Occult tethered cord syndrome: a survey of practice patterns

Survey Research Among Neurosurgeons: A Bibliometric Review of the Characteristics, Quality, and Citation Predictors of the Top 50 Most-Influential Publications in the Neurosurgical Literature

Survey research enables the gathering of information on individual perspectives in a large cohort. It can be epidemiological, attitude or knowledge focussed. Assessment of survey studies sampling neurosurgeons is currently lacking in the literature. This study aimed to highlight the characteristics, quality, and citation predictors of the most influential survey research studies published in the neurosurgical literature. Using PubMed and Google Scholar, the 50 most cited survey research publications were identified and reviewed. Data relating to the characteristics of the articles, participants and questionnaires were retrieved. The studies' quality and citation patterns were assessed. The median articles' age and publishing journal impact factor (IF) were 15.5 years and 2.82, respectively. Thirty-two (64%) articles were first authored by researchers from the USA while 28(56%) studies were focussed on specific disease management. The median number of participants and response rates were 222 and 51%, respectively. A full version of the questionnaire was provided in 18 (36%) articles. Only four (8%) articles reported validation of the questionnaire. The overall quality of reporting of the surveys was considered fair (based on good grading in five parameters, fair grading in one parameter, and poor grading in four parameters). The median citation number was 111. The citation analysis showed that the participant number, article age (≥15.5 years), and questionnaire category (surgical complications) were significant predictors of citation numbers. The citation rates were not influenced by the response rates or the journal's IF. In conclusion, high-impact survey publications in the neurosurgical literature were moderately cited and of fair quality. Their citation numbers were not affected by response rates but were positively influenced by the publication age, number of participants, and by novel data or the questions raised in the survey category. Surveys are valuable forms of research that require extensive planning, time, and effort in order to produce meaningful results. Increasing awareness of the factors that could affect citations may be useful to those who wish to undertake survey research.

Patient-Reported Outcomes Following Sectioning of the Filum Terminale for Treatment of Tethered Cord Syndrome Associated With Ehlers-Danlos Syndrome

Introduction Tethered cord syndrome (TCS) was first reported as a potential complication of Ehlers-Danlos Syndrome in 2009. However, there have been few publications on the subject since that time, and optimal treatment of TCS in the setting of the hypermobile Ehlers-Danlos Syndrome (hEDS) population remains unknown. The purpose of this study was to determine the safety and efficacy of surgical release of the filum terminale (FT) for the treatment of TCS in this patient population. Methods We performed a retrospective chart review of consecutive hEDS patients with TCS who were treated with surgical release after providing informed surgical consent over a 4.5-year period by a single neurosurgeon. Eighty-four patients were identified and asked to complete surveys with items regarding pre and postoperative symptoms, pain levels, and satisfaction. Results Thirty patients with a mean age of 30.8 ± 11.9 years, all female, were included. Low back pain was significantly improved across the entire cohort. For patients with both pre and postoperative data available, the distance they were able to walk also improved significantly. The majority of patients were "highly satisfied" with surgery (66%), followed by 21% "satisfied", 10% "neutral", and one patient who was "dissatisfied". One patient required repair of a dural leak one week postoperatively, and no other complications were noted. Conclusions Surgical release of the FT for TCS in patients with hEDS was safe and effective in this cohort. For most patients, there was a significant improvement in low back pain, urinary symptoms, and ability to ambulate distance. The majority of respondents reported subjective satisfaction with this operation. A further prospective study is warranted.

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.

Occult tethered cord syndrome: a rare, treatable condition

PURPOSE

Occult tethered cord syndrome (OTCS) is an entity that shows tethered cord syndrome (TCS) with normal spinal MRI findings. The definition and treatment of OTCS have been controversial since first proposal. The purpose of this study was to evaluate the existence, prevalence, histological characteristics, and surgical outcomes of OTCS.

METHODS

We retrospectively analyzed patients who underwent untethering surgery for OTCS from January 2010 to December 2019. Inclusion criteria were (1) clinical manifestation of TCS; (2) supported by urodynamic study (UDS) or electromyography/nerve conduction study; (3) no structural lesions in the urological tract or spinal cord, and no developmental delay; and (4) postoperative follow-up for > 6 months. Sectioned fila from OTCS patients were histologically compared with those from cases of thickened filum or low-lying conus.

RESULTS

Five (four female, one male) of 439 patients (1.1%) who underwent untethering surgeries for occult spinal dysraphism corresponded to OTCS. Mean age at the time of surgery was 16 years (7-22 years). Mean postoperative follow-up duration was 45 months (15-114 months). The main symptom was urinary dysfunction in four patients and leg pain in one. All patients had detrusor-sphincter dyssynergia. Fila from OTCS patients revealed increased fibrous tissue as in TCS patients. Four patients showed postoperative improvement and one with preoperative static course had no improvement.

CONCLUSIONS

This study suggests that OTCS is a definitely existing entity although rare. OTCS is curable when timely treatment is given. Sudden onset with rapid progression of symptom seems the best indication for surgery.

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.

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.

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.

Spinal dysraphism as a new entity in V.A.C.TE.R.L syndrome, resulting in a novel acronym V.A.C.TE.R.L.S

Anorectal malformation (ARM) is the most common symptom in VACTERL syndrome (vertebral, anal, cardiac, tracheo-esophageal fistula, renal, and limb anomalies). The association of ARM and spinal dysraphisms (DYS) is well documented. We aim to better evaluate children with VACTERL association and ARM, considering the presence or not of DYS. Between 2000 and 2015, 279 children with VACTERL associations were identified in Necker Children's Hospital, Paris. We identified 61 VACTERL children (22%) with ARM. A total of 52 VACTERL children with ARM were included. DYS were identified in 36/52 of cases (69.2%). A total of 33 (63.5%) VACTERL children presented with sphincterial dysfunction. We constated that 28/33 (84.8%) of them had DYS + (p < 0.0001). More children in ARM (DYS +) subgroup are presenting with initial urinary sphincter dysfunction (58 vs 19%, p < 0.009) than ARM (DYS -). We identified 29 lipoma filum in our series, which were not statistically associated with urinary disorders (p = 0.143).Conclusion: We propose to refine the definition of VACTERL association, by adding S as Spinal defect to include it as an integral part of this syndrome, resulting in a novel acronym V.A.C.TE.R.L.S.What is Known:• The VACTERL association: congenital anomalies of the bony vertebral column (V), anorectal malformation (A), congenital cardiopathy (C), tracheo-esophageal defects (TE), renal and urinary tract anomalies (R), and limb malformations (L).• VACTERL children needs a complete appraisal, as early as possible, to adopt the most appropriate therapeutic management.What is New:• Include spine dysraphism (DYS) as a part of this syndrome, resulting in a novel acronym V.A.C.TE.R.L.S.• The significant correlation between VACTERL/DYS and urinary dysfunction requires to investigate the spine cord prenatally.

Homogeneous Spinal-Shortening Axial Decompression as a Revision Surgery After Untethering Surgery in Pediatric Patients with Tethered Cord Syndrome

OBJECTIVE

To evaluate surgical outcomes of homogeneous spinal-shortening axial decompression (HSAD) for reoperation in pediatric patients with tethered cord syndrome.

METHODS

Twenty consecutive pediatric patients (≤18 years old, 7 boys, 13 girls) who underwent HSAD after untethering surgery between June 2012 and May 2015 were included. The Japanese Orthopaedic Association score and visual analog scale were used to evaluate preoperative and postoperative neurologic function and pain. The International Consultation on Incontinence Questionnaire-Short Form and urodynamics were used to evaluate urinary function. The Rintala score was used to evaluate stool function.

RESULTS

Mean age of patients was 13.4 ± 3.6 years (range, 7-18 years). The mean duration of follow-up was 31.2 ± 12.7 months (range, 12-48 months). The Japanese Orthopaedic Association score was increased from 13.31 ± 4.03 preoperatively to 19.15 ± 4.17 at final follow-up (P < 0.01). The visual analog scale score was decreased from 5.25 ± 1.78 preoperatively to 2.21 ± 1.63 at final follow-up (P < 0.01). The International Consultation on Incontinence Questionnaire-Short Form score was decreased from 14.94 ± 4.15 preoperatively to 7.63 ± 4.40 at final follow-up (P < 0.01). All urodynamics parameters improved compared with before the operation. The Rintala score improved from 5.26 ± 3.45 preoperatively to 12.32 ± 3.43 at final follow-up (P < 0.01).

CONCLUSIONS

Outcomes of HSAD for revision surgery of tethered cord syndrome were satisfactory. HSAD improved neurologic function of patients significantly. HSAD could become an alternative surgical treatment of reoperation for tethered cord syndrome.

Minimally Invasive Surgery in the Management of Anorectal Malformations

Imperforate anus, a variant of anorectal malformation (ARM), is a common congenital anomaly requiring surgical attention in the newborn period. It may present with a variety of anatomic configurations, largely dependent on the presence and location of a fistula. The location (or characteristics) of a fistula, which usually lies between the gastrointestinal tract and the genitourinary tract or perineum, is often used in determining the type and timing of operative management. This article discusses the work-up and management, modes of treatment and their postoperative outcomes, and continued controversy regarding the use of minimally invasive surgical approaches to ARM.

Surgical Outcome of Children and Adolescents with Tethered Cord Syndrome

STUDY DESIGN

Retrospective cohort study.

PURPOSE

To compare long-term results of surgery with the outcomes of symptomatic and asymptomatic tethered cord syndrome (TCS) in children and adolescents and to assess the surgery duration for those with TCS.

OVERVIEW OF LITERATURE

Pediatric patients with TCS continue to pose significant diagnostic and management challenges.

METHODS

We retrospectively analyzed the outcomes of 31 patients (16 males, 15 females) with TCS, including 21 with lumbosacral lipoma. All were surgically treated between 1989 and 2015. They were divided into symptomatic and asymptomatic TCS groups. The results of the treatment were summarized and analyzed using a non-parametric Mann-Whitney U test.

RESULTS

Nineteen patients had symptomatic TCS and 12 had asymptomatic TCS. Patients had a median age of 34 months (range, 0-201 months). The median follow-up period was 116 months (range, 7-223 months). Of the 19 symptomatic TCS patients, preoperative deficits improved after surgery in two (10.5%) and remained stable in 17 (89.5%) patients. One of the 12 asymptomatic TCS (8.3%) patients showed an exacerbated illness after surgery, and one in 11 patients remained stable (11.7%). There were significant differences in monthly age at surgery, preoperative bowel and bladder dysfunction, neurological function, presence/absence of clean intermittent catheterization introduction, and presence/absence of motor disorder at final follow-up (all p<0.05). In the univariate analysis, the presence/absence of preoperative bowel and bladder dysfunction, and symptoms were strongly associated with the risk of children and adolescents with TCS (p<0.05).

CONCLUSIONS

Early accurate diagnosis and adequate surgical release might lead to successful outcomes in children and adolescents with TCS. Surgical untethering is a safe and effective method for treatment of children with TCS.

Overactive bladder in children

Overactive bladder (OAB) is a ubiquitous syndrome that is defined by urinary urgency with, or without urinary incontinence. OAB is observed in all parts of the world, with a prevalence of 5-12% in children (5-10 years of age) and a prevalence of 0.5% in older adolescents (16-18 years of age). Published data indicate that around a third of children with OAB are likely to become adults with similar complaints. Studies in children and in adults with OAB indicate that these individuals are more likely to also have anxiety, depression and attention deficit problems, and that appropriate treatment of these comorbidities can often improve the patient's OAB symptoms. Furthermore, data from twin studies and familial surveys seem to indicate a genetic component of OAB. Pharmacological treatments of OAB in children have improved in the past 5 years, moving beyond anticholinergic agents and including the off-label use of α-blockers, β3-agonists and intravesical botulinum toxin. Use of several different electrical stimulation techniques is also effective, both as first-line treatments, and for patients with treatment-refractory symptoms. Overall the outlook of children with OAB seems to be improving, with a greater understanding of the pathophysiology of this syndrome. Treatment modalities that target the source of the underlying problem, especially in children, are likely to provide the best patient outcomes.

Syringomyelia and tethered cord in children

INTRODUCTION

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

PATHOPHYSIOLOGY

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

CLINICAL PRESENTATION

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

TREATMENT

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

CONCLUSION

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

Tethered cord syndrome in adolescents: Report of two cases and review of literature

The symptoms of tethered cord syndrome (TCS) cases mostly appear during infancy and childhood. Though the adolescent presentation of TCS is well-recognized, it continues to pose significant diagnostic and management controversies. In this report, we describe two cases of adolescent onset TCS associated with two different etiologies. Our first case, an 18-year-old girl who presented due to overflow incontinence in association with TCS was diagnosed to have lumbar meningocele. The second case, a 19-year-girl presenting with perianal anesthesia and bowel and bladder incontinence had lipomyelomeningocele as the cause of TCS. Both of them underwent untethering surgery. The clinical charts and follow-up data were studied in respect to the clinical manifestation, surgical intervention and outcome with a brief review of pertinent literature.

Retethering in children after sectioning of the filum terminale

BACKGROUND/AIM

Sectioning of the filum terminale is performed when spinal cord tethering is suspected, sometimes without clinical symptoms. Retethering can occur and require reoperation due to the presentation of either recurrent or new symptoms. The purpose of this institutional review was to identify the retethering rate in children, especially in those who were initially asymptomatic, and to discuss the role of surgery.

METHODS

The medical records of all children at the Children's Hospital of Eastern Ontario (CHEO) who underwent tethered cord surgery between 1978 and 2009 for a thickened filum terminale were retrospectively reviewed, as well as those who retethered.

RESULTS

A total of 146 patients with a mean age of 4.3 years underwent a low lumbar single or partial laminectomy for sectioning of the filum terminale; 44 patients (30.1%) were asymptomatic at the time of surgery, 51.4% had bladder and bowel dysfunction, 26.7% had neuroorthopedic findings, 15.8% had pain and 6.2% had progressive scoliosis; 11 children with a median age of 8.9 years had symptoms of retethering requiring reoperation (median time to retether was 4.3 years) and 4 were initially asymptomatic. Repeat surgery was successful at alleviating the new symptoms that occurred as a result of retethering.

CONCLUSIONS

Of the 146 patients at CHEO who underwent surgery, 7.5% retethered, with 36% being initially asymptomatic. Those operated in the first year of life were not found to be at a higher risk. The level of the conus medullaris did not influence the rate or retethering or urological dysfunction. Children who were initially asymptomatic improved after surgery for retethering, but may not have required surgery in the first place.

The value of postoperative MR in tethered cord: a review of 140 cases

PURPOSE

This study aimed to determine the justification for routine postoperative MRI (POMR) following surgical release of tethered cord (TC) given that an MR, in this situation, mostly serves as a baseline and rarely has immediate clinical implications. Furthermore, later in the course of the disease, the presence of retethering is mostly assessed by clinical parameters, rather than imaging.

METHODS

A single-center retrospective review of patients who underwent tethered cord release surgery between the years 1997 and 2009 at the Department of Pediatric Neurosurgery, Tel Aviv Medical Center, Israel was performed. Collected data including basis for diagnosis, pathology, associated clinical and radiologic findings, surgical procedure and outcome, postoperative follow-up and morbidities, and postoperative MRI findings were recorded and analyzed.

RESULTS

One hundred forty patients operated upon between 1997 and 2009 for tethered cord syndrome were reviewed. Routine postoperative MR was performed in all cases 6-18 months after surgery. All cases were fully untethered. MR revealed relevant information in eight cases, two with residual dermoid, and six with significant terminal syrinx. None of these findings led to repeat surgery or special treatment. Retethering operations were performed in two cases in which retethering was diagnosed based on clinical evaluation.

CONCLUSIONS

Based on analysis of our series of 140 consecutive patients who all underwent POMR 6-18 months after TC release, we suggest that POMR as routine clinical practice is not justified for uncomplicated cases of TC release. In cases of high risk for retethering, or significant preoperative syrinx or dermoid, POMR is recommended to establish a baseline for future clinical follow-up.

Spinal cord stimulation as a treatment for refractory neuropathic pain in tethered cord syndrome: a case report

Introduction

The spinal cord is a target for many neurosurgical procedures used to treat chronic severe pain. Neuromodulation and neuroablation are surgical techniques based on well-known specific anatomical structures. However, anatomical and electrophysical changes related to the tethered spinal cord make it more difficult to use these procedures.

Case presentation

We report the case of a 37-year-old Caucasian woman who had several surgical interventions for tethered cord syndrome. These interventions resulted in severe neuropathic pain in her lower back and right leg. This pain was treated by spinal cord stimulation using intra-operative sensory mapping, which allowed the cord's optimal placement in a more caudal position.

Conclusion

The low-voltage and more caudally placed electrodes are specific features of this treatment of tethered cord syndrome.

Surgical management and outcome of tethered cord syndrome in school-aged children, adolescents, and young adults

OBJECTIVE

The adolescent presentation of tethered cord syndrome (TCS) is well-recognized, but continues to pose significant diagnostic and management controversies. The authors conducted a retrospective study of clinical outcomes after surgical intervention in 24 school-aged children, adolescents, and young adults with TCS.

METHODS

All 83 patients with a lipomyelomeningocele (LMMC) underwent untethering surgery for caudal cord tethering between 1987 and 2007. The clinical charts and follow-up data were reviewed. Of these patients, 24 school-aged children, adolescents, and young adults with TCS were studied with respect to the clinical, radiologic, pathologic features, and surgical outcomes.

RESULTS

Untethering procedures were performed in 24 patients (age range, 7-25 years) for TCS of various origins (lipoma, lipomyelomeningocele, and tight filum terminale). Specific circumstances involving additional tugging of the already tight conus, and direct trauma to the back precipitated the onset of symptom in 50% of the patients. Diffuse and non-dermatomal leg pain, often referred to the anorectal region, was the most common presenting symptom. Progressive sensorimotor deficits in the lower extremities, as well as bladder and bowel dysfunction, were also common findings, but progressive foot and spinal deformities were noted less frequently. The most common tethered lesions were intradural lipomas, thickened filum and fibrous band adhesions into the placode sac. The surgical outcome was gratifying in relation to pain and motor weakness, but disappointing with respect to resolution of bowel and bladder dysfunction. Of the 24 patients with TCS, pre-operative deficits improved after surgery in 14 (58.3%), remained stable in 8 (33.4%), and worsened in 2 (8.3%).

CONCLUSION

The pathologic lesions of tethered cord syndrome in school-aged children, adolescents, and young adults, are mostly intradural lipomas and tight filum. It is suggested that the degree of cord traction results in neurologic dysfunction in late life due to abnormal tension, aggravated by trauma or repeated tugging of the conus during exercise. Early diagnosis and adequate surgical release might be the keys to the successful outcome in school-aged children, adolescents, and young adults with TCS.

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.