Clinical features, investigation and treatment of post-traumatic syringomyelia

The Physiological Occlusion of the Central Canal May Be a Prerequisite for Syringomyelia Formation

OBJECTIVE

Syringomyelia is a common central nervous system disease characterized by the dilation of the central canal (CC). Regarding the pathogenesis of syringomyelia, cerebrospinal fluid (CSF) circulation obstruction in the subarachnoid space (SAS) of the spinal cord has been widely accepted. However, clinical and animal studies on obstructing the CSF in SAS failed to form syringomyelia, challenging the theory of SAS obstruction. The precise pathogenesis remains unknown.

METHODS

We utilized an extradural compression rat model to investigate the pathogenesis underlying syringomyelia. Magnetic resonance imaging enabled detection of syringomyelia formation. To assess CSF flow within the SAS, Evans blue was infused into the cisterna magna. Histological analysis allowed morphological examination of the CC. Furthermore, CSF flow through the CC was traced using Ovalbumin Alexa-Flour 647 conjugate (OAF-647). Scanning electron microscopy (SEM) enabled visualization of ependymal cilia.

RESULTS

The findings showed that the dura mater below the compression segment exhibited lighter coloration relative to the region above the compression, indicative of partial obstruction within the SAS. However, the degree of SAS occlusion did not significantly differ between syringomyelia (SM-Y group) and those without (SM-N group). Intriguingly, hematoxylin and eosin staining and CSF tracing revealed occlusion of the CC accompanied by reduced CSF flow in the SM-Y group compared to SM-N and control groups. SEM images uncovered impairment of ependymal cilia inside the syringomyelia.

CONCLUSION

CC occlusion may represent a physiological prerequisite for syringomyelia formation, while SAS obstruction serves to initiate disease onset. The impairment of ependymal cilia appears to facilitate progression of syringomyelia.

Suppression of TGFβR-Smad3 pathway alleviates the syrinx induced by syringomyelia

BACKGROUND

Syringomyelia is a cerebrospinal fluid (CSF) disorder resulted in separation of pain and temperature, dilation of central canal and formation of syrinx in central canal. It is unclear about mechanisms of the dilation and syrinx formation. We aimed to investigate roles of ependymal cells lining central canal on the dilation, trying to reduce syrinx formation in central canal.

METHODS

We employed 78 Sprague-Dawley (SD) rats totally with syringomyelia to detect the contribution of ependymal cells to the dilation of central canal. Immunofluorescence was used to examine the activation of ependymal cells in 54 syringomyelia rat models. BrdU was used to indicate the proliferation of ependymal cells through intraperitoneal administration in 6 syringomyelia rat models. 18 rats with syringomyelia were injected with SIS3, an inhibitor of TGFβR-Smad3, and rats injected with DMSO  were used as control. Among the 18 rats, 12 rats were used for observation of syrinx following SIS3 or DMSO administration by using magnetic resonance imaging (MRI) on day 14 and day 30 under syringomyelia without decompression. All the data were expressed as mean ± standard deviation (mean ± SD). Differences between groups were compared using the two-tailed Student's t-test or ANOVA. Differences were considered significant when *p < 0.05.

RESULTS

Our study showed the dilation and protrusions of central canal on day 5 and enlargement from day 14 after syringomyelia induction in rats with activation of ependymal cells lining central canal. Moreover, the ependymal cells contributed to protrusion formation possibly through migration along with central canal. Furthermore, suppression of TGFβR-Smad3 which was crucial for migration reversed the size of syrnix in central canal without treatment of decompression, suggesting TGFβR-Smad3 signal might be key for dilation of central canal and formation of syrinx.

CONCLUSIONS

The size of syrinx was decreased after SIS3 administration without decompression. Our study depicted the mechanisms of syrinx formation and suggested TGFβR-Smad3 signal might be key for dilation of central canal and formation of syrinx.

Radiographic assessment of surgical treatment of post-traumatic syringomyelia

Context: Symptomatic post-traumatic syringomyelia can affect the quality of life in patients whose neurologic function has already been impacted by a spinal cord injury.Objective: To investigate the radiographic and clinical outcomes following surgery for syringomyelia, we present a literature review along with a case series from a single surgeon's experience.Methods: A retrospective review was conducted on patients with post-traumatic syringomyelia who were treated by a single surgeon. Thirty-four patients who underwent surgical treatment consisting of syrinx fenestration, lysis of adhesions, and duraplasty were identified. In addition, a narrative literature review was conducted with a primary focus on diagnosis and management of post-traumatic syringomyelia.Results: Literature review suggests that regardless of age, sex, vertebral location, or severity of trauma, patients who experience a spinal cord injury should be closely monitored for post-traumatic syringomyelia. Retrospective review of our 34 patients revealed 24 patients for whom pre- and post- operative MRI was available. The predominant location of the injury was cervical (15). The average syrinx length, measured in spinal segments, was similar when comparing pre- and post-operative MRIs; average syrinx length was 5.5 and 5.4 spinal segments, respectively. In contrast, syrinx axial dimension was decreased in 16 of the patients post-operatively and stable or increased in the other eight. The change in syrinx size did not correlate with clinical outcomes.Conclusion: Current surgical treatment of post-traumatic syringomyelia involves restoration of normal CSF flow dynamics; further prospective work is needed to correlate the clinical state, radiographic measures, and efficacy of surgical intervention.

Development of pre-syrinx state and syringomyelia following a minor injury: a case report

Background

A generally accepted rule is that posttraumatic syringomyelia (PTS) results from spinal cord injury (SCI).

Case presentation

Here, we report the development of syringomyelia without SCI in a 54-year-old Caucasian man following a mild motor vehicle accident. The computed tomography on admission excluded an injury of the spine. Because of neck and back pain, magnetic resonance imaging was performed on day 3 post-injury and demonstrated minimal changes from a ligamentous strain at the cervicothoracic transition. Any traumatic affection of the bone, vertebral discs, intraspinal compartment, or spinal cord were excluded. Some limb weakness and neurogenic bladder dysfunction started manifesting within the following weeks. Repeated MRIs following the accident demonstrated arachnoid adhesions at the C1–2 level and spinal cord edema equivalent to a pre-syrinx state at 12 months and syrinx formation at 24 months. Because of further deterioration, decompression was performed at 36 months.

Conclusions

We conclude that even after a minor trauma PTS can occur and that medullary edema (pre-syrinx state) may precede syrinx formation.

Treatment of posttraumatic syringomyelia: evidence from a systematic review

Background

Following spinal cord injury (SCI), the routine use of magnetic resonance imaging (MRI) resulted in an incremental diagnosis of posttraumatic syringomyelia (PTS). However, facing four decades of preferred surgical treatment of PTS, no clear consensus on the recommended treatment exists. We review the literature on PTS regarding therapeutic strategies, outcomes, and complications.

Methods

We performed a systematic bibliographic search on (“spinal cord injuries” [Mesh] AND “syringomyelia” [Mesh]). English language literature published between 1980 and 2020 was gathered, and case reports and articles examining syrinx due to other causes were excluded. The type of study, interval injury to symptoms, severity and level of injury, therapeutic procedure, duration of follow-up, complications, and outcome were recorded.

Results

Forty-three observational studies including 1803 individuals met the eligibility criteria. The time interval from SCI to the diagnosis of PTS varied between 42 and 264 months. Eighty-nine percent of patients were treated surgically (n = 1605) with a complication rate of 26%. Symptoms improved in 43% of patients postoperatively and in 2% treated conservatively. Stable disease was documented in 50% of patients postoperatively and in 88% treated conservatively. The percentage of deterioration was similar (surgery 16%, 0.8% dead; conservative 10%). Detailed analysis of surgical outcome with regard to symptoms revealed that pain, motor, and sensory function could be improved in 43 to 55% of patients while motor function deteriorated in around 25%. The preferred methods of surgery were arachnoid lysis (48%) and syrinx drainage (31%).

Conclusion

Even diagnosing PTS early in its evolution with MRI, to date, no satisfactory standard treatment exists, and the present literature review shows similar outcomes, regardless of the treatment modality. Therefore, PTS remains a neurosurgical challenge. Additional research is required using appropriate study designs for improving treatment options.

Effect of extradural constriction on CSF flow in rat spinal cord

Background

Fluid homeostasis in the central nervous system (CNS) is essential for normal neurological function. Cerebrospinal fluid (CSF) in the subarachnoid space and interstitial fluid circulation in the CNS parenchyma clears metabolites and neurotransmitters and removes pathogens and excess proteins. A thorough understanding of the normal physiology is required in order to understand CNS fluid disorders, including post-traumatic syringomyelia. The aim of this project was to compare fluid transport, using quantitative imaging of tracers, in the spinal cord from animals with normal and obstructed spinal subarachnoid spaces.

Methods

A modified extradural constriction model was used to obstruct CSF flow in the subarachnoid space at the cervicothoracic junction (C7–T1) in Sprague–Dawley rats. Alexa-Fluor 647 Ovalbumin conjugate was injected into the cisterna magna at either 1 or 6 weeks post–surgery. Macroscopic and microscopic fluorescent imaging were performed in animals sacrificed at 10 or 20 min post–injection. Tracer fluorescence intensity was compared at cervical and thoracic spinal cord levels between control and constriction animals at each post-surgery and post-injection time point. The distribution of tracer around arterioles, venules and capillaries was also compared.

Results

Macroscopically, the fluorescence intensity of CSF tracer was significantly greater in spinal cords from animals with a constricted subarachnoid space compared to controls, except at 1 week post-surgery and 10 min post-injection. CSF tracer fluorescence intensity from microscopic images was significantly higher in the white matter of constriction animals 1 week post surgery and 10 min post-injection. At 6 weeks post–constriction surgery, fluorescence intensity in both gray and white matter was significantly increased in animals sacrificed 10 min post-injection. At 20 min post-injection this difference was significant only in the white matter and was less prominent. CSF tracer was found predominantly in the perivascular spaces of arterioles and venules, as well as the basement membrane of capillaries, highlighting the importance of perivascular pathways in the transport of fluid and solutes in the spinal cord.

Conclusions

The presence of a subarachnoid space obstruction may lead to an increase in fluid flow within the spinal cord tissue, presenting as increased flow in the perivascular spaces of arterioles and venules, and the basement membranes of capillaries. Increased fluid retention in the spinal cord in the presence of an obstructed subarachnoid space may be a critical step in the development of post-traumatic syringomyelia.

Electronic supplementary material

The online version of this article (10.1186/s12987-019-0127-8) contains supplementary material, which is available to authorized users.

Direct-trauma model of posttraumatic syringomyelia with a computer-controlled motorized spinal cord impactor

OBJECTIVE The pathogenesis of posttraumatic syringomyelia remains enigmatic and is not adequately explained by current theories. Experimental investigations require a reproducible animal model that replicates the human condition. Current animal models are imperfect because of their low reliability, severe neurological deficits, or dissimilar mechanism of injury. The objective of this study was to develop a reproducible rodent model of posttraumatic syringomyelia using a spinal cord impactor that produces an injury that more closely mimics the human condition and does not produce severe neurological deficits. METHODS The study consisted of 2 parts. Seventy animals were studied overall: 20 in Experiment 1 and 48 in Experiment 2 after two rats with severe deficits were killed early. Experiment 1 aimed to determine the optimal force setting for inducing a cystic cavity without neurological deficits using a computer-controlled motorized spinal cord impactor. Twenty animals received an impact that ranged from 50 to 150 kDyn. Using the optimal force for producing an initial cyst determined from Experiment 1, Experiment 2 aimed to compare the progression of cavities in animals with and those without arachnoiditis induced by kaolin. Forty-eight animals were killed at 1, 3, 6, or 12 weeks after syrinx induction. Measurements of cavity size and maximum anteroposterior and lateral diameters were evaluated using light microscopy. RESULTS In Experiment 1, cavities were present in 95% of the animals. The duration of limb weakness and spinal cord cavity size correlated with the delivered force. The optimal force chosen for Experiment 2 was 75 kDyn. In Experiment 2, cavities occurred in 92% of the animals. Animals in the kaolin groups developed larger cavities and more vacuolations and enlarged perivascular spaces than those in the nonkaolin groups. CONCLUSIONS This impact model reliably produces cavities that resemble human posttraumatic syringomyelia and is suitable for further study of posttraumatic syringomyelia pathophysiology.

Surgical management of post-traumatic syringomyelia

STUDY DESIGN

Systematic review.

OBJECTIVE

To determine the indications for surgical intervention and optimal surgical treatment technique for patients with post-traumatic syringomyelia and spinal cord tethering.

SUMMARY OF BACKGROUND DATA

The proper management strategy for post-traumatic syringomyelia has not been established. Most modern surgical series have documented improvement in symptomatic patients who have an internal decompression of their syrinx. Several options exist and include shunting the syrinx (to the subarachnoid space or to either the pleural or peritoneal cavities) as well as spinal cord untethering (with or without expansile duraplasty).

METHODS

A systematic review of literature followed by expert panel consensus was performed. English language literature published between 1980 and 2010 was gathered to examine articles search was conducted using the search terms syringomyelia, syrinx, spinal cord injury, traumatic syringomyelia, post-traumatic syringomyelia. Case reports and articles examining syrinx due to other cause were excluded. Articles were graded for strength of evidence according to the GRADE approach. The evidentiary tables were reviewed and approved by all 4 authors, and disagreements were resolved by consensus.

RESULTS

The literature search yielded a total of 296 abstracts, and 22 articles were found to fulfill all the criteria specified above. All identified articles were of low or very low evidence levels. The reported incidence of post-traumatic syringomyelia is 0.5% to 4.5%; the incidence is twice as common in complete versus incomplete injuries. The literature consistently demonstrated that surgery post-traumatic syringomyelia is effective at arresting or improving motor deterioration, but not sensory dysfunction or pain syndromes. The literature does not support surgical intervention for incidental, asymptomatic syrinx. The literature does not support one surgical technique as superior for the treatment of post-traumatic syringomyelia.

CONCLUSION

The literature supports and the consensus panel recommended that there is no indication for direct decompression at the time of initial injury specifically for the purpose of limiting future risk of syringomyelia. The literature supports and the consensus panel gave a strong recommendation for surgical intervention in the setting of motor neurologic deterioration as a consequence of post-traumatic syrinx/tethered cord. The panel gave a weak recommendation against surgical intervention for patients developing sensory loss/pain syndrome or for asymptomatic but expanding syrinx. Finally, the literature does not provide strong evidence to support the superiority of one surgical technique over the others; however, the consensus panel gave a weak recommendation that spinal cord untethering with expansile duraplasty is the preferred first-line surgical technique.

Long-term result of the Echols procedure for treating syringomyelia

In 1974, a 9-year-old girl with syringomyelia and scoliosis was treated using the Echols procedure, a surgical technique that makes use of a metal stent to maintain drainage of fluid from the syrinx into the subarachnoid space. The patient presented to the authors' institution 34 years later with a history of progressive myelopathy and surgically treated deformities of the thoracic spine, lumbar spine, and right foot. Computer-assisted myelography indicated that the metal wire remained in place and that the syrinx had collapsed. Neurological examination and neurophysiological testing confirmed the presence of thoracic myelopathy, which may have been due to the wire tethering the thoracic spinal cord to the dorsal dura. This case is believed to be the only long-term report of the effects of the Echols procedure. The history of direct treatment of syringomyelia is reviewed and is contrasted with indirect treatment of syringomyelia, which relieves the condition by opening obstructed CSF pathways within the foramen magnum or spine.

Post-traumatic syringomyelia producing paraplegia in an infant

BACKGROUND

Post-traumatic syringomyelia is described in adults after spinal trauma but extremely rarely seen in children, especially in the first year of life.

MATERIALS AND METHODS

We describe a boy who, at the age of 7 months, suffered spinal trauma during a car accident when he was held at his mother's lap and suffered extreme flexion of his torso. He suffered a mid-shaft fracture of his right femur, treated with hip spica for 6 weeks. After removal of the spica, it was noticed that he was not moving his legs, but he had preserved pain sensation in the lower half of his trunk and legs. A spine magnetic resonance scan performed 2 months after the injury showed a compressed wedge fracture of the body of T5 vertebra, kyphosis and a large syringomyelia cavity extending from T4 to T8. He had two operations to control the syringomyelia with laminotomy-laminoplasty, dissection of the arachnoid adhesions initially and drainage of the cavity on the second operation, with only modest success. He remains paraplegic 7 years after the injury. He has received thoracic brace immediately after the first spinal operation, which avoided kyphosis.

DISCUSSION

Spinal trauma is rare in the first year of life; hence, post-traumatic syringomyelia is very rarely seen in infants. Nevertheless, it should be suspected after a major trauma, in the presence of paraplegia. Surgical treatment of post-traumatic syringomyelia in young children has the additional consideration of post-laminotomy kyphosis; hence, thoracic brace should be used early.

Post-traumatic syringomyelia

Progressive post-traumatic cystic syringomyelia is an uncommon and increasingly recognized cause of morbidity following spinal cord injury. We hereby report a 35-year-old gentleman who sustained wedge compression fracture of L-1 vertebral body 15 years back and had complete paraplegia with bowel/bladder involvement. The neurological deficit recovered with minimal residual motor deficits and erectile dysfunction. He presented now with increasing neurological deficits associated with pain and paresthesia. The MRI spine showed a syrinx extending from the site of injury up to the medulla. He underwent a syringo-peritoneal shunt and at followup his pain and motor functions had improved but erectile dysfunction was persisting.

Cordectomy for the treatment of posttraumatic syringomyelia

✓Cordectomy is an effective treatment option in patients in whom posttraumatic syringomyelia develops following complete spinal cord injuries. Since the introduction of cordectomy, numerous approaches to the surgical treatment of posttraumatic syringomyelia have been developed. These newer developments have drawn the attention of surgeons and researchers away from cordectomy. In this report, the authors encourage a reconsideration of cordectomy for the treatment of posttraumatic syringomyelia after complete spinal cord injury. They describe four patients with posttraumatic syringomyelia who were treated successfully with cordectomy and review appropriate literature, examining the effectiveness of cordectomy in the treatment of posttraumatic syringomyelia. The findings of this review indicate that neurological improvement or stabilization occurred in 88% of patients in published reports of posttraumatic syringomyelia treated with cordectomy. The indications for cordectomy as well as factors that may contribute to the procedure’s success are discussed.

The Application of Surgical Cordectomy in the Management of an Intramedullary-Extramedullary Atypical Meningioma

BACKGROUND

The English literature describes only four cases of intraspinal tumors requiring surgical intervention in the form of cordectomy; none of these cases was for meningiomas. Intraspinal meningiomas, typically extramedullary-intradural, require treatment in the form of resection with dural margin excision. The presentation of an intramedullary atypical World Health Organization grade II meningioma is rare. The authors report a case of a transformed intramedullary-extramedullary atypical meningioma treated with cordectomy.

METHODS

The patient was a 65-year-old woman who presented with a recurrent thoracic meningioma status post three attempted resections, radiation therapy, and a trial of hydroxyurea chemotherapy. The patient presented paraplegic with reports of burning paresthesias bilaterally in her upper extremities 12 months after her third resection attempt.

RESULTS

Magnetic resonance imaging on this current presentation revealed a heterogeneously enhancing hypointense mass extending from T2 to T6. Extension of abnormal T2 signal within the cord superiorly to C7 was noted with a 1-cm enhancing extra-axial lesion at T10 and an extradural mass posteriorly T12 also noted. The patient underwent a T2-T7 laminectomy with a T2-T8 cordectomy. Two months postoperatively, the patient was doing well with no further deterioration in neurologic function.

CONCLUSIONS

This case highlights the viability of surgical cordectomy in the treatment of varying intramedullary processes under appropriate indications.

Familial spinal arachnoiditis with secondary syringomyelia: clinical studies and MRI findings

We report the clinical and MRI findings of two patients with familial spinal arachnoiditis. Although their initial symptoms were various, they both showed spastic paraparesis and sensory disturbance below the thoracic level. Cytokines and WBC in the CSF were studied, but they were not elevated at all. The spinal magnetic resonance images of each showed extensive arachnoiditis and a cystic structure. The other impressive features included: (i) an enhancement within the thickened arachnoid and an adhesion between the spinal cord and the dura mater, (ii) deformation of the thoracic cord where the arachnoid adhered, and (iii) secondary syrinx formation. Laminectomy may have an adverse outcome for such patients.

CT-guided percutaneous drainage of syringomyelia

PURPOSE

Our purpose is to describe CT-guided percutaneous drainage of syringomyelia as a possible contribution in patient management.

METHOD

CT-guided percutaneous drainage was performed on three patients with symptomatic syringomyelia. We determined the success of percutaneous decompression by subsequent CT and MRI. The effect of syringomyelia decompression in relation to the patient's symptoms was determined. This information was then used to help guide clinical management.

RESULTS

In Case 1, percutaneous drainage of a large syrinx in a C5 quadriplegic patient with increasing lower extremity spasticity demonstrated significant decompression by imaging but did not result in clinical improvement. A surgical procedure to decompress the syrinx was not performed on the basis of this information. In Case 2, percutaneous drainage of a large syrinx in a quadriplegic patient with increasing upper extremity numbness and weakness demonstrated significant decompression by imaging and resulted in sustained clinical improvement, temporarily obviating the need for surgery. In Case 3, percutaneous drainage of the rostral aspect of a septated syrinx cavity in a patient with a Chiari I malformation and a syringoperitoneal shunt in place resulted in decompression by imaging but failed to relieve the patient's newly developed symptoms. An additional shunt was therefore not placed. In no case did the patient experience periprocedural complications or worsening of symptoms.

CONCLUSION

CT-guided percutaneous drainage of syringomyelia is a safe and successful technique. It can be used diagnostically to identify patients that may or may not benefit from surgical syrinx decompression and in some cases may provide a temporary therapeutic alternative to surgery.

Management and outcome of posttraumatic syringomyelia

Traumatic paraplegia is the most common cause of nonhindbrain-related syringomyelia. Fifty-seven patients with a mean age of 34.3 years at presentation were treated at the Midland Centre for Neurosurgery and Neurology between 1973 and 1993. A variety of treatment strategies have been used over the years, including syringosubarachnoid and syringopleural shunts, spinal cord transection, and pedicled omental graft transposition. More recently decompressive laminectomy, subarachnoid space reconstruction and formation of surgical meningocele have been used. A total of 81 operations were performed in these patients, 69 of them at the Syringomyelia Clinic. Combinations of strategies were often chosen; the use of one strategy such as drainage did not preclude another such as transection or augmentation of the cerebrospinal fluid pathways. The overall postoperative complication rate was 12%. Problems specific to the operation type included dislodged, blocked, and infected drains (10 patients). Acute gastric dilation was seen following pedicled omental graft (one patient). At 6 years only 49% of the drains inserted still functioned. A higher than expected rate of cervical spondylotic myelopathy has been noted. Two patients developed Charcot's joints. Thirty-six patients were asked to score themselves with regard to limb function and performance of daily living activities and 30% reported improvement, particularly ion arm function. Since the use of magnetic resonance imaging has become widespread, it has become apparent that decompressive laminectomy with subarachnoid space reconstruction is effective in controlling the syrinx cavity. In complete paraplegia, spinal cord transection is an effective alternative. Pedicled omental grafting was associated with poor outcome and an increased complication rate and has been abandoned.

Dysesthetic pain in patients with syringomyelia

Dysesthethic pain is a common complaint of patients with syringomyelia, traumatic paraplegia, and various myelopathic conditions. Because cavitary lesions of the spinal cord can be defined with good resolution by magnetic resonance imaging, syringomyelia provides a potential model for examining anatomic correlates of central pain. In this study, a syndrome of segmental dysesthesias, characterized by burning pain, hyperesthesia, and a variable incidence of trophic changes, was described by 51 of 137 patients (37%) with syringomyelia at the time of clinical presentation. Complete magnetic resonance scans, including axial images, demonstrated extension of the syrinx into the dorsolateral quadrant of the spinal cord on the same side and at the level of pain in 43 of 51 patients (84%). Surgical treatment of syringomyelia resulted in the relief or improvement of dysesthetic pain in 22 of 37 patients (59%), but 15 patients (41%) reported no improvement or an intensification of pain despite collapse of the syrinx. Postoperative dysesthetic pain was often a disabling complaint that responded poorly to medical therapy, including analgesics, sedatives, antiepileptics, antispasmodics, and anti-inflammatory agents. In most cases, there was a gradual improvement of symptoms, although six patients continued to complain of pain 24 to 74 months postoperatively. Prompt but transient relief was achieved in two of two patients with regional sympathetic blocks, and prolonged relief was achieved in one patient by stellate ganglionectomy. We conclude that painful dysesthesias can be caused by a disturbance of pain-modulating centers in the dorsolateral quadrant of the spinal cord and have certain causalgia-like features that respond in an unpredictable way to surgical collapse of the syrinx.

Incidence, management, and outcome of post-traumatic syringomyelia. In memory of Mr Bernard Williams

OBJECTIVE

To determine the incidence of clinically diagnosable post-traumatic syringomyelia (PTS).

METHODS

A population of 815 consecutive patients with traumatic spinal cord injuries was studied between January 1990 and December 1992.

RESULTS

Reviews of all records, full clinical evaluation, and thorough neurological examination of all patients disclosed 28 patients in whom PTS was confirmed radiologically (3.43%). The incidence of the presenting symptoms, including bladder dysfunction, is described. The level and density of cord lesion was correlated with incidence and it was found that posttraumatic syringomyelia was twice as common in patients with complete injuries than in patients with incomplete injuries. The highest incidence was found in patients with complete dorsal and complete dorsolumbar injuries. The interval between injury and diagnosis ranged from six months to 34 years (mean 8.6 years). This interval was shortest in patients with complete dorsal and incomplete cervical and dorsolumbar cord injuries.

CONCLUSIONS

Reduction of the size of the syrinx seen on postoperative MRI correlated well with a satisfactory clinical outcome in 85% of patients.

Post-traumatic syringomyelia (cystic myelopathy): a prospective study of 449 patients with spinal cord injury

OBJECTIVES

To assess the incidence of post-traumatic syringomyelia (PTS), to correlate the presence of PTS with its most common signs and symptoms, and to compare results from the Swiss Paraplegic Centre with those reported in the medical literature.

METHODS

A total of 449 recent traumatic paraplegic and tetraplegic patients admitted to the Swiss Paraplegic Centre in Zurich between 1 January 1987 and 31 December 1993 were prospectively analysed. Yearly clinical tests with conventional radiographs and additional T1 and T2 weighted images were performed as soon as PTS was diagnosed.

RESULTS

Of these 449 patients 20 patients displayed symptoms of PTS (4.45%). Ten non-operated patients remained clinically stable (average time: 37 months). Ten worsened--three refused operation, seven were operated on. Mean worsening time was 97 months. Deterioration was closely related to the enlargement of the cyst whereas in operated patients neurological improvement or stabilisation correlated with collapse of the cyst.

CONCLUSIONS

Delay between appearance of the first symptoms of PTS and deterioration making surgery necessary may be long (mean five years in the seven operated patients) underlining the need for regular tests. "Slosh" and "suck" mechanisms could explain cyst enlargement as surgical realignment of the spine resulted in a complete cyst collapse in two of the operated patients (normalisation of CSF flow? ). Cord compression, tense syrinx at the fracture site, and kyphosis seemed to be closely linked to the enlargement of the cyst with subsequent further neurological deterioration.

The cystic spinal cord

Images

Mean term follow-up of a series of post-traumatic syringomyelia patients after syringo-peritoneal shunting

We report the follow-up of a series of post-traumatic syringomyelia patients treated by syringo-peritoneal shunting (SPS). The neurological status was determined following the international ASIA/IMSOP standards for neurological classification of spinal cord injury; this was completed by a modified Silberstein classification that identifies the ascending neurological symptoms as well as the increasing myelopathic symptoms in patients with post-traumatic syringomyelia. Magnetic resonance imaging (MRI) was systematically performed to assess the presence of a postoperative residual syrinx or of meningeal fibrosis. Eight patients were studied (five men, three women) with an age ranging from 17 to 54 years (mean of 30.7 years) at the time of the spinal cord injury. Three had a complete or nearly complete paraplegia, five were incomplete. The post-traumatic syringomyelia was diagnosed from 2 to 8 years after the spinal cord injury and was treated by syringo-peritoneal shunting. Early complications occurred in three patients: (1) displacement of the catheter, (2) obstruction of the catheter, and (3) haematomyelia, which disappeared after a new surgical procedure was performed. The postoperative follow-up ranged from 3 to 9 years (mean of 4.5 years). The neurological level decreased in every case and the ascending neurological symptoms decreased or were stabilised in seven patients. The postoperative ASIA/IMSOP scores and the increasing myelopathic symptoms improved in four patients but worsened in the four others, incomplete. The MRI showed an important decrease of the syrinxes in every patient associated with a serious meningeal fibrosis in five cases. Syringo-peritoneal shunting seems to be efficient in the treatment of the syrinx but may have a poor effect regarding the prevention of meningeal fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

A critical appraisal of drainage in syringomyelia

The use of drains in the treatment of syringomyelia has a simple and immediate appeal and has been practiced widely since the report of Abbe and Coley over 100 years ago. Good short-term results have been claimed in the past, but long-term outcome is largely unknown. An experience in Birmingham, England is reviewed in which 73 patients who had had some form of syrinx drainage procedure performed were subsequently followed up. In these cases, a total of 56 syringopleural and 14 syringosubarachnoid shunts had been inserted. Ten years after the operations, only 53.5% and 50% of the patients, respectively, continued to remain clinically stable. A 15.7% complication rate was recorded, including fatal hemorrhage, infection, and displacement of the drain from the pleural and syrinx cavities. At second operation or necropsy, at least 5% of shunts were discovered to be blocked. The effect of other drainage procedures that do not use artificial tubing, such as syringotomy and terminal ventriculostomy, was analyzed but found not to offer any substantial benefit. These results indicate that drainage procedures are not an effective solution to remedying the progressive, destructive nature of syringomyelia. It is suggested that, rather than attempting to drain the syrinx cavity, disabling the filling mechanism of the syrinx is more appropriate. Most forms of syringomyelia have a blockage at the level of the foramen magnum or in the subarachnoid space of the spine. Surgical measures that aim to reconstruct the continuity of the subarachnoid space at the site of the block are strongly recommended. Lowering the overall pressure of the cerebrospinal fluid is advocated when reestablishment of the pathways proves impossible. Syrinx drainage as an adjuvant to more physiological surgery may have a place in the treatment of syringomyelia. If two procedures are done at the same time, however, it is difficult to ascribe with certainty a success or failure, and it is suggested that the drainage procedure be reserved for a later attempt if the elective first operation fails.

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.

Thecoperitoneal shunt for post-traumatic syringomyelia

A case of post-traumatic syringomyelia developing two years after spinal cord injury is presented. The patient was treated with the placement of a thecoperitoneal shunt incorporating a low pressure valve. Response was excellent with restoration of neurological function and almost complete collapse of the cavity at one year follow up. The rationale of this form of treatment is discussed in the light of recent evidence concerning the pathogenesis of the condition.

Segmental hyperhidrosis in syringomyelia with Chiari malformation

Segmental hyperhidrosis was seen in three cases of syringomyelia with Chiari malformation confirmed by magnetic resonance imaging. Using the iodine-starch reaction, all three cases showed hyperhidrosis in the areas roughly corresponding to those of sensory disturbances. Two possible modes of pathogenesis are discussed: stimulation of preganglionic neurons and interference to the inhibitory tract.

Posttraumatic spinal cord tethering. Case report

A 53-year-old woman with a complete C-7 traumatic quadriplegia developed progressive neurological deterioration, including bulbar symptoms, 3 years after her initial injury. Magnetic resonance imaging showed tethering of the spinal cord at the level of her injury, with marked stretching of the cervical cord associated with medullary and tonsillar herniation. Following transection of the spinal cord, there was some improvement in her condition. Possible etiological factors accounting for this unique presentation are discussed.

Intraoperative endomyelography during syrinx drainage: technical note

There is no currently available noninvasive technique to ascertain with certainty the continuity of the cavity of a septated syrinx. A technique is described that allows the confirmation of the continuity before the surgical drainage of a syrinx. This technique may prevent the failure of the drainage because of septations and double cavities. Intraoperative endomyelography is simple to perform and requires no special equipment. Pressure measurements made before the injection of the contrast agent may provide insights into the pathogenesis of the syrinx and may be of prognostic and therapeutic significance.

MRI in chronic spinal cord trauma

Eighty-seven patients aged 16-68 years have been examined by magnetic resonance imaging (MRI) following spinal injury. The MRI findings have been correlated with length of history between trauma and investigation, extent of residual function and site of injury. They include changes at the site of injury consistent with myelomalacia in 37%, a syrinx in 40%, persistent cord compression in 32% and atrophy in 18%. An extensive syrinx can develop within 2 months of injury and it is nearly twice as common in patients with complete paralysis as in those whose paralysis was incomplete. It is suggested that investigation and management of spinal trauma should include early and repeated MRI examinations to detect sequelae at an early stage.

The value of magnetic resonance imaging (MRI) in the follow-up management of spinal injury

Twenty-seven patients with spinal injury have been studied with follow-up Magnetic Resonance Imaging (MRI). MRI has helped (a) to determine the extent of cord injury; (b) to detect continuing compression to the spinal cord; (c) to discover unexpected pathologies and most importantly (d) to detect the development of post traumatic syrinx. MRI was most valuable in patients with post-traumatic syrinxes to evaluate any changes in the size, and, in those who had a shunting procedure, to assess the efficacy of the procedure. MRI also aided in planning complicated one stage operations by giving a 'complete' picture of the injury inflicted to the vertebrae, soft tissue structures and the spinal cord. As well as advantages in clinical audit it makes financial sense. It provides more information than CT myelography and is non-invasive. When compared to the cost of neurological deterioration it is much more cost effective to follow-up spinal injury patients with MRI. It is the authors' contention that after the acute phase all patients with spinal injury should have at least one MRI.

Post-traumatic syringomyelia following uncomplicated spinal fracture

Two cases of post-traumatic syringomyelia presenting 10 and 41 years after spinal injuries that had caused lumbar vertebral fractures but no lasting neurological deficits are reported. In both patients the caudal end of the syrinx cavities, as shown by MRI, corresponded to the level of the previous vertebral fractures. Patients presenting with post-traumatic syringomyelia after uncomplicated spinal fracture are very rare, and the significance of the past history of spinal trauma may be overlooked.

Pathogenesis and treatment of delayed post-traumatic syringomyelia

The role of trauma in the pathogenesis of syringomyelia has been known for a long time. Repeated microtraumata have been considered to play a role in triggering the classical syringomyelia on the basis of a congenital predisposition. It has been proven that post-traumatic arachnoiditis can cause cavitation in the spinal cord and probably syringomyelia stricto sensu as well. The delayed appearance of syringomyelia after a severe single spinal trauma resulting in contusion of the spinal cord without the complication of arachnoiditis is a more recent issue, but is now well-known. Delayed syringomyelia after a minor single spinal trauma, with at first complete recovery, is extremely rare, and is probably often disregarded as a diagnosis. Having studied such a case, with complete neuroradiological work-up, we want to draw attention to the pathogenetic aspects and the possibilities for treatment, of which the syringoperitoneal shunt seems to be the most efficient one.

Post-traumatic syringomyelia, an update

Post-traumatic and post-arachnoiditic syringomyelia is described in 31 patients from the Midland Centre for Neurosurgery and Neurology (MCNN). It is suggested that the mechanisms may be similar in the two groups and that treatment is best directed to disabling the likely filling mechanisms by opening up the cerebrospinal fluid (CSF) pathways and deliberately leaving the dura open to create an artificial meningocele. It is suggested that drainage on its own is inappropriate but that when drainage of the syrinx is chosen as an ancillary technique then syringopleural drainage may be the procedure of choice.

Syringomyelia and arachnoiditis

Five patients with chronic arachnoiditis and syringomyelia were studied. Three patients had early life meningitis and developed symptoms of syringomyelia eight, 21, and 23 years after the acute infection. One patient had a spinal dural thoracic AVM and developed a thoracic syrinx 11 years after spinal subarachnoid haemorrhage and five years after surgery on the AVM. A fifth patient had tuberculous meningitis with transient spinal cord dysfunction followed by development of a lumbar syrinx seven years later. Arachnoiditis can cause syrinx formation by obliterating the spinal vasculature causing ischaemia. Small cystic regions of myelomalacia coalesce to form cavities. In other patients, central cord ischaemia mimics syringomyelia but no cavitation is present. Scar formation with spinal block leads to altered dynamics of cerebrospinal fluid (CSF) flow and contributes to the formation of spinal cord cystic cavities.

Pain and spinal cysts in paraplegia: treatment by drainage and DREZ operation

About 10% of paraplegics suffer from intractable pain. The onset of pain may be immediate or delayed for months to several years after the injury. The delayed onset of pain is highly suggestive of the development of a spinal cyst. This is a report of 18 paraplegics who developed a delayed onset of intractable pain who were found at the time of surgery to have associated spinal cord cysts. Treatment consisted of the dorsal root entry zone (DREZ) operation in addition to evacuation of the cyst. Burning pain was the most common complaint occurring years after the trauma. In this study we compared the relationship between the onset and character of the pain, the time of the spinal injury, the operative findings, and the results of the DREZ procedure and evacuation of the traumatic spinal cyst. We believe that the combination of paraplegia, pain and spinal cyst has not been emphasized in the neurosurgical literature although it is well known that cystic formation can follow spinal trauma. Two patients developed spinal cysts with nontraumatic lesions of the spinal cord. A single cyst was found in 14 patients while four had two separate cysts. The diagnosis was made on the basis of history and clinical examination with radiographic confirmation using delayed CT scan and myelography and more recently magnetic resonance imaging. Intraoperative ultrasound was employed in the study of some patients. All patients were treated with combined DREZ lesions and evacuation of the cysts with good pain relief in 77.7%.

Surgical management of syringomyelia--current results

A retrospective study of the surgical results of 98 patients with syringomyelia was carried out. As primary surgical management, 38 cases were treated by craniovertebral decompression, 28 cases by craniovertebral decompression with syringotomy, and 22 cases in which Gardner's operation was performed. Primary syringoperitoneal shunt was done on six patients and the other primary procedures were performed on four. As the secondary operation, syringostomy was performed on nine patients and syringoperitoneal shunt on seven. Better results were obtained in patients managed by craniovertebral decompression with syringotomy or Gardner's operation. However, Gardner's operation had a higher mortality rate and a higher incidence of complication. If a second operation was required, syringoperitoneal shunt had a higher rate of stabilization than syringostomy.

A case of post-traumatic syringomyelia. Neuropathological findings after 1 year of cystic drainage

A 58-year-old man sustained C4-C5 post-traumatic myelopathy with C3-C4 subluxation, slight compression of C3 vertebral body, C4 spinous process fracture and C6 compression fracture. He subsequently developed syringomyelia from C4 to C6, which was shunted into the subarachnoid space. Postoperatively, there was some but insignificant improvement of his symptoms although a postoperative metrizamide spinal computerised tomography showed complete drainage of the cyst. This patient died 1 year later. Autopsy examination of the spinal cord showed extensive damage of the posterior half of the cord at C3-C4 but the damage was much less extensive from C4 to C6 (where the syrinx was located), affecting mainly the right dorsal column at C4 and the right dorsal column and right anterior horn at C5-C6. In this patient, the syrinx developed in the partially damaged segments of the cord at the level of the spinal fractures and complete drainage of the cyst was not followed by satisfactory relief of his symptoms.

Mechanisms and treatment in post-traumatic syringomyelia

The aetiology, pathophysiology, and treatment of post-traumatic syringomyelia is discussed. The data collected from clinical observation, radiodiagnostic methods, and operative findings are illustrated. It is concluded that at least five different processes may contribute to this progressive disease. A deeper understanding of these mechanisms could help in patient management.

Posttraumatic syringomyelia

Posttraumatic syringomyelia is becoming increasingly recognized as a sequel to major and minor spinal cord injury, paralleling the development and widespread availability of magnetic resonance imaging as a diagnostic modality for evaluating possible spinal pathologic lesions. Delayed, subacute, or progressive neurologic deterioration in victims of traumatic spinal injury with "fixed deficits" should raise the suspicion of posttraumatic syringomyelia. Alternatively, it may present as sensory or motor complaints occurring on a delayed basis after minor spinal trauma causing no initial neurologic impairment. At our institution, we have treated six of eight patients with this condition by shunting fluid from the intramedullary cyst to the peritoneal cavity by means of a simple valveless shunt, resulting in sustained neurologic improvement in five patients.

Microcystic spinal cord degeneration causing posttraumatic myelopathy. Report of two cases

Two cases of progressive myelopathy occurring years after incomplete cervical spinal cord injury are presented. In both patients, the clinical features, as well as the "bull's-eye" appearance of the delayed computerized tomography (CT) myelography study and the circumscribed low density of the magnetic resonance image, were consistent with posttraumatic syringomyelia, but surgical exploration including intra-operative spinal sonography failed to reveal a syrinx. Although arachnoiditis was present in both patients, the striking abnormality found at surgery was the softened appearance and the microcystic degeneration of the cord. The microcystic spinal cord degeneration found in these cases represents a previously undescribed cause of late deterioration after spinal cord injury that may mimic the clinical, CT-myelographic, and magnetic resonance features of posttraumatic syringomyelia.