Surgical management of syringomyelia associated with spinal adhesive arachnoiditis

Surgical Management of Lumbar Adhesive Arachnoiditis Postmeningitis: A Bermuda Triangle?—Case Report and Review of Literature

Spinal arachnoiditis can occur as a delayed sequel of meningitis. Cerebrospinal fluid flow disturbances and adhesive loculations can cause cord compression and traction on roots causing the symptoms. The surgical treatment of this condition is often considered a limited option, because of the high chances of recurrence of symptoms and adhesions, often considered as surgical failure. Here, we report a patient with extensive lumbar–sacral adhesive arachnoiditis successfully treated with limited adhesiolysis under neuromonitoring and cystoperitoneal shunt placement.

Flexible thecoscopy for extensive spinal arachnoiditis

OBJECTIVE

Chronic adhesive spinal arachnoiditis (SA) is a complex disease process that results in spinal cord tethering, CSF flow blockage, intradural adhesions, spinal cord edema, and sometimes syringomyelia. When it is focal or restricted to fewer than 3 spinal segments, the disease responds well to open surgical approaches. More extensive arachnoiditis extending beyond 4 spinal segments has a much worse prognosis because of less adequate removal of adhesions and a higher propensity for postoperative scarring and retethering. Flexible neuroendoscopy can extend the longitudinal range of the surgical field with a minimalist approach. The authors present a cohort of patients with severe cervical and thoracic arachnoiditis and myelopathy who underwent flexible endoscopy to address arachnoiditis at spinal segments not exposed by open surgical intervention. These observations will inform subsequent efforts to improve the treatment of extensive arachnoiditis.

METHODS

Over a period of 3 years (2017-2020), 10 patients with progressive myelopathy were evaluated and treated for extensive SA. Seven patients had syringomyelia, 1 had spinal cord edema, and 2 had spinal cord distortion. Surgical intervention included 2- to 5-level thoracic laminectomy, microscopic lysis of adhesions, and then lysis of adhesions at adjacent spinal levels performed using a rigid or flexible endoscope. The mean follow-up was 5 months (range 2-15 months). Neurological function was examined using standard measures. MRI was used to assess syrinx resolution.

RESULTS

The mean length of syringes was 19.2 ± 10 cm, with a mean maximum diameter of 7.0 ± 2.9 mm. Patients underwent laminectomies averaging 3.7 ± 0.9 (range 2-5) levels in length followed by endoscopy, which expanded exposure by an average of another 2.4 extra segments (6.1 ± 4.0 levels total). Endoscopic dissection of extensive arachnoiditis in the dorsal subarachnoid space proceeded through a complex network of opaque arachnoidal bands and membranes bridging from the dorsal dura mater to the spinal cord. In less severely problematic areas, the arachnoid membrane was transparent and attached to the spinal cord through multifocal arachnoid adhesions bridging the subarachnoid space. The endoscope did not compress or injure the spinal cord.

CONCLUSIONS

Intrathecal endoscopy allowed visual assessment and safe removal of intradural adhesions beyond the laminectomy margins. Further development of this technique should improve its effectiveness in opening the subarachnoid space and untethering the spinal cord in cases of extensive chronic adhesive SA.

Spinal adhesive arachnoiditis: three case reports and review of literature

Spinal adhesive arachnoiditis is a rare pathology involving pia mater of the spinal cord and nerve roots. It can potentially lead to disability—many patients end up wheelchair-bound due to subsequent paraparesis. It is an infrequent but possible cause of lower extremities weakness in patients with a history of spinal surgery, epidural anaesthesia, myelography or spinal tumors. Three patients, one male and two females, admitted to our unit due to paraparesis presented at least one of the above mentioned risk factors. Each of them had a severe course of illness—progressive paresis of lower extremities. All above cases were diagnosed with spinal adhesive arachnoiditis confirmed with Magnetic Resonance Imaging (MRI) scan—the most sensitive and specific diagnostic tool. Despite conservative treatment and intensive rehabilitation none of the presented patients preserved the ability to mobilise independently. Considering spinal adhesive arachnoiditis in patients with paraparesis and history of typical risk factors should be included in clinical diagnostic procedure.

Safety and Efficacy of Syringoperitoneal Shunting with a Programmable Shunt Valve for Syringomyelia Associated with Extensive Spinal Adhesive Arachnoiditis: Technical Note

OBJECTIVE

Although syringomyelia associated with extensive spinal adhesive arachnoiditis (SAA) can be a progressive disease that has potentially devastating clinical consequences, its surgical resolution has remained poorly defined. The aim of the present study was to verify the safety and efficacy of syringoperitoneal shunting for syringomyelia associated with extensive SAA.

METHODS

The present retrospective study included 15 patients who had undergone syringoperitoneal shunting with a programmable shunt valve for the diagnosis of syringomyelia associated with extensive SAA from October 2012 to June 2018. The shunt pressure was appropriately adjusted according to the postoperative sequential clinical condition and change in syringomyelia evaluated using magnetic resonance imaging. The average postoperative follow-up duration was 32.7 months.

RESULTS

No surgery-related complications such as shunt dysfunction or infection occurred during the follow-up period, except for 2 patients with minor issues with the shunt tube. The average shunt pressure at the last follow-up examination was 4.5 cm H₂O. The findings from the clinical assessment suggested that the average grade on the sensory pain scale was 2.9 before surgery and had improved significantly to 2.5 at the most recent follow-up examination. Radiological analysis suggested that improvement of syringomyelia was noted in 14 of the 15 patients (93.3%), with no cases of radiological aggravation. No recurrence of syringomyelia developed during the follow-up period in the present study.

CONCLUSION

Syringoperitoneal shunting with a programmable shunt valve was safe and effective for clinical control of syringomyelia associated with extensive SAA. Long-term follow-up is mandatory to monitor for shunt dysfunction and mechanical trouble.

Posttubercular syringomyelia in HIV-infected patients: A report of 10 cases and literature review

OBJECTIVES

To describe the clinical presentation, spinal magnetic resonance imaging (MRI) findings and outcome of HIV-infected patients with tuberculosis (TB)-associated syringomyelia and to compare these findings between all HIV-infected and -uninfected cases published in the literature.

METHODS

A retrospective observational study conducted over a 12.5-year period at a public-sector referral hospital in South Africa. HIV-infected adults with neurological TB in whom MRI confirmed a syrinx were included. We searched PubMed to identify all published syringomyelia cases.

RESULTS

Ten patients were enrolled. Syringomyelia complicated neurological TB within four years of initial diagnosis in all patients (median: 21 months, range: 0-39) after initial diagnosis. Six patients were treated conservatively (TB treatment = 5, no treatment = 1); four improved, but only one was ambulant during follow-up. Four patients underwent syringoperitoneal shunting; three improved and one died three months later. Our literature review identified 50 additional cases (HIV-infected = 2, HIV-uninfected = 9, HIV status not documented = 39 [presumed HIV-uninfected]). Clinical and imaging findings and outcomes were similar between HIV-infected and -uninfected cases, except for time of presentation following neurological TB diagnosis, which was delayed (>4 years) in 46% of HIV-uninfected cases, compared to 8% of HIV-infected cases. Conclusions Syringomyelia is a disabling complication of neurological TB that usually presents early after neurological TB diagnosis in HIV coinfected patients.

Surgical Management of Syringomyelia Associated with Spinal Adhesive Arachnoiditis, a Late Complication of Tuberculous Meningitis: A Case Report

Syringomyelia associated with tuberculous meningitis is an extremely rare condition. Only a few studies have reported clinical experience with syringomyelia as a late complication of tuberculous meningitis. Twenty-six years after a tuberculous meningitis episode, a 44-year-old man presented with progressively worsening spastic paresis of the lower limbs and impaired urinary function for 2 years. Radiological examination revealed syringomyelia extending from the level of C2 to T9 and arachnoiditis with atrophy of the spinal cord between C2 and T3. We performed laminectomy from C7 to T1, dissected the arachnoid adhesion and placed a syringo-pleural shunt via keyhole myelotomy. One year after the operation, his neurological condition improved. The postoperative control magnetic resonance imaging revealed the correctly located shunt and significantly diminished syringomyelia cavities. We aim to discuss the mechanism of syrinx formation following tuberculous meningitis and to share our surgical therapeutic experience with this rare disease entity.

Treatment of Posttubercular Syringomyelia Not Responsive to Antitubercular Therapy: Case Report and Review of Literature

Posttubercular adhesive arachnoiditis is a rare, late complication of tubercular meningitis. Syringomyelia can develop as a consequence of intramedullary cystic lesions and cerebrospinal fluid (CSF) flow disturbance around the spinal cord, even after successful chemotherapy. We reviewed the literature related to posttubercular syringomyelia treatment and suggest a new combined surgical approach. A 25-year-old Nigerian male patient presented with legs numbness, urinary disturbance, and legs weakness. Spinal magnetic resonance revealed a T5-T7 syringomyelia, secondary to adhesive spinal arachnoiditis related to a history of tuberculous meningitis. Adhesiolysis by direct visualization with a flexible endoscope was performed and a handmade S-italic syringe-subdural shunt was placed to restore CSF flow. During the postoperative course, the neurological deficits improved together with the resolution of the syrinx. Long-term magnetic resonance imaging follow-up documented no recurrences or shunt displacements. We suggest that, when antitubercular therapy is not effective to resolve postarachnoiditis syrinx, arachnolysis with a flexible endoscope together with the placement of an S-italic shunt allowed free CSF communication between the syrinx and the subarachnoid space. Furthermore, we support that the use of an s-shaped shunt could prevent displacement or migration of the device and allows an easier revision in case of acute or late complications.

Visualization of regional cerebrospinal fluid flow with a dye injection technique in focal arachnoid pathologies

Surgical lysis of the thickened arachnoid membrane is the first choice of treatment in spinal arachnoid pathologies that cause flow disturbances or blockage of CSF. However, it is important to consider that while extensive lysis of the arachnoid may temporarily provide a wide pathway for CSF, an extensive lytic procedure may later cause secondary adhesion. Thus, it is ideal for the proper extent of the arachnoid lysis to be determined after careful analysis of regional CSF flow. The authors report their limited experience with intraoperative visualization of CSF flow in spinal arachnoid pathologies. Two patients with a dorsal arachnoid web (DAW) with cervical syringomyelia and 1 patient with focal adhesive arachnoiditis causing edema of the spinal cord were surgically treated at the authors' institution between 2007 and 2013. In all cases, the presence of a DAW or focal adhesive arachnoiditis was suspected from the findings on MRI, namely 1) an indentation on the upper thoracic spinal cord and 2) syringomyelia and/or edema of the spinal cord above the indentation. Exploratory surgery disclosed a transversely thickened arachnoid septum on the dorsal side of the indented cord. To prove blockage of the CSF by the septum and to decide on the extent of arachnoid lysis, regional CSF flow around the arachnoid septum was visualized by subarachnoid injection of gentian violet solution close to the web. Injected dye stagnated just close to the arachnoid septum in all cases, and these findings documented CSF blockage by the septum. In 2 cases, a 2-minute observation showed that the injected dye stayed close to the web without diffusion. The authors performed not only resection of the web itself but also lysis of the thickened arachnoid on both sides of the spinal cord to make a CSF pathway on the ventral side. In the third case, the dye stagnated close to the web at first but then diffused through the nerve root to the ventral CSF space. The lysis procedure was completed after exclusive removal of the dorsal web. Postoperative MR images confirmed reduction of the syrinx and/or improvement of the edema in all cases, suggesting that the extent of arachnoid lysis was optimal in each case. No adverse effect was observed after subarachnoid injection of gentian violet. The authors believe that their technique of visualizing regional CSF flow will be helpful to decide the optimal extent of lysis in some local arachnoid pathologies.

Compressive Cervicothoracic Adhesive Arachnoiditis following Aneurysmal Subarachnoid Hemorrhage: A Case Report and Literature Review

We present the case of a 55-year-old woman with diffuse adhesive arachnoiditis in the posterior fossa and cervicothoracic spine following posterior inferior cerebellar artery aneurysmal subarachnoid hemorrhage (SAH). She underwent aneurysm clipping with subsequent gradual neurologic decline associated with sensory disturbances, gait ataxia, and spastic paraparesis. Magnetic resonance imaging revealed diffuse adhesive arachnoiditis in the posterior fossa and cervicothoracic spine, syringobulbia, and multiple arachnoid cysts in the cervicothoracic spine along with syringohydromyelia. Early surgical intervention with microlysis of the adhesions and duraplasty at the clinically relevant levels resulted in clinical improvement. Although adhesive arachnoiditis, secondary arachnoid cysts, and cerebrospinal fluid flow abnormalities resulting in syrinx are rare following aneurysmal SAH, early recognition and appropriate intervention lead to good clinical outcomes.

Symptomatic spinal cord kinking due to focal adhesive arachnoiditis, with ossification of the ligamentum flavum: a case report

STUDY DESIGN

A case report.

OBJECTIVE

To describe a rare case of symptomatic spinal cord kinking due to focal adhesive arachnoiditis, with ossification of the ligamentum flavum (OLF).

SUMMARY OF BACKGROUND DATA

Spinal cord kinking without spinal surgery is rare, and symptomatic spinal cord kinking due to focal adhesive arachnoiditis, with OLF is even rarer.

METHODS

A 66-year-old female presented with numbness of the lower extremities and subsequently experienced gait disturbance due to motor weakness. Magnetic resonance imaging of the thoracic spine showed anterior displacement and kinking of the spinal cord from T11 to T12. Laminectomy and OLF resection were performed. The arachnoid membrane at the affected part was markedly thick and seemed cloudy. Adhesiolysis for arachnoid adhesion and release of spinal kinking were performed.

RESULTS

She could walk with a cane 6 months postoperatively. One year postoperatively, thoracic computed tomography-myelography showed that the cord was repositioned in the dural sac, and that release of the spinal cord kink was maintained.

CONCLUSION

Symptomatic spinal cord kinking due to focal adhesive arachnoiditis, with OLF is a rare clinical condition. It was difficult to diagnose the precise pathology of the spinal cord before surgery. Microsurgical arachnoidolysis resolved the spinal cord kinking, and no recurrence was noted within the follow-up period.

LEVEL OF EVIDENCE

N/A.

Syringomyelia and arachnoid cysts associated with spinal arachnoiditis following subarachnoid hemorrhage

A 66-year-old woman with primary Sjogren syndrome developed syringomyelia following two episodes of subarachnoid hemorrhage (SAH) due to the rupture of basilar artery aneurysms. Gait disturbance and abnormal sensation with pain over the foot and abdomen appeared 3 years after the last SAH. Magnetic resonance (MR) imaging revealed a syringomyelia throughout the thoracic cord, from the T2 to T11 levels. In addition, the thoracic cord was compressed by multiple arachnoid cysts in the ventral side of spinal cord. Computed tomography myelography revealed complete block of cerebrospinal fluid (CSF) flow at the T7 level. Surgery for microlysis of the adhesions and restoration of the CSF flow pathway was performed. Postoperatively, leg motor function slowly improved and she could walk unaided. However, abdominal paresthesia was persisted. Postoperative MR imaging revealed diminished size of the syrinxes. We should recognize syringomyelia and arachnoid cysts due to adhesive arachnoiditis as a late complication of SAH. Microlysis of the adhesions focusing on the lesion thought to be the cause of the symptoms is one of the choices to treat massive syringomyelia and arachnoid cysts associated with arachnoiditis following SAH.

Novel surgical management of spinal adhesive arachnoiditis by arachnoid microdissection and ventriculo-subarachnoid shunting

Spinal cord tethering and cerebrospinal fluid (CSF) flow disturbance are two major features in the pathophysiology of spinal adhesive arachnoiditis. We hypothesized that insufficient CSF supply to the surgically untethered spinal cord may be one of the causes of the typical post-operative recurrent extensive lesion. We report a patient with extensive spinal adhesive arachnoiditis, who was successfully treated using a novel surgical technique consisting of two procedures. First, microdissection of the thickened adherent arachnoid was performed to resolve spinal cord tethering. Next, a ventriculo-subarachnoid shunt was placed to provide sufficient flow of CSF. Clinical improvement was sustained for at least 22 months after surgery. The present surgical procedure may improve clinical outcome in patients with longitudinally extensive spinal adhesive arachnoiditis.

Focal adhesive arachnoiditis of the spinal cord: Imaging diagnosis and surgical resolution

Background:

Although adhesive arachnoiditis of the spinal cord can cause progressive symptoms associated with syringomyelia or myelomalacia, its surgical resolution based on the imaging diagnosis is not well characterized. This study aims to describe the use of imaging for the diagnosis of focal adhesive arachnoiditis of the spinal cord and its surgical resolution using microsurgical arachnoidolysis.

Materials and Methods:

Four consecutive patients with symptomatic syringomyelia or myelomalacia caused by focal adhesive arachnoiditis underwent microsurgical arachnoidolysis. Comprehensive imaging evaluation using constructive interference in steady-state (CISS) magnetic resonance imaging (MRI) or myelographic MR imaging using true fast imaging with steady-state precession (TrueFISP) sequences was included before surgery to determine the surgical indication.

Results:

In all four patients a focal adhesion was identified at the cervical or thoracic level of the spinal cord, a consequence of infection or trauma. Three patients showed modest or minor improvement in neurological function, and one patient was unchanged after surgery. The syringomyelia or myelomalacia resolved after surgery and no recurrence was noted within the follow-up period, which ranged from 5 months to 30 months.

Conclusions:

MRI diagnosis of focal adhesive arachnoiditis is critical to determine the surgical indication. Microsurgical arachnoidolysis appears to be a straightforward method for stabilizing the progressive symptoms, though the procedure is technically demanding.

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 caused by intrathecal remnants of oil-based contrast medium

✓ Oily contrast medium had been in use since the early 19th century as a radiographic agent for detecting spinal lesions and spinal cord tumors until the late 20th century. At that point computed tomography scanning and magnetic resonance imaging, or other hydrophilic contrast medium substituted for it. Adverse effects of oil-based dye, both acute and chronic, had been reported since the middle of the 20th century. In this paper the authors report the case of syringomyelia that seemed to be caused mainly by remaining oily contrast medium for 44 years.

Syringomyelia secondary to adhesive arachnoiditis caused by oily contrast medium after a long period of time is well known. In the present case, however, surgery revealed only mild arachnoiditis at the level of syringomyelia as well as both solid and liquid remnants of contrast medium.

Generally, cerebrospinal fluid (CSF) blockage due to an arachnoid adhesion is considered to cause syringomyelia following adhesive arachnoiditis. The authors speculated that in the present case syringomyelia was induced by a mechanism different from that in the previously reported cases; the oily contrast medium itself seems to have induced the functional block of CSF and impaired the buffer system of the intrathecal pressure. No reports on thoracic adhesive arachnoiditis and syringomyelia caused by oil-based dye referred to this mechanism in reviewing the literature.

Cervicothoracic postarachnoiditic hydrosyringomyelia secondary to pedicular hook dislocation: case report

BACKGROUND

Pedicular hook dislocation is a rare complication of spinal instrumentation. We report on the first case of hydrosyringomyelia secondary to intracanalar hook displacement after scoliosis surgery.

CASE DESCRIPTION

A 15-year-old girl presented to our institution with a 7-month history of persistent neck and occipital pain as well as numbness of the lower extremities and previous dorsolumbar instrumentation with dorsal pedicular hooks and lumbar screws. Magnetic resonance imaging showed intramedullary cystic cavity from C5 to T7, isointense to cerebrospinal fluid (CSF) on T1- and T2-weighted images. Computed tomographic scan showed intracanalar displacement of the left hook. On admission, the patient presented with mild weakness of the lower extremities, hypalgesia below the level of T4, and urinary disturbance. The patient underwent surgical hook removal, T4 laminectomy, and midline dural opening: the arachnoid membrane was found to be thick and adhered to the dura and dorsolateral spinal cord. The arachnoid scarring was dissected, and the cord was untethered. A small posterior-median myelotomy was performed, and a syringosubarachnoid catheter was placed into the subarachnoid space to restore CSF flow.

CONCLUSIONS

Late intracanalar displacement of spinal devices is an event that may complicate spinal instrumentation for scoliosis. This case highlights the importance of correct spinal device positioning and that of careful follow-up after instrumentation to detect complications early. We also discuss the pathogenetic pathway of the postarachnoiditic syringomyelia in this case.

Concurrent syringomyelia and intradural extramedullary tuberculoma as late complications of tuberculous meningitis

Tuberculous meningitis (TBM) is a common presentation of extrapulmonary tuberculosis. TBM is associated with many complications. However, concurrent syringomyelia and intradural extramedullary tuberculoma occurring in a patient treated for TBM is rare. Only one such case has been reported earlier. A 27-year-old woman presented with paraparesis of 2 months duration. She had been treated for TBM 8 months earlier. She was found to have an extensive syringomyelia from C2 to the conus medullaris and an intradural extramedullary tuberculoma at the lower thoracic levels. At surgery, a thick, granulomatous lesion was found in the intradural extramedullary plane. Following excision of the granulomatous lesion, a syringostomy was done. The patient was treated with antituberculous drugs and steroids. Six months after treatment, there was no significant change in her neurological status. Concurrent syringomyelia and intradural extramedullary tuberculoma should be entertained in the differential diagnosis when a patient presents with myelopathy following TBM. The pathogenesis of syringomyelia in this condition is discussed.

two-stage operation for resection of spinal cord astrocytomas: technical case report of three cases

OBJECTIVE AND IMPORTANCE

Surgery for excision of intramedullary spinal cord tumors without increasing neurological deficit is one of the more difficult operations in spinal surgery. In particular, infiltrating astrocytomas without a clear cleavage between the tumor and normal spinal cord parenchyma are difficult to remove totally without producing additional neurological impairment. In this study, we describe a two-stage resection facilitating total resection of intramedullary tumors.

CLINICAL PRESENTATION

Three cases of spinal cord astrocytomas were treated using a two-staged method.

TECHNIQUE

The first surgery included myelotomy, biopsy and duroplasty. A thin expanded polytetrafluoroethylene sheet was placed between the dorsal surface of the spinal cord and dura mater to prevent adhesions. Two or 3 weeks after surgery, a second surgery was performed to remove the now exophytic tumor.

RESULTS

Magnetic resonance imaging scans showed exophytic extrusion of the tumor in all three cases before the second operation. In each patient, we were able to carry out gross total removal of the tumors without additional neurological deficit except for transient joint position sense loss in one case. All three patients remain neurologically stable without evidence of tumor recurrence more than 3 years after surgery.

CONCLUSION

A two-stage operation may enhance the surgeon's ability to completely resect extensive low-grade spinal cord astrocytomas and, at the same time preserve neurological function.

Clinical features and pathomechanisms of syringomyelia associated with spinal arachnoiditis

BACKGROUND

Syringomyelia is a common intramedullary lesion associated with spinal arachnoiditis and obstruction of the foramen magnum such as in Chiari's malformation. Disturbance of cerebrospinal fluid flow around the spinal cord has an important role in the development of syringomyelia due to spinal arachnoiditis; however, the exact mechanisms have not been clarified. The purpose of this retrospective study is to understand the clinical features and pathomechanisms of syringomyelia secondary to spinal arachnoiditis and to provide the current choice of surgical treatment in this difficult clinical entity.

METHODS

Clinical and radiological findings in 15 patients with syringomyelia associated with spinal arachnoiditis who underwent surgical treatment in our institutes between 1982 and 2000 were reviewed. All patients presented with paraparesis or tetraparesis on admission.

RESULTS

Magnetic resonance imaging (MRI) or computed tomography-myelography revealed that the syrinx predominantly existed at the thoracic levels. Five patients showed complete block of the thoracic subarachnoid space by conventional myelography. T2-weighted MRI showed diffuse intramedullary hyperintensity at the level of arachnoiditis. As the first surgical treatment, 10 patients underwent syringo-peritoneal shunt placement. Three patients were treated with a syringo-subarachnoid shunt, and 2 patients were treated with a ventriculoperitoneal shunt. Eight patients required further shunting operations for syringomyelia 2 months to 12 years after the first surgery. Neurologic improvement was obtained in 9 patients (60%) with decreased size of the syrinx. One patient remained stable; 5 patients showed gradual deterioration.

CONCLUSIONS

The syrinx originated from the thoracic levels where severe adhesion of the subarachnoid space was present. The mechanisms of syrinx formation may be based on the increased interstitial fluid in the spinal cord. Shunting procedures were effective in some population of the patients. Decompression procedures of the spinal subarachnoid space may be an alternative primary surgical treatment except for patients with longitudinally extensive arachnoiditis.

Seprafilm superior to Gore-Tex in the prevention of peridural fibrosis

OBJECT

This is an investigation into the effects of two barrier membranes in the prevention of peridural fibrosis in an animal model.

METHODS

Seprafilm or Gore-Tex was applied to a laminectomy defect overlying the dura mater in rats separated into treatment groups. A third group of rats underwent laminectomy only and served as controls. Two months postoperatively a histological study was performed to compare the amount of scar tissue in each group. The gross dissection demonstrated that both membranes created a controlled dissection plane, facilitated access to the epidural space, and provided a reduction in the amount of tissue adhering to the dura mater. Statistically, Seprafilm was superior to Gore-Tex in preventing peridural fibrosis (p < 0.05).

CONCLUSIONS

Seprafilm can prevent peridural fibrosis better than Gore-Tex and can be used in humans in spinal surgery.

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.

Imaging in chronic spinal cord injury--indications and benefits

As most patients who have suffered spinal cord injury can now expect a normal life span, the late complications of these injuries are seen increasingly frequently. Regular surveillance of both the renal tract and the central nervous system (CNS) is important as the treatment of impending, potentially fatal complications can be implemented before damage has progressed too far. Renal tract complications are particularly dangerous as they are often clinically silent but regular surveillance to detect early deterioration in renal function, particularly from reversible causes such as reflux or obstruction can pre-empt problems. Follow-up protocols depend on the bladder management regime but most centres advocate regular ultrasound with less frequent isotope function studies. With the increasing ability to diagnose and treat the neurological complications, surveillance of the state of the spinal cord with MRI is also important and many centres now advocate checks every few years with sagittal midline T2W sections are sufficient unless changes are noted, when axial T1W sections can be added without significant examination time penalty. Imaging is critical in acute problems. In addition to suffering from the usual normal conditions, patients with spinal cord injury suffer others peculiar to, or particularly related to, the injury, which may be missed as their symptomatology is greatly altered by their paraplegic or quadriplegic status and they may often present as generally unwell but with no obvious cause. This review discusses the role of radiology in routine surveillance of the CNS and the renal tract as well as in assessing specific conditions such as deteriorating neurology or renal function, pain, spinal instability, pressure sores, ectopic ossification, muscular spasm, spinal instability, airway problems and elective operations on the renal tract.