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

CSF-dynamics in syringomyelia: intracranial pressure and resistance to outflow

The several theories on the pathogenesis of syringomyelia have not resulted in the satisfactory selection of those patients who can be treated by CSF diversion. In the present paper three types of syringomyelia are described by case studies. The classification is made by investigation of CSF-dynamics, a measurement of CSF pressure and resistance to outflow of CSF. It is proposed that in a subgroup of patients with syringomyelia the cause is defective CSF resorption and that this group may be selected out and treated accordingly.

Chiari malformation in adults: a review of 40 cases

Forty adult patients (average age 40 years), with the clinical and radiological features of the Chiari malformations, were seen at the Toronto Western Hospital between 1967 and 1984. Surgical confirmation of the diagnosis was obtained in 32 cases; of these, 23 were classified as Chiari I malformation while 9 fulfilled the anatomic criteria of Chiari II. The patient population consisted of 22 males and 18 females. Common presenting symptoms included head and neck pain (60%), sensory complaints (60%), upper extremity weakness (42%), and gait disturbance (40%). Neurological findings included signs of central cord dysfunction (73%), long-tract motor and/or sensory findings (58%), brainstem signs (38%), cerebellar dysfunction (18%), and increased intracranial pressure (15%). The majority of patients underwent myelography with or without computed tomography of the cervical-medullary junction. Two recent patients had 0.15T MRI scans which helped demonstrate an intramedullary syrinx. Thirty-three patients underwent 47 operative procedures (discounting spinal fusion and CSF shunt revisions). Open surgical management was performed in 32 patients, with CSF shunting along in one patient. Five patients (15%) incurred surgical complications within a six week postoperative period. Follow-up to date, ranges from one month to 11 years. In the 33 surgically treated patients, 18 are improved (55%), 10 are neurologically stable (30%), and five have worsened clinically (15%), including one death. Based on this study it appears that the Chiari II malformation may be more common in adults than previously recognized. Surgical intervention has a favourable outcome in the majority of patients but a significant proportion continue to deteriorate.

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.

Chiari type I malformation with an associated intramedullary schwannoma

A case of Chiari type I malformation associated with a cervical intramedullary schwannoma is presented. A review of the literature concerning intramedullary schwannomas revealed their most frequent location to be in the cervical region. Their optimal treatment seems to be total removal as early in the course as is feasible. Emphasis is given to the need for actual demonstration of the cystic nature of the swollen spinal cord when dealing with Chiari type I malformation.

The natural history and the influence of surgical treatment in syringomyelia

A retrospective analysis was made of the natural history and treatment of 44 patients with syringomyelia, followed for a median interval of 10 years after diagnosis. Twenty-four patients were treated surgically. Four of 12 patients who had a laminectomy with aspiration of the syrinx or syringostomy, and 7 of 15 patients who underwent decompression and exploration of the cervicomedullary junction, showed sustained improvement or stabilisation of their neurological deficits. When symptoms had been present for more than 2 years, when there was a moderate or severe neurological disability, and when the patient was more than 40 years old, the long-term outlook of posterior fossa surgery was usually poor. Of the 20 patients who did not have an operation, 7 had no further progression in symptoms after presentation and prolonged survival was usual. It is concluded that in many cases syringomyelia is compatible with prolonged survival, and although improvement can follow surgery, its influence on the disease in the long-term is uncertain.

Surgical treatment of syringomyelia. Favorable results with syringoperitoneal shunting

The authors reviewed the clinical findings, radiological evaluation, and operative therapy of 39 patients with syringomyelia. Syringoperitoneal (SP) shunting was used in 15 patients and other procedures were used in 24 patients. Follow-up periods ranged from 1 1/2 to 12 years. During the period of this study, metrizamide myelography in conjunction with early and delayed computerized tomography scanning replaced all other diagnostic procedures in patients with syringomyelia. Preoperative accuracy for the two procedures was 87%. The most common symptoms were weakness (79%), sensory loss (67%), pain (38%), and leg stiffness (28%). Surgery was most effective in stabilizing or alleviating pain (100%), sensory loss (81%), and weakness (74%); spasticity, headache, and bowel or bladder dysfunction were less likely to be reversed. Approximately 80% of patients with idiopathic and posttraumatic syringomyelia and 70% of those with arachnoiditis improved or stabilized. Better results were obtained in patients with less severe neurological deficits, suggesting the need for early operative intervention. A higher percentage of patients had neurological improvement with SP shunting than with any other procedure, especially when SP shunting was the first operation performed. Patients treated with SP shunts also had the highest complication rate, most often shunt malfunction. These results indicate that SP shunting is effective in reversing or arresting neurological deterioration in patients with syringomyelia.

Long-term results of the surgical treatment of syringohydromyelia

Long-term results of 26 patients suffering from syringohydromyelia are reported. The patients underwent laminectomy and myelotomy with marsupialisation of the intracord cavity. Two different long term objective examinations have been performed demonstrating favorable results in 65% of patients at the first examination (mean 8 years following the operation) and in 60% of these at a second examination (mean 14 years following the operation). The limitations of posterior fossa decompression and other surgical procedures have also been discussed. The absence of surgical mortality and the length of follow-up period of this series supported the conclusions that laminectomy and myelotomy with marsupialisation of the intracord cavity represents a reliable method to relieve the effects of associated foramen magnum abnormalities avoiding posterior fossa surgery.

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.