Management of posttraumatic syringomyelia using an expansile duraplasty. A case report

Intradural spinal arachnoid cyst resection: implications of duraplasty in a large case series

OBJECTIVE Optimal diagnosis and management strategies for intradural spinal arachnoid cysts (SACs) are still unresolved given the rare nature of this entity, with few large case series and virtually no statistical analyses of patient characteristics in the literature. Here, the authors studied a large patient cohort with these lesions to determine whether pre- or postoperative attributes could be used to aid in either diagnosis or prognosis. METHODS A chart review was completed at a single institution for the period from 2002 to 2016 to determine the preoperative characteristics and postoperative outcomes of 21 patients with exclusively intradural SACs. Patients were assessed for symptoms such as weakness, pain, sensory changes, bowel and/or bladder dysfunction, and gait changes. Postoperatively, patients were analyzed for symptom improvement, complication occurrence, and duration of follow-up. RESULTS Approximately two-thirds of the patients in this series had developed SACs idiopathically, and the mean duration of symptoms prior to diagnosis was 15 months among all patients. A slight majority (57%) underwent CT myelography in the course of diagnosis, and a quarter of the patients had a syrinx. There was a statistically significant association between location of the SAC and number of presenting signs and symptoms; that is, patients with cysts in the lumbosacral region had more symptoms than those with cysts at the cervical or thoracic levels (p = 0.031). Overall, outcomes were largely positive, with approximately 60%-70% of patients experiencing postoperative improvement in symptoms, with motor weakness showing the highest response rate (71%) and pain symptoms the least likely to subside (50%). In the cohort with preoperative pain, those who had undergone expansile duraplasty were significantly more likely to experience relief of their pain symptoms (p = 0.028), which may have been a result of the superior restoration of cerebrospinal fluid pathways allowing for more adequate reduction in compression. CONCLUSIONS In this large case series on intradural SACs, new light has been shed on aspects of both pre- and postoperative care for patients with these rare lesions. Specifically, the authors revealed that lumbosacral intradural SACs may be associated with a higher disease burden and that patients who undergo expansile duraplasty may have an increased likelihood of experiencing postoperative pain relief.

Syringomyelia following surgery for a spontaneous spinal subdural hematoma in a 13-year-old girl with congenital von Willebrand disease: case report and literature review

BACKGROUND AND IMPORTANCE

Spontaneous spinal subdural hematomas are rare. Their occurrence in a child with congenital von Willebrand disease and the complication of their surgery by a large secondary syringomyelia have never been previously reported.

CASE PRESENTATION

A 13-year-old girl with congenital von Willebrand disease presented to our emergency department in January 2011 for sudden onset of severe back pain centered in her thoracic spine rapidly aggravated by signs of acute myelopathy without any precipitating factor. MRI scan revealed a thoracic subdural collection anterior to the spinal cord at the T7-T9 level, hyperintense on T1- and T2-weighted sequences consistent with an acute spinal subdural hemorrhage. Evacuation of the subdural hematoma was realized immediately after hemostasis parameter correction, and post-operative course was uneventful with full functional recovery. One year later, the patient presented once again but with progressive and more severe myelopathy caused by a large syringomyelia extending from the T5 level to the conus medullaris. A syringopleural shunting was performed and the patient was unrolled under an intensive care and rehabilitation program. Her condition remarkably improved and she became able to walk independently within 2 weeks post-operatively.

CONCLUSIONS

von Willebrand disease should be included as a possible factor of spontaneous spinal subdural hemorrhage. Surgery is advised in emergency and can be associated with remarkable recovery especially in children. Delayed syringomyelia can complicate the post-operative course and can be successfully addressed by syringopleural shunting. Long-term clinical and radiological follow-up is advocated.

Post-traumatic syringomyelia: CSF hydrodynamic changes following spinal cord injury are the driving force in the development of PTSM

Post-traumatic syringomyelia (PTSM) is a disorder that occurs infrequently following spinal cord injury (SCI), characterized by progressive neurological deterioration resulting from syrinx expansion originating in proximity to the traumatic epicenter. Several pathogenetic factors are associated with this disorder, however, the precise mechanism of the development of PTSM is controversial. Combined anatomical alterations and molecular changes following trauma to the spinal cord and arachnoid participate in the development of this condition. These factors include narrowing or obstruction of the subarachnoid space (SAS), central canal occlusion, myelomalacia, and alterations in intramedullary water permeability. If a patient sustains a SCI with delayed progressive deterioration in neurological function, in association with the MRI appearance of syringomyelia (SM), the diagnosis of PTSM is straightforward. The treatment of PTSM has not undergone any significant changes recently. The surgical treatment of PTSM consists of reconstructing the SAS or shunting fluid away from the syrinx to other locations. The advantages and disadvantages of each procedure will be discussed. With greater understanding of the mechanisms contributing to the development of SM, including advanced diagnostic methods and further advances in the development of artificial dural and shunting tubing, future therapies of PTSM will be more effective and long-lasting. Incorporation of alterations of AQP4 expression provides an intriguing possibility for future treatment of PTSM.

Treatment of Syringomyelia Related to Nontraumatic Arachnoid Pathologies of the Spinal Canal

BACKGROUND:

Disturbances of cerebrospinal fluid (CSF) flow are the commonest cause of syringomyelia. Spinal arachnopathies may lead to CSF flow obstructions but are difficult to diagnose. Consequently, associated syringomyelias are often categorized as idiopathic.

OBJECTIVE:

To present and analyze the diagnosis of and long-term outcomes in an observational study of patients with nontraumatic arachnopathies from 1991 to 2011.

METHODS:

A total of 288 patients (mean age, 47 ± 15 years; follow-up, 54 ± 46 months) were evaluated. Decompression with arachnolysis, untethering, and duraplasty for restoration of CSF flow was recommended to patients with neurological progression. Neurological examinations, magnetic resonance images, and follow-up data were evaluated. Individual symptoms were analyzed during the first postoperative year, and long-term outcomes were analyzed with Kaplan-Meier statistics to determine rates of progression-free survival.

RESULTS:

In total,189 patients either refused an operation or were managed conservatively for lack of progression. Among 79 unoperated patients with follow-up information available for up to 8 years, 2 patients deteriorated. Ninety-nine patients with progressive symptoms underwent 116 operations: 108 decompressions and 8 other surgeries. Three months postoperatively, 53% considered their status improved and 37% were unchanged. In the long term, surgery on arachnopathies limited to 2 spinal segments was followed by progression-free survival for 78% over 10 years, in contrast to 31% with extensive arachnopathies.

CONCLUSION:

Surgery on nontraumatic arachnopathies related to syringomyelia should be reserved for patients with progressive symptoms. Arachnolysis, untethering, and duraplasty provide good long-term results for focal arachnopathies. For extensive pathologies with a history of subarachnoid hemorrhage or meningitis, treatment remains a major challenge.

Pathophysiology of primary spinal syringomyelia

OBJECT

The pathogenesis of syringomyelia in patients with an associated spinal lesion is incompletely understood. The authors hypothesized that in primary spinal syringomyelia, a subarachnoid block effectively shortens the length of the spinal subarachnoid space (SAS), reducing compliance and the ability of the spinal theca to dampen the subarachnoid CSF pressure waves produced by brain expansion during cardiac systole. This creates exaggerated spinal subarachnoid pressure waves during every heartbeat that act on the spinal cord above the block to drive CSF into the spinal cord and create a syrinx. After a syrinx is formed, enlarged subarachnoid pressure waves compress the external surface of the spinal cord, propel the syrinx fluid, and promote syrinx progression.

METHODS

To elucidate the pathophysiology, the authors prospectively studied 36 adult patients with spinal lesions obstructing the spinal SAS. Testing before surgery included clinical examination; evaluation of anatomy on T1-weighted MRI; measurement of lumbar and cervical subarachnoid mean and pulse pressures at rest, during Valsalva maneuver, during jugular compression, and after removal of CSF (CSF compliance measurement); and evaluation with CT myelography. During surgery, pressure measurements from the SAS above the level of the lesion and the lumbar intrathecal space below the lesion were obtained, and cardiac-gated ultrasonography was performed. One week after surgery, CT myelography was repeated. Three months after surgery, clinical examination, T1-weighted MRI, and CSF pressure recordings (cervical and lumbar) were repeated. Clinical examination and MRI studies were repeated annually thereafter. Findings in patients were compared with those obtained in a group of 18 healthy individuals who had already undergone T1-weighted MRI, cine MRI, and cervical and lumbar subarachnoid pressure testing.

RESULTS

In syringomyelia patients compared with healthy volunteers, cervical subarachnoid pulse pressure was increased (2.7 ± 1.2 vs 1.6 ± 0.6 mm Hg, respectively; p = 0.004), pressure transmission to the thecal sac below the block was reduced, and spinal CSF compliance was decreased. Intraoperative ultrasonography confirmed that pulse pressure waves compressed the outer surface of the spinal cord superior to regions of obstruction of the subarachnoid space.

CONCLUSIONS

These findings are consistent with the theory that a spinal subarachnoid block increases spinal subarachnoid pulse pressure above the block, producing a pressure differential across the obstructed segment of the SAS, which results in syrinx formation and progression. These findings are similar to the results of the authors' previous studies that examined the pathophysiology of syringomyelia associated with obstruction of the SAS at the foramen magnum in the Chiari Type I malformation and indicate that a common mechanism, rather than different, separate mechanisms, underlies syrinx formation in these two entities. Clinical trial registration no.: NCT00011245.

Treatment of posttraumatic syringomyelia

Object

This paper presents results of a prospective study for patients undergoing surgery for posttraumatic syringomyelia between 1991 and 2010.

Methods

A group of 137 patients with posttraumatic syringomyelia were evaluated (mean age 45 ± 13 years, mean follow-up 51 ± 51 months) with pre- and postoperative MRI and clinical examinations presenting in this period and followed prospectively by outpatient visits and questionnaires. Surgery was recommended for symptomatic patients with a progressive course. Short-term results were determined within 3 months of surgery, whereas long-term outcomes in terms of clinical recurrences were studied with Kaplan-Meier statistics.

Results

Three groups were distinguished according to the type of trauma: Group A, patients with spinal trauma but without cord injury (ASIA E, n = 37); Group B, patients with an incomplete cord injury (ASIA C or D, n = 55); and Group C, patients with complete loss of motor function or a complete cord injury (ASIA A or B, n = 45). Overall, 61 patients with progressive symptoms underwent 71 operations. Of these operations, 61 consisted of arachnolysis, untethering, and duraplasty at the trauma level (that is, decompression), while 4 ASIA A patients underwent a cordectomy. The remaining procedures consisted of placement of a thecoperitoneal shunt, 2 opiate pump placements, and 2 anterior and 1 posterior cervical decompression and fusion. Seventy-six patients were not treated surgically due to lack of neurological progression or refusal of an operation. Neurological symptoms remained stable for 10 years in 84% of the patients for whom surgery was not recommended due to lack of neurological progression. In contrast, 60% of those who declined recommended surgery had neurological progression within 5 years. For patients presenting with neurological progression, outcome was better with decompression. Postoperatively, 61% demonstrated a reduction of syrinx size. Although neurological symptoms generally remained unchanged after surgery, 47% of affected patients reported a postoperative improvement of their pain syndrome. After 3 months, 51% considered their postoperative status improved and 41% considered it unchanged. In the long-term, favorable results were obtained for Groups A and C with rates for neurological deterioration of 6% and 14% after 5 years, respectively. In Group B, this rate was considerably higher at 39%, because arachnolysis and untethering to preserve residual cord function could not be fully achieved in all patients. Cordectomy led to neurological improvement and syrinx collapse in all 4 patients.

Conclusions

The technique of decompression with arachnolysis, untethering, and duraplasty at the level of the underlying trauma provides good long-term results for patients with progressive neurological symptoms following ASIA A, B and E injuries. Treatment of patients with posttraumatic syringomyelia after spinal cord injuries with preserved motor functions (ASIA C and D) remains a major challenge. Future studies will have to establish whether thecoperitoneal shunts would be a superior alternative for this subgroup.

Decompressive surgery in a patient with posttraumatic syringomyelia

Posttraumatic syringomyelia may result from a variety of inherent conditions and traumatic events, or from some combination of these. Many hypotheses have arisen to explain this complex disorder, but no consensus has emerged. A 28-year-old man presented with progressive lower extremity weakness, spasticity, and decreased sensation below the T4 dermatome five years after an initial trauma. Magnetic resonance imaging (MRI) revealed a large, multi-septate syrinx cavity extending from C5 to L1, with a retropulsed bony fragment of L2. We performed an L2 corpectomy, L1-L3 interbody fusion using a mesh cage and screw fixation, and a wide decompression and release of the ventral portion of the spinal cord with an operating microscope. The patient showed complete resolution of his neurological symptoms, including the bilateral leg weakness and dysesthesia. Postoperative MRI confirmed the collapse of the syrinx and restoration of subarachnoid cerebrospinal fluid (CSF) flow. These findings indicate a good correlation between syrinx collapse and symptomatic improvement. This case showed that syringomyelia may develop through obstruction of the subarachnoid CSF space by a bony fracture and kyphotic deformity. Ventral decompression of the obstructed subarachnoid space, with restoration of spinal alignment, effectively treated the spinal canal encroachment and post-traumatic syringomyelia.

Direct fluoroscopic drainage of symptomatic post-traumatic syringomyelia. A case report and review of the literature

SUMMARY

First described in 1928, percutaneous aspiration of syringomyelia is infrequently performed to aid in diagnosis and surgical management. We describe a case of post traumatic syringomyelia successfully treated with direct fluoroscopic drainage with substantial resolution of syrinx-related neurologic symptoms. The patient is a 36-year-old man involved in a motorcycle accident who sustained multiple vertebral fractures resulting in dense paraplegia below T4, ultimately treated with multilevel laminectomy and pedicle screw fixation. The patient began to experience phantom leg paresthesias and muscle spasm felt to be related to an extensive spinal cord syrinx extending to the conus. Syrinx drainage was accomplished fluoroscopically at the level of the conus by percuntaneous needle drainage after cord localization with intrathecal myelographic contrast. Clear spinal fluid was drained from the syrinx cavity without complication. Immediately during and after drainage, the patient recognized a decrease in phantom pelvic and lower extremity paresthesias with significantly reduced spasticity. Syrinx collapse was documented with post-drainage CT imaging. Sustained relief of paresthesias and muscle spasms was achieved with gradual syrinx and symptom return requiring subsequent drainages performed at nine, 22 and 37 months following the initial drainage. In addition to confirming the symptomatic nature of syringomyelia in those with atypical symptoms, fluoroscopically guided drainage of syrinx can in select instances provide sustained relief. This modality may have additional advantages including serving as an adjunctive maneuver to improve operative access to the subarachnoid space by collapsing the cord, and serving as a temporizing measure for those patients who are poor surgical candidates. Maneuvers such as fluoroscopic table angulation provide an additional benefit in both the localization and drainage of syringomyelia and thus may be preferred over other minimally invasive procedures such as CT-guided drainage.

Mechanistic insights into posttraumatic syringomyelia based on a novel in vivo animal model. Laboratory investigation

OBJECT

Although posttraumatic syringomyelia (PTS) develops in up to 30% of patients after spinal cord injury (SCI), the pathophysiology of this debilitating complication is incompletely understood. To provide greater insight into the mechanisms of this degenerative sequela of SCI, the authors developed and characterized a novel model of PTS.

METHODS

The spinal cords of 64 female Wistar rats were injured by 35-g modified aneurysm clip compression at the level of T6-7. Kaolin (5 microl of 500 mg/ml solution) was then injected into the subarachnoid space rostral to the site of the injury to induce inflammatory arachnoiditis in 22 rats. Control groups received SCI alone (in 21 rats), kaolin injection alone (in 15 rats), or laminectomy and durotomy alone without injury (sham surgery in 6 rats).

RESULTS

The combination of SCI and subarachnoid kaolin injection resulted in a significantly greater syrinx formation and perilesional myelomalacia than SCI alone; SCI and kaolin injection significantly attenuated locomotor recovery and exacerbated neuropathic pain (mechanical allodynia) compared with SCI alone. We observed that combined SCI and kaolin injection significantly increased the number of terminal deoxytransferase-mediated deoxyuridine triphosphate nick-end labeled-positive cells at 7 days after injury (p<0.05 compared with SCI alone) and resulted in a significantly greater extent of astrogliosis and macrophage/microglial-associated inflammation at the lesion (p<0.05).

CONCLUSIONS

The combination of compressive/contusive SCI with induced arachnoiditis results in severe PTS and perilesional myelomalacia, which is associated with enhanced inflammation, astrogliosis, and apoptotic cell death. The development of delayed neurobehavioral deficits and neuropathic pain in this model accurately reflects the key pathological and clinical conditions of PTS in humans.

Syringomyelia associated with intradural arachnoid cysts

Object

Intradural arachnoid cysts are relatively uncommon pouches of cerebrospinal fluid (CSF) found within the subarachnoid space. The authors present a series of eight symptomatic patients in whom syrinx cavities were associated with arachnoid cysts, and they discuss treatment strategies for this entity.

Methods

The population comprised eight men whose mean age was 50 years (range 35–81 years). All patients experienced gait difficulty, and it was the chief complaint in seven; arm pain was the primary complaint in one. No patient had a history of spinal trauma, meningitis, or previous spinal surgery at the level of the syrinx cavity or arachnoid cyst. In each patient imaging revealed a syrinx cavity affecting two to 10 vertebral levels. Posterior thoracic arachnoid cysts were found in proximity to the syrinx cavity in each case. There was no evidence of cavity enhancement, Chiari malformation, tethered cord, or hydrocephalus.

All patients underwent thoracic laminectomy and resection of the arachnoid cyst wall, and postoperative neurological improvement was documented in each case. The mean follow-up duration was 19 months (range 4–37 months). Follow-up magnetic resonance imaging demonstrated the disappearance of the arachnoid cyst and a significant decrease in syrinx cavity size in each patient.

Conclusions

Spinal arachnoid cysts can be associated with syringomyelia, likely due to alterations in normal CSF dynamics. In symptomatic patients these cysts should be resected and the normal CSF flow restored. The results of the present series indicate that neurological improvement and reduction in syrinx cavity size can be achieved in patients with syringomyelia associated with intradural arachnoid cysts.

Myelopathy: a report of two cases

OBJECTIVE

To present diagnostic imaging findings of two cases of cervical myelopathy, with different etiologies, presenting to a chiropractic office.

CLINICAL FEATURES

The patient with acute transverse myelitis had neck and upper back pain and nonspecific headaches for 40 years. The patient with posttraumatic syringomyelia experienced intermittent left arm pain starting in the anterolateral shoulder and radiating down the arm into the third, fourth, and fifth digits. Neither of these patients presented with typical myelopathic symptoms.

INTERVENTION AND OUTCOME

Chiropractic spinal manipulative therapy using high-velocity low-amplitude thrusts and concomitant medical management were used for the patient with posttraumatic syringomyelia. The patient with acute transverse myelitis was not treated.

CONCLUSION

Practitioners should be aware of the etiology, pathophysiology, clinical features, laboratory, diagnostic imaging findings, and treatment options pertaining to patients with cervical myelopathy.

Syringomyelia associated with intradural arachnoid cysts

Object

Intradural arachnoid cysts are relatively uncommon pouches of cerebrospinal fluid (CSF) found within the subarachnoid space. The authors present a series of eight symptomatic patients in whom syrinx cavities were associated with arachnoid cysts, and they discuss treatment strategies for this entity.

Methods

The population comprised eight men whose mean age was 50 years (range 35–81 years). All patients experienced gait difficulty, and it was the chief complaint in seven; arm pain was the primary complaint in one. No patient had a history of spinal trauma, meningitis, or previous spinal surgery at the level of the syrinx cavity or arachnoid cyst. In each patient imaging revealed a syrinx cavity affecting two to 10 vertebral levels. Posterior thoracic arachnoid cysts were found in proximity to the syrinx cavity in each case. There was no evidence of cavity enhancement, Chiari malformation, tethered cord, or hydrocephalus.

All patients underwent thoracic laminectomy and resection of the arachnoid cyst wall, and postoperative neurological improvement was documented in each case. The mean follow-up duration was 19 months (range 4–37 months). Follow-up magnetic resonance imaging demonstrated the disappearance of the arachnoid cyst and a significant decrease in syrinx cavity size in each patient.

Conclusions

Spinal arachnoid cysts can be associated with syringomyelia, likely due to alterations in normal CSF dynamics. In symptomatic patients these cysts should be resected and the normal CSF flow restored. The results of the present series indicate that neurological improvement and reduction in syrinx cavity size can be achieved in patients with syringomyelia associated with intradural arachnoid cysts.

Conservative treatment of a patient with syringomyelia using chiropractic biophysics protocols

OBJECTIVE

To present a case of a 41-year-old man with syringomyelia and intractable pain and the subsequent reduction of symptoms.

CLINICAL FEATURES

This patient acquired a traumatically induced syrinx in his upper cervical spinal cord after he fell approximately 9 feet and landed on his head, upper back, and neck 9 years before presenting for care. He was diagnosed with a spinal cord cyst (syrinx), located at approximately C2 through C4 after magnetic resonance imaging. In 1995, the patient underwent occipitoatlantal decompression surgery, which improved his symptoms for a short time.

INTERVENTION AND OUTCOMES

The patient was treated using Clinical Biomechanics of Posture protocol. The patient was seen 26 times over the course of 3 weeks. His scale for pain severity decreased 50% and other subjective complaints decreased. His posture improved based upon pretreatment and posttreatment lateral cervical radiographs, showing a change from a 10 degrees lordosis with midcervical kyphosis to a 30 degrees lordosis. One-year follow-up examination showed stable improvement in the cervical lordosis and pain intensity.

CONCLUSION

This case represents a change in subjective and objective measurements after conservative chiropractic care. This case provides an example that structural rehabilitation may have a positive effect on symptoms of a patient with syringomyelia.

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.

Spontaneous chronic spinal subdural hematoma associated with spinal arachnoiditis and syringomyelia

Spontaneous chronic spinal subdural hematoma is rare. We describe a case of spontaneous chronic spinal subdural hematoma associated with arachnoiditis and syringomyelia in a 76-year old woman who presented with a 14-year history of progressive myelopathy. MRI scan revealed a thoraco-lumbar subdural cystic lesion and a thoracic syrinx. The patient underwent thoracic laminectomy and decompression of the lesion, which was a subdural hematoma. A myelotomy was performed to drain the syrinx. Pathological examination revealed features consistent with chronic subdural membrane. This report attempts to elucidate the pathogenesis of chronic spinal subdural hematoma. We discuss possible etiological factors in light of the current literature and pathogenesis of both spinal subdural hematoma and syrinx formation.

The role of excitotoxic injury in post-traumatic syringomyelia

Fifty percent of patients with neurological deterioration from post-traumatic syringomyelia do not respond to treatment. Treatment failure is due in part to an incomplete understanding of the underlying aetiology. An animal model that mimics the human disease is required to investigate underlying pathophysiology and treatment options. A previous study was designed to mimic trauma-induced effects on the spinal cord that result in syringomyelia, combining an excitotoxic insult with kaolin-induced arachnoiditis. In this excitotoxic model, syringes were produced in 82% of animals. The aims of the current study were to improve the model to produce syringes in all animals treated, to examine the relative influences of excitotoxic injury and neuronal loss on syrinx formation, and to use magnetic resonance imaging (MRI) to examine syringes non-invasively. A temporal and dose profile of intraparenchymal quisqualic acid (QA) and subarachnoid kaolin was performed in Sprague Dawley rats. MRI was used to study four syrinx and six control animals. In one subgroup of animals surviving for 6 weeks, 100% (eight of eight) developed syringes. Syrinx formation and enlargement occurred in a dose and time dependent manner, whilst significant neuronal loss was only dose dependent. Animal syrinx histology closely resembled human post-traumatic syringomyelia. Axial T2-weighted MR images demonstrated syrinx presence. The results suggest that the formation of an initial cyst predisposes to syrinx formation in the presence of subarachnoid adhesions.

Post-traumatic syringomyelia: a review

More than a quarter of spinal cord injured patients develop syringes and many of these patients suffer progressive neurological deficits as a result of cyst enlargement. The mechanism of initial cyst formation and progressive enlargement are unknown, although arachnoiditis and persisting cord compression with disturbance of cerebrospinal fluid flow appear to be important aetiological factors. Current treatment options include correction of bony deformity, decompression of the spinal cord, division of adhesions, and shunting. Long-term improvement occurs in fewer than half of patients treated. Imaging evidence of a reduction in syrinx size following treatment does not guarantee symptomatic resolution or even prevention of further neurological loss. A better understanding of the causal mechanisms of syringomyelia is required to develop more effective therapy.

Surgical treatment of post-traumatic myelopathy associated with syringomyelia

STUDY DESIGN

Retrospective review.

OBJECTIVE

Evaluate the clinical outcome of surgical intervention for post-traumatic syringomyelia.

INTRODUCTION

Progressive post-traumatic cystic myelopathy (PPCM), or syringomyelia, can occur after spinal cord injury. The authors present their surgical treatment protocol and treatment outcome of a series of patients with post-traumatic syringomyelia.

METHODS

The medical records of 53 patients with PPCM undergoing surgical treatment were reviewed. Laminectomies and intraoperative ultrasonography were performed. For patients with no focal tethering and only a confluent cyst on ultrasonography, a syringosubarachnoid shunt (stent) was inserted. For patients with both tethering and a confluent cord cyst, an untethering procedure was performed first. When a cyst showed significant size reduction (>50%) after untethering, no shunt was placed. When the cyst size persisted on ultrasonographic images, a short syringosubarachnoid shunt was used. The mean follow-up was 23.9 months for the 45 patients available for follow-up (range 12-102 months).

RESULTS

The interval between the causative event and the operation was from 5 months to 37 years (mean 6.5 years). Pain was the most frequent manifestation, followed by motor deterioration and spasticity. Postoperative improvements in >50% of the patients were noted in those presenting with worsening motor function or spasticity. In 19 of 28 patients with associated tethered spinal cord, untethering alone caused significant collapse of the cyst. Postoperative MRI demonstrated cyst collapse in 95% of the patients with untethering alone and 93% of the patients with a syringosubarachnoid shunt.

CONCLUSION

Post-traumatic syringomyelia can occur with or without cord tethering. Untethering alone for patients with cord tethering and cyst formation can reduce cyst size and alleviate the symptoms and signs of syringomyelia in the majority of these cases. Untethering with expansion of subarachnoid space with an expansile duraplasty may be a more physiologic way of treating a tethered cord with associated syringomyelia, i.e., treating the cause rather than the result.

Feasibility and safety of neural tissue transplantation in patients with syringomyelia

Transplantation of fetal spinal cord (FSC) tissue has demonstrated significant potential in animal models for achieving partial anatomical and functional restoration following spinal cord injury (SCI). To determine whether this strategy can eventually be translated to humans with SCI, a pilot safety and feasibility study was initiated in patients with progressive posttraumatic syringomyelia (PPTS). A total of eight patients with PPTS have been enrolled to date, and this report presents findings for the first two patients through 18 months postoperative. The study design included detailed assessments of each subject at multiple pre- and postoperative time points. Outcome data were then compared with each subject's own baseline. The surgical protocol included detethering, cyst drainage, and implantation of 6-9-week postconception human FSC tissue. Immunosuppression with cyclosporine was initiated a few days prior to surgery and continued for 6 months postoperatively. Key outcome measures included: serial magnetic resonance imaging (MRI) exams, standardized measures of neurological impairment and functional disability, detailed pain assessment, and extensive neurophysiological testing. Through 18 months, the first two patients have been stable neurologically and the MRIs have shown evidence of solid tissue at the graft sites, without evidence of donor tissue overgrowth. Although it is still too soon to draw any firm conclusions, the findings from the initial two patients in this study suggest that intraspinal grafting of human FSC tissue is both feasible and safe.

Intraoperative measurement of spinal cord blood flow in syringomyelia

The role of spinal cord ischemia in the pathophysiology of syringomyelia remains undetermined. Previous reports in the literature suggest that shunting of syringes can improve spinal cord blood flow. In order to determine the effects of syrinx decompression on spinal cord blood flow in patients with syringomyelia, we prospectively measured regional spinal cord blood flow (RSCBF) intraoperatively pre and post shunting in patients with symptomatic syringomyelia using laser doppler flowmetry. Six patients with MRI documented syringomyelia were studied (three with Arnold Chiari I malformation and associated syrinx and three with post-traumatic syringomyelia). Surgery was performed on all patients with either a syringopleural or syringoperitoneal shunt. Laser doppler blood flow and somatosensory evoked potentials were monitored prior to myelotomy and after shunt insertion. Results indicate that there was a significant increase in RSCBF after decompression of the syrinx. This study supports the hypothesis that spinal cord ischemia is important in the pathophysiology of syringomyelia and confirms previous reports in the literature regarding RSCBF in syringomyelia.

Outcome after surgical treatment of progressive posttraumatic cystic myelopathy

OBJECT

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.

METHODS

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.

CONCLUSIONS

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.

Treatment of posttraumatic syringomyelia with extradural decompressive surgery

The authors review the management of five patients with posttraumatic syringomyelia (PTS) associated with an uncorrected spinal deformity. Patients with evidence of progressive neurological deterioration underwent ventral spinal decompressive surgery. The mean patient age at the time of injury was 39 years, and the time between injury and the diagnosis of PTS ranged from 2 to 22 years. Mechanisms of injury consisted of fracture/subluxations in three patients and burst fractures in two. All patients experienced delayed neurological deterioration consistent with PTS. Magnetic resonance imaging revealed ventral deformities, and the spinal canal stenosis ranged from 20 to 50% (mean 39%). All patients underwent ventral epidural spinal decompressive surgery to correct the bone deformity and restore the spinal canal. The mean follow-up period was 38 months. The decompressive intervention was initially successful in treating the neurological deterioration in all patients. Symptoms resolved completely in four patients, and the other experienced neurological improvement. Postoperative magnetic resonance imaging revealed a reduction in the size of syrinx cavity in the patients whose symptoms resolved and no change in the remaining patient. Two patients required a subsequent second-stage posterior intradural exploration and duraplasty for recurrence of symptoms and/or syrinx. Posttraumatic spinal deformity may cause spinal canal stenosis and alter subarachnoid cerebrospinal fluid (CSF) flow in certain patients. Ventral epidural spinal decompressive surgery may result in neurological improvement and a reduction of the syrinx cavity, avoiding the need for placement of a shunt or other intradural procedures. However, some patients will also require reconstruction of the posterior subarachnoid space with duraplasty if the ventral decompressive procedure achieves only partial restoration of the subarachnoid CSF flow.

Treatment of terminal syringomyelia in association with tethered cord syndrome: clinical outcomes with and without syrinx drainage

Object

Current use of magnetic resonance (MR) imaging has led to increased awareness of the frequency of terminal syringomyelia in patients with tethered cord syndrome. However, that the surgical treatment of terminal syringomyelia is necessary remains unclear.

In this study the authors attempted to assess the clinical impact, if any, brought after syrinx decompression on the clinical outcome of tethered cord syndrome.

Methods

They randomly assigned 30 cases of pediatric tethered cord into two treatment groups: those in whom an untethering procedure was performed (Group I) and those in whom this procedure was combined with syrinx decompression (Group II). The 1-year follow-up clinical results obtained in the two groups, in correlation with MR imaging findings, were compared to evaluate the benefit of added syrinx drainage.

Clinical follow-up evaluation revealed that surgical drainage of the syrinx, when combined with spinal cord untethering, resulted in better outcomes in terms of resolution of sensory deficits (p = 0.036) and bladder dysfunction (p = 0.05). The improvement in clinical outcome correlated with the radiologically documented resolution of the syrinx cavity; however, response rates of symptoms differed for each tethering subgroup.

Conclusions

Preliminary results of this study indicated that terminal syringomyelia should be considered as a comorbidity that contributes to the clinical outcome of patients with tethered cord syndrome. A better clinical outcome is achieved following successful decompression of the syrinx in addition to untethering the spinal cord. These findings emphasize the importance of recognizing, evaluating, and treating this pathological entity.