Computerized axial tomography in syringomyelia

The History of Neurosurgical Spinal Oncology: From Inception to Modern-Day Practices

The neurosurgical management of spinal neoplasms has undergone immense development in parallel with advancements made in general spine surgery. Laminectomies were performed as the first surgical procedures used to treat spinal neoplasms. Since then, neurosurgical spinal oncology has started to incorporate techniques that have developed from recent advances in minimally invasive spine surgery. Neurosurgery has also integrated radiotherapy into the treatment of spine tumors. In this historical vignette, we present a vast timeline spanning from the Byzantine period to the current day and recount the major advancements in the management of spinal neoplasms.

Imaging Technologies in Spine Surgery

This article presents a comprehensive review of the evolution of both invasive and noninvasive imaging technologies that are part of the arsenal of spinal diagnostics and surgical therapy. The text provides not only a historical lens to the evolution of the imaging technologies that are part of routine contemporary practice but also provides a detailed sketch of emerging imaging technologies, such as endoscopic and exoscopic systems. Augmented reality, virtual reality, and mixed reality are new technologies that have enhanced the preparation of surgery and provide excellent case-specific training modules to break down each step of an operation in isolation.

Neuroradiology back to the future: spine imaging

Although radiography of the spine began shortly after Roentgen's discovery in 1895, there was little written in the medical literature about spine imaging until nearly 25 years later with the development of myelography, first by using air and then a variety of positive contrast agents. The history of spine imaging before CT and MR imaging is, in large part, a history of the development of contrast agents for intrathecal use. The advent of CT and, more important, MR imaging revolutionized spine imaging. The spinal cord and its surrounding structures could now be noninvasively visualized in great detail. In situations in which myelography is still necessary, advances in contrast agents have made the procedure less painful with fewer side effects. In this historical review, we will trace the evolution of spine imaging that has led to less invasive techniques for the evaluation of the spine and its contents and has resulted in more rapid, more specific diagnosis, therapy, and improved outcomes.

Post-traumatic syringomyelia: a review of the literature

The need for increased awareness and a high index of suspicion for post traumatic syringomyelia is emphasised. Early clinical diagnosis confirmed by MRI and early treatment can avert or minimise the potentially devastating effects of post traumatic syringomyelia. The regular and frequent follow up of the patient on a yearly or alternate year basis to monitor the patient with spinal injury for this complication, as well as other complications, is the best way to ensure that post traumatic syringomyelia is diagnosed and managed early in order to avoid further disability.

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.

Syringohydromyelia: radiological evaluation of 82 patients in a developing country

A series of 82 patients presenting with syringohydromyelia and confirmed at operation were studied by conventional radiological techniques and computed tomography (CT). Cord collapse was demonstrated in 71% of the patients with wide bony canals and only 11% of patients with normal bony canals. It was most reliably shown with high resolution CT. Intrathecal CT metrizamide myelography (CTMM) failed to demonstrate contrast percolation into many cavities shown in the plain scans. Obliteration of the subarachnoid space at C1-2 levels appreciated in the plain scans strongly indicated coexisting tonsillar herniation, making CTMM unnecessary. In almost all patients, CTMM was found to be non-contributory if the high resolution plain CT scan failed to reveal cord cavitation.

Hydromyelic hydrocephalus. Correlation of hydromyelia with various stages of hydrocephalus in postshunt isolated compartments

The clinical features and pathophysiology of specific forms of hydromyelia are analyzed in this report together with the chronological changes of associated hydrocephalus. Nine patients were studied; all had hydromyelia with varying degrees of associated hydrocephalus. Clinically applicable classification systems were used to evaluate the progression of hydrocephalus (Stages I to IV) and to define the compartment isolated after shunting in the previously communicating cerebral ventricles (Types I to IV). Four patients had Stage IV disease (holoneural canal dilatation); one had Stage II and four had Stage I disease (both Stages I and II with supratentorial hydrocephalus). All patients were initially treated by ventriculoperitoneal shunting at an average age of 9.9 years. Five patients had progressive spinal symptoms before or after treatment of their hydrocephalus. Two patients had Type III isolation (an isolated rhombencephalic ventricle) with a functioning ventricular shunt; ventriculography confirmed a communication between the fourth ventricle and the hydromyelia, and both patients improved after placement of a shunt in the fourth ventricle. The remaining patients had Type IV isolation (isolated central canal dilatation) with a functioning ventricular shunt. This study indicates that in some cases the pathophysiology of hydromyelia is closely related to associated hydrocephalus. A new concept of the development of an isolated compartment after shunting is proposed to explain the progression of hydromyelia in these cases.

[Syringomyelia: review of the literature and report of a case]

A thorough review of history, pathophysiology, clinical manifestations, diagnosis and treatment of syringomyelia is presented by the authors, followed by a case report in which the diagnosis was confirmed by magnetic resonance imaging.

Hydromyelia: a critical review

The author reviews current concepts involving the etiology, pathogenesis, and treatment of hydromyelia. A critical evaluation of current surgical approaches in relation to the type of hydromyelia present is discussed.

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.

Computer-tomographic investigations in malformations of the occipito-cervical junction

The diagnosis of occipito-cervical dysplasias has been improved markedly by computer-tomography. Two millimetre transverse cuts with sagittal and coronal reconstructions are necessary. Based on nine cases with nearly all types of malformations it is shown that even complex osseous (mesodermal) malformations and dysplasias as well as isolated or combined neuroectodermal dysplasic or secondary compressive lesions of the medulla oblongata and cord can be detected. Transverse and AP diameters of the foramen magnum and spinal canal and the classical lines and angles can be measured. This time-consuming procedure will give more information than the classical radiological methods and avoid myelographic and cisternal examinations. Its disadvantages are the impossibility of dynamic functional studies and the length of the procedure.

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.

Considerations in the diagnosis and treatment of syringomyelia and the Chiari malformation

A series of patients with abnormalities of the craniocervical junction with and without syringomyelia is reviewed. The impact of computerized tomography scanning on current radiological evaluation is discussed. Air myelography may no longer be necessary for accurate diagnosis. While the results of surgery for the Chiari malformation were good, at least one-half of the patients with syringomyelia showed continued progression of symptoms after posterior fossa surgery. More effective surgical therapy requires a better understanding of the pathogenesis of the syrinx.

[Incidental syringohydromyelography: report of a case]

The radiological findings of syringomyelography are described in a five years old patient who underwent a percutaneous injection of opaque contrast medium (Lipiodol) into the intraspinal syringomyelic cavity. The clinical picture, the usual diagnostic methods and the place of syringomyelography for the diagnosis of syringomielia are discussed.

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.

Progressive posttraumatic cystic myelopathy: neuroradiologic evaluation

The neuroradiologic evaluation and findings in 25 symptomatic patients with surgically proven progressive posttraumatic cystic myelopathy are reviewed. To follow patients with spinal cord injury, neuroradiologic algorithms were developed to confirm and define cystic myelopathy. The algorithm used in the early and mid 1970s relied on the myelographic demonstration of a large cord for suspicion of a cyst. Review of this material found that in progressively symptomatic patients 14 of 25 proven cysts were in large cords. A more recent algorithm used computed tomographic metrizamide myelography. In nine of 11 patients studied in this fashion, the cyst filled with contrast material 2--4 hr after injection, yet it did not communicate with the subarachnoid space at subsequent surgery. The origin of the cyst fluid and mechanism of cyst demonstration with metrizamide may be associated with transneural migration of fluid. This condition must be clinically suspected and radiologically confirmed for surgical treatment (cyst-shunt procedure) if neurologic preservation of function is to be maintained.

Radiographic studies of the ventricles in syringomyelia

Radiographic investigations of 171 patients with "communicating' syringomyelia have been reviewed. Hydrocephalus was found in one-third of the cases and has occasionally progressed after operation on the posterior fossa, sometimes with accompanying clinical deterioration. The outlets of the fourth ventricle were usually abnormal; tonsillar descent, arachnoiditis and both together were seen. Arachnoiditis correlated strongly with a history of difficult birth. The foramen of Magendie was sometimes patent and sometimes blocked. There was no consistent level of occlusion corresponding to a persistent roof of the fourth ventricle. The cisterna magna was usually small or obliterated but some examples of large cisterns or subarachnoid pouches were found. Radiological demonstration of a communication from the fourth ventricle to the syrinx occurred in only seven patients by positive contrast material and not by air. It is suggested that a sizable communication is rare at the time when patients seek treatment.

Morphology of the cervical spinal cord on computed myelography

To ensure adequate use of the technique of computed myelography (CM) it is necessary to have an exact picture of the morphology of the normal spinal cord as demonstrated by this technique. This has been obtained by studying the morphology and measuring the frontal and sagittal diameter of the cervical cord in 20 patients. The normal values are presented. The changes of this morphology in one patient with a tumour, one patient with atrophy of the spinal cord and in some patients with congenital malformations are also reported.

Xenon enhancement for computed tomography of the spinal cord

The spinal cord is not consistently shown by plain computed tomography or with iodide enhancement. Xenon enhancement increases the attenuation of the spinal cord and visualization is improved considerably; fluid-filled cavities, including syringohydromyelia, do not enhance and are clearly defined.

Computed tomography in syringomyelia and the associated Arnold-Chiari type I malformation

A total of 20 patients with an Arnold-Chiari Type I malformation, i.e. without skeletal abnormality and associated with a syringomyelic syndrome, were studied using the EMI Whole Body Scanner CT5000. Two groups were considered: (i) a retrospective series of 12 patients without intrathecal water soluble contrast media and (ii) a prospective series of eight patients after the introduction of intrathecal Metrizamide. In the first group tonsillar herniation could not be conclusively identified on CT and cord visualisation was possible in only two cases. In the second group, tonsillar herniation and cord expansion were consistently demonstrated. Cord cavitation has also been detected. In both groups it was possible to assess the size and position of the ventricular system. The results of this study indicate that evaluation of the upper cervical cord cerebellar tonsillar herniation, may be achieved, but only following opacification of the CSF. The precise extent of cerebellar tonsillar herniation may be difficult to evaluate. The reasons for these findings are discussed.

CAT of the spine and spinal cord

CAT for spine and spinal cord studies was carried out in 182 patients aged 7-80 years during 12 months (April 1977 to March 1978) with the EMI body scanner CT 5005. Three methods were used: (1) standard (noncontrast) scanning; (2) the same, with IV contrast enhancement; (3) the same again, after CSF enhancement with Amipaque (computer-assisted myelography). The combined use of Amipaque and CT seems particularly interesting.

Computed tomography of the cervical spine and spinal cord

A number of cases are presented to illustrate the diagnostic effectiveness of computed tomography in the cervical spine and spinal cord, specifically in syringomyelia, spinal stenosis, and fractures. Certain limitations in the examination are also presented, and problems related to interpretation, particularly in regard to spinal stenosis, are discussed.

Computer tomography for lesions of the craniovertebral region

The images obtained by computed tomography constitute a new and interesting approach to lesions of the craniovertebral region. The criteria of basilar invagination must be systematically checked in routine examination. The main interest of CT scanning is the simultaneous view of the bony structures as well as the central nervous system in a completely innocuous way.

Computed tomography of the spinal canal and cord

Selective cases have been presented to demonstrate the usefulness of computed tomography in disorders of the spine and spinal cord. The osseous structures are more readily demonstrated than the soft tissues. The cord is difficult and inconsistently identified. However, cystic lesions (syringomyelia) may, at times, be demonstrated. The transverse projection of the CT scan is an added benefit in demonstrating bony spinal lesions. The use of metrizamide with faster scanners should improve the usefulness of this technique in evaluating intraspinal lesions.

Computerized transaxial tomography: its role in the post-operative tumor case

The role of computerized transaxial tomography (CTT) of the brain in 100 post-operative tumor cases is assessed. CTT proves an accurate method of determining tumor recurrence and in evaluating such complications as intracerebral hemorrhage, subdural or extradural hemorrhage, cerebral infarction, hydrocephalus and shunt patency. Its accuracy decreases the need for interventional procedures. Its usefulness may be limited by the presence of metal clips or plates, by radio-opaque contrast media or intracranial air.