Tethered Cord Syndrome Patients Research Articles

Endoscopic spinal cord untethering using a 1 cm skin incision technique in pediatrics: a technical case report

BackgroundSpinal cord untethering by sectioning the filum terminale is commonly performed in tethered cord syndrome patients with minor abnormalities such as filar lipoma, thickened filum terminale, and low conus medullaris. Our endoscopic surgical technique, using the interlaminar approach, allows for sectioning the filum terminale through a very small skin incision. To our knowledge, this procedure has not been previously reported. This is the first case report involving a 1 cm skin incision.Case presentationA 9-month-old male patient was referred to our neurosurgical department due to a coccygeal dimple. MRI revealed a thickened fatty filum. After considering the treatment options for this patient, the parents agreed to spinal cord untethering. A midline 1 cm skin incision was made at the L4/5 vertebral level. Untethering by sectioning the filum terminale was performed by full endoscopic surgery using the interlaminar approach. The procedure was uneventful and there were no postoperative complications.ConclusionsIn terms of visibility and minimizing invasiveness, our surgical technique of using the interlaminar approach with endoscopy allows for untethering by sectioning the filum terminale through a very small skin incision.

Is Intervertebral Disc Degeneration a Compensatory Mechanism in Adult Tethered Cord Syndrome?

The purpose of the present study was to evaluate the influence of high nerve tension on lumbar disc degeneration and sagittal morphologies. A total of 50 young and middle-aged patients (mean age 32.1±7.4years, 22 men and 28 women) who suffered from tethered cord syndrome (TCS) were retrospectively assessed by two observers. Demographic and radiological data were recorded, including lumbar disc degeneration, disc height index and lumbar spine angle, and were compared with 50 patients (mean age 29.7±5.4 years, 22 men and 28 women) without spinal cord abnormalities. Statistical associations were assessed by student's t-test and chi-square test. Our results showed patients with TCS had a significantly higher rate of lumbar disc degeneration in L1/2, L2/3, L4/5 and L5/S1 than in those without TCS (P < 0.05). Moreover, the rates of multilevel disc degeneration and severe disc degeneration in TCS group were significantly higher than those in control group (P < 0.01). The mean disc height index of L3/4 and L4/5 in TCS group was significantly lower than that in control group (P < 0.05). The mean lumbosacral angle of TCS patients was significantly higher than that of patients without TCS (38.4±3.5°vs. 33.7±5.9°, P < 0.01). We found a certain correlation between TCS and lumbar disc degeneration and lumbosacral angle enlargement, suggesting that the spine reduces the high tension of the spinal cord through disc degeneration. Therefore, it is speculated that there is a "compromised regulation" mechanism in the body under the condition of neurological abnormalities.

Comparison of Ultrasonographic Findings between Patients with Tethered Cord Syndrome and Healthy Children.

Tethered cord syndrome (TCS) is a type of occult spinal dysraphism, which necessitates early detection as an essential component of patient management in reducing complications. This study aimed to compare the findings of spinal cord ultrasonography between TCS patients and healthy individuals. The current study is a case-control study of patients who were admitted to the Akbar and Ghaem Hospitals (Mashhad, Iran) in 2019. The study population comprised 30 children with TCS aged under two years old, and the control group included 34 healthy peers of the same age. The maximum distance of the spinal cord from the posterior canal wall was measured in millimeters using ultrasonography. Demographic and sonographic findings of each participant were recorded in checklists, which were then entered into SPSS software. P values less than 0.05 were considered statistically significant. The study included 30 children with TCS and 34 healthy individuals with a mean age of 7.67±6.39 months. TCS patients had a significantly shorter maximum distance of the spinal cord from the posterior wall of the spinal canal than the control group (1.75±0.62 mm vs. 2.79±0.76, P<0.001). After performing corrective surgery, the TCS patients indicated significant improvement in this interval (1.57±0.54 mm to 2.95±0.49 mm, respectively, P=0.001). In comparison to children without TCS, the spinal cord was substantially closer to the posterior canal wall in TCS patients. However, these outcomes were improved significantly in patients after surgery.

Surgical treatment of tethered cord syndrome showed promising outcome in young children with short duration.

Aside from the severity, surgical interventions for the treatment of neurological dysfunctions remain controversial. This study aimed to find factors predicting the benefits of tethered cord syndrome (TCS) surgery. 80 children with TCS were included and followed up for pre- and post-operative factors along with neurophysiological analysis. Outcomes were assessed by univariate and multivariate analysis. Surgical treatment not only improved preoperative signs and symptoms in 79% of TCS patients but it showed to be an efficient procedure for the occurrence of future neurological defects. Univariate analysis also revealed that surgical intervention in TCS children (age <1 year) can modulate filar lipoma location and cutaneous abnormalities three months after surgery. Neurophysiological assessment revealed only 5.0% of surgical complications in TCS patients. Two patients had cerebrospinal fluid leakage, and two cases of CNS infection were detected. Surgical intervention is highly recommended for the prevention of neurological deficits in children with TCS. Electrophysiological monitoring revealed rare complications following the surgery.

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

This study aims to characterize tight filum terminale (TFT) in motor evoked potential (MEP) testing by comparing TFT patients with both tethered cord syndrome (TCS) patients and healthy subjects. Fifty TFT patients, 18 TCS patients, and 35 healthy volunteers participated in this study. We recorded MEPs following transcranial magnetic stimulation from the bilateral abductor hallucis muscles as well as compound muscle action potentials and F-waves evoked by electrical stimulation of the tibial nerve from the bilateral abductor pollicis brevis muscles. The peripheral conduction time (PCT) was calculated from the latency of the compound action potential and F-wave. Furthermore, the central motor conduction time (CMCT) was calculated by subtracting PCT from MEP latency. TFT and TCS patients had a significantly longer MEP latency than healthy subjects. PCT in TFT patients was significantly longer than those in TCS patients or healthy subjects. Using the cutoff values for PCT, we were able to diagnose patients with TFT patients with a sensitivity of 72.0% and a specificity of 91.4%. Prolonged PCT in the MEP test may be a useful indicator for TFT and suggests that MEP may be used as an adjunct diagnostic tool for TFT.

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

AbstractMagnetic 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 (&lt;18 years; 63%) and adult (&gt;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.

Tethered spinal cord syndrome in adults in the MRI era: recognition, pathology, and long-term objective outcomes.

Tethered cord syndrome (TCS) has been well described in pediatric patients. Many recent reports of TCS in adult patients have grouped retethering patients with newly diagnosed ones without separately analyzing each entity and outcome. The authors reviewed their experience of newly diagnosed adult TCS patients to identify and explore TCS misdiagnosis, recognition, subtype pathology, and individual objective outcomes. This study included 24 adult patients (20 female and 4 male) who fit the criteria of being newly diagnosed and aged 20 years and older (age range 20-77 years). Preexisting dermal sinus was present in 6 patients, hypertrichosis in 5, skin tag/cleft/dimple and fatty subcutaneous masses in 5, scoliosis in 2, and neurological abnormalities in 4 patients. The pathology consisted of TCS with taut filum in 8 patients, conus lipoma with TCS in 7, diastematomyelia in 7, and cervical cord tethering in 2 patients. Of the 24 study patients, nondermatomal low-back or perineal pain occurred in 19 patients, bladder dysfunction in 21, and motor, sensory, and reflex abnormalities in 21 patients. Aggravating factors were repeated stretching, multiple pregnancies, heavy lifting, and repeated bending. Urological evaluation included bladder capacity, emptying, postvoid residuals, detrusor function, pelvic floor electromyography (EMG), bladder sensitivity, and sphincter EMG, which were repeated at 6 months and 1 year postoperatively. The follow-up was 1 to 30 years. Detailed postoperative neurological findings and separate patient outcome evaluations were recorded. Four of the 24 patients did not have an operation. Resolution of pain occurred in 16 of the 19 patients reporting low-back or perineal pain. Motor and sensory complaints resolved in 17 of 20 patients. Regarding bladder dysfunction, in the 20 patients with available data, bladder function returned to normal in 12 patients, improved in 3 patients, and was unchanged in 5 patients. If the symptom duration was less than 6-8 months, there was recovery of all parameters of pain, bladder dysfunction, and neurological deficit, and recovery from hyperreflexia matched that from neurological deficit. Fifteen patients were employed preoperatively and returned to work, and an additional 3 others who were unable to work preoperatively were able to do so postoperatively. Most adults with newly diagnosed TCS have unrecognized neurocutaneous abnormalities and neurological deficits. The triad of nondermatomal sacral or perineal pain, bladder dysfunction, and neurological deficit should not be confused with hip or degenerative lumbosacral disease. Addressing the primary pathology often leads to successful results.

Evaluation of the Filum Terminale in Hereditary Equine Regional Dermal Asthenia.

The objectives of this study were to describe the anatomy, histology, and ultrastructure of the equine filum terminale (FT) and to describe the FT in hereditary equine regional dermal asthenia (HERDA), a model of human Ehlers-Danlos syndromes (EDS). Those humans suffer from tethered cord syndrome (TCS) caused by an abnormally structured FT wherein its attachment at the base of the vertebral column leads to long-term stretch-induced injury to the spinal cord. The pathophysiology of TCS in EDS is poorly understood, and there is a need for an animal model of the condition. Histopathologic and ultrastructural examinations were performed on FT from HERDA (n = 4) and control horses (n = 5) and were compared to FT from human TCS patients with and without EDS. Adipose, fibrous tissue, and neuronal elements were assessed. CD3 and CD20 immunohistochemistry was performed to clarify cell types (HERDA n = 2; control n = 5). Collagen fibrils were assessed in cross-section for fibril diameter and shape, and in longitudinal section for fibril disorganization, swelling, and fragmentation. The equine and human FT were similar, with both containing fibrous tissue, ependyma, neuropil, and nerve twigs. Hypervascularity was observed in both HERDA horses and human EDS-TCS patients and was not observed in equine or human controls. Moderate to severe abnormalities in collagen fibril orientation and architecture were observed in all HERDA horses and were similar to those observed in human EDS-TCS patients.

Growth profile assessment of young adults with tethered cord syndrome: a retrospective cohort analysis of Korean conscription data.

Tethered cord syndrome (TCS) is characterized by progressive spinal cord degeneration secondary to congenital spinal dysraphism. The associated accompanying physical inactivity and musculoskeletal deformities have raised interest in the growth profile of adult TCS patients. However, few previous studies have investigated the growth profile of adult TCS patients. We retrospectively reviewed the demographic data and medical records of 20-year-old Korean conscription examinees who were registered between April 2004 and September 2019. In total, 151 examinees with a diagnosis of TCS were enrolled. The height, weight, and body mass index (BMI) of 300 randomly selected examinees were compared to the TCS group. Obesity was defined by the World Health Organization and Asian-Pacific criteria for BMI and compared between the groups. Growth profile differences according to tethering location and musculoskeletal deformities were analyzed in both groups. The mean height, weight, and BMI values of the TCS group were lower than those of the control group. The TCS group had a lower proportion of obese and overweight individuals, and a higher proportion of underweight individuals, according to both BMI criteria. The tethering level was not associated with the degree of obesity in the tethered group. The mean height, weight, and BMI were lower in the tethered group regardless of the existence of musculoskeletal deformity. Enrollees with a history of TCS were smaller than controls of the same age. Monitoring of health behaviors, including nutrition, diet, and exercise, is warranted for TCS patients.

Is detethering necessary before deformity correction in congenital scoliosis associated with tethered cord syndrome: a meta-analysis of current evidence

To compare the clinical and radiological outcomes in patients with congenital scoliosis (CS) and tethered cord syndrome (TCS) undergoing deformity correction with (NI group) versus without (NNI group) prior neurosurgical intervention aimed at detethering the cord. A systematic review and meta-analysis were performed. The databases PubMed, Embase and Google Scholar were searched until March 2020. Inclusion criteria was studied describing performance of deformity correction and fusion surgery for congenital scoliosis with tethered cord syndrome with or without prior detethering procedure. Studies describing growth sparing procedures or congenital scoliosis associated with non-tethering pathologies such as syrinx were excluded. Case reports and series with less than 10 subjects were also excluded. NIH quality assessment tool was used for assessing quality of individual study. Sixteen studies were included for analysis of which eight were found to be retrospective case series (level IV evidence) and retrospective case–control studies (level III evidence) each. Overall proportional meta-analysis found no significant difference in correction rate, operative duration, blood loss or complication rate between the NI and NNI groups. However, subgroup analysis performed after inclusion of only level III evidence studies revealed significantly lesser operative duration and blood loss with comparable correction and complication rate in NNI group. Deformity correction and fusion surgery may be performed safely and effectively in CS with TCS patients without the need of a prior detethering procedure.

Tethered cord syndrome and transitional vertebrae.

Tethered cord syndrome (TCS) usually presents with low-lying conus medullaris and thickened filum terminale. Spinal cord anomalies usually accompany congenital malformations and variations of the vertebral column. Transitional vertebrae (TV) are common variant, especially in the lumbosacral region. Accurate definition of the spine level is essential for proper radiological diagnosis and treatment. In this study, congenital spinal cord and vertebral anomalies and the relation with TV groups and types were evaluated in TCS patients. The study was performed in 97 patients. Radiological imaging findings [computed tomography (CT), magnetic resonance imaging (MRI), and radiography] and medical records were evaluated. Spine bony malformation, spinal cord malformation, and spinal level of malformation were compared with TV and non-TV groups in TCS patients. In addition, TV groups and types were compared with each other for these anomalies. There was no statistically significant difference between TV and non-TV group in terms of the presence of vertebral bone and spinal cord anomalies. There were some significant differences in some of the spine bone and spinal cord anomalies among the groups and types of TV. Sixty-two point nine percent TCS patients had TV. Although these findings indicate that TV is common in patients with TCS, no significant difference is observed in most of the studied anomalies. However, there were some differences among the TV groups and TV types in relation to congenital malformations. It can be concluded that TV anomaly could be a distinct malformation apart from all the other anomalies that were studied. Transitional vertebrae may cause pain due to biomechanical changes in addition to progressive neurological symptoms which are usually seen with TCS.

Surgical Outcome of Children and Adolescents with Tethered Cord Syndrome

Study DesignRetrospective cohort study.PurposeTo 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 LiteraturePediatric patients with TCS continue to pose significant diagnostic and management challenges.MethodsWe 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.ResultsNineteen 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).ConclusionsEarly 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.

Comparison of Electrophysiological Outcomes of Tethered Cord Syndrome and Spinal Intradural Tumors: A Retrospective Clinical Study.

Electrophysiological evaluation of the outcomes of spinal procedures is important for neurosurgeons. Somatosensorial evoked potentials (SSEPs) are used for electrophysiological evaluation of tethered cord syndrome (TCS) and spinal intradural tumors (SIT). The aim of this study was to document the electrophysiological outcomes of surgery for TCS and SIT and to compare the results based on the preoperative diagnosis. The data of 30 patients, who were operated for TCS and SIT between 2011 and 2013, were reviewed retrospectively. Surgical release of the spinal cord was performed for TCS and tumor removal was performed for SIT. Median and tibial nerve SSEPs at the left and right sides were measured at preoperative, early and late postoperative periods and compared statistically based on the diagnosis and the time of electrophysiological assessment. The diagnosis was TCS in 12 (40%) patients and SIT in 18 (60%) patients. There was a significant difference between preoperative, and early and late postoperative SSEPs values. Tibial nerve latencies were prolonged in the early postoperative, but shortened in the late postoperative period. In contrast, median nerve latencies were shortened in the early postoperative, but prolonged in the late postoperative period. There was no significant difference between the TCS and SIT groups based on the surgical intervention. Tibial nerve latency may be prolonged in the early postoperative period of TCS and SIT patients. However, electrophysiological changes were not predictive for these patients. Further studies with more patients are needed for other spinal lesions.

Surgical treatment outcomes in children with tethered spinal cord syndrome. A prognosis on the basis of spinal 3T MRI tractography

The study objective was to identify factors affecting surgical treatment outcomes in children with tethered cord syndrome (TCS). The study included 21 TCS patients aged 1 to 14 years who underwent tethered cord release. The preoperative and postoperative data of clinical and neurophysiological examination and high field (3T) MRI tractography of the caudal spinal cord were compared. Regression of the TCS clinical and electrophysiological signs and the lack of pathological changes in the spinal cord tracts were observed in patients with filum terminale abnormalities and caudal lipomas after surgery. In patients with secondary spinal cord tethering caused by scar formation after lumbosacral myelomeningocele repair, a motor deficit was related to the interruption level of the spinal tracts, and surgical treatment did not lead to significant regression of the TCS clinical and electrophysiological signs. We consider the absence of pathological changes in the caudal spinal cord, based on spinal MRI tractography, as a favorable prognostic factor in TCS surgical treatment.

Utility of neurophysiology in the diagnosis of tethered cord syndrome.

The diagnosis of tethered cord syndrome (TCS) remains difficult, and the decision to operate is even more complex. The objective of this study was to examine how detailed examination of neurophysiological test results can affect the diagnosis for patients undergoing a surgical cord release. Patients undergoing tethered spinal cord releases were matched by age and sex with control patients undergoing scoliosis correction in the absence of spinal cord pathology. The latency and width of the P37 peak of the posterior tibial nerve somatosensory evoked potential (SSEP) and the motor evoked potential (MEP) latencies were examined. Immediate changes as a result of the surgical procedure were reported. The width of the P37 response differed significantly between TCS and control patients and changed significantly during the surgical procedure. Nonsignificant trends were seen in SSEP and MEP latencies. The width of the P37 response may be a useful marker for TCS and may play a role in presurgical decision making.

Microsurgical treatment for tethered cord syndrome

Objective To investigate the methods and results of microsurgical treatment for tethered cord syndrome (TCS).Methods The clinical manifestation,microsurgical methods,effects and complications of 49 patients with TCS treated in our department from March 2004 to March 2010 were studied retrospectively.Results 34 cases (70％) showed postoperative improvement during the hospitalization (5-10 days).44 patients were followed-up,during the ollow-up period (26-96 months),18％ of cases were healed,40％ of cases got significant improvement,29％ moderate improvement and 11％ of cases had no improvement.Tfhe overall efficiency rate was 87％.There was no serious complication.Post-surgery JOA scale is significantly improved comparing to pre-surgery (P ＜ 0.05).Conclusions The surgical effects could be significantly improved by applying different microneurosurgical techniques according to different preoperative manifestation of MRI and interoperative findings for TCS patients. Key words: Tethered cord syndrome; Microsurgical treatment

Wirbelsäulenerkrankungen und assoziierte ZNS-Fehlbildungen – Tethered-Cord und Arnold-Chiari-Fehlbildung

Tethered cord syndrome (TCS) and the Chiari malformation (CM) are generally related to congenital malformations, but both entities can be acquired.TCS often presents with progressing sensory and motor symptoms that can be attributed to increased tension of the spinal cord. Fixation of the spinal cord can occur congenitally (primary TCS) or in association with other intraspinal pathologies or postoperative scarring (secondary TCS). Exact diagnosis in the adult can be difficult if symptoms are interpreted as being related to degenerative disorders of the spine. In the presence of neurological symptoms, surgery is indicated. A preventive surgical procedure in asymptomatic patients is discussed controversially in the literature and is established in TCS patients only with correction of a scoliosis. However, most patients suffering from TCS benefit from surgical treatment.CM can be divided into four abnormal alterations of the posterior fossa, with most cases being of types I and II. In adults, Chiari type I is most common. Chiari I may present congenitally; however, it is also secondarily observed following lumboperitoneal shunting or in association with hydrocephalus. Surgical intervention is recommended depending on the extent of herniated tissue and the neurological symptoms. The optimal surgical procedure is still controversial. Most centers recommend bony decompression with dural graft extension for Chiari I.The appropriate treatment of both complex disorders requires a close and critical interdisciplinary approach in order to offer patients an individually adapted therapy.

Ultrastructural Study of the Filum Terminale and Its Elastic Fibers

The filum terminale (FT) is a fibrovascular band involved in the pathophysiology of tethered cord syndrome (TCS). Its morphological and ultrastructural properties remain largely unknown even though they are thought to play a role in the generation of TCS in adult patients with normal level conus medullaris. Twenty fresh adult human cadavers had their fila measured and removed. Transversal and longitudinal sections of the proximal, middle, and distal thirds of FT were submitted to light microscopy analysis with four different techniques. Five fila were selected for longitudinal and transversal scanning electron microscopy analysis. The bulk of the FT is composed of 5- to 20-microm thick longitudinal bundles of Type 1 collagen separated by 3- to 10-microm intervals, although capillaries and other elements may be present. A delicate (0.05-1.5 microm) meshwork of predominantly Type 3 collagen transversal fibers connects these bundles. Abundant longitudinally oriented elastic and elaunin fibers are found inside collagen bundles. A complex tridimensional structure is evidenced on electron microscopy. The longitudinal arrangement of collagen bundles and the impressive amount of elastic and elaunin fibers should elicit considerable elastic properties to the FT. An altered elasticity mechanism has been proposed for TCS; further studies are needed with TCS patients to define whether the collagen structure, Type 1/Type 3 proportion, or elastic fiber content are altered, which could lead to new histopathological definitions of TCS, helping neurosurgeons in the difficult management of TCS patients with normal level conus medullaris.

Adult tethered cord syndrome: relative to spinal cord length and filum thickness

The adults with tethered cord syndrome (TCS) are divided into two groups: group-1 adult TCS patients with spinal dysraphism; and group-2 patients without dysraphism who develop signs and symptoms in adulthood. A significant number of group-2 patients failed to show elongation of the spinal cord and abnormally thick filum terminale. This paper reports the combinations of the location of the caudal end of the spinal cord and the thickness of the filum terminale in 104 patients with group-2 adult TCS. The caudal end of the spinal cord was found at the L2–3 intervertebral space or above in 37 patients (35.6%) and below L2–3 level in 67 patients (64.4%). The diameter of the filum was <2 mm in 60 patients (57.7%) and ≥2 mm in 44 patients (42.3%). These data clearly indicate that the pre-operative diagnosis of adult TCS must rely primarily on the neurological symptomatology and the specific imaging feature, posterior displacement of the conus and filum that attach the posterior arachnid membrane.