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The term meningocele manqué (MM) was coined in 1972 to describe a broad range of surgical findings characterized by intradural bands tethering neural structures to the dorsal dura. Over the following decades, reports continued to lump intradural tethering bands associated with a variety of comorbidities under the umbrella term MM. In more recent years, disorders previously called MM have been identified as embryologically distinct and were reclassified. While this sectioning continues, there remains a set of intradural tethering disorders for which no better term than MM exists. Herein, we comprehensively review the literature surrounding MM, including embryological disorders, clinical, radiographic, and surgical presentation, as well as alternative classification methods and MM treatment.

Introduction: A discontinuous, functionally disconnected spinal cord is an extremely rare finding, with only three known reports in the literature. Titled junctional neural tube defect (JNTD), this newly reported dysraphism is believed to arise from a developmental error occurring during junctional neurulation, a transitory stage of development marked by the end of primary neurulation and the beginning of secondary neurulation. Herein, we report a newborn case of JNTD., Case Report: We report a newborn boy born with anorectal atresia. Physical examination revealed normal movement in the upper and lower extremities. Imaging revealed distal sacral agenesis and a spinal cord that was discontinuous at the thoracolumbar junction. Three vertebral segments inferiorly, at the L2 vertebral level, the distal end of the spinal cord (i.e., conus medullaris) were visualized. No signs of a tethered cord were identified., Conclusions: Characterized by an error in junctional neurulation in which the primary and secondary NT fail to integrate appropriately, JNTD has been recently classified. We believe the current patient to represent only the fourth reported case of JNTD in the literature.

Background: Timing of surgical treatment for tethered cord syndrome due to a lipomyelomeningocele (LMM) has been controversial. The purpose of this study was to evaluate populations of patients treated surgically for LMM in a meta-analysis in order to better understand how outcomes differ based on follow-up time, symptomatology, and LMM classification., Methods: An extensive search on PubMed and Google Scholar was performed for LMM and surgical outcomes to identify case series of patients for inclusion in this analysis. Patients were sorted based upon symptomatology prior to surgery and Chapman's LMM classification, where possible. Deterioration rates were determined by symptomatic retethering of the spinal cord that led to repeat surgery., Results: Of 608 (19 %) patients, 115 were included in the study experienced deterioration leading to repeat surgery. Symptomatic and asymptomatic patients did not experience significantly different rates of deterioration after surgical untethering. There was a significant positive linear correlation between follow-up time of studies and percentage of patients deteriorating with an increase of 3.3 % per year of follow-up. Transitional LMM had a significantly higher rate of deterioration compared to the caudal type along with the entire patient pool., Conclusions: Outcomes of primary surgical treatment in regard to late deterioration are not significantly affected by patient symptomatology. Patient deterioration increases linearly over time. Additional studies should be performed to adequately determine the natural history of asymptomatic patients that are treated conservatively for LMM.

Object: Various cutaneous stigmata and congenital anomalies are accepted as sufficient reasons to perform lumbar ultrasonography as a screening tool to rule out occult spinal dysraphism (OSD). The purpose of this study was to correlate presenting cutaneous findings with lumbar ultrasonography results based on a large number of lumbar ultrasonography tests obtained by regional primary care providers., Methods: Over the course of 5 years, 1273 infants underwent lumbar ultrasonography screening at a major pediatric tertiary referral center. Of these infants, 1116 had adequate documentation for retrospective chart review. Referral sources included urban academic, urban private practice, and surrounding rural private practitioners. Presence of cutaneous stigmata and/or congenital anomalies and lumbar ultrasonography results were reviewed for all patients. When present, surgical findings were reviewed., Results: A total of 943 infants were referred for presumed cutaneous stigmata, the most common of which was a sacral dimple (638 patients [68%]) followed by hairy patch (96 patients [10%]). Other reported cutaneous findings included hemangioma, deviated gluteal fold, skin tag, and skin discoloration. In comparison, 173 patients presented with congenital anomalies, such as imperforate anus (56 patients [32%]) and tracheoesophageal fistula/esophageal atresia (37 patients [21%]), most of which were detected prenatally by fetal ultrasonography. A total of 17 infants underwent surgical exploration. Occult spinal dysraphism was diagnosed in 7 infants in the cutaneous stigmata group and in 10 infants in the group with congenital abnormalities. None of the cutaneous stigmata as recorded were found to be indicative of the presence of OSD., Conclusions: Cutaneous markers as currently defined by general practitioners are not useful markers for predicting OSD. The vast majority of findings on lumbar ultrasonography studies performed under these circumstances will be negative.

Intracranial endoscopy in the treatment of hydrocephalus, arachnoid cysts, or brain tumors has gained wide acceptance, but the use of endoscopy for intradural navigation in the pediatric spine has received much less attention. The aim of the authors' present study was to analyze their experience in using spinal endoscopy to treat various pathologies of the spinal canal. The authors performed a retrospective review of intradural spinal endoscopic cases at their institution. They describe 4 representative cases, including an arachnoid cyst, intrinsic spinal cord tumor, holocord syrinx, and split cord malformation. Intradural spinal endoscopy was useful in treating the aforementioned lesions. It resulted in a more limited laminectomy and myelotomy, and it assisted in identifying a residual spinal cord tumor. It was also useful in the fenestration of a multilevel arachnoid cyst and in confirming communication of fluid spaces in the setting of a complex holocord syrinx. Endoscopy aided in the visualization of the spinal cord to ensure the absence of tethering in the case of a long-length Type II split spinal cord malformation. Conclusions Based on their experience, the authors found intradural endoscopy to be a useful surgical adjunct and one that helped to decrease morbidity through reduced laminectomy and myelotomy. With advances in technology, the authors believe that intradural endoscopy will begin to be used by more neurosurgeons for treating diseases of this anatomical region.

Object: Tethered cord release for a tight filum terminale is a common pediatric operation associated with low morbidity and mortality rates. While almost all would agree that keeping patients lying flat after the operation will prevent a CSF leak, the optimal period of doing so has not been determined. In this study, the authors examined whether a longer length of stay in the hospital for the sole purpose of maintaining patients flat correlates with a decreased rate of CSF leakage., Methods: Intraoperative and postoperative data were retrospectively collected in 222 cases of simple tethered cord release at 3 large children's hospitals. Risk factors for postoperative CSF leakage were identified., Results: Thirty-eight patients were maintained lying flat for 24 hours, 86 for 48 hours, and 98 for 72 hours at the individual surgeon's discretion. A CSF leak occurred in 13 patients (5.9%) and pseudomeningocele developed in 9 patients (4.1%). In the univariate analysis, operating time, use of the microscope, use of dural sealant, and duration of remaining flat after surgery failed to correlate with the occurrence of complications., Conclusions: A longer hospital stay for maintaining patients flat after a simple tethered cord release appears not to prevent CSF leakage. However, a larger patient cohort will be needed to detect small differences in complication rates.

The treatment of a patient with symptoms of a tethered spinal cord and in whom a fatty infiltrated terminal filum is found is controversial. The authors review their experience and the literature regarding this aspect of occult spinal dysraphism. From experience, transection of a fatty terminal filum in patients with symptoms related to excessive caudal cord tension is a minor procedure that generally yields good results. The most problematic issue in the literature is what patients and symptoms are best suited to surgical treatment.

In certain highly selected circumstances, division of a distally nonfunctional or dysfunctional cord can be a means of definitive untethering that spares and protects more rostral neurological function and results in definitive untethering. The authors reviewed their institutional experience with such cases and evaluated the limited literature. Based on their experience, treatment can be effective in carefully selected patients who undergo spinal cord transection, and the rate of repetitive tethered spinal cord can be decreased.

We report a 13-year-old female who presented to an outside emergency room following blunt trauma to the head. As part of her evaluation, an unenhanced CT of the face and radiographs of the cervical spine were performed. She was referred to our clinic with "abnormal" imaging. Radiographs revealed dysmorphic cervical spine and ventral clefting of the vertebral bodies from C7-T2. A subsequent MRI was obtained that demonstrated a large spinal cord mass. MRI demonstrated an unenhanced intramedullary mass of the cervicothoracic spinal cord measuring approximately 1.5 cm in greatest axial diameter. Surgical exploration of her intraspinal mass revealed a neurenteric cyst. Spinal neurenteric cysts are categorized in the spectra of occult spinal dysraphism and most likely arise from incomplete separation of the developing notochord and foregut in the embryo. We discuss potential etiologies for the formation of such cysts. The clinician should consider neurenteric cysts in their differential diagnosis of patients with spinal dysraphism and/or intraspinal masses., (Copyright 2006 Wiley-Liss, Inc.)

Neural tube defects (NTDs) are the second most common birth defects (1 in 1000 live births) in the world. Periconceptional maternal folate supplementation reduces NTD risk by 50-70%; however, studies of folate related and other developmental genes in humans have failed to definitively identify a major causal gene for NTD. The aetiology of NTDs remains unknown and both genetic and environmental factors are implicated. We present findings from a microsatellite based screen of 44 multiplex pedigrees ascertained through the NTD Collaborative Group. For the linkage analysis, we defined our phenotype narrowly by considering individuals with a lumbosacral level myelomeningocele as affected, then we expanded the phenotype to include all types of NTDs. Two point parametric analyses were performed using VITESSE and HOMOG. Multipoint parametric and nonparametric analyses were performed using ALLEGRO. Initial results identified chromosomes 7 and 10, both with maximum parametric multipoint lod scores (Mlod) >2.0. Chromosome 7 produced the highest score in the 24 cM interval between D7S3056 and D7S3051 (parametric Mlod 2.45; nonparametric Mlod 1.89). Further investigation demonstrated that results on chromosome 7 were being primarily driven by a single large pedigree (parametric Mlod 2.40). When this family was removed from analysis, chromosome 10 was the most interesting region, with a peak Mlod of 2.25 at D10S1731. Based on mouse human synteny, two candidate genes (Meox2, Twist1) were identified on chromosome 7. A review of public databases revealed three biologically plausible candidates (FGFR2, GFRA1, Pax2) on chromosome 10. The results from this screen provide valuable positional data for prioritisation of candidate gene assessment in future studies of NTDs.

Object: The authors describe the technique of transecting the spinal cord in children born with myelomeningocele who have undergone multiple detherings and are functionally paraplegic., Methods: The authors' technique involves identifying the neural placode and sectioning the normal spinal cord just superior to this site. No postoperative complications have been identified in 14 patients undergoing this procedure over an 11-year period. No patient at last follow up was found to have symptoms referable to a tethered spinal cord. The advantage of this procedure is to excise the normally pia-coated cord, which is unlikely to retether compared with the neural placode, which is often covered with scar tissue and does not have a well-formed pial surface--hence, predisposing it to frequent dorsal adhesions., Conclusions: The authors believe that this technique is of benefit in a small, carefully selected group of myelodysplastic patients with repetitive tethering of the spinal cord.

The authors present three children born with myelomeningocele and hydrocephalus. Each presented with symptoms/signs of ventriculoperitoneal shunt malfunction. All patients at the time of presentation exhibited significant urinary bladder infections and were appropriately treated for their infection. No patient was found to have an underlying shunt infection. All patients without medically threatening symptoms were carefully observed and noted to have resolution of their shunt dysfunction symptoms/signs following treatment of their urinary bladder infections and thus did not undergo a shunt operation. Based on the courses of these patients, we believe that significant urinary bladder infection in patients with myelodysplasia in whom a shunt has been placed may often be enough to bring a subclinical shunt malfunction to clinical attention or even to be the cause of temporary distal peritoneal shunt malabsorption. Although the exact mechanism for this dysfunction is unclear, treatment of the bladder infection may address the symptomatic shunt dysfunction in some patients so as to avoid operative intervention. We emphasize, however, that careful observation of these patients should be performed during hospitalization because they often rely on adequate cerebrospinal fluid diversion. Only patients with mild symptomatology should be observed first as the initial line of treatment.

Self-mutilation after deafferentation injuries has rarely been reported in humans. The authors report on a 16-year-old girl who was born with a myelomeningocele. In adolescence it was noted that concurrent with her spinal cord becoming symptomatically tethered she began to self-mutilate her digits. A rare manifestation of the tethered spinal cord may be dysesthesias that led to self-mutilation.

Many have equated the term tethered spinal cord to a conus that is pathologically elongated. Most authorities have declared radiologic coni located inferior to the L-2 as pathologic. However, we have described previously a small series of patients in whom symptoms of a tethered spinal cord were evident clinically yet radiologically the conus medullaris was found to lie at a widely acceptable normal anatomic site. Following a review of the extant literature prior to our publication in 1993, several authors had operated on patients for symptoms of a distally tethered spinal cord in whom a conus was found to terminate at a 'normal' vertebral level. We believe that there is indeed a subset of the tethered cord patient population in whom the tip of the conus lies at even liberally accepted normal levels. We would encourage clinicians treating patients with symptoms of tethered cord syndrome not to treat the patient based simply on imaging but imaging coupled with clinical symptoms and physical exam. It is important to point out that in lieu of the many publications of conus termination that one accepts that there is no one single 'normal' position of the terminal cord but rather a normal range. Perhaps a superior way of interpreting 'tethered' cord is to view this as tautness of the cord and not necessarily elongation of the distal cord in every case.

Case Report: We report a 20-year-old male with Russell Silver syndrome and tethered cord syndrome. This patient presented with non-painful scoliosis. MRI demonstrated a conus medullaris at the superior aspect of the L3 vertebral body. Axial images demonstrated no fat within the filum terminale. There was a horizontal sacrum. The patient had no cutaneous stigmata over the lumbosacral spine indicative of occult spinal dysraphism. At operation, the filum terminale was found to be quite large at approximately 5.0 mm in diameter. Grossly, the filum was found to have several large vessels both anterior and posterior to it. Following transection of the filum the distal cord was noted to withdraw cephalad indicating caudal traction., Discussion: We believe this to be the first report of Russell Silver syndrome in conjunction with tethered cord syndrome. Following additional reports, Russell Silver syndrome may be added to the differential diagnoses for tethered cord syndrome.

Mirror movements usually seen in the Klippel-Feil syndrome are most commonly appreciated in the upper extremities. Lower extremity involvement is seen rarely and when observed, is found in conjunction with upper extremity mirror movements. We report what we believe to be the first case of mirror movements found exclusively in the lower extremities in a female patient presenting with tethered cord syndrome. Our hopes are that this report will help elucidate mechanisms involved with these anomalous movements, as currently there is no commonly accepted etiology.

Object: Neurenteric cysts are infrequently reported congenital abnormalities believed to be derived from an abnormal connection between the primitive endoderm and ectoderm. The authors report a series of 13 patients treated over a 50-year period., Methods: Of the 13 patients, seven were female and six were male. Their ages at presentation ranged widely from 5 weeks to 52 years of age. Children presented more commonly with cutaneous stigmata of occult spinal dysraphism (OSD) whereas adults presented primarily with pain. Neurological deficit as a presenting symptom was less common in our series, a finding that reflects the slow growth of these lesions. In all but one patient some form of vertebral anomaly was associated with the cystic lesions, including two patients with Klippel-Feil abnormalities. There was a high incidence of associated forms of OSD including split cord malformation, lipoma, dermal sinus tract, and tethered spinal cord. In previous reports the authors have suggested that neurenteric cysts are more common in the cervical region and in a position ventral to the cord. In the present series these cysts most commonly occurred as intradural, extramedullary masses in the thoracolumbar region, situated dorsal to the spinal cord. The median follow-up period was 7.5 years, and postoperative outcome reflected a patient's preoperative neurological status; in no patient was outcome worsened due to surgery., Conclusions: Complete excision of the neurenteric cyst remains the treatment of choice, as subtotal excision is associated with recurrence.

Object: The management of tethered cord syndrome with onset of symptomatology occurring in adulthood remains controversial, although the necessity of early surgery in the pediatric tethered cord syndrome population is well established. To ascertain the results of surgery in adult patients with this anomaly, the authors undertook a retrospective review of 34 cases., Methods: The authors studied the hospital records of 34 consecutive patients who presented in adulthood with tethered cord syndrome and conducted follow-up phone interviews with 28 of them. The population consisted of 12 men and 22 women, ranging in age from 18 to 70 years (mean 34 years). The most common presenting feature was pain, followed by weakness and incontinence. All patients underwent surgery. The most common operative findings were tight filum terminale, split cord malformation, and lipomyelomeningocele, paralleling those observed in pediatric studies. Long-term surgical results and patient outcome ratings were encouraging. After a mean clinical follow-up period of 4 years, significant improvement occurred in 22 of 27 patients presenting with pain, 13 of 27 patients with motor or sensory dysfunction, and 11 of 18 patients with bowel and bladder disturbance. In addition, telephone interviews were obtained after a period of 8.6 years. Twenty-two (79%) of 28 patients called the operation a long-term success; 21 (75%) of 28 patients believed that they had significant postoperative improvement (and not just stabilization) in pain and/or neurological function. Surgical complications were generally minor. Surgery-related complications included one cerebrospinal fluid leak and five pseudomeningoceles. Two patients complained of worsening motor or sensory dysfunction and one of worsening bladder dysfunction, whereas four patients experienced persistent pain and one complained of worsening pain postoperatively. According to the patients, the vast majority of these complications were minor. Nineteen (86%) of 22 employed patients returned to work after surgery. Two (33%) of six patients who were not employed before surgery worked full time postoperatively. Only two of the 28 patients interviewed had received Workers' Compensation benefits; both of these had good outcomes and returned to work., Conclusions: Tethered spinal cord syndrome in adults is an uncommon entity that can become symptomatic. Although surgery in adults involves greater risk of neurological injury than in children, it is a low-risk procedure with encouraging results. Because neurological deficits are generally irreversible, early surgery is recommended.

Neural tube defects (NTD) are one of the most common birth defects and are caused by both environmental and genetic factors. The approach to identifying the genes predisposing to NTD, through linkage analysis and candidate gene analysis, is reviewed along with characteristics of a large, nationally ascertained cohort of families. Results from specific assessments of p53, PAX3 and MTHFR failed to suggest that these genes play a major role in NTD development in these families. Advances in genetic laboratory and statistical techniques have made this a prime opportunity for investigation into the causes of complex disorders, such as NTD. However, traditional approaches may prove to be challenging due to the difficulty of ascertaining samplable multiplex families., (Copyright 2000 S. Karger AG, Basel)

Mutations in the gene for methylenetetrahydrofolate reductase (MTHFR) have been implicated as a risk factor in the formation of neural tube defects. We investigated this gene in a series of 65 sporadic American Caucasian patients with lumbosacral NTD and their unaffected parents, using both case-control design and assessment of linkage disequilibrium. We found no evidence to support mutations in MTHFR as a significant risk factor for NTD in this population.