Outcome after surgical treatment of progressive posttraumatic cystic myelopathy

• Published in: Journal of neurosurgery Vol. 92; no. 2; pp. 149 - 154
• Main Authors: LEE, T. T, ALAMEDA, G. J, GROMELSKI, E. B, GREEN, B. A
• Format: Journal Article
• Language: English
• Published: Park Ridge, IL American Association of Neurological Surgeons 01-04-2000
• Subjects: Adult; Aged; Aged, 80 and over; Biological and medical sciences; Cerebrospinal Fluid Shunts; Female; Follow-Up Studies; Humans; Injuries of the nervous system and the skull. Diseases due to physical agents; Magnetic Resonance Imaging; Male; Medical sciences; Middle Aged; Neural Tube Defects - diagnosis; Neural Tube Defects - surgery; Neurologic Examination; Postoperative Complications - diagnosis; Postoperative Complications - etiology; Spinal Cord Injuries - diagnosis; Spinal Cord Injuries - surgery; Syringomyelia - diagnosis; Syringomyelia - surgery; Traumas. Diseases due to physical agents; Sonography; Human; Nervous system diseases; Spinal cord; Intraoperative; Trauma; Syringomyelia; Treatment; Surgery; Central nervous system disease; Echography; Evolution; Technique; Spinal cord disease
• ISSN: 0022-3085; 1547-5654; 1933-0693
• DOI: 10.3171/spi.2000.92.2.0149

Progressive posttraumatic cystic myelopathy (PPCM) can occur after an injury to the spinal cord. Traditional treatment of PPCM consists of inserting a shunt into the cyst. However, some authors have advocated a more pathophysiological approach to this problem. The authors of the present study describe their surgical treatment protocol and outcome in a series of patients with syringomyelia.
Medical records of 34 patients undergoing surgical treatment for PPCM were reviewed. Laminectomies and intraoperative ultrasonography were performed. In patients without focal tethering of the spinal cord and in whom only a confluent cyst had been revealed on ultrasonography, a syringosubarachnoid shunt was inserted; in those with both tethering and a confluent cord cyst, an untethering procedure was performed first. When a significant reduction (>50%) in the size of the cyst was shown after the untethering procedure, no shunt was inserted. When no changes in cyst size were demonstrated on ultrasonography, a short syringosubarachnoid shunt was used. The mean follow-up period was 28.7 months (range 12-102 months). The interval between the mechanism of injury and the operation ranged from 5 months to 37 years (mean 11 years). Pain was the most frequent symptom, which was followed by motor deterioration and spasticity. Postoperative improvement was noted in 55% of patients who experienced motor function deterioration and in 53% of those who demonstrated worsening spasticity. In 14 of 18 patients with an associated tethered spinal cord, tethering alone caused significant collapse of the cyst. Postoperative magnetic resonance imaging demonstrated cyst collapse in 92% of patients who had undergone untethering alone and in 93% of those who underwent syringosubarachnoid shunt placement. Treatment failure was observed in 7% of the former group and in 13% of the latter.
Posttraumatic cystic myelopathy can occur with or without the presence of tethered cord syndrome. Intraoperative ultrasonography can readily demonstrate this distinction to aid in surgical decision making. Untethering alone in patients with tethered cord syndrome and cyst formation can reduce the cyst size and alleviate symptoms and signs of posttraumatic cystic myelopathy in the majority of these cases. Untethering procedures in which duraplasty is performed to expand the subarachnoid space may be a more physiologically effective way of treating tethered cord with associated syringomyelia.