The tethered spinal cord: diagnosis by high-resolution real-time ultrasound

International Children's Continence Society's recommendations for initial diagnostic evaluation and follow-up in congenital neuropathic bladder and bowel dysfunction in children

PURPOSE

The objective of this ICCS standardization document is to report the initial diagnostic evaluation and subsequent work-up of children with neuropathic bladder dysfunction.

MATERIALS AND METHODS

Due to a paucity of level I or level II, "levels of evidence" publications, these recommendations are actually a compilation of best practices because they seem to be effective and reliable, although not with any control.

RESULTS

Throughout the document, the emphasis is on promoting early, comprehensive evaluation of lower urinary tract function that is thorough but with a minimum of unnecessary testing. This includes what tests to order, when to order them and what to do with the results. Some of the recommendations may not be practical in various worldwide locations but the suggested testing should be considered the ideal approach to completely diagnosing and then promulgating treatments based on the full knowledge of the condition and its effect on urinary tract function. Once the findings are delineated, those lower urinary tract patterns of dysfunction that put the kidneys at risk for deterioration, that are barriers to attaining eventual continence, and that have long-term consequence to the lower urinary track can be obviated by specific management recommendations. The indications and timing of investigations to achieve these objectives are clearly defined in each diagnostic category and during follow-up.

RECOMMENDATIONS

This document should be used as a basis for appropriate evaluation and timely surveillance of the various neuro-urologic conditions that affect children.

Evaluation of thoracic spinal cord motion using dynamic MRI

The aim of study was to assess the thoracic spinal cord motion during normal breathing using dynamic magnetic resonance imaging (dMRI). We found that the mean motion range at different thoracic levels is typically within 0.5mm. The good stability makes this an excellent position for stereotactic radiotherapy (SBRT).

Imaging of congenital anomalies and variations of the caudal spine and back in neonates and small infants

Spinal dysraphisms are categorized in open dysraphisms with prominent abnormal nervous tissue above the skinlevel and closed dysraphisms with a skin covered malformation. Especially the occult dysraphisms are marked by suspect skin masses and other dermal anomalies. The purpose of this review is to demonstrate the indications and spectrum of spinal sonography in neonates and infants. In comparison typical dysraphisms are demonstrated in sonography and MR Imaging. We demonstrate the value of ultrasound in comparison to MRI and describe a usefull handling of the methods in neonates and infants. The differentiation between the potentially dangerous dimples associated with dermal sinus, which can lead to meningitis and the harmless coccygeal dimple in the cranial gluteal cleft is presented. An inconspicious examination does not need a further imaging, but suspicious results of sonography need an MR imaging dependent of clinical conditions. Neurologically conspicious infants need MR imaging completed by sonography. Great advantages of sonography are the real time examination and the potential to show oscillations of the conus, filum and cauda equina in M-mode-imaging.

Adult tethered cord syndrome in patients with postrepair myelomeningocele: an evidence-based outcome study

OBJECT

As patients with myelomeningocele age, tethered cord syndrome (TCS) in adults with postrepair myelomeningocele has become more common. The authors have structured an evidence-based review of the literature for the purpose of addressing the following questions. (1) How is the diagnosis made? (2) What is the natural history that occurs in adults with postrepair myelomeningocele and TCS? (3) What are the criteria for operative intervention? (4) What is the functional outcome for patients with postrepair myelomeningocele?

METHODS

A computerized search of the National Library of Medicine of the English-language literature published from 1966 to 2003 was performed. Articles pertaining to the clinical aspects and management of postrepair myelomeningocele in adults, TCS in adults resulting from closed defects, and pediatric patients with postrepair myelomeningocele were reviewed. No Level 1 or 2 data were located; however, the search yielded Level 3 and 4 evidence in the literature in which the clinical syndrome, underlying pathology, and the imaging and electrophysiological evaluation for TCS in adults are discussed.

CONCLUSIONS

Analysis of the available data indicates the following. (1) A lower lesion level predisposes patients to symptomatic tethering; moreover, orthopedic and urological deterioration will occur in the majority of these patients. (2) Tethered cord release should be considered for adult patients with postrepair myelomeningocele when clinical symptoms, imaging studies, urodynamics, and somatosensory evoked potentials are consistent with TCS. (3) Prompt, aggressive untethering surgery within 5 years of symptom onset, along with long-term follow up to check for delayed retethering, is recommended. The overall outcome for patients with postrepair myelomeningocele may not be as good as the outcome for adults with closed dysraphism.

The value of ultrasonic examination of the lumbar spine in infants with specific reference to cutaneous markers of occult spinal dysraphism

AIM

To present part of the rationale behind the recent update to the M12 guideline in The Royal College of Radiologists' publication "Making the best use of a department of clinical radiology", 4th edition 1998, which stated that ultrasound was useful in screening for dysraphism in infants with cutaneous markers such as sacral dimple or hairy patch.

MATERIALS AND METHODS

Over a 10-year period a total of 223 infant lumbar spines were scanned, for various clinical indications. Forty of these patients had already had abnormalities detected antenatally by foetal ultrasonography. One hundred and eight-three patients had abnormalities detected on postnatal clinical examination; most of these had various cutaneous markers, some had other congenital abnormalities.

RESULTS

There were a total of 29 patients with dysraphism; 24 were detected antenatally and five postnatally. Of the five, two had two or more cutaneous markers and three had anorectal anomalies. All 86 of the patients with simple sacral dimples, pits or sinuses were normal.

CONCLUSION

As an isolated abnormality, simple dimples or pits are not useful markers of spinal dysraphism. The authors suggest a new imaging protocol, resulting in improved diagnostic efficiency.

Spinal ultrasound in infants

This paper discusses the indications for spinal ultrasound, including its advantages and disadvantages compared with spinal MRI. The features and ultrasound findings both in normal infants and in those with spinal dysraphism are reviewed.

Cutaneous signs of neural tube dysraphism

Cutaneous markers have a crucial role in the detection and diagnosis of occult neural tube dysraphism. Recognition of these stigmata and appropriate radiologic imaging decrease the long-term morbidity of this condition.

Birthmarks to worry about. Cutaneous markers of dysraphism

Most birthmarks are benign lesions of little concern. On rare occasions, though, congenital cutaneous lesions may indicate an underlying systemic disorder. This article provides an overview of midline cutaneous lesions that are associated with underlying cranial and spina dysraphic conditions.

Transition of the craniocaudal velocity of the spinal cord: from cervical segment to lumbar enlargement

RATIONALE AND OBJECTIVES

The authors investigate the craniocaudal velocity of the spinal cord over its full length by using magnetic resonance imaging.

METHODS

A spin-echo pulse sequence with velocity encoding gradients was used to examine five normal volunteers. Oblique-axial phase images at nine levels, from cervical spinal cord to lumbar enlargement, were obtained with prospective electrocardiogram gating. Time-velocity curves were then generated for these levels.

RESULTS

Every part of the spinal cord moves first caudally after the R-wave of the electrocardiogram, then cranially. When compared with the cranial levels, peak velocity tend to occur later and their values tend to be smaller at the more caudal levels.

CONCLUSIONS

Craniocaudal velocity is transmitted from cervical segment to lumbar enlargement.

The tethered spinal cord: diagnosis, significance, and management

Tethered cord is the result of fixation of the spinal cord, which limits motion in the caudal-rostral direction. Most children either have cutaneous markers or a predisposing condition. Prophylactic release of the spinal cord can prevent the long-term disabilities associated with this condition. Although delayed release, following the onset of a neurological deficit, may reverse some lost function, it is unlikely to restore bladder and bowel function.

Cutaneous stigmata of occult spinal dysraphism

We describe a 4-year-old Hispanic boy with a dermal pit and an overlying macular vascular malformation in the lumbosacral area. Magnetic resonance imaging of the region revealed an intraspinal lesion at L1-L2. A fibrous tract was excised. A benign lipoma intrinsic to the roots of the cauda equina was noted at surgery. The cutaneous stigmata of occult spinal dysraphisms are reviewed.

Ultrasound assessment of congenital spinal anomalies presenting in infancy

Sonography of the infant spine can rapidly and safely exclude or confirm the presence of a congenital malformation. This article reviews the embryology of the spinal cord, abnormal and normal sonographic findings, and findings associated with occult dysraphic lesions. Patient selection for sonographic assessment is also discussed. Illustrations of normal anatomy and the more common dysraphic lesions are provided.

Sonographic evaluation of traumatic spinal cord lesions in the newborn infant

We present a case of spinal cord injury due to birth trauma and assess the value of sonography for diagnosis, lesion characterization, and follow-up. Sonography is a non-invasive and easily reproducible imaging method for examining a ventilated child, and its initial sensitivity is comparable to that of MRI. Sonography is the method of choice for guiding diagnosis in this type of traumatic lesion to the newborn.

Sonographic Evaluation of the Spine in Infants and Neonates

Ultrasound is a rapid, noninvasive, cost-effective method of evaluating the spine in infants younger than six months of age. This report reviews sonographic scan procedure and normal sonographic spinal anatomy, and illustrates the sonographic appearance of occult spinal anomalies, such as meningocele, meningomyelocele, tethered cord, diastematomyelia, and sacrococcygeal teratoma.

Occult neurovesical dysfunction in children with imperforate anus and its variants

Neurovesical dysfunction (NVD) is frequently encountered in children with imperforate anus and its variants. Such functional urologic problems are often compounded by associated anatomic urologic abnormalities that in combination may profoundly alter the course and prognosis of children with imperforate anus. Herein, we report 16 such cases. Management of NVD in children with imperforate anus offers several unique challenges that require important alterations in management. Specific recommendation are presented.

Tethered-cord syndrome after repair of meningomyelocele

The occurrence of tethered-cord syndrome is one of the delayed consequences of the repair of meningo-myelocele. The existing neurological deficit worsens, or a new deficit is superimposed on the existing one. In addition, urological and orthopedic symptoms are also frequently encountered. Although radiological studies may be suggestive of tethering of the cord, not all children are symptomatic. Magnetic resonance imaging is the best radiologic study available. Ultrasonography, although economical and easy to perform, does not yield an optimal image. It appears that a careful periodic clinical evaluation is the best way to evaluate the patients for surgery.

Spinal dysraphism: use of magnetic resonance imaging in evaluation

Three cases of children with spinal dysraphism are reported. Magnetic resonance imaging (MRI) was used as a primary diagnostic examination. The ages of the patients were 2 days, 4 years, and 16 years. In all instances the scan gave a precise diagnosis as well as well as an accurate delineation of the structural abnormalities before surgical treatment. Plain radiographs and ultrasound analysis may not be helpful, and invasive procedures can be associated with morbidity. Technical ease, safety, and anatomic precision suggest that MRI should be performed as a primary radiologic examination in the diagnostic workup of spinal dysraphism.

Magnetic resonance imaging of dysraphic myelodysplasia. Findings in 56 children and adolescents with postrepair meningomyelocele

The spinal cord in 56 children and adolescents was examined by magnetic resonance imaging (MRI) many years after neonatal surgery on a meningomyelocele (average age 12 years). In a high percentage of cases, the diagnosis "tethered cord" was made. Associated anomalies were found with a frequency of 21%. Typical findings are presented and the impact of these results on therapy planning is discussed.

Pediatric spinal sonography. Part II: Malformations and mass lesions

The most important spinal disorders in childhood are malformations and mass lesions. The sonographic appearance of the various kinds of dysraphism and their differentiation, of malformations at the cranio-cervical junction, and of mass lesions is demonstrated and illustrated. Based on our preliminary experience, spinal sonography appears to be useful as the first imaging device for the differentiation of complex malformations and as a screening method for occult dysraphism. In mass lesions spinal sonography is useful to diagnose and follow-up disease, with additional imaging procedures currently needed for confirmation of diagnosis.

Anorectal malformations: evaluation of associated spinal dysraphic syndromes

The early recognition and treatment of correctable lesions of the terminal spinal cord in patients with anorectal malformations may preserve important neurologic function. Tethered cord and intraspinal masses are detectable with the use of high-resolution ultrasonography in the neonate. Fourteen infants and children with anorectal malformations and associated spinal dysraphism have been identified in our institution over the past 7 years. Six patients had cloacal exstrophy, and eight had imperforate anus (four high and four low lesions). The spinal lesions caused symptoms in only seven children; progressive neurologic deficit in five, and urinary incontinence or retention in two others. Five asymptomatic patients with cutaneous abnormalities on the back were studied and two were discovered during scoliosis evaluation. Imaging techniques included high-resolution ultrasonography, computed tomography with and without metrizamide myelography, and magnetic resonance imaging. Spinal sonography was highly accurate in the neonatal period. The application of ultrasonography can be of great advantage in early screening of patients with anorectal malformations and, in some cases, may eliminate the need for invasive imaging techniques.

Magnetic resonance imaging of postrepair-myelomeningocele--findings in 31 children and adolescents

Magnetic resonance imaging has clearly demonstrated its efficacy in the diagnosis of pathological processes in the C.N.S. We examined 31 children who had undergone plastic closure of myelomeningocele a few days post partum. We could show that a high percentage of the patients (89%) presented the pathological anatomy of a tethered spinal cord; clinical symptoms of the tethered spinal cord syndrome, i.e. progressive neurological symptoms, however, are rarely observed. Possible revision of neurosurgical treatment of MMC is discussed.

Pediatric neurosonography

Neurosonography is an excellent modality for imaging a wide array of intracranial pathology in the infant and newborn. Neurosonography is also finding increasing use in other accessible regions of the central nervous system, including the adult brain during craniotomy and the spine during laminectomy. Sonography represents the primary modality for the evaluation of the preterm brain. Because of the high incidence of pathology in gestationally immature neonates, screening sonography is required in every infant. The sonographic features of intracranial hemorrhage include areas of increased echogenicity in the region of the germinal matrix, within the ventricles, or in the surrounding cerebral parenchyma. Careful follow-up of these children for sometimes severe posthemorrhagic hydrocephalus is essential. Premature neonates are also at risk for ischemic disease, particularly periventricular leukomalacia, which is accurately diagnosed sonographically and implies a poor prognosis in almost every infant so affected. Cranial sonography is also an excellent method to evaluate abnormalities that are not associated with gestational immaturity. Cranial sonography offers excellent anatomic imaging of the brain when evaluating for congenital anomalies; because sections may be obtained in a multitude of orientations, sonography is actually more versatile than computed tomographic (CT) scans. Cranial sonography is also of use when evaluating children with inflammatory processes such as ventriculitis; sonography is superior to CT scans in identifying intraventricular septae typical of the process. Intrauterine inflammatory processes, however, are frequently associated with intracranial calcifications, CT scans may be more accurate in these cases. CT scans may also be more efficacious in the diagnosis of subdural, epidural, and subarachnoid hemorrhage. Intracranial neoplasms are rare in the younger population and although they are visible with ultrasound, CT scans with contrast are essential in an effort to obtain added information and because of a greater experience using CT scans. Sonography represents an excellent modality with which to evaluate the infant and neonatal brain. In a number of diseases it may be diagnostic alone. The informed clinician, however, should keep in mind those instances where a complimentary modality such as CT scanning can add additional or even essential information.

Ultrasonic anatomy of the normal neonatal and infant spine: correlation with cryomicrotome sections and CT

High resolution computed neurosonography now displays the details of the spinal canal, subarachnoid space, spinal cord and some emerging nerve roots in axial and sagittal planes. Those familiar with this anatomy may use sonography to detect spinal pathology.

[Tethered spinal cord syndrome: report of 2 cases]

The tethered spinal cord syndrome is a disease that is part of the group of spinal dysraphisms, that was recently recognized as an individualized nosological entity, yet not frequently diagnosed among us. It is characterized by shortening and thickening of the filum terminale which prevents the ascent of the spinal cord into spinal canal, the conus medularis abnormally remaining in a low place. It is associated in all cases with spina bifida. The diagnosis is simple, once the disease is suspected. It is manifested by progressive motor or sensory deficit in the legs, urinary incontinence, scoliosis and leg or back pain, specially in young children. The plain lumbosacral RX always shows spina bifida. Myelography makes the diagnostic. It shows, basically, the negative image of the thickened filum terminale and the low placed conus medularis. Other exams which can help are the computerized tomography and the ultra-sound of the spinal cord. The surgical treatment is very simple and heals without sequels if done in due time. It consists in a sectioning of the filum terminale through laminectomy. Two cases diagnosed and treated at Hospital da Baleia, from Fundação Benjamin Guimarãcs, Belo Horizonte, are reported in this paper.

Real-time ultrasonography of the spinal cord: intraoperative and postoperative imaging

Fourteen subjects with spinal cord pathology were studied with 10 MHz linear array or 5 MHz mechanical sector ultrasound scanners. Twelve patients were studied intraoperatively. The examinations were rapid, aiding the surgeon at the time of exploration. Sonography defined cysts, outlined the extent of neoplasia and aided in the localization of bone fragments. Guidance for placement of syringo -subarachnoid shunts reduced the amount of surgical manipulation. Four patients were examined postoperatively through laminectomy defects, three confirming adequate position and function of shunts and in one case demonstrating tumor recurrence.