dorsal dural adhesions. Postoperatively, her pain resolved, and her bowel and bladder control improved.

CONCLUSIONS

Sectioning of both abnormal and apparently normal fila has become a relatively common procedure in pediatric neurosurgery. As more children with this surgical history mature and present for neurosurgical consultation as adults, retethering must be considered in the differential diagnosis.

Spinal dysraphism with anorectal malformation: lumbosacral magnetic resonance imaging evaluation of 120 patients

PURPOSE

We evaluated the prevalence of spinal dysraphism (SD) in patients with anorectal malformation (ARM) by magnetic resonance imaging (MRI).

METHODS

From January 2002 to March 2009, 120 patients with ARM who underwent anorectal reconstruction were evaluated for SD with sacral plain film, spinal ultrasonography (US), and lumbosacral MRI. We adopted Krickenbeck international classification of ARM.

RESULTS

Spinal dysraphism was present in 41 (34.2%) of 120 patients with ARM, 3 (13.0%) of 23 patients with perineal fistula, 7 (29.2%) of 24 patients with vestibular fistula, 4 (36.4%) of 11 patients with rectovesical fistula, 18 (40.9%) of 44 patients with rectourethral fistula, and 9 (60.0%) of 15 patients with cloacal anomaly (P = .04). Among 41 patients having SD detected by MR, 26 patients (26/41; 63.4%) underwent detethering surgery for tethered spinal cord. The mean sacral ratio (SR) in patients who underwent detethering surgery (0.54 +/- 0.19) was significantly lower than in patients who did not undergo detethering surgery (0.69 +/- 0.13; P < .001). The optimal cutoff for the SR value predicting SD requiring detethering surgery was 0.605, with sensitivity of 65.4% and specificity of 77.7%.

CONCLUSIONS

Spinal dysraphism is common in patients with ARM, and its prevalence is higher in patients with complex ARM. Spinal anomalies can occur even with benign types of ARM and, therefore, that all patients should be screened. Magnetic resonance imaging is useful in detecting occult SD that may be missed by conventional radiologic evaluation, physical examination, and spinal US. We further recommend a lumbosacral MRI examination in those whose SR is lower than 0.6.

Intractable voiding dysfunction in children with normal spinal imaging: predictors of failed conservative management

OBJECTIVES

To identify the factors that might predict which individuals ultimately fail to resolve voiding symptoms by analyzing their presenting symptoms and video-urodynamic findings. Older children with intractable voiding dysfunction and no evidence of neurologic abnormality, who are recalcitrant to medical treatment, pose a management challenge.

METHODS

The charts of neurologically normal children with intractable voiding dysfunction, who had fluorourodynamic studies and normal lumbosacral magnetic resonance imaging, were reviewed. A database was created that included the urodynamics, presenting urinary symptoms, presence of soiling or constipation, age at onset of symptoms, cystogram and bladder ultrasound findings, and treatments given. Long-term follow-up was determined from chart review (all patients) or by a mailed survey (15 patients). Patients without symptoms and off medication were defined as normal.

RESULTS

A total of 50 children met the criteria mentioned earlier in the text, presented at a mean age of 9.4 years (range, 3.8-17.3) and were followed up for a mean of 4 years (range, 1-11) from their initial urodynamic evaluation. Of them, 33 (66%) remained symptomatic and 1 (34%) normalized. A total of 31 were found to have uninhibited bladder contractions (UBCs) with daytime wetting, of which 24 (77.4%) failed to normalize (P = .037). All 9 with UBCs and detrusor-sphincter dyssynergia remained symptomatic (P = .02).

CONCLUSIONS

The majority failed to resolve their voiding symptoms. Children who presented with daytime wetting, UBC, and detrusor-sphincter dyssynergia were the most likely to remain symptomatic. Patients with these characteristics might be considered for more aggressive alternative therapies, after a period of medical management.

Association of Chiari malformation type I and tethered cord syndrome: preliminary results of sectioning filum terminale

OBJECTIVE

The pathogenesis of CM-I is incompletely understood. We describe an association of CM-I and TCS that occurs in a subset of patients with normal size of the PCF.

METHODS

The prevalence of TCS was determined in a consecutively accrued cohort of 2987 patients with CM-I and 289 patients with low-lying cerebellar tonsils (LLCT). Findings in 74 children and 244 adults undergoing SFT were reviewed retrospectively. Posterior cranial fossa size and volume were measured using reconstructed 2D computed tomographic scans and MR images. Results were compared to those in 155 age- and sex-matched healthy control individuals and 280 patients with generic CM-I. The relationships of neural and osseus structures at the CCJ and TLJ were investigated morphometrically on MR images. Intraoperative CDU was used to measure anatomical structures and CSF flow in the lumbar theca.

RESULTS

Tethered cord syndrome was present in 408 patients with CM-I (14%) and 182 patients with LLCT (63%). In 318 patients undergoing SFT, there were no significant differences in the size or volume of the PCF as compared to healthy control individuals. Morphometric measurements demonstrated elongation of the brain stem (mean, 8.3 mm; P < .001), downward displacement of the medulla (mean, 4.6 mm; P < .001), and normal position of the CMD except in very young patients. Compared to patients with generic CM-I, the FM was significantly enlarged (P < .001). The FT was typically thin and taut (mean transverse diameter, 0.8 mm). After SFT, the cut ends of the FT distracted widely (mean, 41.7 mm) and CSF flow in the lumbar theca increased from a mean of 0.7 cm/s to a mean of 3.7 cm/s (P < .001). Symptoms were improved or resolved in 69 children (93%) and 203 adults (83%) and unchanged in 5 children (7%) and 39 adults (16%) and, worse, in 2 adults (1%) over a follow-up period of 6 to 27 months (mean, 16.1 months +/- 4.6 SD). Magnetic resonance imaging 1 to 18 months after surgery (mean, 5.7 months +/- 3.8 SD) revealed upward migration of the CMD (mean, 5.1 mm, P < .001), ascent of the cerebellar tonsils (mean, 3.8 mm, P < .001), reduction of brain stem length (mean, 3.9 mm, P < .001), and improvement of scoliosis or syringomyelia in some cases.

CONCLUSIONS

Chiari malformation type I/TCS appears to be a unique clinical entity that occurs as a continuum with LLCT/TCS and is distinguished from generic CM-I by enlargement of the FM and the absence of a small PCF. Distinctive features include elongation and downward displacement of the hindbrain, normal position of the CMD, tight FT, and reduced CSF flow in the lumbar theca. There is preliminary evidence that SFT can reverse moderate degrees of tonsillar ectopia and is appropriate treatment for cerebellar ptosis after Chiari surgery in this cohort.

Preoperative predictors for improvement after surgical untethering in occult tight filum terminale syndrome

BACKGROUND/AIMS

An occult tight filum terminale syndrome has been described wherein clinical symptoms result from tension on the spinal cord despite nondiagnostic spinal magnetic resonance imaging (MRI). Recent reports have suggested a role for surgical untethering in this patient population; however, controversy remains regarding the surgical treatment of this condition. Owing to the various clinical presentations, the relationship of presenting signs and symptoms to postoperative outcomes might be useful in surgical selection.

METHODS

A retrospective review was conducted of 22 pediatric cases of surgical untethering for suspected occult tight filum terminale syndrome. All patients had nondiagnostic MRI findings, defined as a conus medullaris above the L(3) vertebral body and a filum terminale diameter of less than 2 mm. Preoperative symptoms, signs and urodynamic test results were collected and compared with surgical outcomes determined by clinical notes and postoperative urodynamics reports. Abnormal findings on presentation were categorized as dermatologic, urologic, orthopedic and neurologic.

RESULTS

Patient age ranged from 7 months to 17 years, and 12 were female. Sixteen (73%) patients experienced subjective and/or objective improvement following surgical untethering. Fourteen patients had abnormal preoperative urodynamic testing, of which 12 underwent postoperative urodynamic testing. Five of these 12 (42%) demonstrated objective improvement postoperatively. Patients presenting with abnormal findings in at least 2 categories were more likely to improve following untethering (88%) than those with abnormalities in only 1 category (20%; p = 0.009).

CONCLUSION

Spinal cord untethering is a treatment option for occult tight filum terminale syndrome. Further evaluation of the relationship between preoperative findings and surgical outcomes may facilitate the selection of surgical candidates.

Significant clinical and radiological resolution of a spinal cord syrinx following the release of a tethered cord in a patient with an anatomically normal conus medullaris. Case report

The authors describe a case of progressive neurological deficit caused by syringomyelia in a 7-year-old boy with a normally positioned conus medullaris. This deficit responded favorably to surgical untethering of the filum terminale, with subsequent clinical and radiological improvement. The authors discuss the implications of their findings in the context of the current understanding of the pathophysiology of tethered cord syndrome, particularly in relation to the ongoing debate in the neurosurgical literature.

The neurogenic bladder: introducing four contributions

Neurogenic bladder dysfunction in children is frequently seen in patients with meningomyelocele (MMC). The disorder carries a high risk for all kinds of complications, with renal damage being the most important. More than 95% of MMC patients have a neurogenic bladder, the paramount manifestation of which is a disturbed coordination between detrusor and sphincter muscles. This vesicourethral dysfunction leads to defective filling and emptying of the urinary bladder. Voiding at will is almost never possible. According to the location and extent of the neural tube lesion, patients have either an atonic or a hypertonic pelvic floor and either an atonic or a hypertonic detrusor, leading to four classic combinations. Hypertonic sphincter and detrusor hyperactivity lead to the most dangerous form of neurogenic bladder, referred to as the "unsafe" bladder. The presence of residual urine in a high-pressure container causes either decompensation of the detrusor with vesicoureteral reflux or deterioration of the bladder wall with hypertrophy and stiffness resulting in uterovesical obstruction. The subsequent insufficient drainage of the upper urinary tract leads to decompensation of the ureters and finally to chronic renal disease, the process being accelerated by urinary tract infections. The aim of treatment is to restore as much as possible both essential functions: urine storage and timely emptying of the reservoir. What should and can be achieved is a more or less adequate, low-pressure, functional capacity of the bladder that is emptied as completely as possible by clean intermittent catheterization (CIC). MMC leads to the prototype of neurogenic bladder in childhood. What we know and what we do for MMC patients can roughly be applied to all other forms of neurogenic bladder, either congenital or acquired.

Section of the terminal filum for occult tethered cord syndrome: toward a scientific answer

The concept of an occult tethered cord syndrome (OTCS), in which a normally located conus is tethered by the terminal filum, is controversial. Children with OTCS typically present with neurogenic urinary incontinence that has been refractory to medical management. Authors of a number of case series have suggested that section of the terminal filum may improve urinary symptoms, but the quality of the evidence supporting this treatment is not good. The literature related to OTCS is reviewed and the progress toward a randomized controlled trial to assess the value of filum section in OTCS is detailed. A scientific answer to the question of filum section for OTCS awaits the results of an ongoing pilot randomized controlled trial and a more definitive trial to follow.

Comparison of section of filum terminale and non-neurosurgical management for urinary incontinence in patients with normal conus position and possible occult tethered cord syndrome

OBJECTIVE

Patients with persistent urinary incontinence and a normal location of the conus on magnetic resonance imaging scans may have occult tethered cord syndrome (OTCS). We compare outcomes in such patients after filum section versus nonoperative treatment.

METHODS

We performed a retrospective analysis of a consecutive series of children with refractory urinary incontinence and normal location of the conus who were offered section of the filum for treatment of possible OTCS.

RESULTS

Eight children, aged 4.4 to 9.8 years, underwent filum section, with one child undergoing two such operations. Clinical urological improvement occurred in seven children at a mean follow-up period of 3.1 years, with improved urodynamic findings in four of the seven children tested postoperatively. Other non-urological back or lower limb abnormalities improved in five out of six children with such findings. None of the patients underwent additional urological operations after filum section. Seven children, aged 3.1 to 13.5 years, all of whom had abnormal urodynamic findings, did not undergo filum section. At a mean follow-up period of 3.3 years, two patients had urological improvement and three patients had undergone bilateral ureteric reimplantations. Other non-urological back and/or lower limb abnormalities were present in five patients and did not improve. One patient had the filum cut after 8 years and improved thereafter.

CONCLUSION

Section of the filum in children with refractory urinary incontinence and OTCS may produce better urological outcomes than continued medical management. A definitive answer to the question of whether section of the filum is better than non-neurosurgical medical management for children with OTCS awaits the conclusion of a randomized controlled trial.

Minimal tethered cord syndrome: what's necessary to justify a new surgical indication?

✓Traditionally, surgical division of the terminal filum (filum terminale) has been reserved for patients with imaging-apparent spinal cord tethering. The occurrence of medically refractory voiding dysfunction of neurogenic origin, without magnetic resonance (MR) imaging documentation of abnormality in the spine, has been termed “minimal” tethered cord syndrome (TCS). The rationale for and utility of using surgical division of the terminal filum in the treatment of minimal TCS are unproven.

Six studies that involved surgical division of the terminal filum for minimal TCS were identified and reviewed. A seventh study conducted prior to the MR imaging era, in which authors used myelography, was also included. In addition, two investigations of the clinicopathological findings in such cases were analyzed. A tripartite criterion for justifying the introduction of a new surgical indication is proposed and analyzed in light of this evidence.

In children with minimal TCS there are definite pathological changes in the terminal filum that are not visible on routine spinal MR imaging. These changes suggest that the pathophysiology of minimal TCS, like TCS that is demonstrated on neuroimaging, may involve abnormal traction on the distal spinal cord. Additional data are needed regarding the sensitivity and specificity of various clinical studies intended to identify children with minimal TCS. All existing data supporting the efficacy of surgery for minimal TCS have been generated by Class III studies. Clinical equipoise exists for this surgical indication, and, therefore, a prospective randomized trial should be completed.