Syringomyelia after operation:diagnosis and its formational mechanism

Objective： To describe the MRI findings and discuss the pathogenesis formation mechanism of syringomyelia in the patients after spine surgical operation. Methods： Totally 13 patients were been enrolled in the study. Before operation, none of our patients presented with spinal cord syringomyelia. The mean follow-up duration was 6 years （range 2-10 months） by MRI. Four of the 13 patients after spinal cord tumor removed operation, 3 patients after spinal trauma operation, 2 cases had scoliosis before, 2 cases were cervical spondylotic myelopathy and 2 cases had tethered cord syndrome before operation. MR features of pre- and post-operation on all patients were been studied in contrast with surgical results and clinical symptoms. The radiology diagnostic was made by 3 different radiologists respectively. The characteristics of length, width, signals, shape of cavity and spinal cord position as well as subarachnoid shape were focused on. Results： All the patients had no syringomyelia on MRI before operation. The spinal cord of 7 patients showed persist compression and 2 patients had tethered cord before operation. MRI features of syringomyelia after operation in our cases showed longitudinal cavity with syrinx fluid had T1 and T2 relation characteristics of cerebrospinal fluid （CSF）. The mean length was 5.5 spinal segment, 4 cord of 13 patients presented cord compressed from anterior materials, 4 occurred postoperative adhesion to the back of lumbar spinal canal and spinal cord of 1 cases clung to the front wall of cervical spinal canal. Conclusion： The mechanism of syringomyelia in the patients after spinal surgical intervention may be the persisting compression or intention of the spinal cord in the period of pre- or post-operation. The edema, cyst, malacia of spinal cord are the most important lesions and risk factors resulted in the syringomyelia.

Clinical manifestations and significance of post-traumatic thoracolumbar syringomyelia

Objective: To analyze the pathogenic mechanism and the clinical significance of post traumatic thoracolumbar syringomyelia through reviewing the clinical manifestations. Methods: The data of 15 patients (14 males and 1 female, aged from 28 to 56 years, with an average of 36 years) with post traumatic syringomyelia treated in our hospital from December 1997 to February 2002 were studied retrospectively. Two patients suffered from T 11 fractures, 7 from T 12 fractures and 6 from L 1 fractures. There were 12 patients with burst fractures and 3 with fracture dislocations. Anterior decompression, bone graft, bone fusion and internal fixation were made on 6 patients, posterior decompression, bone graft, bone fusion and internal fixation on 1 patient, and non surgical treatment on 8 patients. Results: Syringomyelia of the patients was diagnosed accurately with magnetic resonance imaging at 0.5 4 years after the original thoracolumbar fracture. The cavern was round in 6 cases, elliptic in 6 cases, and irregular in 3 cases. The patients also suffered from pain (80%), myodynamia attenuation in lower extremities ( 66.7 %), aggravated spasm ( 46.7 %), sensation loss or hypesthesia ( 46.7 %), decreased coordinate function of lower extremities (20%) and autonomic nerve symptom ( 6.7 %). Conclusions: Post traumatic thoracolumbar syringomyelia should be suspected if the patient has new neurological symptoms, such as myodynamia attenuation in lower extremities, after the neural function becomes stable for certain time.

Surgery for posttraumatic syringomyelia:a retrospective study of seven patients

Objective： To analyze retrospectively the clinical symptoms, signs, radiological findings and results of treatment of posttraumatic syringomyelia. Methods： The data of 7 patients with posttraumatic syringomyelia confirmed by computerized tomography （CT） and magnetic resonance imaging （MRI） in our hospital between 1999 and 2004 were reviewed retrospectively. The patients underwent decompressive laminectomy or syringo-subarachnoid （S-S） shunting with microsurgery. Long-term follow-up was available （range： 13-65 months）. Results： The major dinical manifestations of posttraumatic syringomyelia usually included the onset of increasing signs and the development of new symptoms after an apparently stable period. The clinical symptoms included pain, sensory disturbance, weakness, and problems in autonomic nerves. Syrinx existed merely at the cervical level in 4 cases and extended downward to the thoracic levels in the other 3 cases. One case underwent decompressive laminectomy, 6 cases were treated by S-S shunting. During the early postoperative period, all the patients showed an improvement of symptoms of syrinx without major complication or death. The decreased size or collapse of the syrinx was demonstrated by postoperative MRI. Conclusions ： Posttraumatic syringomyelia is a disabling sequela of spinal cord injury, developing months to years after spinal injury. MRI is the standard diagnostic technique for syringomyelia. The patients with posttraunmtic syringomyelia combined with progressive neurological deterioration should be treated with operations. S-S shunting procedure is effective in some patients with posttraumatic syringomyelia. Decompressive procedure may be an alternative primary surgical treatment for patients with kyphosis and cord compression.