Tethered cord syndrome: overview of diagnosis and treatment

Morphological analysis of the filum terminale and detailed description of the distal filum terminale externum: a cadaveric study

This observational, descriptive anatomical cadaveric study aimed to identify, characterize, and analyze the morphometric parameters of the filum terminale (FT) and macroscopically describe the distal insertion of the FTE. The FT is a complex, three-dimensional, fibro-cellular structure of connective tissue and glial cells, extending from the conus medullaris (CM) to the dural sac (DS) and coccyx. It is divided into two segments: an intradural filum terminale internum (FTI) and extradural filum terminale externum (FTE). Few studies have comprehensively addressed its morphometric characteristics in the last decades. Thirty-eight embalmed (M = 16, F = 22) human cadavers were examined to determine the CM-FTI and DS-FTE vertebral levels and FT, FTI, and FTE lengths and widths. FTI and FTE segmental diameters, correlations, gross characteristics, tension, and mobility in situ and ex vivo were assessed. FTE distal insertion is thoroughly described. FT, FTI, and FTE mean lengths were 254.32 mm (±26.46), 152.75 mm (±22.02), and 106.64 mm (±12.21), respectively. The CM-FTI junction was observed at the L1-L2 disk space (32.1%), DS-FTE fusion in the upper third of S2 (39.3%), and FTI-DS fusion in the DS midline (46.4%). FT length and FTI, FTE lengths were directly correlated, as were all FTI diameters. FT gross characteristics were an irregular surface (71.4%), bright hue (57.1%), macroscopic FTI-CM contrast (64.3%), filiform shape (60.7%), and movement-resistance (53.6%). The FTE exhibited a flattened shape (64.3%), immobility (60.7%), distal insertion at Cx1 (67.8%) and one distal strand (60.7%). FTI segments ≥ 2 mm were uncommon (21.4%). The FTE distal insertion is variable, inserting as strands, with vascular tissue surrounding it. A distal coccygeal venous plexus and single or multiple strand-like insertions of the distal FTE are for the first time described in detail. Discrepancies in the morphometric parameters of the FT between studies highlight the need for standardized protocols, especially given the FT's anatomic-clinical importance and potential role as a neural progenitor niche. We provide a comprehensive basis for future standardized morphometric analyses, acknowledging the limitations of embalmed cadaveric studies.

Proteomic study of cerebrospinal fluid in adult tethered cord syndrome: Chemical structure and function of apolipoprotein B

Adult tethered cord syndrome (ATCS) has a hidden onset and delayed clinical symptoms. The purpose of this study is to identify hub proteins in the cerebrospinal fluid of ATCS patients through bioinformatics analysis, and to find significant heterogeneity in these proteins between ATCS patients and non ATCS patients (control group). Firstly, differential genes were screened based on proteomic results. Compared with the control group, 18 differentially expressed proteins were upregulated and 18 differentially expressed proteins were downregulated in the cerebrospinal fluid of ATCS patients. Then, GO, KEGG, and GESA functional enrichment analysis showed that ATCS patients were active in biological processes such as coagulation, inflammatory response, and regulation of humoral immune response, suggesting the possibility of spinal cord injury. In addition, protein network interaction analysis indicates that APOB, APOC3, FGA, and FGG are defined as hub proteins. The correlation between ATCS patients and immune characteristics was analyzed using the CIBERSORT algorithm, which may have generated a unique immune microenvironment. Finally, Western blotting was used to experimentally validate APOB, APOC3, FGA, and FGG. The results showed that APOB, APOC3, FGA, and FGG were upregulated in the cerebrospinal fluid of ATCS patients and had an important impact on the repair and functional maintenance of spinal cord injury. They can be used as key proteins for early and accurate diagnosis and treatment of spinal cord thrombosis syndrome, and suggest that the spinal cord of ATCS patients may be damaged, which can serve as potential therapeutic targets.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Recurrent tethering in conus lipomas: a late complication not to be ignored

BACKGROUNDS

Recurrent symptomatic tethered cord (RTC) is a long-term complication of spinal cord lipomas, responsible for progressive motor deficits, urologic dysfunction and aggravation of spinal deformities.We retrospectively analysed all cases of recurrent tethering after spinal cord lipoma surgery, the clinical and radiological features that led to the diagnosis, the surgical management and the neuro-orthopedic outcome at the last follow-up.

METHODS

The study was carried out over a period of 20 years on a total of 209 pediatric patients from a single institution, initially treated for a conus lipoma.

RESULTS

9 patients (4,8 %) were surgically treated for a RTC. The age at retethering ranged from 2 to 12 years -median of 7, 4 years. The time before the first and the second surgical procedure, ranged from 19 to 140 months - median of 7 years and a half. The follow-up period after the second surgery ranged from 3 months to 13 years with a median of 50 months. Among symptoms, pain responded very well to surgery. Gait disturbances improved in 50 % after the surgery. One patient with bladder dysfunctions also improved. The rest of the patients maintained the pre-surgical status.

CONCLUSIONS

When RTC is confirmed, child should be referred to surgery as soon as possible, as we showed that the post- operative clinical outcome improved and surgery did not worsen patients. We stressed the fact that the follow-up should be as long as possible for these patients.

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.

Clinical Significance of Terminal Syringomyelia and Accompanying Congenital Anomalies of Neurosurgical Interest in Adult and Pediatric Patients with Tethered Cord Syndrome

Magnetic resonance imaging (MRI) can be used to examine tethered cord syndrome (TCS) and terminal syringomyelia (TS). Additionally, there is increasing evidence of an association between congenital anomalies and TCS. We aimed to identify the clinical and radiological characteristics of syringomyelia and other anomalies in pediatric and adult patients with TCS. This study included 54 TCS patients (mean age, 17.37 ± 15.83 years; 31 females) admitted to our department between 2010 and 2019. The patients were divided into two age groups: pediatric (<18 years; 63%) and adult (>18 years). Clinical findings, direct vertebrae radiographs, lower extremity radiographs, and spinal/cranial MRI findings were used to evaluate all patients. Computed tomography (CT) was performed to reveal the structure of the septum in patients with Diastematomyelia. Cranial ultrasonography or CT was performed if the fontanel was open or closed, respectively, in pediatric hydrocephalus cases. Pelvic ultrasonography and urodynamic tests were performed to evaluate other comorbid anomalies and urinary system pathologies. A thick filum terminale (73.3%) and diastematomyelia (44.4%) were found to cause spinal tension. The most common accompanying pathology was syringomyelia (78%). The common symptoms were urinary incontinence and bowel problems (71%), scoliosis (68%), and progressive lower extremity weakness (64.4%). It is difficult to distinguish the exact cause of symptoms in patients with TCS and TS. Due to the greater occurrence of other congenital spinal anomalies accompanying TCS, both preoperative symptoms and clinical findings are more severe in the pediatric group than in the adult group, and postoperative results may be more negative.

Spinal cord detethering without laminectomy or laminotomy

Background:

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

Case Description:

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

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

Conclusion:

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

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

Background

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

Case presentation

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

Conclusions

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

Three-Dimensional Sonographic Evaluation of the Position of the Fetal Conus Medullaris at First Trimester

OBJECTIVE

The objective of this study was to assess the position of the conus medullaris (CM) at the first trimester 3D ultrasound in a cohort of structurally normal fetuses.

METHODS

This was a multicenter prospective study involving a consecutive series of structurally normal fetuses between 11 and 13 weeks of gestation (CRL between 45 and 84 mm). All fetuses were submitted to 3D transvaginal ultrasound using a sagittal view of the spine as the starting plane of acquisition. At offline analysis, the position of the CM was evaluated by 2 independent operators with a quantitative and a qualitative method: (1) the distance between the most caudal part of the CM and the distal end of the coccyx (CMCd) was measured; (2) a line perpendicular to the fetal spine joining the tip of the CM to the anterior abdominal wall was traced to determine the level of this line in relation to the umbilical cord insertion (conus to abdomen line, CAL). Interobserver agreement for the CCMd was evaluated. Linear regression analysis was used to determine the association between the CMCd and CRL, and a normal range was computed based on the best-fit model. The absence of congenital anomalies was confirmed in all cases after birth.

RESULTS

In the study period between December 2019 and March 2020, 143 fetuses were recruited. In 130 fetuses (90.9%), the visualization of the CM was feasible. The mean value of the CMCd was 1.09 ± 0.16 cm. The 95% limits of agreement for the interobserver variability in measurement of the CMCd were 0.24 and 0.26 cm. The interobserver variability based on the intra-class correlation coefficient (ICC) for the CCMd was good (ICC = 0.81). We found a positive linear relationship between the CCMd and CRL. In all these fetuses, the CAL encountered the abdominal wall at or above the level of the cord insertion.

CONCLUSION

In normal fetuses, the assessment of the CM position is feasible at the first trimester 3D ultrasound with a good interobserver agreement. The CM level was never found below the fetal umbilical cord insertion, while the CMCd was noted to increase according to the gestational age, confirming the "ascension" of the CM during fetal life.

Spinal shortening osteotomy for adult tethered cord syndrome evaluated by intraoperative ultrasonography

BACKGROUND

Spinal shortening osteotomy (SSO) reduces the tension indirectly in the spinal cord and minimizes perioperative complications. However, the most effective and safe length to which the spine can be shortened is still unknown. In our practice, we use somatosensory-evoked potentials, motor-evoked potentials, and intraoperative ultrasonography when performing SSO. This study aimed to introduce the clinical outcomes of our SSO technique for tethered cord syndrome (TCS) in adults.

METHODS

This retrospective study included 7 adult patients (2 males and 5 females) with TCS treated between December 2010 and December 2018. The average age and average preoperative duration were 40 and 5 years, respectively. All patients received SSO with somatosensory-evoked potentials, motor-evoked potentials, and ultrasonography. After surgery, all patients were followed for an average of 4 years.

RESULTS

The mean operation time was 328 (284-414) min for SSO. The mean blood loss was 828 ml (501-1252 ml). Postoperative bony fusion was confirmed in all patients. Postoperative computed tomography (CT) demonstrated an average of 16 mm (11-20 mm) of spinal column shortening, compared with preoperative CT. Clinical improvements were obtained in all 7 cases, and there was no case of exacerbation. An indicator of shortening is that the ultrasonography gives pulsation and relaxation of the spinal cord. There were no abnormalities observed while monitoring the spinal cord.

CONCLUSIONS

Spinal shortening should be done under somatosensory-evoked potentials, motor-evoked potentials, and intraoperative ultrasonography to obtain safe and sufficient shortening.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Mouse Models of Neural Tube Defects

During embryonic development, the central nervous system forms as the neural plate and then rolls into a tube in a complex morphogenetic process known as neurulation. Neural tube defects (NTDs) occur when neurulation fails and are among the most common structural birth defects in humans. The frequency of NTDs varies greatly anywhere from 0.5 to 10 in 1000 live births, depending on the genetic background of the population, as well as a variety of environmental factors. The prognosis varies depending on the size and placement of the lesion and ranges from death to severe or moderate disability, and some NTDs are asymptomatic. This chapter reviews how mouse models have contributed to the elucidation of the genetic, molecular, and cellular basis of neural tube closure, as well as to our understanding of the causes and prevention of this devastating birth defect.

Morphometric analysis of spinal cord termination in Cavalier King Charles Spaniels

BACKGROUND

There is an association between Chiari malformations, syringomyelia (CMSM) and tethered cord syndrome (TCS) in people, suggesting Cavalier King Charles Spaniels (CKCS) with CMSM could also have TCS. Currently there are no data on the position of the caudal spinal cord structures in CKCS.

OBJECTIVE

To describe and compare location of spinal cord termination in CKCS with weight-matched controls and to examine the relationship between SM and spinal cord termination.

ANIMALS

Thirty-nine CKCS and 33 controls with thoracolumbar MRIs; 34 of 39 CKCS also had cervical MRIs.

METHODS

Blinded retrospective study. Spinal cord and dural sac termination were determined from T2-weighted sagittal and transverse images and half-Fourier acquisition single-shot turbo spin echo sequences. Intra-observer reliability was determined using kappa analysis. Presence of SM was compared with location of spinal cord and dural sac termination.

RESULTS

Intra-observer reliability was moderate for identifying spinal cord termination (Kappa = 0.6) and good for dural sac termination (Kappa = 0.8). The spinal cord terminated at lumbar vertebra 6 (L6) in 1, 7 (L7) in 22, and sacrum in 16 CKCS versus 9 at L6, 23 at L7, 1 at sacrum in controls. Spinal cord (P < .001) and dural sac (P = .002) termination were significantly more caudal in CKCS compared to controls. The presence of thoracolumbar SM was associated with more caudal dural sac termination in CKCS (P = .03).

CONCLUSIONS AND CLINICAL IMPORTANCE

The relationship between TL SM and possible spinal cord tethering because of a more caudal dural sac termination should be investigated.

Multiple neurosurgical treatments for different members of the same family with Currarino syndrome

INTRODUCTION

Currarino's syndrome (CS) is an autosomal dominant disorder of embryonic development causing a rare malformating syndrome characterized by a triad of an anorectal malformations, presacral mass (most commonly an anterior sacral meningocele) and sacral bony defects. Mutations of the HLXB9 gene have been identified in most CS cases, but a precise genotype-phenotype correlation has not been described so far. Family screening is obligatory. The diagnosis is usually made during childhood and rarely in adulthood. In this context, imaging, and especially MRI plays a major role in the diagnosis of this syndrome. Surgical management is provided by pediatric surgeons or neurosurgeons.

FAMILIAL CASE REPORT

Here, we present a family case report with CS requiring different neurosurgical management. The son, a 3-year-old boy, developed a tethered spinal cord syndrome associated to a lipoma of the filum terminale, a sacro-coccygeal teratoma and an anal adhesion. A combined surgical approach permitted a good evolution on the urinary and digestive functions despite a persistent fecal incontinence. The 2-year-old daughter presented with a cyst of the thyreoglossal tract infected and fistulized to the skin. She was also followed for a very small lipoma of the filum terminale that required a neurosurgical approach. The father, 44-year-old, manifested functional digestive and urinary disorders caused by a giant anterior sacral meningocele. The ligation of the neck of the cyst and aspiration of the liquid inside in full through a posterior partial approach permit a complete collapse of the cyst with an instantly satisfactory clinical outcome.

CONCLUSION

In these cases, cooperation between pediatric surgeons and neurosurgeons was crucial. The follow-up of these patients should be done in a spina bifida clinic. A geneticist evaluation must be offered to the patient in the case of a CS as well as a clinical evaluation of the relatives (parents, siblings).

Response of Scoliosis in Children with Myelomeningocele to Surgical Release of Tethered Spinal Cord

Objective: To examine the effect of surgical tethered cord release (TCR) on scoliosis in children with myelomeningocele. Methods: A retrospective review of 65 pediatric patients with myelomeningocele and TCR. The final sample consisted of 20 patients with scoliosis who were managed conservatively after TCR. Results: Average age at TCR was 6.2 years with average follow-up of 3.8 years. Scoliosis of 1 (5%) patient improved, 7 (35%) were stable, and 12 (60%) worsened (≥10°). Fifty percent of patients ultimately required definitive spinal surgery. TCR release delayed definitive spine surgery for an average of 3.2 years. Sixty-four percent of patients with curves less than or equal to 45° had progression of their curves compared to 50% with curves greater than 45°. For patients with curves less than or equal to 45°, curves progressed in 80% of those younger than 10 years as compared to 25% of those older than 10 years. For patients with curves less than or equal to 45°, 43% required definitive spine surgery as opposed to 83% with curves greater than 45°. Level of neurological involvement (ie, lumbar versus thoracic) and age at untethering emerged as factors influencing the effects of TCR for patients with curves less than or equal to 45°. Lumbar curves had more favorable results. Conclusion: Pediatric patients with myelomeningocele and scoliosis should be closely assessed and monitored. A selective approach for youth with lumbosacral level myelomeningocele and progressive curves less than or equal to 45° may result in scoliosis stabilization and avoidance of definitive surgery.

Percutaneous Fully Endoscopic İnterlaminar Approach to the Filum Terminale: A Cadaveric Study

OBJECTIVE

To investigate the utility, safety, and feasibility of a novel endoscopic technique for the visualization and surgical manipulation of the filum terminale in fresh postmortem adult human cadavers.

METHODS

The filums from 18 fresh postmortem adult human cadavers were explored with a percutaneous fully endoscopic interlaminar approach. After the filum was identified and the nerve roots were dissected away from it, the filum was cut. A specimen was sent for histopathologic examination.

RESULTS

In 15 of 18 (83%) cadavers, the filum terminale could be visualized. A specimen for histopathologic examination was obtained from 11 of 15 (73%) visualized filums. Histopathologic examination revealed that 2 of them were fatty filums, 7 were normal filums, and 2 were peripheral nerves.

CONCLUSIONS

We have described a successful and feasible percutaneous fully endoscopic interlaminar approach to the filum terminale. This technique provides a smaller skin incision, narrow durotomy, and minimal tissue damage. Animal studies are necessary to prove the feasibility and safety of our method before clinical use.

Tethered cord syndrome in children: a single-center experience with 162 patients

PURPOSE

Tethered cord syndrome (TCS) is not an uncommon clinical problem in children. The aim of this retrospective study is to document our experience on the surgical treatment of TCS in childhood.

METHODS

The data of 162 children who underwent surgical treatment for TCS in a 15-year period were reviewed retrospectively. Their demographic, clinical, radiological, and surgical features were documented. They were divided into two groups as primary and secondary TCS, and the surgical technique for each group was demonstrated. Untethering the spinal cord and correction of the associated malformation were the standard surgical technique for each patient. The results of the treatment were summarized.

RESULTS

Among the 162 children, 101 (62.3%) of them were female and 61 were male with a mean age of 62 months. Primary TCS was detected in 43 patients while secondary TCS was found in 119 (73.4%) patients. Hypertrichosis was the most common physical finding while back pain was the common complaint. Lipoma, split cord malformation, dermal sinus tract, and myelomeningocele were the associated malformations for secondary TCS.

CONCLUSIONS

Children should be individualized for the treatment of TCS. Each patient must be evaluated neurologically and radiologically for the accurate diagnosis. Surgical untethering is the safe and effective method of treatment for children with TCS.

Pathophysiology of tethered cord syndrome and other complex factors

There are different interpretations of tethered cord syndrome (TCS) partly due to difficulty in understanding the concept of this syndrome as a functional disorder not merely based on gross anatomy of congenital anomalies. The essential mechanical factor of cord tethering is that any of the inelastic structures fastening the caudal end of the spinal cord produces traction effects on the lumbosacral cord. The production of such traction is the key to understanding this disorder. In a significant number of patients who present with the typical clinical signs and symptoms of TCS, the diameter of the filum terminale is found within normal limits and the caudal end of the spinal cord is located in the normal position. Therefore, the definition of TCS requires the demonstration that there is a posterior displacement of the conus and filum by MRI, lack of viscoelasticity by the stretch test of the filum during surgery, and fibrous displacement of glial tissue within the filum by histological studies. This is because there is inconsistency from such studies as ultrasonography, MRI and CT myelography, which attempt to establish the presence of a tight filum terminale. A goal of this article is to provide basic understanding of TCS so that clinicians can use the concept of stretch-induced spinal cord dysfunction for proper diagnosis and treatment of this disorder.

Outcomes of tethered cord repair with a layered soft tissue closure

BACKGROUND

Previous studies have demonstrated the benefit of releasing symptomatic tethered cords; however, complications such as seroma, cerebrospinal fluid leak, and infection continue to plague these patients. We propose that composite tissue closure of tethered cord repairs yields superior outcomes and that a collaborative effort between neurosurgery and plastic surgery may result in enhanced structural and functional results.

METHODS

This is a retrospective study comprised of consecutive patients with tethered cord syndrome by 2 neurosurgeons and 2 plastic surgeons between 1994 and 2008 at a single institution. All consecutive patients who underwent tethered cord release by neurosurgery and subsequent composite tissue closure with fascial and musculofascial flaps by plastic surgery were included. Data were collected by retrospective chart review and analyzed using parametric methods.

RESULTS

A total of 86 consecutive patients were included in this study, with follow-up ranged from 12 to 144 months (average follow-up, 29 months). There were no statistical differences in follow-up time, comorbidities, or surgeon when comparing hospital readmission or reoperation. There was no statistical difference in complications when comparing the different flap closures. We had a 1.2% infection rate, a 4.7% readmission rate, and a 3.5% reoperation rate.

CONCLUSION

We believe that local soft tissue rearrangement improves the closure by providing an additional layer of vascularized tissue between the skin and the spinal cord. We believe our series represents a significant sample size compared with those previously reported for an experience that achieves multilayered soft tissue closure after tethered cord repair. Our results support the idea that neurosurgeons should consider consultation of plastic surgeons when treating patients with tethered cord syndrome surgically.

When only partial spinal cord detethering is possible

In most instances, initial surgery to untether a tethered spinal cord is successful. But what happens when it is not? The authors describe the case of a now 18-year-old woman with spina bifida in whom surgery for tethered cord was required on two occasions. In both instances, due to the extent of her underlying lesion and fibrous tissue, only partial detethering was possible without acutely sacrificing significant neurological function. The authors detail the patient's course and review the peer-reviewed scientific literature on outcomes in patients in whom only partial cord detethering is achieved. In their review of all case series and clinical studies pertaining to the surgical treatment of tethered cord syndrome identified during an online search of 2184 scientific abstracts and 2 major neurosurgery textbooks, excluding the present case, the authors identified 53 confirmed or presumed cases of incomplete detethering in eight articles, incorporating 390 patients, for an overall prevalence of roughly 13.6%. Although no investigators have reported statistical comparisons of outcomes in those in whom just partial and complete detethering has been achieved, the evidence generally suggests poorer outcomes in the former. Prospective multicenter studies addressing this important issue clearly are warranted. To date, the authors believe that incomplete detethering is grossly underreported in the medical literature.

Concurrent Chiari decompression and spinal cord untethering in children: feasibility in a small case series

BACKGROUND AND PURPOSE

We describe the rationale and safety of concurrent decompression of Chiari type 1 malformation (CM1) and untethering of the spinal cord. Spinal cord traction is considered one of the pathogenic mechanisms involved in the development of CM, and 14% of patients with CM1 have tethered cord syndrome (Milhorat et al., Surg Neurol 7:20-35, 2009; Roth, Neuroradiology 21:133-138, 1981; Royo-Salvador, Rev Neurol 24:937-959, 1996; Royo-Salvador et al., Acta Neurochir 147:515-523, 2005). Therefore, intraspinal anomalies that require intervention are commonly treated before surgical decompression of Chiari malformation (Cheng et al., Neurologist 8:357-362, 2002; Menezes, Pediatr Neurosurg 23:260-269, 1995; Milhorat et al., Surg Neurol 7:20-35, 2009; Royo-Salvador et al., Acta Neurochir 147:515-523, 2005; Schijman and Steinbok, Childs Nerv Syst 20:341-348, 2004; Yamada et al., Neurol Res 26:719-721, 2004). However, in the interval between the spinal cord untethering and the decompression surgery, patients may continue to suffer from the untreated symptoms of CM. In a series of four patients with concurrent severe and progressive symptoms referable to both conditions, we performed both surgeries simultaneously.

METHODS

Charts of four patients who underwent concurrent Chiari decompression and spinal cord untethering were reviewed.

RESULTS

All patients tolerated the procedures well without complication. They reported significant or complete early postsurgical resolution of headaches and ambulating difficulties. On average, patients started to walk on postoperative day 3 (3 ± 1 days) and were discharged on hospital day 6 (6 ± 1 days). No patient experienced a persistent subcutaneous or transcutaneous cerebrospinal fluid leak. Subsequent postoperative courses were uneventful.

CONCLUSION

Concurrent Chiari decompression and untethering of the spinal cord is a feasible option and in some patients may be preferred in lieu of staged procedures.

Posterior vertebral column subtraction osteotomy for the treatment of tethered cord syndrome: review of the literature and clinical outcomes of all cases reported to date

Tethered cord syndrome (TCS) is a debilitating condition of progressive neurological decline caused by pathological, longitudinal traction on the spinal cord. Surgical detethering of the involved neural structures is the classic method of treatment for lumbosacral TCS, although symptomatic retethering has been reported in 5%–50% of patients following initial release. Subsequent operations in patients with complex lumbosacral dysraphic lesions are fraught with difficulty, and improvements in neurological function are modest while the risk of complications is high. In 1995, Kokubun described an alternative spine-shortening procedure for the management of TCS. Conducted via a single posterior approach, the operation relies on spinal column shortening to relieve indirectly the tension placed on the tethered neural elements. In a cadaveric model of TCS, Grande and colleagues further demonstrated that a 15–25-mm thoracolumbar subtraction osteotomy effectively reduces spinal cord, lumbosacral nerve root, and filum terminale tension. Despite its theoretical appeal, only 18 reports of the use of posterior vertebral column subtraction osteotomy for TCS treatment have been published since its original description. In this review, the authors analyze the relevant clinical characteristics, operative data, and postoperative outcomes of all 18 reported cases and review the role of posterior vertebral column subtraction osteotomy in the surgical management of primary and recurrent TCS.

Tethered cord syndrome: a review of the literature from embryology to adult presentation

Tethered cord syndrome (TCS) is a clinical condition of various origins that arises from tension on the spinal cord. Radiographic findings may include the conus medullaris in a lower than normal position, fatty infiltration of the filum terminale, lipomyelomeningocele, myelomeningocele, myelocystocele, meningocele, split cord malformations, dermal sinus, anorectal malformations, and intraspinal tumors. The clinical constellation of signs and symptoms associated with TCS may include dermatologic, urological, gastrointestinal, neurological, and orthopedic findings. The current review focuses on TCS by age group of the more common causes of the condition, including myelomeningocele, lipomyelomeningocele, as well as the adult presentation of occult TCS. Pertinent review of the neuroembryology and normal anatomical position of the conus medullaris is included.

Tethered cord syndrome in identical twins

The diagnosis of tethered cord syndrome (TCS) without typical conus medullaris symptoms and the radiological features such as a low set conus medullaris or dysraphic malformation is difficult. We report 11 year old identical twin brothers with TCS associated with the conus at the normal level. Their presenting symptom was progressive leg pain and both patients underwent surgical interruption of the filum terminale. The pain recurred in one patient treated surgically only after symptom became worse but resolved immediately in the other sibling treated promptly. We indicate the importance of early diagnosis and treatment of TCS to obtain excellent long-term outcome despite the absence of a low set conus or specific symptoms. Furthermore, when a twin or sibling of an affected person has neurological symptoms and the cutaneous signature of spinal dysraphism, radiological examination should be performed to establish the cause.

Spine-shortening vertebral osteotomy in a patient with tethered cord syndrome and a vertebral fracture

The authors report a rare case of tethered cord syndrome with low-placed conus medullaris complicated by a vertebral fracture that was successfully treated by a spine-shortening vertebral osteotomy. The patient was a 57-year-old woman whose neurological condition worsened after a T-12 vertebral fracture because a fracture fragment and the associated local kyphotic deformity directly compressed the tethered spinal cord. An osteotomy of the T-12 vertebra was performed in order to correct the kyphosis, remove the fracture fragment, and reduce the tension on the spinal cord. Postoperative radiographs showed the spine to be shortened by 22 mm, and the kyphosis between T-11 and L-1 improved from 23° to 0°. Two years after the surgery, the patient's neurological symptoms were resolved. The bone union was complete with no loss of correction.

Prevalence of primary tethered cord syndrome associated with occult spinal dysraphism in primary school children in Turkey

The prevalence and associated factors of primary tethered cord syndrome (PTCS) in primary school children were investigated. A cross-sectional study was performed in four demographically different primary schools in Turkey. Demographic, familial and physical data were collected from 5,499 children based on enuresis as a predominant symptom and dermatologic and orthopedic signs as clues of occult spinal dysraphism. Statistical analysis and input of the data were carried out with the SPSS package program 10.00, and logistic regression analysis was used to identify discriminating factors between enuretic children with or without neurologic signs. Of 5,499 analyzed children, 422 (7.7%) had enuresis nocturna, and 19.9% of 422 children had also daytime incontinence. Sixteen of these 422 enuretic children (3.8%) had several dermatologic signs. Five of them had spina bifida on plain radiographies, and 4 of them had cord tethering on lumbar MRI. Fifteen of 422 enuretic children (3.7%) had gait disturbances and orthopedic anomalies without cutaneous manifestations. Six of 15 children had spina bifida on plain graphies and 2 of them had tethered cord syndrome on MRI. The general prevalence of PTCS was found to be 0.1% of 5,499 analyzed children and 1.4% of enuretic children. A good outcome after untethering was found in 83.0% in this series. Practitioners should be aware of these clues of occult spinal dysraphism and resort to further radiologic and neurosurgical assessment. Early surgical intervention may halt the progression of the neurologic deficits and stabilize or reverse symptoms.