Diastematomyelia

Comprehensive Radiological Imaging for the Characterization of Spinal Dysraphism and Associated Anomalies in a Pediatric Case

Spinal dysraphism is a spectrum of congenital anomalies caused by incomplete neural tube closure during early development, leading to spine and spinal cord defects. These can be broadly categorized into anomalies of gastrulation (including disorders of notochord formation and integration), anomalies of primary neurulation (such as premature disjunction and nondisjunction), combined anomalies of gastrulation and primary neurulation, and anomalies of secondary neurulation. This case report focuses on a 15-year-old male patient who exhibits a range of congenital spinal anomalies of spinal dysraphism spectrum, each contributing to a complex clinical picture. The primary aim of this report is to highlight the critical role of multimodal imaging in the evaluation of such conditions. Detailed imaging studies, particularly magnetic resonance imaging (MRI), are indispensable in accurately diagnosing, guiding surgical planning, and managing the diverse anomalies associated with spinal dysraphism. In this case, imaging findings were pivotal in identifying multiple congenital abnormalities, including scoliosis, butterfly vertebrae, block vertebrae, spina bifida occulta, and diastematomyelia. These conditions pose significant diagnostic and management challenges due to their varied presentations and complications.

A Case of Diastematomyelia Presenting With Minimal Neurologic Deficits in a Middle-Aged Patient

Diastematomyelia is a rare congenital deformity of the spine in which the spinal cord is split into two hemicords along the sagittal plane. This condition belongs to the group of spinal dysraphisms, is more common in females, and is usually diagnosed prenatally or during childhood; rarely is it diagnosed in adults. We report a male patient in his 50s in which diastematomyelia of the thoracic spine was incidentally encountered after receiving a CT scan of the chest for shortness of breath. Although most patients with this condition are symptomatic, the patient did not display any significant acute neurological complaints at the time. The patient had a history of spina bifida and is paraplegic, both of which are commonly associated with diastematomyelia. The lack of progressive neurologic symptoms, diagnosis in the patient’s adult life, and the presence of the anomaly solely in the thoracic spine make this a rare and unusual case. Early recognition and diagnosis of this condition, by prenatal ultrasound or MRI, can help to prevent further damage to the spinal cord and allow affected patients to seek treatment sooner, thus improving quality of life.

Split cord malformation in adults: Literature review and classification

The objective of this study was to summarize the available literature describing the presentation, diagnostic evaluation, and management for adults with Type 1 and Type 2 split spinal cord malformations. A review of the literature was performed using the CINAHL, PubMed, Embase, and Web of Science database, alongside all associated bibliographies, to include studies describing Type 1 and Type 2 split cord malformations diagnosed in patients above the age of 18. All relevant studies of split cord malformations were included, regardless of the year published and terminology used to describe the dysraphism. Clinical case series (≥ 2 patients), cohort studies, and review articles comprising adult patients with radiographically diagnosed diastematomyelia, diplomyelia, or dimyelia were included (Class of Evidence I-IV). A total of 17 unique articles, describing 146 unique adult spinal cord malformation subjects, were included. The most common associated condition was tethered cord syndrome (59.8 %). Operative management for symptomatic split cord malformation was performed in 72.3 % of cases. For those with preoperative neurologic deficits, operative management resulted in symptomatic improvement in 96.6 %, compared to 0 % conservative management (p < 0.05). For those with pain alone, operative management resulted in improvement of 91.1 %, compared to 12.5 % conservative management (p < 0.05). To date, this is the only literature review to include all split cord malformations (SCM Types I and II) presenting in adulthood, with clinical characteristics, associated conditions, and long-term treatment outcomes.

Split spinal cord malformations: report of 22 cases and review of the literature

OBJECT

The aims of this study were to describe the embryological changes that drive the formation of a split spinal cord malformation, analyse the forms of presentation, evaluate the diagnostic procedures and discuss the indications for the different forms of therapy for each case.

METHODS

Clinical and radiological features of 22 cases of split spinal cord malformations (SSCM) are reported. Three groups of patients are considered: group a, patients with signs of tethered cord or scoliosis; group b, patients with midline cutaneous stigmata and group c, patients with a meningocele or meningomyelocele.

CONCLUSION

While CT scan is particularly useful for the evaluation of vertebral bodies and posterior arch abnormalities and spur characteristics in SSCM, MRI gives complementary information on the anatomy of spinal cord, dural sac, conus and filum terminale and permits the exclusion of associated lesions such as hydro-syringomyelia, dermal sinus or dermoid and epidermoid cysts. Surgery should be considered indicated in all cases of SSCM, even the asymptomatic ones, except in very badly handicapped meningomyelocele patients with nonprogressive disability and type II SSCM.

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.

Split cord malformation: Part I: A unified theory of embryogenesis for double spinal cord malformations

Much confusion still exists concerning the pathological definitions and clinical significance of double spinal cord malformations. Traditional terms used to describe the two main forms of these rare malformations, diastematomyelia and diplomyelia, add to the confusion by their inconsistent usage, ambiguities, and implications of their dissimilar embryogenesis. Based on the detailed radiographic and surgical findings of 39 cases of double cord malformations and the autopsy data on two other cases, this study endorses a new classification for double cord malformations and proposes a unified theory of embryogenesis for all their variant forms and features. The new classification recommends the term split cord malformation (SCM) for all double spinal cords. A Type I SCM consists of two hemicords, each contained within its own dural tube and separated by a dura-sheathed rigid osseocartilaginous median septum. A Type II SCM consists of two hemicords housed in a single dural tube separated by a nonrigid, fibrous median septum. These two essential features necessary for typing, the state of the dural tube and the nature of the median septum, do not ever overlap between the two main forms and can always be demonstrated by imaging studies so that accurate preoperative typing is always possible. All other associated structures in SCM such as paramedian nerve roots, myelomeningoceles manqué, and centromedian vascular structures frequently do overlap between types and are not reliable typing criteria. The unified theory of embryogenesis proposes that all variant types of SCMs have a common embryogenetic mechanism. Basic to this mechanism is the formation of adhesions between ecto- and endoderm, leading to an accessory neurenteric canal around which condenses an endomesenchymal tract that bisects the developing notochord and causes formation of two hemineural plates. The altered state of the emerging split neural tube and the subsequent ontogenetic fates of the constituent components of the endomesenchymal tract ultimately determine the configuration and orientation of the hemicords, the nature of the median septum, the coexistence of various vascular, lipomatous, neural, and fibrous oddities within the median cleft, the high association with open myelodysplastic and cutaneous lesions, and the seemingly unlikely relationship with fore and midgut anomalies. The multiple facets of this theory are presented in increasing complexity against the background of known embryological facts and theories; the validity of each facet is tested by comparing structures and phenomena predicted by the facet with actual radiographic, surgical, and histopathological findings of these 41 cases of SCM.

Congenital diastematomyelia in the upper thoracic spine. Diagnostic comparison of CT, CT-myelography, MRI, and US

Diastematomyelia (DM) in the upper thoracic spine is a rare congenital abnormality. The case presented is a comparison of CT, CT myelography, magnetic resonance imaging (MRI), and high resolution ultrasound imaging (US) in a female newborn.

Computed tomographic myelography in the investigation of childhood scoliosis and spinal dysraphism

The combined investigations of positive contrast myelography and computed tomographic (CT) myelography were performed on 53 consecutive children. Thirty-eight (72%) of these investigations were performed as a routine pre-operative procedure to identify occult spinal dysraphism in patients with childhood scoliosis; the remainder were because of the "orthopaedic syndrome", cervical radiculopathy, back pain and patients with clinical findings to suggest spinal dysraphism. In the 20 patients (38%) with idiopathic scoliosis, there was no case of spinal dysraphism and CT myelography provided no additional information to the myelogram. In the seven patients with spinal dysraphism the plain radiographic abnormalities identified were lumbar vertebral abnormalities (five), thoracic vertebral abnormalities (one), and sacral agenesis (one). Diastematomyelia was found in four patients, a low tethered cord and lipoma in two patients and a large lipoma in one patient. In all of these cases the myelogram indicated the intraspinal abnormalities; however, CT myelography provided more precise anatomical detail. We conclude that CT myelography is not indicated in the initial preoperative assessment of idiopathic scoliosis but should be reserved for patients with congenital or complicated scoliosis where the association with dysraphism is well recognised.

Diastematomyelia associated with teratomas. Report of two cases

Diastematomyelia, a complete or incomplete sagittal division of the neural axis into halves, is usually accompanied by a number of other malformations. However, true teratomas arising in dorsal juxtaposition to the spinal axis and associated with diastematomyelia are extremely rare. In this paper, two infants with this neoplastic-malformative complex are discussed. The two most prevalent hypotheses in the pathogenesis of diastematomyelia are reviewed. The hypothesis of a persistent neurenteric canal continues to be generally accepted, but, until more is known about the pathogenesis of extragonadal human teratomas, it is not possible to say how these neoplasms relate to the associated spinal cord malformation. Individually, each of the lesions present is extremely rare; it is possible that their concurrence in two patients may not be purely coincidental.

New data on diastematomyelia

Five cases of diastematomyelia are described and illustrated. These and a further 60 cases from the literature are analyzed. The data corroborate the opinion that early diagnosis and treatment result in a better prognosis.

Diastematomyelia--rare and unusual features

Diastematomyelia is an uncommon congenital anomaly of the spine. Four unusual variations of diastematomyelia are presented. These include (1) double diastematomyelia, (2) adult presentation, (3) diastermatomyelia without a septum and unusual termination of two halves of the spinal cord, and (4) recurrence of a fibrous band following removal of an osseous septum.

Diastemaomyelia

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