Diagnosis and Management of Tethered Cord Syndrome.

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

Prevention of retethering in untethering surgery of a tight filum terminale.

OBJECTIVE: Untethering surgery for a tight filum terminale is a common treatment with considerable efficacy and safety. On the other hand, retethering has been reported to occur. One of the major mechanisms of retethering is adherence of the cut end of the sectioned filum to the midline dorsal dural surface. To prevent retethering, the authors sectioned a filum terminale at the rostral level to the dural incision to keep the distance between the cut end of the sectioned filum and the dural incision and investigated whether this procedure decreased the occurrence of retethering. METHODS: Among the patients who underwent untethering surgery for a tight filum terminale between 2012 and 2016, patients followed up more than 5 years were included in the study. Symptoms, comorbid malformations, preoperative imaging, surgical details, perioperative complications, and long-term outcomes were reviewed retrospectively. RESULTS: Retrospective data for a total of 342 cases were included. The median age at surgery was 11 months (range 3-156 months). Preoperative MRI revealed 254 patients (74.3%) had a low-set conus. There were 142 patients (41.5%) with filar lipoma and 42 patients (12.3%) with terminal cyst. Syringomyelia was found in 29 patients (8.5%). In total, 246 patients (71.9%) were symptomatic and 96 patients (28.1%) were asymptomatic. There were no perioperative complications that required surgical intervention or prolonged hospitalization. The mean postoperative follow-up was 88 months (range 60-127 months). There were 4 patients (1.2%) with retethering who presented with bladder and bowel dysfunction. The mean time from initial untethering to retethering was 54 months (range 36-80 months). All 4 patients underwent untethering surgery, and preoperative symptoms resolved in 3 patients. CONCLUSIONS: The retethering rate after untethering surgery for a tight filum terminale in our series was lower than those in previously reported studies. Sectioning the filum terminale at the rostral level to the dural incision was considered an effective way to prevent retethering.

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

PURPOSE: First, to assess the number of spinal cord anomalies (SCA), specifically tethered spinal cord (TSC) in patients with anorectal malformations (ARM), identified with spinal cord imaging (i.e. spinal cord US and/or MRI). Second, to report outcomes after TSC treatment. METHODS: A retrospective mono-center study was performed. All ARM patients born between January 2000 and December 2021 were included. Screening for SCA consisted of spinal cord US and/or MRI. Radiology reports were scored on presence of SCA. Data were presented with descriptive statistics. RESULTS: In total, 254 patients were eligible for inclusion, of whom 234 (92.1%) underwent spinal cord imaging. In total, 52 (22.2%) patients had a SCA, diagnosed with US (n = 20, 38.5%), MRI (n = 10, 19.2%), or both US and MRI (n = 22, 42.3%), of whom 12 (23.5%) with simple, 27 (52.7%) intermediate, and 12 (23.5%) complex ARM types. TSC was identified in 19 patients (8.1%), of whom 4 (21.1%) underwent uncomplicated neurosurgical intervention. CONCLUSIONS: SCA were present in 22% of ARM patients both in simple, as well as more complex ARM types. TSC was present in 19 patients with SCA, of whom 4 underwent uncomplicated neurosurgical intervention. Therefore, screening for SCA seems to be important for all ARM patients, regardless of ARM type. LEVEL OF EVIDENCE: Level III.

Motor-evoked potential monitoring from urinary sphincter muscle during pediatric untethering surgery: a case series.

PURPOSE: Postoperative urinary dysfunction following untethering surgery for spinal lipoma is devastating. To assess urinary function, we invented a pediatric urinary catheter equipped with electrodes for the direct transurethral recording of myogenic potential from the external urethral sphincter (EUS). This paper presents two cases in which urinary function was monitored intraoperatively by recording of motor-evoked potential (MEP) from EUS during untethering surgery in children. METHODS: Two children (aged 2 and 6 years) were included in this study. One patient had no preoperative neurological dysfunction, while the other had frequent urination and urinary incontinence. A pair of surface electrodes was attached to a silicone rubber urethral catheter (6 or 8 Fr; diameter, 2 or 2.6 mm). The MEP from the EUS was recorded to assess the function of the centrifugal tract from the motor cortex to the pudendal nerve. RESULTS: Baseline MEP waveforms from the EUS were successfully recorded with latency and amplitude of 39.5 ms and 66 µV in patient 1 and 39.0 ms and 113 µV in patient 2, respectively. A significant decrease in amplitude was not observed during surgery in the two cases. No new urinary dysfunction and complications associated with the urinary catheter-equipped electrodes developed postoperatively. CONCLUSION: Using an electrode-equipped urinary catheter, monitoring of MEP from the EUS could be applicable during untethering surgery in pediatric patients.

Intraoperative feasibility of bulbocavernosus reflex monitoring during untethering surgery in infants and children.

Bulbocavernosus reflex (BCR) monitoring is used to assess the integrity of urinary and bowel function. In this study, we evaluated the feasibility of BCR monitoring during untethering surgery in infants and children to predict postoperative urinary and bowel dysfunction. The records of 22 patients ranging from 4 days to 10 years old (mean 2.7 ± 3.3 years) were reviewed. Anesthesia was maintained by propofol or sevoflurane/opioid without neuromuscular blockade. BCR waveforms induced by electrical stimulation (20-40 mA, train-of-four pulses with 500 Hz) to the penis or clitoris were recorded from bilateral external anal sphincters. To assess the sensitivity and specificity of BCR monitoring, we investigated the association between a significant continuous decrease in BCR amplitude at the end of surgery and postoperative urinary and bowel dysfunction after surgery. Reproducible baseline BCR waveforms were successfully recorded in 20 of 22 patients (90.9%). A significant continuous decrease in BCR amplitude was observed in 8 patients. The results of intraoperative BCR monitoring included three true-positives, twelve true-negatives, five false-positives, and zero false-negatives. Therefore, the sensitivity and specificity of BCR monitoring used to predict postoperative urinary and bowel dysfunction were 100 and 70.6%, respectively. BCR monitoring during untethering surgery in infants and children under general anesthesia was found to be a feasible method to prevent postoperative urinary and bowel dysfunction.

Impact of the associated anorectal malformation on the outcome of spinal dysraphism after untethering surgery.

PURPOSE: To analyze the outcome after untethering surgery in patients with spinal dysraphism (SD), with or without associated anorectal malformation (ARM). METHODS: Patients operated on for SD, with (Group A) or without (Group B) associated ARM (1999-2015), were included. The post-operative outcome was analyzed in the two groups in terms of improving of clinical symptoms (neuro-motor deficits, bladder dysfunction, bowel dysfunction) and of instrumental examinations (urodynamics, bladder ultrasound, neurophysiology). Fisher's exact test and χ2 test were used as appropriate; p < 0.05 was considered statistically significant. MAIN RESULTS: Ten patients in Group A and 24 in Group B were consecutively treated. One patient was lost at follow up. Six patients (25%) in Group B underwent prophylactic surgery. The analysis of the pre-operative symptoms in the two groups showed that a significantly higher number of patients in group A needed bowel management and presented with neuro-motor deficits, compared to group B (p = 0.0035 and p = 0.04, respectively). Group A showed a significant post-operative neuro-motor improvement as compared to group B (p = 0.002). CONCLUSIONS: Based on our results, untethering seems to be effective in neuro-motor symptoms in selected patients with ARM. In ARM patients, untethering surgery does not seem to benefit intestinal and urinary symptoms. The presence of the associated ARM does not seem to impact the medium-term outcome of patients operated for SD.

Clinical Outcomes of Primary and Revision Untethering Surgery in Patients with Tethered Cord Syndrome and Spinal Bifida.

BACKGROUND: Tethered cord syndrome (TCS) is an increasingly recognized clinical condition, with untethering surgery considered the classically effective treatment. Yet, as evidence has aggregated, the surgical outcomes of untethering remain controversial. This study aimed to systematically evaluate the clinical outcomes in patients who underwent primary or revision untethering. METHODS: This retrospective study was conducted at the Department of Spine Surgery of Changzheng Hospital between January and December 2016. Patients with TCS who underwent untethering surgery were recruited for the study. Information collected included demographic data, main clinical manifestations, and outcomes after untethering surgery. RESULTS: A total of 112 patients (60 males and 52 females) were included in this study, with mean follow-up of 13.7 years. The surgical outcomes of the primary untethering varied among symptoms, with remission rates of 30.0% for pain, 24.4% for paresthesia, 18.6% for motor deficit, 12.6% for bladder dysfunction, and 21.2% for bowel dysfunction. Moreover, 23.3%-40.2% of patients suffered deterioration after surgery during the follow-up period. Twenty-eight patients underwent revision untethering surgery. In these patients, the remission rate decreased by 5.6%-16.7% compared with the primary operation. Moreover, most patients (58.8%-70.6%) experienced no benefits after revision surgery. CONCLUSIONS: With a possible high risk of recurrence, further exploration of the indications and timing of the untethering surgery is needed. Conservative treatment and omnidirectional care might be a better choice for patients with retethering with recurrent symptoms.

Long-term functional outcome after untethering surgery for a tethered spinal cord in patients with anorectal malformations.

BACKGROUND: Anorectal malformation (ARM) is associated with a tethered spinal cord (TSC). Long-term functional outcome of untethering surgery for TSC in patients with ARM has not been well evaluated. METHODS: Patients aged 7 years and older who underwent repair of ARM and spinal magnetic resonance imaging from January 1995 to December 2008 were reviewed retrospectively. Untethering surgery was performed in all patients who were diagnosed with TSC, regardless of the presence or of neurological symptoms. Clinical symptoms reflecting anorectal, urinary, and lower limb function were compared between patients complicated with TSC (TSC group, n = 17) and those without TSC (non-TSC group, n = 14). RESULTS: The median age at functional evaluation was 11.7 and 12.9 years in the TSC and non-TSC groups, respectively (p = 0.52). Untethering surgery for TSC was performed at a median age of 1.3 years. Preoperative urinary and lower limb dysfunction, except for vesicoureteral reflux in the TSC group in one patient, was improved after surgical detethering. Current anorectal function was comparable between the groups. CONCLUSIONS: Long-term functional outcome in patients with ARM and TSC undergoing untethering surgery is equivalent to that in those without TSC. Prophylactic surgical detethering for patients with ARM and TSC can be a treatment of choice to maximize neurological functional outcome.