Occult tethered cord syndrome: a rare, treatable condition

A 31-year follow-up of those with occult spinal dysraphism, who underwent spinal cord untethering: Lower urinary tract function, skin stigmata, fertility, and work participation

OBJECTIVES

This study evaluated patients with occult spinal dysraphism who underwent spinal cord untethering.

METHODS

Twenty-four patients who visited us between 1983 and 2000 were followed-up for a mean duration of 31 years. We studied their lower urinary tract function, skin stigmata, fertility, and work participation.

RESULTS

Questionnaires sent in 2022 revealed that 5 patients had normal voiding (Group A) and 19 patients had abnormal voiding (Group B). Groups A and B underwent spinal cord untethering at a mean age of 5.7 and 13.0 years, respectively, showing a significant statistical difference (p = 0.036). After spinal cord untethering, the number of patients with detrusor normoactivity increased from 0 to 5, i.e., 3 of 6 with detrusor overactivity (50%), 1 of 2 not examined, and 1 of 5 not known. Patients with detrusor underactivity also increased from 11 to 19. Severity of incontinence in the International Consultation on Incontinence Questionnaire-Short Form resulted in a mean value of 2.4 in Group A, which was significantly superior to the mean value of 9.1 in Group B (p = 0.004). Fourteen patients (58.3%) were married and had 21 healthy children. A majority of patients have had full-time jobs. A variety of skin stigmata were present in the lumbosacral region, and changes in vesico-urethral configurations were observed during a video-urodynamic study.

CONCLUSIONS

Our study identified that the early timing of spinal cord untethering performed in neonates or infants and detrusor overactivity prior to untethering surgery are important factors in achieving normal bladder function.

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

ABSTRACT

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Diagnosis and Management of Tethered Cord Syndrome

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

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.