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 cord syndrome and transitional vertebrae.

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Fatty filum terminale (FFT) as a secondary tethering element in children with closed spinal dysraphism.

PURPOSE: The purpose of this study was to assess the prevalence of FFT as an additional tethering element in children operated for closed spinal dysraphism, where FFT was not the primary tethering pathology. METHODS: This is a retrospective study of 195 children (< 18 years of age) who underwent surgery for closed spinal dysraphism and did not have FFT as the primary diagnosis. All patients were operated during the period 2005-2017 by a single surgeon. The commonest diagnosis was a lipomyelomeningocele (LMMC, n = 81, 41.5%), followed by split cord malformations (SCM, types I and II, n = 61, 31.3%), dermal sinus (n = 28, 14.4%), and dermoid cyst (n = 10, 5.1%). Factors such as age and sex, presenting symptoms, intraoperative findings, and radiological presence of a FFT on a magnetic resonance imaging (MRI) were documented, and the relationship between the primary diagnoses and presence of FFT was analyzed. RESULTS: FFT as a secondary finding was seen in 63 patients (32.3%). The mean age of the cohort was 54 months (4.5 years) and the sex distribution was relatively even (51.8% girls). The commonest symptom at presentation was a swelling in the back, followed by lower limb weakness. The mean duration of symptoms was nearly 30 months. FFT was seen on the MRI and confirmed intraoperatively in 55 patients (28.2%). There were 8 patients (4.1%) where a FFT was seen intraoperatively, but was not diagnosed on the preoperative MRI. In 16 patients, FFT was seen > 2 segments away from the primary tethering pathology, 8 of which mandated a second skin incision for sectioning of the FFT. Secondary FFT was most commonly associated with a SCM (types I and II combined) and was seen in 42.6% of those patients. It was least commonly associated with intradural dermoid cysts. CONCLUSION: The presence of a secondary FFT should be considered and actively sought on preoperative thin-slice T1W axial MR images in the sacral region in all patients with spinal dysraphism. Even if a FFT is not seen on preoperative MR images, the filum should be explored and sectioned if it is in the vicinity of the primary surgical field, especially in patients with SCM.

Sirenomelia and caudal malformations in two families.

We report on two families with co-occurrence of sirenomelia and caudal malformations. In the first family, the mother had undergone surgery for a short form of imperforate anus. Her first pregnancy was terminated because of bilateral renal agenesis with oligohydramnios. Her second pregnancy was interrupted because of sirenomelia. The second family was referred to us because of caudal malformation in their two children. The parents' spinal radiographs were normal. The first pregnancy resulted in a girl with imperforate anus, absence of S3-S5 and coccyx, abnormal pelvic floor, and an almost bifid anteriorly located bladder. The second pregnancy resulted in a baby girl with sirenomelia. No diabetes was present during the pregnancies in either of these two families. These families confirm the hypothesis that major genes are responsible for the embryogenesis of the caudal part of the embryo, with variable expression, as has been already described in sirenomelia mouse models (CYP26A1, BMP7/tsg). Molecular studies are underway in these families and in sporadic cases in our laboratory to explore the genetic basis of sirenomelia in humans.

Ultrasonography reveals a high prevalence of lower spinal dysraphism in children with urogenital anomalies.

BACKGROUND: Lower spinal dysraphism is frequently reported in anorectal anomaly combined with urogenital anomalies. The prevalence of the spinal dysraphism has not been comprehensively studied in children with simple urogenital anomalies. We evaluated the prevalence of the spinal dysraphism using ultrasound data of the lumbosacral area in children with urogenital anomalies. METHODS: Lumbosacral ultrasound images of 259 children who underwent urological surgery with simple urogenital anomalies were reviewed by an ultrasound-specialized radiologist. The primary outcome measures were the conus medullaris (CM) level and the thickness of the filum terminale. The spinal ultrasonographic findings that were assessed in children showed abnormal spinal findings compared with the other children having normal findings. Two years later, the follow-up telephone interviews were made with the parents of the children with abnormal findings. RESULTS: Eighteen children were differentiated as the abnormal finding group. They were suspected of spinal cord tethering. The level of CM was lower, and the filum terminale was thicker compared to the normal group [L2(lower (L)) vs. L1(L), 2.2 mm vs. 0.8 mm]. Of eighteen children, four were confirmed as tethered spinal cord with lipoma on magnetic resonance imaging by the time of surgery, and two were strongly suspected of occult spinal dysraphism (OSD) based on ultrasound findings and follow-up interviews. CONCLUSIONS: The prevalence of OSD in children under 24 months of age with simple urogenital anomaly was higher than what was reported for the general population. Ultrasound examination of spinal structures before caudal block in children with urogenital anomaly should be considered.

Multiple spinal cavernous malformations in Klippel-Trenaunay-Weber syndrome.

Klippel-Trenaunay-Weber syndrome (KTWS) is a rare, congenital vascular disorder characterized by cutaneous haemangiomas, venous varicosities, and hypertrophy of the osseous and soft tissue. Various vascular anomalies of the central nervous system have been described in this syndrome. Two previous associations between KTWS and spinal cord cavernous malformations have been reported in the English literature. In this report, we present a patient in whom multiple cavernous malformations located in the conus medullaris region and cauda equina were associated with KTWS. General physical examination as well as neuroradiological and operative findings are described.

Cauda Equina Arteriovenous Malformation with Bilateral Arterial Feeders.

Cauda equina arteriovenous malformation (AVM) is extremely rare. To our knowledge, only 2 cases have been reported previously and are supplied by a unilateral lateral sacral artery (LSA). Here, we report a rare cauda equina AVM at the level of L5-S1, which is supplied by the bilateral LSAs. Given the multiple feeders and complex angioarchitecture, endovascular embolization was performed with Onyx (ev3) successfully. The postoperative course of the patient was uneventful, and symptoms gradually improved. The present case demonstrated the angioarchitecture of the bilateral arterial supplies and venous drainage of the cauda equina AVMs. Cauda equina AVM with bilateral arterial feeders is extremely rare. However, clinicians should be aware of the possibility of this condition and the importance of selective spinal angiography of bilateral LSAs.

Fatty filum with different histological features. Case report.

Split cord malformation and fatty filum are completely different clinical entities and thought to arise via different pathophysiologies. Recognition of these distinct lesions in the same patient is important for appropriate diagnosis and management. A 3 year-old boy presented with skin lesions and mild leg weakness suggestive of spinal malformation. Magnetic resonance imaging revealed type II split cord malformation at T12-L1, syringomyelia at T8-T10 levels associated with tethered cord and fatty filum terminale. The patient underwent a T12-L1 laminotomy for the removal of fibrous band between the 2 hemicords and L4-L5 laminotomy for transection of the fatty filum. Histopathological examination of the filum confirmed the presence of bone, fat, and ciliated epithelial cells associated with meningothelial proliferation in the same specimen. We report an unusual case of type II split cord malformation coexisting with a fatty filum which have different histological patterns. To the best of our knowledge, this histological appearance of a fatty filum has not yet been reported and this raises the question of a possible associative or causative relationship between these distinct pathologies.

Tethered Cord Syndrome Caused by Duplicated Filum Terminale in an Adult with Split Cord Malformation.

BACKGROUND: Tethered cord syndrome (TCS) is a clinical diagnosis of progressive neurologic aggravation of the lower spinal cord due to a traction on the conus medullaris. Untethering surgery is effective for most TCS; however, when anatomic variations of spinal cord and filum terminale (FT) exist, regular untethering may lead to a failed outcome. CASE DESCRIPTION: The authors present the case of a 45-year-old patient with TCS caused by duplicated FT with split cord malformation (SCM). Lumbosacral magnetic resonance imaging revealed a type II SCM with a significant low-lying conus medullaris. Laminectomy was performed. Neurophysiologic monitoring was used for nerve root identification and 2 thickened fila, which failed to respond on stimulation, were found during the surgery. Both fila were sectioned, and the diagnosis was finally confirmed by pathologic examination. Postoperatively, the patient's symptoms disappeared immediately and no neurologic sequela was found after surgery. CONCLUSIONS: This is the first documented adult of duplicated FT with preoperative radiologic evidence and reported in association with SCM as a cause of TCS. When SCM exists, a careful observation for duplicated FT is warranted on preoperative magnetic resonance imaging and during surgery. Complete transection of the double FT under intraoperative neurophysiologic monitoring is the best treatment for this anomaly.

Endoscopic spinal tethered cord release: operative technique.

PURPOSE: This study aims to describe solely endoscopic surgical techniques for the treatment of spinal pathology. Here, we present a novel endoscopic technique for surgical untethering of the spinal cord by filum sectioning and discuss endoscopic surgical management of this entity. METHODS: Two patients (ages 8 months and 10 years) presented with leg weakness, urine and bowel dysfunction, low back and neck pain, and thickened, fatty filum terminale. The elder patient presented with clinical incontinence and abnormal urodynamic studies. RESULTS: Both patients underwent a solely endoscopic approach using 0 degrees and 30 degrees , 4 mm in diameter and 18 cm in length rigid endoscopes via a hemilaminectomy. Intradural microdissection under a direct visualization of endoscope delivered the fatty filum into the durotomy. Electrical stimulation was performed while the lower extremities and the anal sphincter were monitored for electromyographic activity. After acquisition of positive controls, the filum was identified by the lack of sphincter and lower extremity electromyographic responses and was then cauterized and cut. Both patients had significant improvement of their preoperative symptoms, and one patient had resolution of the abnormal urodynamics and her Chiari symptoms. CONCLUSION: Tethered spinal cords can be safely and effectively untethered endoscopically. This procedure provides the advantages of reduced soft tissue injury, less postoperative pain, minimal blood loss, a smaller incision, and a shorter hospitalization. However, whether the endoscopic untethering technique achieves benefits above those associated with the open procedure remains to be determined by a control study.

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.

Congenital spinal lipomatous malformations: part I--Classification.

BACKGROUND: Congenital spinal lipomatous malformations constitute a diverse group of lesions. There is considerable confusion in the literature regarding their terminology and a proper classification is long overdue. The first part of this two part report sets out a proposed classification scheme. METHODS: On the basis of this author's experience with 80 patients with a congenital spinal lipomatous malformation treated over a 10 year period, a new classification is proposed. The proposed classification divides congenital spinal lipomatous malformations into two broad groups: 1. Lipomas without dural defect and, 2. Lipomas with dural defect. Within each group, there are several subtypes. These two broad groups differ from one another in their embryology, clinical presentation, operative findings, complications and prognosis FINDINGS: Group I consists of Lipomas without dural defect. Included in this group are: Filum lipoma, caudal lipoma without dural defect, and intramedullary lipoma. Group II consists of lipomas with dural defect. Included in this group are: dorsal lipoma, caudal lipoma with dural defect, transitional lipoma, lipomyelocele, and lipomyelomeningocele. The definitions of the various subtypes and radiological and operative findings of all these lesions are described. CONCLUSIONS: Congenital spinal lipomatous malformations constitute a wide spectrum of lesions ranging from relatively simple lipomas of the filum terminale to complex malformations. These lesions differ from one another in their embryology, clinical presentation, operative strategies, complications and prognosis. Failure to differentiate between the different forms of congenital spinal lipomatous malformations may lead to inaccurate assumptions regarding prognosis and inappropriate management. The proposed classification seeks to address these issues.

Congenital spinal lipomatous malformations: part II--Clinical presentation, operative findings, and outcome.

BACKGROUND: To report this author's experience with patients with a congenital spinal lipomatous malformation with special emphasis on variations in clinical presentation, operative findings, and outcome based on the classification scheme proposed in the first part of this two part article. METHODS: From January 1995 to July 2005, 80 patients with a congenital spinal lipomatous malformation were treated. All patients underwent routine neurological examination, plain radiographs of the spine and all but 10 patients underwent MRI. Ten patients underwent CT-myelography. Hoffman's functional grading scale was used for preoperative and postoperative clinical assessment. The operative findings, complications and outcome were assessed. FINDINGS: Age ranged from 18 days to 19 years. The female: male ratio was 3:2. The malformations were divided into two groups: Group I: Lipomas without a dural defect and, Group II: Lipomas with a dural defect. Included in Group I were: 22 patients out of which there were Caudal lipomas: 10, Filum lipomas:11 and intramedullary lipoma: 1. In Group II there were 58 patients out of which there were Dorsal lipomas: 8, Caudal lipomas with dural defect: 8, Transitional lipomas: 10, lipomyelomeningoceles:28, lipomyeloceles: 4. Most of the group I patients were >5 years of age; cutaneous markers were absent in 60%, older children more often presented with sphincter disturbances. Surgery in group I was straight forward and consisted of sectioning of the filum in filum lipomas, debulking and untethering in caudal lipomas. Duroplasty was seldom required. CSF leak was rare. No patient deteriorated following surgery and no retethering was noted during follow-up. In Group II, all patients had cutaneous markers, most were <2 years of age, 19 were asymptomatic, older children had more severe neurological deficits. Duroplasty was required in most cases. A CSF leak occurred in 12%. Two patients deteriorated temporarily following surgery. Two patients presented with retethering 4 and 8 years after initial surgery. Improvement of more than one Hoffman's functional grade occurred when surgery was done <2 years of age. CONCLUSIONS: Congenital spinal lipomatous malformations do not constitute a single homogenous entity. They can be broadly classified into two groups depending on the presence or absence of a dural defect. These two groups are different from one another embryologically, clinically, surgically and prognostically.

The clinical significance of redundant nerve roots of the cauda equina in lumbar spinal stenosis patients: A systematic literature review and meta-analysis.

OBJECTIVES: Decompression surgery for lumbar spinal stenosis (LSS) is the most performed spine surgery procedure in patients older than 65 years. Around 40% of LSS patients scheduled for decompression surgery have evidence of redundant nerve roots (RNR) of the cauda equina on their magnetic resonance images (MRI). Little is known about the clinical significance of RNR in LSS patients. The objective was to assess the effects of RNR on clinical scores and recovery in older adults diagnosed with LSS. PATIENTS AND METHODS: A systematic literature search was performed in April 2018 on PubMed, Web of Science, MEDLINE and Cumulative Index to Nursing and Allied Health Literature (CINAHL). Prospective and retrospective cohort studies undertaken to assess differences in clinical outcomes in patients diagnosed with LSS with versus without evidence of RNR on their MRIs were selected. Two authors independently selected studies, abstracted data and assessed risk of bias. We calculated weighted mean differences (WMD) for continuous variables and odds ratio (OR) for variables reported in frequencies. RESULTS: Seven studies comprising a total of 1046 LSS patients were included in the meta-analysis. LSS patients with evidence of RNR (RNR+) were older, WMD 5.7 95% CI [2.2-9.2], p = 0.001, had smaller cross sectional area (CSA) of the stenotic level, WMD -12.2 95% CI [-17.7 to -6.7], p < 0.0001 and longer symptom onset duration, WMD 13.2 95% CI [-0.2-26.7], p = 0.05. The pooled preoperative clinical score in the RNR + group was worse but the difference was not statistically significant, WMD -3.8 95% CI [-7.9 to 0.2], p = 0.07. After decompression surgery RNR + patients had worse clinical scores, -4.7 95% CI [-7.3 to -2.1], p = 0.0004 and lower recovery rates, -9.8 95% CI [-14.8 to -4.7], p = 0.0001. CONCLUSION: There is limited quality evidence that RNR + patients are older, have a longer symptom history and present higher degrees of lumbar stenosis as given by the narrow CSA in comparison to RNR- patients. After decompression surgery RNR + patients have worse clinical scores and lower recovery rates. In view of these results RNR can be seen as a negative prognostic factor in LSS patients.

Crossed fused renal ectopia with segmental fusion of bilateral ureters and abdominal aortic anomalies in a patient with caudal regression syndrome.

Caudal regression syndrome consists of multiple congenital anomalies, mainly caudal segment defects. We describe a preterm baby born to a healthy mother with typical caudal regression picture, including imperforated anus with rectovesical fistula, sacral agenesis, multiple rib and vertebral anomalies, and club feet. Crossed fused renal ectopia with fused ureters resulting in urinary obstruction was managed with transureteroureterostomy and cutaneous vesicostomy. We also found a single large umbilical artery with high abdominal aortic insertion which usually presents in sirenomelia. Because of the anatomical diversity of the urinary and cardiovascular systems associated with multiple congenital anomalies, careful evaluation is mandatory.

Duplicated filum terminale in non-split cord malformations: An underrecognized cause for treatment failure in tethered cord syndrome.

CONTEXT: Anatomical variations of the filum terminale (FT) have been described in association with split cord malformations (SCM) but they appear to be a rare finding in its absence. We report the first case in literature of a duplicated FT in a patient presenting with tethered cord syndrome (TCS) without any radiological evidence of SCM. FINDINGS: A 47-year-old man presented with invalidating back pain radiating to both legs. Magnetic resonance imaging revealed an intradural dorsal lipoma in a low-lying conus. Intraoperatively two distinct fibrous bands were anatomically and electrophysiologically identified as the FT and both were sectioned. The diagnosis of FT was confirmed for both specimens by histology. CONCLUSION: In absence of SCM, a duplicated FT has not been previously described as a cause of TCS. It may be a cause of treatment failure for TCS if unrecognized on preoperative imaging and during surgery if one filum remains intact. We highlight the importance of a meticulous cauda equina dissection supported by intraoperative nerve stimulation to identify this rare anomaly. We hypothesize that this entity may represent a variant of SCM involving the caudal neural tube but which requires further validation at an embryological level.