High resolution computed tomography in cervical syringomyelia

Syringohydromyelia following meningomyelocele surgery--role of metrizamide myelography and computed tomography

Five children developed symptoms attributable to syringohydromyelia several years following neonatal surgery for lumbosacral meningomyelocele. Metrizamide injection followed by computed tomography (CT) was performed in all five patients. In two patients, there was direct opacification of both the subarachnoid space and the syringohydromyelia. In a further two patients, delayed CT demonstrated late opacification of the central cavity from contrast introduced into the subarachnoid space. In the fifth patient via a suboccipital puncture, there was fortuitous filling of a caudally displaced fourth ventricle communicating with a central cavity within the cord, but there was no visualization of the subarachnoid space. Surgery with decompression and plugging of the obex halted the progression of the disease in all the patients.

The natural history and results of surgery in 50 cases of syringomyelia

In recent years, new neuroimaging techniques have revived interest in syringomyelia with respect to indications and results of surgery. Fifty patients, 36 of whom underwent surgery, have been reviewed. All patients but 3 underwent a new clinical assessment and 33 of them were also neurophysiologically investigated. In approximately one-third of the non-surgically treated patients the clinical course was benign. In 26 of the surgically treated patients an improvement was noted at the short-term assessment both for spasticity and pain, but in most of them it was not maintained in the medium term. Therefore, an accurate selection of the patients to be treated surgically is strongly recommended, particularly when the natural history of the disease is considered. Decompression of the posterior fossa seems to give the best results, yet no curative surgical treatment has been devised to date.

Symptomatic Chiari malformations. An analysis of presentation, management, and long-term outcome

The Chiari malformation is a condition characterized by herniation of the posterior fossa contents below the level of the foramen magnum, and is categorized into three types based on the degree of herniation. The authors review their surgical experience between 1975 and 1985 with 50 patients afflicted with symptomatic Chiari malformations. Any patient with associated myelomeningocele, tethered spinal cord, lipoma, or diastematomyelia was excluded from this series. Forty-one patients had Chiari I malformations, seven were classified as having Chiari II, and two as having Chiari III. The presentation of pediatric and adult patients was identical. Treatment was directed at the posterior fossa pathology. Seven patients with accompanying ventral bone compression underwent transoral decompression of the cervicomedullary junction, 42 had posterior decompressive procedures, and six received ventriculoperitoneal shunts. The posterior decompression included opening the outlet foramina of the fourth ventricle, occluding any communication between the spinal cord central canal and the obex, shunting the fourth ventricle, and placing a dural graft. Postoperatively, 20% of the patients are asymptomatic, 66% improved, and 8% stabilized; in 6% the disease has progressed in spite of multiple procedures. Preoperative signs that are predictive of a less favorable outcome include muscle atrophy, symptoms lasting longer than 24 months, ataxia, nystagmus, trigeminal hypesthesia, and dorsal column dysfunction (p less than 0.05, chi-square test). A model based on the presence or absence of atrophy, ataxia, and scoliosis at the time of the preoperative examination has been generated that allows prediction of long-term outcome at the 95% confidence level.

Use of the syringoperitoneal shunt in the treatment of syringomyelia

A syringoperitoneal shunt is a one-way drain that empties cerebrospinal fluid from the pathological syringomyelic cavity into the abdomen. This treatment technique is based on the principle that the signs and symptoms of syringomyelia are caused by insidious interference with the condition of nerve signals in the spinal cord tracts due to either tearing or compression of the tracts by the distended cavity. A series of eight patients suffering from this disorder were operated upon using a syringoperitoneal shunt. The initial results seem to indicate that this technique is especially useful when pain, atrophy, or both dominate the clinical picture. Clinical signs, diagnostic studies, and surgical considerations are discussed.

Syringomyelia associated with a foramen magnum meningioma

In a 14-year-old boy with a meningioma at the foramen magnum extending to C-2, cervical syringomyelia was found on metrizamide computed tomographic myelography. The mechanism of syrinx enhancement on delayed computed tomographic scanning was considered to be due to transneural passage of metrizamide into the spinal cord. Long-standing spinal block may be responsible for development of syringomyelia. Syringomyelia associated with spinal extramedullary tumors was reviewed in the literature.

Occipital dysplasia and Chiari type I deformity in a family. Clinical and radiological study of three generations

Three generations of a family affected by a craniocervical malformation (CCM) were subjected to clinical and radiological studies. Occipital dysplasia (OD) and Chiari type I deformity (CD.I) were the main features, inheritance being autosomal-dominant. The malformation was variably expressed; it ranged from OD with basilar impression (BI) to OD without BI and from CD.I with OD to CD.I without obvious osseous malformation. Its pathogenesis, and that of other related familial disorders (Klippel-Feil syndrome and syringomyelia), is discussed, the conclusion being drawn that all were elements of one genetic disorder which finds expression in a very variable sequence. The value of high-resolution CT in the detection of asymptomatic carriers is emphasized.

Computed tomography in the diagnosis of syringomyelia

We describe the usefulness of computed tomography (CT) in the diagnosis of syringomyelia in 12 patients for whom the diagnosis had remained unconfirmed with other diagnostic methods. In 7 of these patients, CT myelography revealed an intramedullary cavitation filled with contrast medium. In 3 patients, the cavitation was not filled, and positive contrast medium was not used in another 2. In these 5 cases, however, CT visualized low-density areas within the cord. CT would seem to be the most preferable method for confirming the clinical diagnosis of syringomyelia and is particularly useful in atypical cases.

CT in syringomyelia: three different aspects

Three different CT aspects of patients with myelographic and clinical syringomyelia patterns are presented. In the first the CT pattern was atypical. The second case is a typical example of opacification of the cavity after contrast enhancement and the third shows re-formation of the cavity 7 years after surgical damage.

Computed tomography of "cystic" intramedullary lesions

Using an EMI 5005 scanner with high resolution option, 75% of syrinxes were shown as low density cavities. Most spinal cord tumours caused isodense swellings, but 41% contained low density zones and cystic elements were demonstrated in 76% of these at surgery or by puncture of the spinal cord; a few (11%) of the isodense tumours were cystic. The differential diagnosis of low density intramedullary lesions is discussed.

Computed tomography of the spine and spinal cord; limitations and applications

The author presents a comprehensive review of the literature on spinal computerized tomography in the evaluation of spinal fractures and fracture-dislocations, degenerative processes with bony encroachment into the spinal canal, disc protrusion, cystic degeneration of the cord, communicating hydro-syringomyelia, intra- and extramedullary neoplasms and congenital malformations. Critical analysis of all published data and additional personal experience gained over the past three years make it possible to better define the clinical applications and practical limitations of spinal CT scans.