Magnetic resonance imaging of spinal dysraphism

Diagnostic Utility of 3D Gradient-Echo MR Imaging Sequences through the Filum Compared with Spin-Echo T1 in Children with Concern for Tethered Cord

BACKGROUND AND PURPOSE

Fatty intrathecal lesions are a cause of tethered cord, and detection of these on spinal MR imaging is paramount. Conventional T1 FSE sequences are the mainstay of detecting fatty elements; however, 3D gradient-echo MR images, volumetric interpolated breath-hold examination/liver acquisition with volume acceleration (VIBE/LAVA), are popular, given the increased motion resistance. We sought to evaluate the diagnostic accuracy of VIBE/LAVA compared with T1 FSE for detection of fatty intrathecal lesions.

MATERIALS AND METHODS

In this retrospective, institutional review board-approved study, 479 consecutive pediatric spine MRIs obtained to evaluate cord tethering between January 2016 and April 2022 were reviewed. Inclusion criteria were patients who were 20 years of age or younger who underwent spine MRIs containing both axial T1 FSE and VIBE/LAVA sequences of the lumbar spine. The presence or absence of fatty intrathecal lesions was recorded for each sequence. If fatty intrathecal lesions were present, anterior-posterior and transverse dimensions were recorded. VIBE/LAVA and T1 FSE sequences were evaluated on 2 separate occasions (VIBE/LAVAs first followed by T1 FSE several weeks later) to minimize bias. Basic descriptive statistics compared fatty intrathecal lesion sizes on T1 FSEs and VIBE/LAVAs. Receiver operating characteristic curves were used to determine minimal fatty intrathecal lesion size detectable by VIBE/LAVA.

RESULTS

Sixty-six patients were included, with 22 having fatty intrathecal lesions (mean age, 7.2 years). T1 FSE sequences revealed fatty intrathecal lesions in 21/22 cases (95%); however, fatty intrathecal lesions on VIBE/LAVA were detected in 12/22 patients (55%). Mean anterior-posterior and transverse dimensions of fatty intrathecal lesions measured larger on T1 FSE compared with VIBE/LAVA sequences (5.4 × 5.0 mm versus 1.5 × 1.6 mm, respectively; P values = .039 anterior-posterior; .027 transverse).

CONCLUSIONS

While T1 3D gradient-echo MR images may have decreased the acquisition time and are more motion-resistant than conventional T1 FSE sequences, they are less sensitive and may miss small fatty intrathecal lesions.

Terminal myelocystocele: Surgical management

Background:

The authors describe clinical and imaging findings, surgical technique, and outcomes in myelocystocele.

Methods:

We describe a surgical procedure performed in six patients, four males and two females, with myelocystocele treated at our hospital. We review the images obtained at the time of diagnosis and after surgery. The patients’ age range was 12–56 months and had undergone surgery for terminal myelocystocele between 2015 and 2020. All patients had a large lumbar mass covered with healthy skin and presented spontaneous movements at birth. Two patients presented VACTERL syndrome.

Results:

A watertight closure of the soft tissues was performed in all cases. None of the patients presented postsurgical complications, such as cerebrospinal fluid leak or infection. All the patients had undergone excision of the meningocele sacs, the tethering bands were lysed, and the filum was detethered. The mean follow-up period was 34 (12–56) months. A motor deficit was seen in 2 patients (33.3%).

Conclusion:

Prenatal diagnosis and early corrective surgical intervention are recommended to prevent deterioration in neurological function. VACTERL association is a common condition and should be investigated.

Cutaneous Stigmata of the Spine: A Review of Indications for Imaging and Referral

Cutaneous stigmata of the midline spine are a common question in pediatrics. They are known to be related to a higher likelihood of underlying dysraphic spinal abnormalities. Clear understanding of different types of cutaneous stigmata and correlating dysraphic findings can aid in appropriate imaging workup and timely management of patient pathology. In this article, the authors review midline spinal cutaneous findings in the pediatric population with occult spinal dysraphism.

Postoperative cardiorespiratory arrest in a case of cervical meningocele

Background:

Meningoceles are congenital herniation of meninges and cerebrospinal fluid (CSF) through the skull and are bereft of any cerebral tissue. They are commonly found over the anterior fontanelle. Although some cases of cervical dysraphism have been described in the literature, a true meningocele has rarely been seen. The child usually presents with hydrocephalus with features of raised increased intracranial pressure. Sensory, motor, and sphincter functions may be involved depending on the level of lesion. Closure of meningocele should be ideally done within the first 48 h of birth.

Case Description:

Complications associated with meningocele range from learning disabilities, seizures, and bowel dysfunction to complete paralysis below the level of the lesion. The postoperative complications reported are wound infection, CSF leak/collection, urinary tract infection, deterioration of deficit, and death. Here, we present a postoperative case of an 11-month-old child with cervical meningocele who had an unusual complication almost 2 h after an uneventful surgery in the form of sudden cardiorespiratory arrest was revived successfully.

Conclusion:

A meningocele surgery is usually not associated with severe postoperative complications which can be encountered in meningomyelocele surgery. Here, in our case, the child with uneventful meningocele surgery arrested 2 h postsurgery with the possible cause being cervical cord edema. Hence, a lesson was learned that strict vigilance is also required in postoperative care for meningocele patients.

Structured MRI reporting in spinal dysraphism

Magnetic resonance evaluation of spinal dysraphism can be confusing for inexperienced radiologists and a detailed, step-by-step evaluation of the normal and abnormal imaging findings can help garner the diagnosis. The purpose of this article is to review the existing literature and to provide a comprehensive, structured, template checklist-style format for reporting spinal dysraphism that can help inexperienced radiologists to systematically analyze and report all the significant and ancillary findings in cases of spinal dysraphism and efficiently communicate the findings to the treating physician/surgeon.

Cervical Lipomyelomeningocele Presenting with Progressive Motor Deficit: A Case Report and Review of the Literature

Cervical lipomyelomeningocele is a very rare form of spina bifida occulta, which can cause some complications following tethered cord syndrome. We report a 10-year-old female with a history of progressive upper-extremity weakness, a very small soft-tissue mass at the posterior aspect of her neck, and evidence of lipomyelomeningocele in her radiological study. The patient underwent laminectomy of C6 and C7 together with resection of lipomatous tissue attaching to the cord from superficial tissue and cord untethering, which resulted in progressive improvement of her weakness.

Practical applications of CISS MRI in spine imaging

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Conventional spin echo imaging is limited by low spatial resolution and CSF pulsation artifact.

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CISS MRI enables submillimeter spatial resolution and myelographic contrast.

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Inherent flow compensation of the CISS technique reduces CSF pulsation artifact.

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CISS improves the delineation of a wide variety of spinal pathologies.

Routine magnetic resonance imaging evaluation of the spine is often limited by low spatial resolution and artifacts resulting from cerebrospinal fluid pulsation. Balanced steady-state free precession sequences can supplement routine spin echo sequences and provide exquisite anatomic detail and high cerebrospinal fluid-to-soft tissue contrast, adding significant diagnostic value to the evaluation of a wide variety of spine disorders.

Placode rotation in transitional lumbosacral lipomas: are there implications for origin and mechanism of deterioration?

PURPOSE

Rotation of the lipoma-neural placode has been noted in transitional lumbosacral lipomas. The purpose of this study was to confirm this rotation; that this rotation occurs with a preference to the left, and correlates with clinical symptoms. In addition, this study tests the hypothesis that this rotation occurs through local mechanical forces rather than intrinsic congenital malformation.

METHODS

Lipomas were classified as per the Chapman classification. Degree of rotation of the placode from the coronal plane was recorded along with the presence of herniation outside of the vertebral canal. Abnormalities on urodynamic testing were recorded, along with neuro-orthopaedic signs picked up on formal neuro-physiotherapy assessment.

RESULTS

Placode rotation occurs more frequently in the transitional group. Regardless of lipoma classification, rotation was much more common to the left. Furthermore, when lateralisation of symptoms was present, this strongly correlated with the direct of rotation. There was no difference in rotation of the placode whether it was within (lipomyelocoele) or without the vertebral canal (lipomyelomeningocoele).

CONCLUSIONS

Placode rotation is a feature of transitional lumbosacral lipomas and may account for the increase in symptoms amongst this subgroup. Herniation of the placode outside the vertebral canal does not increase the risk of rotation suggesting a congenital cause for this finding rather than a purely mechanical explanation.

Magnetic Resonance Imaging in Paediatric Spinal Dysraphism with Comparative Usefulness of Various Magnetic Resonance Sequences

INTRODUCTION

Spinal dysraphism occurs due to failure of fusion of parts along dorsal aspect of midline structures lying along spinal axis from skin to vertebrae and spinal cord. Congenital spinal anomalies may be minimal and asymptomatic like spinal bifida occulta, or severe with marked neurological deficits like Arnold-Chiari malformation or caudal regression syndrome. Magnetic Resonance Imaging (MRI) is the modality of choice to diagnose mild to severe spinal dysraphism.

AIM

To diagnose type and extent of clinically suspected spinal anomalies by MRI scan and to compare various sequences for identifying neural tissue and fatty tissue in anomalies.

MATERIALS AND METHODS

Fifty paediatric patients referred with clinical suspicion of spinal anomalies for MRI scan to radiodiagnosis department and diagnosed as having spinal dysraphism on 1.5 Tesla MRI Scan, were included in this observational analytic study. Various MRI sequences were taken in multiple planes. MRI findings of spinal dysraphism were compared with detailed clinical examination or surgical findings. Osseous anomalies like spina bifida occulta were confirmed by radiographs or CT scan.

RESULTS

Out of 50 patients, type II Arnold-Chiari Malformation (34%), Spina Bifida Occulta (22%) and Diastematomyelia (18%) were common anomalies. MRI findings were well correlated with surgical findings in 20 operated cases. Nerve roots with/ without neural placode in thecal sac/outpouching were detected in combination of 3D HASTE myelographic sequence with SE/ TSE T1W sequence in 24 cases; which was significantly high as compared to combinations of SE/TSE T1W sequence with TSE T2W, with STIR and with Single Shot Myelographic sequence {p-value 0.002, < 0.001 and 0.008 respectively}. Fatty component was present in dysraphism in five cases, commonly as isolated anomaly; which was detected by combination of STIR and SE/TSE T1W sequences in all five cases.

CONCLUSION

Paediatric spinal dysraphism and associated malformations are accurately diagnosed on MRI scan. MR myelographic 3D-HASTE and STIR sequences should be a part of protocol to evaluate spinal dysraphism.

Imaging spectrum of spinal dysraphism on magnetic resonance: A pictorial review

Congenital malformations of spine and spinal cord are collectively termed as spinal dysraphism. It includes a heterogeneous group of anomalies which result from faulty closure of midline structures during development. Magnetic resonance imaging (MRI) is now considered the imaging modality of choice for diagnosing these conditions. The purpose of this article is to review the normal development of spinal cord and spine and reviewing the MRI features of spinal dysraphism. Although imaging of spinal dysraphism is complicated, a systematic approach and correlation between neuro-radiological, clinical and developmental data helps in making the correct diagnosis.

Spinal neurenteric cyst in a dog

CASE DESCRIPTION An 11-year-old English Cocker Spaniel was evaluated because of chronic progressive ataxia of the hind limbs. CLINICAL FINDINGS The dog had no history of previous illness, and findings of physical examination and laboratory tests were unremarkable. Neurologic examination revealed that the dog was ambulatory with severe ataxia of the hind limbs. Proprioception was decreased in the right and left hind limbs (right affected more than left), and spinal reflexes were bilaterally unremarkable. Moderate signs of pain were detected during palpation of the lumbar portion of the vertebral column. Findings suggested a lesion within the thoracolumbar or lumbar segments of the spinal cord. Magnetic resonance imaging revealed extradural spinal cord compression attributable to an extradural space-occupying lesion originating from or infiltrating the L4 lamina on the right side. TREATMENT AND OUTCOME Hemilaminectomy was performed to remove the extradural lesion. Histologic findings for tissue samples collected during the procedure were consistent with a neurenteric cyst. The late onset and progression of clinical signs of this rare congenital malformation were suspected to have been the result of enlargement of the neurenteric cyst through continuous production of mucus by goblet cells. The dog responded favorably to surgical decompression and was clinically normal 1 year after surgery. It was euthanized 2 years after surgery for an unrelated reason (end-stage heart disease), and no neurologic deficits were evident before that point. CLINICAL RELEVANCE Congenital neurenteric cysts should be considered as a differential diagnosis for neoplastic disease in dogs in which results of diagnostic imaging indicate the presence of an extradural mass affecting vertebral structures.

Clinical and surgical management of a congenital Type II split cord malformation presenting with progressive cranial neuropathies: case report

Split cord malformation (SCM) is a rare abnormality of notochord development. The majority of cases occur in the thoracolumbar region, with more than 30 cases of cervical SCM reported. The clinical impact of SCMs involving the cervical cord is therefore largely unknown. In addition, the concomitant finding of brainstem involvement is presumably incompatible with life in the majority of patients, resulting in a paucity of data regarding this clinical scenario. In this paper the authors present the first case, to their knowledge, of an incomplete cervical SCM involving the brainstem and discuss its clinical impact, diagnosis, and management.

Magnetic Resonance Imaging Analysis of Caudal Regression Syndrome and Concomitant Anomalies in Pediatric Patients

OBJECTIVE

The aim of this study was to evaluate the magnetic resonance imaging (MRI) findings of caudal regression syndrome (CRS) and concomitant anomalies in pediatric patients.

MATERIALS AND METHODS

A hospital-based cross-sectional retrospective study was conducted. The study group comprised 21 pediatric patients presenting to the Departments of Radiodiagnosis and Pediatric Surgery in a tertiary care hospital from May 2011 to April 2016. All patients were initially evaluated clinically followed by MRI.

RESULTS

In our study, 21 pediatric patients were diagnosed with sacral agenesis/dysgenesis related to CRS. According to the Pang's classification, 2 (9.5%) patients were Type I, 5 (23.8%) patients were Type III, 7 (33.3%) patients were Type IV, and 7 (33.3%) patients were of Type V CRS. Clinically, 17 (81%) patients presented with urinary incontinence, 6 (28.6%) with fecal incontinence, 9 patients (42.9%) had poor gluteal musculatures and shallow intergluteal cleft, 7 (33.3%) patients had associated subcutaneous mass over spine, and 6 (28.6%) patients presented with distal leg muscle atrophy. MRI showed wedge-shaped conus termination in 5 (23.8%) patients and bulbous conus termination in 3 (14.3%) patients above the L1 vertebral level falling into Group 1 CRS while 7 (33.3%) patients had tethered cord and 6 (28.6%) patients had stretched conus falling into Group 2 CRS.

CONCLUSION

MRI is the ideal modality for detailed evaluation of the status of the vertebra, spinal cord, intra- and extra-dural lesions and helps in early diagnosis, detailed preoperative MRI evaluation and assessing concomitant anomalies and guiding further management with early institution of treatment to maximize recovery.

Hemimyeloschisis associated with hydrocephalus

Hemimyeloschisis is a very rare congenital malformation of the spine which is characterized by a split cord malformation associated with complete exposureof the one hemicord to the exterior. We report a case of hemimyeloschisis on the right hemicord in a patient with hydrocephalus. The patient was a female neonate with myeloschisis, skin defect, and hypertrichosis visible at birth in the upper lumbar region. There was also skin defect around the myeloschisis. Computed tomography (CT) revealed a bony septum at the L2 level as well as the myeloschisis on the right hemicord, which enabled us to make a precise preoperative diagnosis of this rare malformation. There was also mild hydrocephalus in cranial CT scan. Closure of the myeloschisis and removal of the septum were successfully performed associated with the closure of the skin in one stage surgery to prevent subsequent infection and neurological deterioration. Ventriculoperitoneal shunt insertion was performed for hydrocephalus. The presence of combined split cord malformation and myeloschisis is consistent with the hypothesis of an ontogenic basis of development. This combination also emphasizes the importance of early imaging for diagnosis in this complex malformation.

In utero diagnosis of caudal regression syndrome

We present a case of caudal regression syndrome (CRS), a relatively uncommon defect of the lower spine accompanied by a wide range of developmental abnormalities. CRS is closely associated with pregestational diabetes and is nearly 200 times more prevalent in infants of diabetic mothers (1, 2). We report a case of prenatally suspected CRS in a fetus of a nondiabetic mother and discuss how the initial neurological abnormalities found on imaging correlate with the postnatal clinical deficits.

Clinical Significance of Prenatal and Postnatal Heavily T2-Weighted Magnetic Resonance Images in Patients with Myelomeningocele

PURPOSE

To compare the utility and limitations of prenatal magnetic resonance (MR) imaging using half-Fourier acquisition single-shot turbo spin-echo (HASTE) with postnatal heavily T2-weighted imaging (hT2WI) for the evaluation of central nervous system abnormalities associated with myelomeningocele (MMC).

METHODS

Sixteen patients with MMC who had undergone pre- and postnatal MR imaging were included in this study. MR imaging, including HASTE, was undertaken in the 3rd trimester, and hT2WI was performed immediately after delivery. The precision with which each could distinguish MMC, hindbrain herniation and ventriculomegaly was compared retrospectively.

RESULTS

The skin defects and MMC sacs were clearly visible on prenatal HASTE images, although it was difficult to identify precisely the level of MMC compared with postnatal hT2WI, in which the detailed anatomical relationships of the spinal cord, neural placode and ventral nerve roots were evident in every case. Hindbrain herniation could be visualized on prenatal HASTE images, although its severity was difficult to evaluate because of the small size of the structures and neck flexion; again, the resolution was superior on postnatal hT2WI. For hydrocephalus, there were no significant differences in the diagnostic precision and ability to grade the severity between pre- and postnatal imaging.

CONCLUSION

Prenatal HASTE imaging permits the diagnosis and understanding of the gross anatomy of MMC and associated hindbrain herniation and ventriculomegaly, but postnatal hT2WI is superior for evaluating detailed anatomy.

Conflicting Diagnosis of Dermal Sinus Tract and Tethered Cord

Dermal sinus tracts (DSTs) are an uncommon form of occult spinal dysraphism that is attributed to incomplete neural tube closure during fetal development. Dermal sinus tracts are found along the midline neuroaxis from the nasion to the coccyx, but they most commonly appear in the lumbar region. Dermal sinus tracts are more commonly associated with other developmental abnormalities such as skin tags, naevi, spinal dermoid cysts, meningocoele, lipomas and spinal cord tethering, and can be complicated by cerebrospinal fluid drainage, shedding of keratin from the epithelialized tract, and infection such as meningitis.

Lipomyelomeningocele: pathology, treatment, and outcomes

Lipomyelomeningocele represents a rare but complex neurological disorder that may present with neurological deterioration secondary to an inherent tethered spinal cord. Radiological testing is beneficial in determining the morphology of the malformation. Specialized testing such as urodynamic studies and neurophysiological testing may be beneficial in assessing for neurological dysfunction secondary to the lipomyelomeningocele. Early surgical intervention may be beneficial in preventing further neurological decline.

MRI of a split cord malformation in a German shepherd dog

A 9 yr old spayed female German shepherd dog was referred for MRI of the thoracic and lumbar spine because she had clinical signs of chronic neurogenic bladder dysfunction of an unknown cause. Transverse T2-weighted images identified a type II split cord malformation (i.e., diastematomyelia) in the thoracic spine. Split cord malformations are forms of spinal dysraphism where the abnormal development of spinal cord results in sagittal splitting of a portion of the cord into two hemicords. The location of the lesion in the thoracic spine was consistent with the dog's clinical signs of an upper motor neuron bladder. Split cord malformations that occur in humans have similar MRI characteristics and can result in similar clinical signs as those identified in the dog described in this report.

MR imaging of neonatal spinal dysraphia: what to consider?

The development of the spinal canal and its contents is highly complex and involves multiple programmed anatomic and functional developmental and maturational processes. Correct and detailed knowledge about spinal malformations is essential to understand and recognize these lesions early (preferably prenatally) to counsel parents during pregnancy, to plan possible intrauterine treatments, and to make decisions about the mode of delivery and the immediate postnatal treatment. This article discusses the imaging findings of the most frequently encountered neonatal spinal malformations and correlates these findings with the relevant embryologic processes. The presented classification is based on a correlation of clinical, neuroradiologic, and embryologic data.

Anterior cervical myelomeningocele: a rare malformation of the spinal cord

Cervical myelomeningocele (MMC) is an uncommon congenital malformation of the spinal cord and accounts for a small proportion of neural tube defects. These lesions mostly occur in the dorsal part of the body. Only a single case of an anterior cervical MMC has been previously reported. The authors report a second case of anterior cervical MMC diagnosed when the patient began to experience symptoms of bilateral hand weakness in adulthood. In this patient, MR imaging of the cervical spine showed an anterior cervical MMC at the C6-7 level with hydrocephalus, thinning of the genu and trunk of the corpus callosum, maldevelopment of the cerebellar tonsils, and expansion of the fourth ventricle, posterior cranial fossa, and subarachnoid space. A CT scan and a 3D CT reconstruction of the cervical spine clearly demonstrated contiguous fusions of multiple lower-cervical vertebrae and neural arches, which was consistent with Type III Klippel-Feil syndrome. The patient was advised to undergo operative treatment to prevent the progression of her neurological deficit. However, after being notified of the potential neurological risks, the patient declined surgery and opted for conservative treatment with a hard neck collar. At 4 months' follow-up, the patient's neurological deficit remains stable with the MMC left untreated. The authors presume that the possible pathogenesis of anterior cervical MMC may greatly differ from that of posterior lesions. This lesion could also be associated with multiple other spinal abnormalities, which highlights the importance of comprehensive preoperative radiological examinations.

MRI of closed spinal dysraphisms

We present a pictorial review of MRI features of various closed spinal dysraphisms based on previously described clinicoradiological classification of spinal dysraphisms proposed. The defining imaging features of each dysraphism type are highlighted and a diagnostic algorithm for closed spinal dysraphisms is suggested.

Is There a Causal Relationship Between Open Spinal Dysraphism and Chiari II Deformity?

BACKGROUND:

Chiari II deformity is associated with open spinal dysraphism. A causal relationship has been proposed by McLone and Knepper. This article evaluates that hypothesis.

OBJECTIVE:

To establish the frequency of Chiari II deformity in fetuses with open spinal dysraphism, assess whether meningocele sac neck area and volume influence the severity of posterior fossa changes, and assess whether the severity of associated findings (ventriculomegaly, amount of extracerebral CSF) are associated with Chiari II deformity.

METHODS:

Sixty-five fetuses with open spinal dysraphism were compared with gestationally aged matched “normal” fetuses on ultrafast MR images. Cerebellar vermis and bony posterior fossa surface area were measured on midline sagittal images. Hindbrain herniation was noted if present. In the open spinal dysraphic group, sac neck area and volume were measured. Ventriculomegaly was assessed by linear measurement of the trigone of the lateral ventricle and extracerebral CSF depth was measured maximally over the lateral surface of the cerebral hemispheres.

RESULTS:

Fifteen of 65 fetuses with open spinal dysraphism did not have Chiari II deformity. Neck area and volume of the sac did not correlate with the presence of Chiari II deformity or reduction in bony posterior fossa size.

CONCLUSION:

A relatively high proportion of fetuses with open spinal dysraphism do not have Chiari II deformity in utero. There is a lack of correlation between indicators of spinal dysraphism severity and the extent of the posterior fossa abnormality. This raises some interesting questions about the causality of the Chiari II deformity.

Management goals for the spina bifida neurogenic bladder: a review from infancy to adulthood

Patients with spina bifida require longitudinal urological care as they transition from childhood to adolescence and then to adulthood. Issues important to urological health, such as protection of the upper tracts and prevention of incontinence, need vigilant follow-up throughout the patient's life. As the child ages, additional issues such as sexual functioning also become increasingly important for social integration. Despite this need for regular assessment, many adult patients with spina bifida lose coordinated urological care after leaving specialized pediatric spina bifida clinics. Consequently, urologists frequently encounter an adult patient with spina bifida in practice and they need to understand the basic urological treatment goals and potential complications for this population.

Lipomyelocele with osseous dysraphic hamartoma in a child: a case report

Lipomyelocele is a well-known vertebral malformation that affects intraspinal and extraspinal tissues and compartments. However, other tissues can be associated with the lipomatous component, such as well-developed bones in unusual sites. This association is consistent with dysraphic hamartoma, one of the rarest malformations of the vertebral canal closure. We describe an 8-year-old girl without neurological deficit with a voluminous lipomyelocele associated with a well-developed flat bone articulated to the left iliac wing. We reviewed the role of magnetic resonance and computed tomography with tridimensional reconstruction in this rare form of spinal dysraphism and described the imaging features.

Cervical spinal dysraphism

OBJECTIVE

Cervical spinal dysraphism is a rare congenital spinal pathology. The results obtained from our series are compared with the results obtained from other series of studies in the literature.

METHODS

Seven patients with cervical myelomeningocele and meningocele who underwent surgery between January 1996 and March 2009 at the YYU Faculty of Medicine in the Department of Neurosurgery were retrospectively studied.

RESULTS

The referral ages of the patients (6 females and 1 male) varied between 4 days and 4 months (median 1 month). A stalk lesion covered with a dysplastic skin formed as a sac and located at the cervical midline was demonstrated in all of the patients. Cervical myelomeningocele was present in 4 patients, while cervical meningocele was present in 3 patients; however, Chiari type II malformation and hydrocephaly were present in 3 patients with myelomeningoceles. Diastematomyelia and a filum terminal lipoma were present in 1 of the patients.

CONCLUSION

In this series, in contrast to the literature, we noted that the number of girls with spinal dysraphism with a cervical myelomeningocele and meningocele was greater than the number of boys. Chiari type II malformation, hydrocephaly and motor weakness in patients with cervical spinal dysraphism are less frequent when compared to patients with caudal spinal dysraphism. The structure of the sac is also more durable and, accordingly, a cerebrospinal fluid leakage is uncommon.

Characteristics and surgery of cervical myelomeningocele

OBJECTIVE

Cervical myelomeningocele (CMMC) is a rare entity in neurosurgical practice, which presents different clinical characteristics compared with other more common lumbosacral variant. Since not much about this lesion has been reported in the literature, this study, herein, demonstrates by cases the clinical characteristics, methods, and techniques of surgical treatment of CMMC in children.

METHODS

A total of 10 children (six boys and four girls) with CMMC were recruited in this study. Their ages ranged from 9 days to 8 years with a median age of 3 months. All patients underwent neurological and radiological examinations. One was found to have had a mild unilateral arm weakness, and others were neurologically intact. Of these 10 patients, five had other associated neurological or orthopedic anomalies, including mild ventriculomegaly in two, cervical diastematomyelia in one, Chiari II malformation and hydrocephalus in one, and sacral spina bifida occulta in one. Surgical excision of the lesion with intradural exploration of the sac to release any potential adhesion bands was performed for all.

RESULTS

No complications, such as cerebrospinal fluid leakage and infection, had been found after operation. During the follow-up of 1-7 years (mean of 3.9 years), all cases did not suffer from aggravation of nervous symptoms. None of the patients deteriorated postoperatively, and the one with left arm weakness improved following surgery. In the two children with mild ventriculomegaly, cerebral ventricle returned to be normal after surgery.

CONCLUSIONS

The management strategies of CMMC are early surgical treatment with standard microneurosurgical techniques to prevent the development of neurological defects. It is safe and effective to adopt surgery excision of the lesions with intradural exploration of the sac to release any potential adhesion bands.

Differential diagnosis of T2 hyperintense spinal cord lesions: Part A

Hyperintense spinal cord signal on T2-weighted images is seen in a wide-ranging variety of spinal cord processes including; simple MR artefacts, congenital anomalies and most disease categories. Characterization of the abnormal areas of T2 signal as well as their appearance on other MR imaging sequences, when combined with clinical context and laboratory investigations, will often allow a unique diagnosis, or at least aid in narrowing the differential diagnosis. A wide range of instructive cases is discussed here with review of the published reports focusing on pertinent MR features to aid in diagnosis.

Sonographic Assessment of the Neonatal Spine and the Potential for New Technologies to Aid in Diagnoses

Many spinal disorders, whether congenital or acquired, are likely to have an improved outcome if they are promptly identified. A rapid diagnosis may eliminate progressive sequela and provide insight to possible treatment plans. Although there are various medical imaging modalities for evaluating the neonatal spine, diagnostic medical sonography provides a safe (no exposure to ionizing radiation), quick, and inexpensive approach. Spinal diagnostic medical sonography can be performed in neonates as long as the vertebral column is not completely ossified. Diagnostic medical sonography is a valuable technique that, in addition to 2D imaging, provides 3D, extended field of view (EFOV), and M-mode imaging. Diagnostic medical sonography can identify normal spinal anatomy and variants, congenital malformations, and acquired diseases subsequent to birth-related trauma and lumbar punctures. This article discusses the normal embryology of the spine. Indications for neonatal spinal diagnostic medical sonography are reviewed along with a description of sonographic examination techniques. A review of spinal pathology and their embryological origin will be outlined as well as normal variants seen with sonography. A detailed literature review is provided evaluating case studies and their findings.

Split-cord malformation and accompanying anomalies

OBJECTIVE

To present the magnetic resonance imaging (MRI) appearances of spinal split-cord malformation (SCM) and to investigate the various types of congenital spinal disorders associated with SCM.

MATERIALS AND METHODS

MR examinations of 23 patients with SCM were carried out in our hospital between June 2002 and May 2007 and retrospectively analysed.

RESULTS

Nineteen (82.6%) patients were diagnosed as type I SCM, while four (17.4%) were diagnosed as type II SCM. The most commonly involved site of SCM was the dorsolumbar area (47.8%) while cervical involvement was the least common (4.3%). No accompanying congenital spinal disorders were detected in four patients (17.4%). In 19 patients (82.6%), congenital spinal disorders accompanying SCM were detected, the most common of which was a low-lying cord, found in 14 patients (60.9%). Other anomalies included hydromyelia in seven patients (30.4%), lipoma in six (26%), meningomyelocele in four (17.4%), thick filum in three (13%) and dermoid cyst in three (13%).

CONCLUSION

In preoperative planning for SCM, its characteristics and those of the accompanying anomalies should be determined. MRI is a valuable tool for making such determinations.

Spinal lipomas: clinical spectrum, embryology, and treatment

✓Spinal lipomas, particularly lipomas of the conus medullaris and terminal filum, are the most common form of occult spinal dysraphism and represent a wide spectrum of disease with regard to anatomy, clinical presentation, and treatment options. These lesions, however, are united by a similar embryology and pathological mechanism by which symptoms arise.

Recently, the treatment of these lesions has generated much controversy, with some physicians advocating surgical treatment for all patients regardless of symptoms and others proposing that surgery be withheld until symptoms develop. The authors discuss lumbosacral spinal lipomas, with particular attention to the theories of their origin, anatomical and pathological features, and treatment options, including a review of current controversies.

A case of split cord malformation associated with myeloschisis

INTRODUCTION

Split cord malformation (SCM) associated with myeloschisis is a very rare form of spinal dysraphism. We encountered a case of SCM associated with myeloschisis showing split neural placodes (hemicords) in the upper lumbar region.

RESULTS

Radiological examinations, including prenatal MRI and postnatal CT scan, clearly demonstrated a bony spur between the two hemicords as well as myeloschisis, which facilitated a precise preoperative diagnosis of this complex anomaly. Resection of the spur, closure of the myeloschisis, and untethering of the thickened filum terminale were successfully accomplished in one stage. The presence of SCM associated with myeloschisis is consistent with the hypothesis of an ontogenic basis of neural development, and we emphasize the importance of early imaging including prenatal MRI for diagnosing this complex anomaly.

Feasibility and limitation of constructive interference in steady-state (CISS) MR imaging in neonates with lumbosacral myeloschisis

INTRODUCTION

The aim of this study was to evaluate three-dimensional Fourier transformation-constructive interference in steady-state (CISS) imaging as a preoperative anatomical evaluation of the relationship between the placode, spinal nerve roots, CSF space, and the myelomeningocele sac in neonates with lumbosacral myeloschisis.

METHODS

Five consecutive patients with lumbosacral myeloschisis were included in this study. Magnetic resonance (MR) CISS, conventional T1-weighted (T1-W) and T2-weighted (T2-W) images were acquired on the day of birth to compare the anatomical findings with each sequence. We also performed curvilinear reconstruction of the CISS images, which can be reconstructed along the curved spinal cord and neural placode.

RESULTS

Neural placodes were demonstrated in two patients on T1-W images and in three patients on T2-W images. T2-W images revealed a small number of nerve roots in two patients, while no nerve roots were demonstrated on T1-W images. In contrast, CISS images clearly demonstrated neural placodes and spinal nerve roots in four patients. These findings were in accordance with intraoperative findings. Curvilinear CISS images demonstrated the neuroanatomy around the myeloschisis in one slice. The resulting images were degraded by a band artifact that obstructed fine anatomical analysis of the nerve roots in the ventral CSF space. The placode and nerve roots could not be visualized in one patient in whom the CSF space was narrow due to the collapse of the myelomeningocele sac.

CONCLUSION

MR CISS imaging is superior to T1-W and T2-W imaging for demonstrating the neural placode and nerve roots, although problems remain in terms of artifacts.

Causes of lumbosacral plexopathy

The lumbosacral plexus represents the nerve supply to the lower back, pelvis and legs. This review will focus on diseases and disorders affecting the pathway as demonstrated by magnetic resonance imaging (MRI) and computed tomography (CT). We stress the need to review the lumbosacral plexus in patients with non-specific symptoms such as back, hip, pelvic pain, and in those who present with sciatica unaccompanied by demonstrable intervertebral disc prolapse. We illustrate that the imaging appearances may be non-specific and re-inforce the importance of the clinical history and the use of tissue sampling to achieve an accurate diagnosis.

Post-mortem MRI of the foetal spine and spinal cord

AIMS

To compare the findings of post-mortem magnetic resonance imaging (MRI) of the foetal spine with autopsy with a view to using post-mortem MRI as an alternative or adjunct to autopsy, particularly in foetal and neonatal cases.

MATERIALS AND METHODS

The brains and spines of 41 foetuses, with a gestational age range of 14-41 weeks, underwent post-mortem MRI before autopsy. Post-mortem MRI of the brain consisted of T2-weighted sequences in three orthogonal planes and MRI of the spine consisted of T2-weighted sequence in the sagittal and axial planes in all cases and coronal planes in selected cases.

RESULTS

Thirty of 41 (78%) foetal spines were found to be normal at autopsy and on post-mortem MRI. Eleven of 41 (22%) foetal spines were abnormal: eight foetuses had myelomeningocoeles and Chiari 2 deformities, one foetus had limited dorsal myeloschisis, one foetus had caudal regression syndrome, and one had diastematomyelia. The post-mortem MRI findings concurred with the autopsy findings in 10/11 of the abnormal cases, the disagreement being the case of diastematomyelia that was shown on post-mortem MRI but was not diagnosed at autopsy.

CONCLUSIONS

In this series, post-mortem MRI findings agreed with the autopsy findings in 40/41(98%) cases and in one case the post-mortem MRI demonstrated an abnormality not demonstrated at autopsy.

Imaging in spine and spinal cord malformations

Spinal and spinal cord malformations are collectively named spinal dysraphisms. They arise from defects occurring in the early embryological stages of gastrulation (weeks 2-3), primary neurulation (weeks 3-4), and secondary neurulation (weeks 5-6). Spinal dysraphisms are categorized into open spinal dysraphisms (OSDs), in which there is exposure of abnormal nervous tissues through a skin defect, and closed spinal dysraphisms (CSD), in which there is a continuous skin coverage to the underlying malformation. Open spinal dysraphisms basically include myelomeningocele and other rare abnormalities such as myelocele and hemimyelo(meningo)cele. Closed spinal dysraphisms are further categorized based on the association with low-back subcutaneous masses. Closed spinal dysraphisms with mass are represented by lipomyelocele, lipomyelomeningocele, meningocele, and myelocystocele. Closed spinal dysraphisms without mass comprise simple dysraphic states (tight filum terminale, filar and intradural lipomas, persistent terminal ventricle, and dermal sinuses) and complex dysraphic states. The latter category further comprises defects of midline notochordal integration (basically represented by diastematomyelia) and defects of segmental notochordal formation (represented by caudal agenesis and spinal segmental dysgenesis). Magnetic resonance imaging (MRI) is the preferred modality for imaging these complex abnormalities. The use of the aforementioned classification scheme is greatly helpful to make the diagnosis.

Spinal dysraphism: MR imaging rationale

Spinal cord development occurs through the three consecutive periods of gastrulation (weeks 2-3), primary neurulation (weeks 3-4), and secondary neurulation (weeks 5-6). Spinal cord malformations derive from defects in these early embryonic stages, and are collectively called spinal dysraphisms. Spinal dysraphisms may be categorized clinically into open and closed, based on whether the abnormal nervous tissue is exposed to the environment or covered by skin. Open spinal dysraphisms include myelomeningocele and other rare abnormalities such as myelocele, hemimyelomeningocele, and hemimyelocele, and are always associated with a Chiari II malformation. Closed spinal dysraphisms are further divided into two subsets based on whether a subcutaneous mass is present in the low back. Closed spinal dysraphisms with mass comprise lipomyelocele, lipomyelomeningocele, meningocele, and myelocystocele. Closed spinal dysraphisms without mass comprise simple dysraphic states (tight filum terminale, filar and intradural lipomas, persistent terminal ventricle, and dermal sinuses) and complex dysraphic states. The latter category involves abnormal notochordal development, either in the form of failed midline integration (ranging from complete dorsal enteric fistula to neurenteric cysts and diastematomyelia) or of segmental agenesis (caudal agenesis and spinal segmental dysgenesis). Magnetic resonance imaging is the imaging modality of choice for evaluation of this complex group of disorders.

Cervical meningocele in association with spinal abnormalities

CASE REPORT

This case report presents a newborn baby girl, who was diagnosed at birth with a mid-cervical meningocele. Further radiographic workup by MRI revealed co-existing thoracic diplomyelia and bilateral tethered cords. At birth the patient was found to be neurologically intact. Surgery was performed at 4 months of age, the patient undergoing simultaneous repair of the cervical meningocele, exploration of the diplomyelia, and release of the tethered cords bilaterally. Long-term follow-up revealed an ambulating patient with no bowel or bladder incontinence, who has developed well for her chronological age so far.

REVIEW OF THE LITERATURE

A review of the literature relevant to this case is also presented.

The Value of Magnetic Resonance Imaging in the Evaluation of Fatty Filum Terminale

OBJECTIVE

To determine whether there are magnetic resonance imaging (MRI) characteristics of fatty fila that are correlated with neurological deficits, especially in the presence of a normal-level conus medullaris.

METHODS

Lumbosacral MRI scans were reviewed for patients with fatty fila who were treated at Duke University Medical Center during a 5-year period. The patients were divided into three groups. Group I patients (n = 5) had fatty fila that were incidentally detected during evaluations for metastases or infections. Group II patients (n = 16) exhibited isolated low back pain but were in neurologically intact condition. Group III patients (n = 15) exhibited neurological impairments consistent with distal spinal cord dysfunction. Several characteristics were measured on the MRI scans, including the location of the conus medullaris, the filum thickness, and the distance of fat from the conus. These results were assessed for statistically significant correlation with the presence of clinical symptoms.

RESULTS

The majority of patients in all three groups demonstrated the normal conus position (L2 or above) and thickened fila. The distance of fat from the conus was the only parameter that demonstrated a statistically significant difference among the groups.

CONCLUSION

The following findings were noted: 1) patients were likely to exhibit neurological deficits at a younger age (&lt;22 yr in Group III versus 47 yr in Groups I and II); 2) a conus level below L2 was associated with neurological deficits (Group III); 3) filum thickness was not correlated with clinical presentation; 4) fat in the filum within 13 mm of the conus medullaris was most predictive of neurological deficits (Group III).

The validity of sacral ratios to identify sacral abnormalities

OBJECTIVE

To test the repeatability and validity of a previously described sacral ratio measurement as a method for detecting sacral abnormalities, as the association between sacral abnormalities and neuropathic bladder is well known but the diagnosis of subtle sacral anomalies is often delayed.

MATERIALS AND METHODS

Fifty sacral radiographs (from 30 patients with anorectal anomalies and 20 normal children) were viewed and reported as normal or abnormal by an expert spinal radiologist (reference standard). Sacral ratios (anteroposterior, AP, and lateral) were measured while unaware of origin by four investigators and the inter- and intra-observer variability examined. Validity was assessed by comparing individual sacral ratio values with the radiological diagnosis, using Pena's criteria for a normal sacrum (normal >/= 0.74 AP; >/= 0.77 lateral).

RESULTS

Sacral ratio estimates were possible in 48 of the 50 selected radiographs. There was good repeatability of measurements and moderate variability among investigators (P > 0.1). For the 20 normal children the mean (sd) AP sacral ratio was 0.74 (0.156); in the 14 with anorectal conditions and a normal sacrum it was 0.87 (0.16) and in the 12 with an abnormal sacrum 0.64 (0.27). There was a difference (P < 0.02) among the three groups (analysis of variance) but there was wide variability in individual sacral ratios within each group, and considerable overlap of values between normal and abnormal sacra. When all sacra were defined as normal or abnormal using Pena's criteria, there was poor agreement using Cohen's kappa (AP and lateral view) with the radiological diagnosis by all four investigators.

CONCLUSION

The sacral ratio has good inter- and intra-observer repeatability. The mean value for a normal AP ratio concurred with that described previously by Pena but the variability of values among similar patients was large, suggesting this single value is of limited value in discriminating a normal from an abnormal sacrum.