Retained Medullary Cord in Humans: Late Arrest of Secondary Neurulation

Neurosurgery ◽  
2011 ◽  
Vol 68 (6) ◽  
pp. 1500-1519 ◽  
Author(s):  
Dachling Pang ◽  
John Zovickian ◽  
Greg S. Moes
Keyword(s):  
Spinal Cord ◽  
Cell Mass ◽  
Tethered Cord ◽  
Underlying Mechanism ◽  
Neurological Deficits ◽  
Tail Bud ◽  
Neural Structure ◽  
Nerve Roots ◽  
Secondary Neurulation ◽  
Caudal Spinal Cord

Abstract BACKGROUND: Formation of the caudal spinal cord in vertebrates is by secondary neurulation, which begins with mesenchyme-epithelium transformation within a pluripotential blastema called the tail bud or caudal cell mass, from thence initiating an event sequence proceeding from the condensation of mesenchyme into a solid medullary cord, intrachordal lumen formation, to eventual partial degeneration of the cavitatory medullary cord until, in human and tailless mammals, only the conus and filum remain. OBJECTIVE: We describe a secondary neurulation malformation probably representing an undegenerated medullary cord that causes tethered cord symptoms. METHOD: We present 7 patients with a robust elongated neural structure continuous from the conus and extending to the dural cul-de-sac, complete with issuing nerve roots, which, except in 2 infants, produced neurological deficits by tethering. RESULTS: Intraoperative motor root and direct cord stimulation indicated that a large portion of this stout neural structure was “redundant” nonfunctional spinal cord below the true conus. Histopathology of the redundant cord resected at surgery showed a glioneuronal core with ependyma-lined lumen, nerve roots, and dorsal root ganglia, corroborating the picture of a blighted spinal cord. CONCLUSION: We propose that these redundant spinal cords are portions of the medullary cord normally destined to regress but are here retained because of late arrest of secondary neurulation before the degenerative phase. Because programmed cell death almost certainly plays a central role during degeneration, defective apoptosis may be the underlying mechanism.

Tethered cord syndrome in adults

2011 ◽  
Vol 15 (3) ◽  
pp. 258-270 ◽  
Author(s):  
Jörg Klekamp
Keyword(s):  
Spinal Cord ◽  
Tethered Cord ◽  
Tethered Cord Syndrome ◽  
Neurological Deficits ◽  
Short Term ◽  
Group A ◽  
The Mean ◽  
Group B

Object The treatment of tethered cord syndromes in adults is discussed regarding the natural history and surgical indications. The author analyzes data obtained in patients who were diagnosed with a tethered cord in adulthood and either underwent surgical or conservative therapy between 1991 and 2009. Methods Since 1991, data obtained in 2515 patients with spinal cord pathologies were entered into the spinal cord database, and prospective follow-up was performed through outpatient visits and questionnaires. Of the 2515 patients, 85 adults with a tethered cord syndrome formed the basis of this study. The tethering effect was caused either by a split cord malformation, a thick filum terminale, a conus medullaris lipoma with extradural extension, or various combinations of these mechanisms. The mean age of the patients was 46 ± 13 years (range 23–74 years) and the mean follow-up duration was 61 ± 62 months. Two groups were distinguished based on the absence (Group A, 43 patients) or presence (Group B, 42 patients) of an associated lipoma or dysraphic cyst (that is, dermoid, epidermoid, or neurenteric cyst). Surgery was recommended for patients with symptoms only. Short-term results were determined within 3 months of surgery, whereas long-term outcomes (clinical recurrences) were evaluated using Kaplan-Meier statistics. Results For all patients, pain was the most common major complaint. Severe neurological deficits were rare. In Group A, 20 of 43 patients underwent surgery, whereas in Group B 23 of 42 patients underwent surgery. Among individuals who did not undergo surgery, 17 patients refused surgery and 25 patients underwent recommended conservative treatment. Short-term postoperative results indicated a significant improvement of pain and a stabilization of neurological symptoms. Long-term results showed a good prognosis in patients in whom first-time (that is, nonrevision) surgery achieved successful untethering, with a 10-year rate of neurological stabilization in 89% of Group A and a 10-year rate of neurological stabilization in 81% of Group B patients. The benefit of secondary operations in Group B was limited, with eventual clinical deterioration occurring in all patients within 10 years. For patients treated conservatively, follow-up information could be obtained in 33 of 42 patients. Twenty-eight patients remained in stable clinical condition. Only 5 of the conservatively treated patients experienced clinical deterioration over time; in 4 of these individuals with deterioration, surgery had been recommended but was refused by the patient. The clinical recurrence rate in all conservatively treated patients was 21% after 10 years. With a recommendation for surgery this figure rose to 47% within 5 years. Conclusions Surgery in adult patients with a tethered cord syndrome should be reserved for those with symptoms. In surgically treated patients, pain relief can often be achieved, and long-term neurological stabilization tends to persist more often than it does in conservatively treated patients. A conservative approach is warranted, however, in adult patients without neurological deficits. Revision surgery in patients with complex dysraphic lesions should be performed in exceptional cases only.

Segmental Spinal Dysgenesis

Neurosurgery ◽  
1988 ◽  
Vol 22 (4) ◽  
pp. 739-744 ◽  
Author(s):  
R. Michael Scott ◽  
Samuel M. Wolpert ◽  
Louis E. Bartoshesky ◽  
Seymour Zimbler ◽  
Lawrence Karlin
Keyword(s):  
Computed Tomography ◽  
Spinal Cord ◽  
Lower Limb ◽  
Thoracolumbar Spine ◽  
Spinal Column ◽  
Neurological Deficits ◽  
Spinal Instability ◽  
Nerve Roots ◽  
Limb Deformities ◽  
Focal Abnormality

Abstract Segmental spinal dysgenesis is characterized by focal agenesis or dysgenesis of the lumbar or thoracolumbar spine, with focal abnormality of the underlying spinal cord and nerve roots. Children are symptomatic at birth with lower limb deformities and neurological deficits that may be segmental. Myelography and computed tomography disclose hypoplastic or absent vertebrae and atrophic or absent neural elements adjacent to the bony deformity; the spinal column distal to the abnormality may be partially bifid, but is otherwise normal. Spinal ultrasonography was a helpful diagnostic adjunct in one patient. Surgery may be helpful in decompressing partially functioning spinal cord or nerve roots, but may exaggerate the tendency toward spinal instability. The embryology of this abnormality is not clear, but two children had other anomalies suggesting a spinal dysraphic syndrome, and its cause is probably related to a segmental maldevelopment of the neural tube.

scholarly journals Successful treatment of a patient with congenital kyphoscoliosis associated with tethered cord

2015 ◽  
Vol 22 (1) ◽  
pp. 64-69 ◽  
Author(s):  
Hui-Ren Tao ◽  
Tian-Li Yang ◽  
Michael S. Chang ◽  
Huan Li ◽  
Da-Wei Zhang ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Tethered Cord ◽  
Congenital Scoliosis ◽  
Conus Medullaris ◽  
Neurological Deficits ◽  
Common Finding ◽  
Vertebral Column Resection ◽  
Apical Vertebra ◽  
Shortening Osteotomy ◽  
Posterior Spine

Tethered cord is a common finding in congenital scoliosis. The most frequently advocated approach for this condition is to perform prophylactic detethering of the cord before scoliosis corrective surgery. The authors report on a 14-year-old patient with congenital thoracic kyphoscoliosis associated with a tethered cord, who developed progressive paraparesis and was successfully treated by posterior spine shortening osteotomy alone without prophylactic untethering. The patient had a 103° scoliotic curve together with a 93° kyphotic curve with an apical vertebra of T-7. Furthermore, he developed a significant progression of neurological deficits, including weakness of both legs and urinary and bowel incontinence. Preoperative MRI revealed that the spinal cord was entrapped by the apical vertebra and the low-placed conus medullaris was at approximately L-5. A posterior vertebral column resection of T-7 was performed for the purpose of simultaneously correcting the kyphoscoliosis and releasing tension on the tethered cord without a true detethering surgery. The patient's spinal cord function recovered completely from Frankel D to Frankel E by 6 months after the procedure. Evaluation at 31 months after surgery showed maintenance of good curve correction and normal neurological function.

scholarly journals Spinal column shortening for tethered cord syndrome associated with myelomeningocele, lumbosacral lipoma, and lipomyelomeningocele in children and young adults

2017 ◽  
Vol 19 (6) ◽  
pp. 703-710 ◽  
Author(s):  
Guillermo Aldave ◽  
Daniel Hansen ◽  
Steven W. Hwang ◽  
Amee Moreno ◽  
Valentina Briceño ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Young Adults ◽  
Spinal Column ◽  
Tethered Cord ◽  
Tethered Cord Syndrome ◽  
Neurological Deficits ◽  
Csf Leak ◽  
Cord Injury ◽  
Children And Young Adults

OBJECTIVETethered cord syndrome is the clinical manifestation of an abnormal stretch on the spinal cord, presumably causing mechanical injury, a compromised blood supply, and altered spinal cord metabolism. Tethered cord release is the standard treatment for tethered cord syndrome. However, direct untethering of the spinal cord carries potential risks, such as new neurological deficits from spinal cord injury, a CSF leak from opening the dura, and retethering of the spinal cord from normal scar formation after surgery. To avoid these risks, the authors applied spinal column shortening to children and transitional adults with primary and secondary tethered cord syndrome and report treatment outcomes. The authors' aim with this study was to determine the safety and efficacy of spinal column shortening for tethered cord syndrome by analyzing their experience with this surgical technique.METHODSThe authors retrospectively reviewed the demographic and procedural data of children and young adults who had undergone spinal column shortening for primary or secondary tethered cord syndrome.RESULTSSeven patients with tethered cord syndrome caused by myelomeningocele, lipomyelomeningocele, and transitional spinal lipoma were treated with spinal column shortening. One patient with less than 24 months of follow-up was excluded from further analysis. There were 3 males and 4 females; the average age at the time was surgery was 16 years (range 8–30 years). Clinical presentations for our patients included pain (in 5 patients), weakness (in 4 patients), and bowel/bladder dysfunction (in 4 patients). Spinal column osteotomy was most commonly performed at the L-1 level, with fusion between T-12 and L-2 using a pedicle screw-rod construct. Pedicle subtraction osteotomy was performed in 6 patients, and vertebral column resection was performed in 1 patient. The average follow-up period was 31 months (range 26–37 months). Computed tomography–based radiographic outcomes showed solid fusion and no instrumentation failure in all cases by the most recent follow-up. Five of 7 patients (71%) reported improvement in preoperative symptoms during the follow-up period. The mean differences in initial and most recent Scoliosis Research Society Outcomes Questionnaire and Oswestry Disability Index scores were 0.26 and –13%, respectively; minimum clinically important difference in SRS-22 and ODI were assumed to be 0.4% and –12.8%, respectively.CONCLUSIONSSpinal column shortening seems to represent a safe and efficacious alternative to traditional untethering of the spinal cord for tethered cord syndrome.

Surgical management of tethered spinal cord in adults: report of 54 cases

2001 ◽  
Vol 95 (2) ◽  
pp. 173-178 ◽  
Author(s):  
Sabine Hüttmann ◽  
Juergen Krauss ◽  
Hartmut Collmann ◽  
Niels Sörensen ◽  
Klaus Roosen
Keyword(s):  
Spinal Cord ◽  
Tethered Cord ◽  
Tethered Cord Syndrome ◽  
Neurological Deficits ◽  
Split Cord Malformation ◽  
Content Type ◽  
Adult Age ◽  
Pregnancy And Childbirth ◽  
Pain Status ◽  
Fine Print

Object. The clinical features specific to tethered cord syndrome (TCS) in adults as well as factors determining outcome and prognosis have rarely been addressed systematically. The authors studied 56 patients, 54 of whom were treated surgically over the last 16 years. Methods. In 17 patients who had been asymptomatic during childhood, TCS was diagnosed 8 years after onset of symptoms. Tethered cord syndrome was diagnosed 4 years after worsening in 39 patients with neurological signs or symptoms since childhood. The patients were followed for an average of 8 years. Features specific to adult-age presentation included nondermatomal pain aggravated by movement in 34 patients and conditions such as pregnancy and childbirth (in five of 11 pregnant patients). The most frequent tethering lesions were lipoma in 32, tight terminal filum in 28, and split cord malformation and secondary adhesions in 12 patients, respectively. Improvement or stabilization of symptoms at 6 months after surgery was noted in 46 (85%) of 54 patients. Improvement in pain status was most frequent (86%) followed by improvements in spasticity (71%), bladder dysfunction (44%), and sensorimotor deficits (35%). Factors associated with adverse outcome included preoperative duration of neurological deficits more than 5 years and incomplete untethering. On average, 8 (80%) of 10 patients with incomplete untethering developed recurrent symptoms 5 years after surgery compared with only seven (16%) of 44 patients in whom complete untethering was achieved. Seven patients underwent reoperation and in five of them stabilization of symptoms was attained. At a mean follow up of 8 years, 46 (85%) of the 54 surgically treated patients were in stable neurological condition, including those in whom reoperation was performed. Conclusions. Surgery for TCS is as beneficial in adults as it is in children. Its success depends on early diagnosis and complete untethering of the spinal cord.

Vertebral column subtraction osteotomy for recurrent tethered cord syndrome in adults: a cadaveric study

2006 ◽  
Vol 4 (6) ◽  
pp. 478-484 ◽  
Author(s):  
Andrew W. Grande ◽  
P. Colby Maher ◽  
Chad J. Morgan ◽  
Ondrej Choutka ◽  
Benjamin C. Ling ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Vertebral Column ◽  
Tethered Cord ◽  
Tethered Cord Syndrome ◽  
Thoracolumbar Junction ◽  
Neural Element ◽  
Nerve Roots ◽  
Tension Reduction ◽  
Increased Risk ◽  
Fresh Frozen

Object The standard treatment for lumbosacral tethered cord syndrome (TCS) in adults is surgical detethering. In patients with recurrent TCS, additional detethering operations are associated with increased risk of complications and subsequent scar formation. The authors studied the effect of undertaking a vertebral column subtraction osteotomy (VCSO) at the thoracolumbar junction to shorten the vertebral column and reduce neural element tension. Methods A model of TCS, developed in fresh-frozen human cadavers, was evaluated in three experiments. In Experiment 1, VCSO of 20 to 25 mm was performed at the T11–12 level. The vertebral column was sequentially shortened and the reduction in tension was measured separately in the terminal filum and the L-1 to S-3 or S-4 nerve roots. In Experiments 2 and 3 the reduction in tension was measured in the spinal cord after a VCSO and after simulating a traditional detethering operation. Vertebral column shortening produced tension reduction in all experiments. Tension decreased to less than 0.6 g in the terminal filum, L1–S3/4 nerve roots, and spinal cord after closure of a 20- to 25-mm VCSO. The mean ± standard deviation of the Δtension/Δdistance was −0.242 ± 0.019 g/mm for the terminal filum, −0.246 ± 0.019 g/mm for the lumbar nerve roots, and −0.216 ± 0.040 g/mm for the sacral nerve roots. A simulated traditional detethering operation required significant neural element release (detethering) to achieve spinal cord tension reduction equivalent to VCSO. Conclusions A VCSO significantly reduced neural tension at the thoracolumbar junction. This novel procedure may provide an alternative to traditional surgical detethering when scarring is excessive and the risk of complications and retethering are high.

Progressive posttraumatic myelomalacic myelopathy: treatment with untethering and expansive duraplasty

1997 ◽  
Vol 86 (4) ◽  
pp. 624-628 ◽  
Author(s):  
Thomas T. Lee ◽  
Jose M. Arias ◽  
Heather L. Andrus ◽  
Robert M. Quencer ◽  
Steven F. Falcone ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Mr Imaging ◽  
Motor Function ◽  
Tethered Cord ◽  
Sensory Function ◽  
Autonomic Dysreflexia ◽  
Nerve Roots ◽  
Content Type ◽  
Fine Print

✓ Patients with progressive posttraumatic myelomalacic myelopathy (PPMM), or tethered cord syndrome, present with symptoms and signs similar to those observed in cases of progressive posttraumatic cystic myelopathy, that is, sensorimotor function deterioration, local and/or radicular pain, increased spasticity, increased autonomic dysreflexia, and sphincter dysfunction. The authors investigated surgical outcomes of untethering combined with expansive duraplasty. Forty patients with PPMM who presented with functional deterioration underwent untethering of the spinal cord and nerve roots with an expansive duraplasty. Meticulous dissections of adhesions on the dorsal and lateral aspects of the spinal cord and nerve roots were performed. Intraoperative ultrasonography was used to detect the presence of a confluent cyst and to assess the success of untethering. After surgery, the patients were treated using a protocol that involved frequent turning for 48 hours and subsequently mobilization. Preoperative magnetic resonance (MR) imaging, with and without administration of a contrast agent, was obtained in all patients, except one patient who underwent immediate and delayed computerized tomography (CT) myelography. The mean follow-up period was 3 years (range 20–57 months) for the 36 patients available for follow-up review. Spinal cord tethering was observed in all patients preoperatively. Trauma was the most common cause of this pathology, accounting for 31 of the 40 cases. Preoperative MR imaging did not demonstrate tumor recurrence in the group of five patients who had undergone an initial operation for tumor excision. The interval between the causative event and the operation was less than 5 years in half of the patients (20 of 40), with the longest interval lasting up to 37 years. Motor function deterioration was the most frequent manifestation; it was present in 31 of 40 patients. Improvements in motor function, autonomic dysreflexia, pain, sphincter dysfunction, and sensory function were found during the most recent follow-up examination in 79%, 75%, 62%, 50%, and 43% of the patients, respectively. Two patients experienced retethering of the spinal cord and one underwent a second operation. Surgical untethering and expansive duraplasty, followed by postoperative position rotation to avoid retethering, provide symptomatic relief for patients with PPMM.

Spine-shortening osteotomy for patients with tethered cord syndrome caused by lipomyelomeningocele

2011 ◽  
Vol 15 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Shoichi Kokubun ◽  
Hiroshi Ozawa ◽  
Toshimi Aizawa ◽  
Ngo Minh Ly ◽  
Yasuhisa Tanaka
Keyword(s):  
Spinal Cord ◽  
Japanese Orthopaedic Association ◽  
Tethered Cord ◽  
Tethered Cord Syndrome ◽  
Neurological Deficits ◽  
Thoracic Myelopathy ◽  
Shortening Osteotomy ◽  
Cord Injury ◽  
Rod System

Object Tethered cord syndrome (TCS) is a disorder involving an abnormal stretching of the tethered spinal cord caused by several pathological conditions and presents with a variety of neurological symptoms. Untethering (tethered cord release) is the gold standard treatment for TCS. However, untethering carries risks of spinal cord injury and postoperative retethering. To avoid these potential risks, the authors applied spine-shortening osteotomy to adult patients with TCS, and report on the surgical procedure and treatment outcomes. Methods Eight patients with TCS caused by a lipomyelomeningocele were surgically treated by the authors' original procedure of spine-shortening osteotomy. Six patients were male and 2 were females; average age at the time of surgery was 31 years old. Spine-shortening osteotomy was performed at the level of L-1 in all but 2 patients, in whom it was performed at T-12, with spinal fusion between T-12 and L-2 or T-11 and L-1 using a pedicle screw–rod system. The average follow-up period was 6.2 years and the patients' pre- and postoperative conditions were evaluated clinically and radiologically. Results Preoperatively, all patients displayed severe neurological deficits such as motor disturbance, muscle atrophy, and bladder dysfunction. Several months before surgery, all showed progressive symptoms. Those symptoms showed initial improvement in 6 patients and stabilized in 2 postoperatively, but the improved symptoms worsened again in 4 of the 6 patients. The osteotomized vertebrae were shortened by 21 mm on average, and all spines showed complete bone union without loss of correction. At the final follow-up evaluations, 6 patients showed stabilization as per the modified Japanese Orthopaedic Association score for thoracic myelopathy. Conclusions Spine-shortening osteotomy successfully helps reduce the spinal cord tension without causing direct neural damage. At minimum, it stabilized the patients' symptoms and/or helped delay neurological deterioration for a period of time. Spine-shortening osteotomy might be a feasible mode of treatment for adult TCS caused by a spinal lipoma.

Reversal of longstanding neurological deficits after a late release of tethered spinal cord

2010 ◽  
Vol 29 (1) ◽  
pp. E11 ◽  
Author(s):  
Gaurav Gupta ◽  
Robert F. Heary ◽  
Jennifer Michaels
Keyword(s):  
Spinal Cord ◽  
Pediatric Population ◽  
Tethered Cord ◽  
Tethered Cord Syndrome ◽  
Neurological Deficits ◽  
Early Surgery ◽  
Tethered Spinal Cord ◽  
Limited Data ◽  
Neurological Improvement ◽  
Asymptomatic Patients

The importance of early surgery for tethered cord syndrome in the pediatric population is well established. Optimal treatment and prognosis of tethered cord in adults, on the other hand, is less clear. Some advocate a conservative approach in asymptomatic patients, while others recommend early detethering in all patients. For symptomatic patients, however, there is a consensus in favor of early surgery to prevent progression of neurological deficit. Many studies have reported cessation of neurological decline or reversal of recently acquired neurological deficits in patients with adult tethered cord syndrome. There are limited data in the literature about late surgery for the treatment of tethered spinal cords when the neurological deficits are longstanding. We report on a 37-year-old woman who demonstrated dramatic neurological improvement after surgical release of a tethered spinal cord more than 20 years after the onset of progressive neurological deficits.

The Mode of Growth of the Tail in Urodele Larvae

Development ◽  
1958 ◽  
Vol 6 (3) ◽  
pp. 466-478
Author(s):  
J. Hubertha Bijtel
Keyword(s):  
Spinal Cord ◽  
Neural Tube ◽  
Cell Mass ◽  
Vital Staining ◽  
Neural Plate ◽  
Tail Bud ◽  
Morphogenetic Movements ◽  
Separate Cell ◽  
A Cell ◽  
Axial Organs

The idea that the hinder part of the trunk together with the tail or the tail alone develops by the outgrowth of a cell mass which is in every respect indifferent has been disproved since 1928 for the Amphibia. The results of experiments with vital staining (Bijtel & Woerdeman, 1928; Bijtel, 1929, 1931) and with microsurgical methods (Bijtel, 1936) have shown that the presumptive rudiments of the tail organs (epidermis, spinal cord, muscle segments, tail-gut) are already present in the neural plate stage as more or less separate cell territories. During and immediately after the transformation of the neural plate into the neural tube, these cell territories are brought together into the tail-bud by morphogenetic movements. Holmdahl (1939 a, b, 1947) and Vogt (1939) have criticized this conception. They adhered to the view that the organs of the hinder part of the runk and of the tail (Holmdahl) or only the axial organs of the tail (Vogt, p. 127) originate from an indifferent blastema.

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