Treatment of syringomyelia associated with arachnoid scarring caused by arachnoiditis or trauma

Primary spinal syringomyelia. Invited submission from the joint section meeting on disorders of the spine and peripheral nerves, March 2005

In the present review the author describes the different types of syringomyelia that originate from abnormalities at the level of the spinal cord rather than at the craniovertebral junction. These include posttraumatic and postinflammatory syringomyelia, as well as syringomyelia associated with arachnoid cysts and spinal cord tumors. The diagnosis and the principles of managing these lesions are discussed, notably resection of the entity restricting cerebrospinal fluid flow. Placement of a shunt into the syrinx cavity is reserved for patients in whom other procedures have failed or who are not candidates for other procedures.

Spinal Arachnoid Cyst Causing Paraplegia Following Skull Base Surgery-Case Report-

A 40-year-old woman presented with a right petroclival meningioma compressing the brainstem and manifesting as a 6-month history of headache and gait difficulty. The patient underwent subtotal removal of the tumor via an anterior transpetrosal approach. The postoperative course was complicated by cerebrospinal fluid rhinorrhea, bacterial meningitis, and acute hemorrhagic rectal ulcer. The patient was discharged home in good condition after prolonged medical treatment. Four months after the surgery, the patient noted recurrence of gait difficulty. Magnetic resonance (MR) imaging of the brain showed enlargement of the ventricles and no residual brainstem compression. A ventriculoperitoneal shunt was placed, but the symptoms were unchanged. The shunt was removed 2 months later because of infection. The patient's gait gradually deteriorated, although repeat brain MR imaging showed no significant increase in ventricular size. Ten months after the initial surgery she became paraplegic. MR imaging of the thoracic spine revealed a large arachnoid cyst extending from C-6 to T-6. The patient underwent T2-4 laminectomy, partial removal of the cyst wall, and duraplasty, but no clinical improvement was observed. Preexisting long-tract signs and coincidental hydrocephalus confused the neurological findings and delayed detection of the spinal lesion in this case. Neurosurgeons should be alert to the possibilities of insidious spinal lesion if the patient has progressive neurological disorder which does not match the known cranial lesion.

Post-traumatic syringomyelia: a review of the cases presenting in a regional spinal injuries unit in the north east of England over a 5-year period

STUDY DESIGN

Retrospective study of the management of patients with a confirmed diagnosis of post-traumatic syringomyelia (PTS) in a regional spinal injuries unit.

OBJECTIVES

To investigate the incidence of PTS in a regional spinal injuries unit, and to assess mode of presentation, management, and subsequent outcome.

SUMMARY OF BACKGROUND DATA

Majority of patients male, mean age 44 years (range 33-60 years), with thoracic spinal cord injury (SCI). Most PTS developed within 5 years after injury (range 6 months to 25 years) and presented with reduced sensation. Fifty percent had surgical intervention at the time of SCI, and 50% managed conservatively. Four patients had additional spinal injury pathology not corrected at time of surgery.

METHODS

Retrospective analysis of the case notes of all patients with a confirmed diagnosis of PTS (n = 16). Demographic details obtained and details of the original injury and subsequent clinical course and management noted.

RESULTS

Incidence of PTS = 0.02%. Magnetic resonance imaging scanning performed in 56% with PTS. The majority of PTS developed around the site of the original lesion. The most common method of management was insertion of a syringoperitoneal shunt (44%). Thirty-one percent improved after surgery, 31% remain stable. One patient died. The symptoms of 3 patients continue to deteriorate slowly despite surgical intervention.

CONCLUSIONS

Incidence of PTS are lower in our study than that quoted in the literature. Benefits of initial surgical management of SCI in reducing development of PTS are unclear. Benefits of surgical management of PTS are unclear. Additional studies are required as this may influence future management of spinal cord injured patients.

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.

Posttraumatic syringomyelia--a serious complication in tetra- and paraplegic patients

Post-traumatic syringomyelia (PTS) is relatively rare, but its complications can be serious. In the beginning of the operative treatment (1900-1930), scarring could be reduced to a certain degree. In modern treatment (1980 1990) a shunt implantation showed also little effect in long-term follow-up studies. Influenced by the work of B. Williams, 58 PTS patients underwent surgery to create a pseudomeningomyelocele, an artificial CSF reservoir, performed to normalize the CSF flow. In a 10-year-postoperative follow-up study (minimum observation two years), good results were obtained in more than 70%.

Surgical treatment of a syringomyelia associated with an idiopathic arachnoid malformation disclosed by preoperative MRI

BACKGROUND

We describe the very rare condition of an idiopathic spinal arachnoid malformation associated with syringomyelia (SM) and depicted on preoperative magnetic resonance imaging (MRI) whose features were confirmed at surgery.

CASE DESCRIPTION

A 34-year-old female suffered from progressive gait impairment because of lower limb palsy and sensory disturbances. MRI demonstrated a bulging membrane at the T6 level that was transversely stretched between the dorsal aspect of the spinal cord and the posterior dura mater. At this level, the spinal cord appeared atrophic and pushed anteriorly against the dura with enlargement of the posterior subarachnoid spaces (SAS) and focal collapse of an associated panmedullar SM. Surgery consisted in releasing the arachnoid malformation and opening the inferior segment of the syringomyelic cavity. Pathological examination revealed a fibro-sclerotic tissue with cellular areas of meningo-endothelial cells. Postoperative neurological status progressively improved but slightly. Three-months and 1 year postoperatively, MRI showed the collapse of the whole SM and restoration of cerebrospinal fluid (CSF) flow at the treated T6 level.

CONCLUSION

Spinal arachnoid malformations associated with SM are very rare and have never been described up to now on MRI. Surgical removal of the causative malformation allows spinal cord decompression and prevents the recurrence of the SM by restoring normal CSF circulation.

Results of spinal meningioma surgery in patients with severe preoperative neurological deficits

Spinal meningiomas are usually benign, slow-growing tumours and are commonly associated with good patient outcome following surgery. However, the existence of a severe preoperative neurological deficit has been considered to be a possible predictor of poor functional outcome after surgery. We retrospectively reviewed data from 33 patients with 35 spinal meningiomas treated in our institution over the past 17 years and exhibiting severe preoperative deficits before surgery. Among them, 20 suffered from paraparesis and 13 were paraplegic. The mean follow-up duration was 70.7 months (range 12-183 months). By the 1-year follow-up, all patients had improved in comparison with their preoperative neurological status, and 60% of them had totally recovered. It can be concluded from this study, that, in the vast majority of cases, patients harbouring spinal meningioma with severe preoperative deficits can expect a good outcome.

The pathogenesis of syringomyelia associated with lesions at the foramen magnum: a critical review of existing theories and proposal of a new hypothesis

Syringomyelia is frequently accompanied by an extramedullary lesion at the foramen magnum, particularly a Chiari I malformation. Although syringomyelia associated with foramen magnum obstruction has characteristic clinical, radiological, and neuropathological features, its pathogenesis remains unclear. Currently prevalent hydrodynamical theories assert that obstruction of the subarachnoid space at the foramen magnum interferes with flow of cerebrospinal fluid (CSF) between the spinal and the intracranial subarachnoid compartments. As a result, spinal CSF is driven into the spinal cord through the perivascular spaces to form a syrinx. These theories are implausible biophysically because none postulates a pump adequate to drive fluid through these spaces. None of the theories can explain why syrinx pressure is higher than CSF pressure; why extensive gliosis, edema, and vascular wall thickening regularly occur; and why the composition of syrinx fluid is not identical with that of CSF. A new theory of pathogenesis is proposed to address these difficulties. In the presence of subarachnoid obstruction at the foramen magnum, a variety of activities, such as assuming the erect posture, coughing or straining, and pulsatile fluctuations of CSF pressure during the cardiac cycle, produce transiently higher CSF pressure above the block than below it. There are corresponding changes in transmural venous and capillary pressure favoring dilation of vessels below the block and collapse of vessels above the block. The spatially uneven change of vessel caliber produces mechanical stress on the spinal cord, particularly caudal to the block. The mechanical stress, coupled with venous and capillary dilation, partially disrupt the blood-spinal cord barrier, allowing ultrafiltration of crystalloids and accumulation of a protein-poor fluid. The proposed theory is consistent with the neuropathological findings in syringomyelia and with the pressure and composition of syrinx fluid. It also accounts for the prolonged course of syringomyelia and its aggravation by cough, strain, and assumption of an erect posture. It contributes to understanding the low incidence and the morphology of syringobulbia. It explains the poorly understood presentation of foramen magnum meningiomas with symptoms of a mid- to low-cervical myelopathy. The theory also affords an understanding of the late recurrence of symptoms in children with hydromyelia who are treated with a ventricular shunt.

Theoretical analysis of the pathophysiology of syringomyelia associated with adhesive arachnoiditis

OBJECTIVE

To apply a theoretical model to analyse the derangement of cerebrospinal fluid (CSF) dynamics in syringomyelia associated with adhesive arachnoiditis.

METHODS

An electrical circuit model of CSF dynamics in the spine was used. With this model, the derangement of CSF dynamics in adhesive arachnoiditis was simulated. The effects of various surgical procedures were then analysed, such as syringo-subarachnoid shunting, subarachnoid bypass, and foramen magnum decompression.

RESULTS

When CSF flow in the subarachnoid space was obstructed at a certain point, the pressure inside the spinal cord increased in the segment immediately distal to the blockage. This location of increased pressure corresponded to the preferred site of syrinx formation in adhesive arachnoiditis. Syringo-subarachnoid shunting, subarachnoid bypass, and foramen magnum decompression were all effective at reducing this pressure gradient.

CONCLUSIONS

Blockage of the spinal subarachnoid CSF pathway produces a relative increase in the pressure inside the spinal cord distal to the blockage point. Repetitive formation of this pressure gradient then induces CSF leakage into the spinal parenchyma, leading to the formation of syringomyelia. Using this model, alternative surgical procedures could be suggested that might be effective in treating this disease.

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.

Altered subarachnoid space compliance and fluid flow in an animal model of posttraumatic syringomyelia

STUDY DESIGN

A histologic study of cerebrospinal fluid tracers in Sprague-Dawley rats undergoing lumboperitoneal shunt insertion in the excitotoxic animal model of posttraumatic syringomyelia (PTS).

OBJECTIVES

To determine the effects of cerebrospinal fluid (CSF) diversion from the subarachnoid space on perivascular flow (PVS) and syrinx formation in posttraumatic syringomyelia.

SUMMARY OF BACKGROUND DATA

In an animal model of PTS, fluid enters syringes from the subarachnoid space via perivascular spaces. Preferential PVS flow occurs at the level of the syrinx. It has been suggested that arachnoiditis predisposes to posttraumatic syringomyelia formation by obstructing subarachnoid cerebrospinal fluid flow and enhancing perivascular flow.

MATERIALS AND METHODS

Thirty-two male Sprague-Dawley rats were investigated using the CSF tracer horseradish peroxidase (HRP), the excitotoxic model of PTS, and lumboperitoneal shunt insertion. Five experimental groups consisted of normal controls, syrinx only and shunt only controls, and shunt insertion before or after syrinx formation. In all groups except normal controls, CSF flow studies were performed 6 weeks after the final intervention. Grading scales were used to quantify HRP staining.

RESULTS

All excitotoxic model animals formed syringes. Perivascular flow was greatest at the level of the syrinx. Cerebral cortex perivascular flow was significantly reduced after shunt insertion in animals with a syrinx (P < 0.05). Shunt insertion did not alter syrinx length or size. There were no significant differences between shunt and syrinx first groups.

CONCLUSIONS

Increasing caudal subarachnoid space compliance with a shunt does not affect local CSF flow into the spinal cord and syrinx. These results suggest that localized alterations in compliance, as opposed to obstruction from traumatic arachnoiditis, may act as an important factor in syrinx pathogenesis.

Spontaneous resolution of syringomyelia: report of two cases and review of the literature

OBJECTIVE AND IMPORTANCE

The natural history of syringomyelia is highly unpredictable, and some patients experience improvement or stabilization without surgery. However, the mechanisms of the formation and spontaneous resolution of syringomyelia remain controversial. This report concerns two patients with syringomyelia who demonstrated spontaneous reductions in syrinx size, accompanied by symptomatic improvement.

CLINICAL PRESENTATION

One patient was a 10-year-old girl with syringomyelia associated with a tight cisterna magna and basilar impression, who demonstrated a spontaneous decrease in syrinx size, accompanied by symptomatic improvement, in 22 months. The other patient was a 39-year-old man with syringomyelia associated with a Chiari I malformation, who demonstrated a spontaneous reduction in syrinx size and neurological improvement, accompanied by elevation of the cerebellar tonsils, 6 months after diagnosis.

INTERVENTION

The patients were monitored.

CONCLUSION

The mechanisms of spontaneous resolution of syringomyelia, as well as the factors leading to the cerebrospinal fluid flow disturbances that cause syringomyelia, may vary. Resolution of foramen magnum lesion-related syringomyelia may be the result of spontaneous correction of the abnormal cerebrospinal fluid flow, as observed in our cases, or of cavity fluid drainage into the spinal arachnoid space because of spinal cord fissuring.

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.

A comprehensive review of spinal arachnoiditis

Spinal arachnoiditis is an insidious disease caused by an inflammatory process of the arachnoid membrane resulting from many possible causes, such as myelograms with oil-based radiographic contract agents and multiple back surgeries. Diagnosis is based on symptoms and magnetic resonance imaging. Arachnoiditis can also mimic the symptoms of other diseases, such as spinal cord tumors, cauda equina syndrome, arachnoiditis ossificans, and syringomyelia. Unfortunately, there is no cure, only treatment of the chronic symptoms. It is an incurable disease that can cause minor to severe symptoms from unexplained rashes to neurologic defects.

Surgical prognosis in hindbrain related syringomyelia

OBJECTIVES

The recommended operative treatment against hindbrain related syringomyelia is suboccipital decompression. The aim of the study was to define prognostic factors for surgical outcome in this disease.

MATERIALS AND METHODS

Between 1990 and 1997, 31 patients with hindbrain related syringomyelia were treated. All patients underwent craniovertebral decompression by suboccipital craniectomy and laminectomy of C1 or C1 and C2, respectively. Additionally, in nearly half of the cases, the tonsils were treated by bipolar coagulation. Mean post-operative observation period was 35 months including clinical and radiological (MRI) examination.

RESULTS

Neither there was correlation between clinical outcome and age nor correlation between clinical outcome and duration of preoperative symptoms. There was good correlation between clinical outcome and result of post-operative MRI: 63% of patients with a sufficient post-operative MRI demonstrated a significant clinical improvement, whereby only 17% of patients with insufficient MRI did so (P < 0.05). None of the patients with coagulation of the tonsils showed clinical improvement. In contrast, 77% of patients without tonsillar manipulation demonstrated clinical improvement (P < 0.01). Additionally, 88% of the patients with dorsal-tenting duraplasty experienced neurological improvement (P < 0.01), too.

CONCLUSIONS

The results give evidence for the prognostic importance of creating an adequate artificial cisterna magna. Dorsal-tenting of the duraplasty is an advantageous means against scarring and adhesions, whereby intradural applications such as extensive bipolar coagulation of the cerebellar tonsils should be avoided.

Decompression of the spinal subarachnoid space as a solution for syringomyelia without Chiari malformation

STUDY DESIGN

Review and analysis of seven cases of syringomyelia treated surgically.

OBJECTIVE

To demonstrate the beneficial role of decompressive surgery for the altered cerebrospinal fluid (CSF) flow dynamics in syringomyelia not associated with Chiari I malformation. A comparison between the pre- and post-operative syrinx size and CSF flow in the subarachnoid space was made using cine-mode magnetic resonance imaging (cine-MRI) and then correlated with clinical improvement.

SETTING

University Hospital, Seoul, Korea.

METHODS

Conventional spinal MRI and cine-MRI were performed in the region of CSF flow obstruction preoperatively in seven patients with syringomyelia not associated with Chiari I malformation. The group consisted of one case of syrinx with post-traumatic compression fracture, one case of post-traumatic arachnoiditis, two cases of holocord syrinx associated with hydrocephalus without Chiari malformation, one case of syrinx with post-traumatic pseudomeningeal cyst, one case of post-laminectomy kyphosis-associated syringomyelia and one case of post-tuberculous arachnoiditis syringomyelia. Based on the preoperative cine-MRI, the types of surgery appropriate to correct the CSF flow obstruction were chosen: decompressive laminectomy-adhesiolysis and augmentation duraplasty in arachnoiditis cases, ventriculoperitoneal shunt for hydrocephalus, cyst extirpation in pseudomeningeal cyst and both anterior and posterior decompression-fusion in the case of post-laminectomy kyphosis. A syrinx-draining shunt operation was performed in three cases; where the syringomyelia was associated with post-traumatic compression fracture refractory to a previous decompression, where hydrocephalus was present in which the decompression by ventriculoperitoneal shunt was insufficient and where post-traumatic arachnoiditis was present in which the decompression was impossible due to diffuse adhesion. Change in syrinx size was evaluated with post-operative MRI in all seven cases and restoration of flow dynamics was evaluated with cine-MRI in three of the cases, two patients with clinical improvement and one patient with no change of clinical status, respectively.

RESULTS

Four out of seven patients showed symptomatic improvement after each decompressive operation. In the remaining three cases, reconstruction of the spinal subarachnoid space was not possible due to diffuse adhesion or was not the main problem as in the patient with syrinx associated with hydrocephalus who had to undergo a shunt operation. One of these three patients showed clinical improvement after undergoing syringosubarachnoid shunt. A decrease of syrinx size was observed in only two out of the five patients who showed clinical improvement after treatment. Of these five patients, two patients underwent post-operative cine-MRI and the restoration of normal CSF flow dynamics was noted in both patients. Of the remaining two patients, one underwent post-operative cine-MRI and there was no change in the CSF flow dynamics evident.

CONCLUSION

These results suggest that the restoration of CSF flow dynamics between the syrinx and the subarachnoid space by decompressive operation is more effective than simple drainage of the syrinx cavity itself in the treatment of syringomyelia without Chiari malformation.

Syringomyelia caused by loosening of multistrand cables following C1-2 Brooks-type fusion in the rheumatoid cervical spine. Case report

The authors report a very rare case of syringomyelia caused by loosening of multistrand cable wires following C1-2 Brooks-type fusion in a 36-year-old woman with a 13-year history of rheumatoid arthritis (RA). The syrinx vanished immediately after removal of the cables, and 2 years later no recurrence of symptoms or deterioration has occurred. The authors contend that multistrand titanium cables should not be used to fix a graft-assisted C1-2 construct in patients with RA, although this material is good for fixing rods. The phenomenon observed in this case adds to our understanding of the pathogenesis of noncommunicating syringomyelia.

Syringomyelia associated with foramen magnum arachnoiditis

OBJECT

Syringomyelia is often linked to pathological lesions of the foramen magnum. The most common cause is hindbrain herniation, usually referred to as Chiari I or II malformation. Foramen magnum arachnoiditis without either Chiari I or II malformation is a rare cause of syringomyelia. The authors undertook a retrospective analysis of 21 patients with foramen magnum arachnoiditis (FMA) and syringomyelia treated between 1978 and 2000 to determine clinical course and optimum management.

METHODS

In the review of records, 21 patients with FMA and syringomyelia were documented. A stable clinical course was demonstrated in three patients in whom surgery was not performed, and one patient refused surgical intervention. Seventeen patients underwent 23 operations to treat progressive neurological disease. Of these 23 operations, 18 involved opening of the foramen magnum, arachnoid dissection, and placement of a large dural graft. One patient underwent insertion of a ventriculoperitoneal shunt for treatment of accompanying hydrocephalus, one patient received a cystoperitoneal shunt for an accompanying arachnoid cyst; two syringoperitoneal and one syringosubarachnoid shunts were also inserted. Hospital and outpatient files, neuroimaging studies, and intraoperative photographic and video material were analyzed. Additional follow-up information was obtained by telephone interview and questionnaires. Standard and cardiac-gated magnetic resonance imaging studies are the diagnostic procedures of choice in these patients. Sensory disturbances, dysesthesias, and pain were the only symptoms likely to improve after foramen magnum surgery. Motor weakness and gait disturbances, which were severe in a considerable number of patients, and swallowing disorders tended to remain unchanged. As a consequence of the rather severe arachnoid lesions in most patients, clinical recurrences were observed in 57% over a 5-year period.

CONCLUSIONS

Surgery for FMA and syringomyelia has to provide clear cerebrospinal fluid pathways between the cerebellopontine cisterns, spinal canal, and fourth ventricle. If this can be achieved successfully, the syrinx decreases in size and the clinical course of the patient may even improve. In patients with severe and widespread areas of arachnoiditis, however, multiple operations may be required at least to stabilize the clinical course.

Shunting for syringomyelia in patients with spinal cord injuries: self-reported, long-term effects in 8 patients

OBJECTIVE

To investigate the long-term effects of shunting on neurologic outcome of syringomyelia, a complication of spinal cord injury (SCI).

DESIGN

Retrospective data collection using telephonic survey.

SETTING

University based medical center.

PARTICIPANTS

Eight of 15 patients who had shunts placed between 1976 and 1999.

INTERVENTIONS

Review of clinical records and self-reported telephone interview.

MAIN OUTCOMES MEASURES

Initial clinical presentation, recovery after shunt placement, and subsequent neurologic status were recorded. Patients were asked to rate symptomatic improvement after surgery on a 100-point analog scale; they were also asked whether they would have the surgery again.

RESULTS

Presenting symptoms were weakness in all 8 patients, pain in 5 patients, and numbness in 5 patients. After shunting, 6 patients had improved strength, all had less pain, and 2 had less numbness. Six patients experienced neurologic decline an average of 2 years after shunt placement, 3 because of shunt failure, 2 from a new syrinx, and 1 from both shunt failure and new syrinx. Two of the 3 patients who underwent second shunt placements for a new syrinx had full neurologic recovery. Six patients said they would repeat the shunting procedure if necessary, 1 was uncertain, and 1 would not.

CONCLUSION

Initial improvements noted after shunting provide long-lasting effects, even though many patients may need a second procedure. Less pain and improved strength are more significant than decreased numbness.

[Arachnoiditis and intraspinal lesion. Complications of tuberculous meningitis in 2 patients with human immunodeficiency virus infection]

Radiculomyelitis (arachnoiditis) (RMA) is a severe complication of tuberculous meningitis (TM). Two patients with HIV infection and TM are here reported. These patients developed RMA. In Spain only four cases of RMA have previously been reported (only one of them was HIV-positive). Clinical manifestations (subacute paraplegia, radicular pain, sensitive level and neurogenic bladder) are reported. Cerebrospinal fluid had inflammatory features, wit predominance of mononuclear cells and remarkable increase in protein content. Magnetic resonance imaging (MRI) is the most suitable diagnostic method. The therapeutic possibilities of this complication are discussed.

Solid human embryonic spinal cord xenografts in acute and chronic spinal cord cavities: a morphological and functional study

While therapeutic spinal cord grafting procedures are of interest in the chronic spinal cord injury stage, previous experimental grafting studies, including human spinal cord tissue, have mainly focused on the acute stage. Therefore, solid human embryonic spinal cord grafts were implanted in acute or chronic spinal cord aspiration cavities of immunodeficient rats to compare the morphological and locomotor outcome to that of lesion alone cases. Locomotor function was assessed using the Basso, Beattie, and Bresnahan open-field locomotor rating scale up to 6 months, while the morphological evaluation of graft survival, growth, and integration was performed at 6 weeks or 6 months after implantation. Graft survival was 94% in both lesion models, while graft growth was enhanced in the chronic compared to the acute cavity group. Human specific Thy-1 and neurofilament immunoreactive fibers were observed up to 7 mm into host white matter, while aminergic fibers were observed up to 1 mm into the grafts. Abundant calcitonin gene-related peptide immunoreactive fibers in the grafts in the absence both of immunoreactive cell bodies and colocalized human-specific neurofilament immunoreactivity, suggested host fiber ingrowth. At 6 months, the grafted cases presented less central canal deformation and lower glial fibrillary acidic protein immunoreactivity at the host cavity border compared to that of the nongrafted cases. The strong compensatory regain of locomotor function after unilateral spinal cord lesions was not affected by the human spinal cord grafts. In conclusion, solid human embryonic spinal cord tissue transplanted to a cavity in the adult injured spinal cord results in beneficial morphological effects in both the acute and chronic spinal cord lesion.

A craniocervical injury-induced syringomyelia caused by central canal dilation secondary to acquired tonsillar herniation. Case report

The authors report on a 19-year-old man with an acquired tonsillar herniation caused by a craniocervical junction injury in which serial magnetic resonance (MR) images demonstrated patent and isolated segments of the central canal participating in the dilation and then formation of a cervical syrinx. The patient was involved in a motor vehicle accident; he developed tonsillar herniation as a complication of subarachnoid and epidural hemorrhage, predominantly observed around the cisterna magna and upper cervical canal. Repeated MR images obtained over an 11-month period indicated the for mation and acute enlargement of the syrinx. Ten months after the accident, the patient presented with sensory disturbance in both upper extremities and spasticity due to syringomyelia. He underwent craniocervical decompressive surgery and doraplasty, which reduced the size of syringomyelia. The authors postulate that the patent central canal may play a role in determining the location of a syrinx remote from a focus of cerebrospinal fluid obstruction.

Disturbances of cerebrospinal fluid flow attributable to arachnoid scarring cause interstitial edema of the cat spinal cord

OBJECTIVE

Spinal arachnoid scarring may be caused by trauma, inflammation, surgery, spinal instability, degenerative diseases, or malformations and may lead to progressive neurological deficits and syringomyelia. We wanted to investigate the effects of focal arachnoid scarring in the cervical spinal canal of cats on pressures in the subarachnoid space and spinal cord tissue, as well as on spinal cord histological features.

METHODS

Twenty-nine adult cats were used for this study. Nine animals served as control animals, whereas 20 animals received a focal arachnoid scar at C1-C2, which was produced by placement of a kaolin-soaked fibrin sponge on the posterior surface of the spinal cord. After 4 months, pressure recordings above and below the scar, in the subarachnoid space and spinal cord, were performed. Elasticity measurements were performed with small bolus injections. Morphometric analyses of brain and ventricle volumes, sizes of the central canal, and sizes of the perivascular spaces in gray and white matter were also performed.

RESULTS

No animal developed clinical or neurophysiological evidence of neurological symptoms at any time. In the kaolin-treated group, pressure recordings revealed a significant increase in the subarachnoid pressure at C1, because of the cerebrospinal fluid flow obstruction. Pressure gradients tended to increase at all measuring points. A significant difference was detected between the spinal cord and subarachnoid space at C2, where the intramedullary pressure exceeded the subarachnoid pressure. Elasticity was significantly increased in the spinal cord at C2. Intracranially, no evidence of hydrocephalus was observed. In the spinal cord, perivascular spaces were significantly enlarged in the posterior white matter above the arachnoid scar and in the central gray matter below the area of scarring in the cervical cord.

CONCLUSION

Arachnoid scarring at C1-C2 produces an interstitial type of edema in the central gray matter below the area of scarring in the cat cervical cord, because of altered cerebrospinal fluid and extracellular fluid flow dynamics. These changes may be interpreted as the initial stage in the development of syringomyelic cavities.

Surgical management of syringomyelia associated with spinal adhesive arachnoiditis

The authors describe a new surgical technique to minimise the postoperative recurrence of adhesion after microlysis of adhesion to treat syringomyelia associated with spinal adhesive arachnoiditis. A 47 year old male presented with numbness of the lower extremities and urinary disturbance and was demonstrated to have a case of syringomyelia from C1 to T2 which was thought to be secondary to adhesive spinal arachnoiditis related to a history of tuberculous meningitis. Following meticulous microlysis of the adhesions, maximal expansion of a blocked subarachnoid space was performed by expansive duraplasty with a Gore-Tex surgical membrane, expansive laminoplasty and multiple tenting sutures of the Gore-Tex graft. Postoperatively, the syringomyelia had be en completely obliterated and improvement of the symptoms had been also achieved. The technique described may contribute to improvement of the surgical outcome following arachnoid dissection by maintaining continuity of the reconstructed subarachnoid space.

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.

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.

Classification of syringomyelia

Syringomyelia poses special challenges for the clinician because of its complex symptomatology, uncertain pathogenesis, and multiple options of treatment. The purpose of this study was to classify intramedullary cavities according to their most salient pathological and clinical features. Pathological findings obtained in 175 individuals with tubular cavitations of the spinal cord were correlated with clinical and magnetic resonance (MR) imaging findings in a database of 927 patients. A classification system was developed in which the morbid anatomy, cause, and pathogenesis of these lesions are emphasized. The use of a disease-based classification of syringomyelia facilitates diagnosis and the interpretation of MR imaging findings and provides a guide to treatment.

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.

Primary spinal syringomyelia: a personal perspective

In this paper the author summarizes currently available surgical approaches to spinal syringomyelia that is unrelated to Chiari I malformation or hindbrain descent. Primary spinal syringomyelia is most comonly associated with spinal trauma but is also encountered as a sequela to intradural inflammatory processes (infections or chemical), as a delayed response to surgical procedures, and in association with intra- and extradural neoplasms as well as disc protrusions. The advantages of placing a shunt are its technical simplicity and immediate reduction of syrinx size; its major disadvantages are the high rate of failure observed in long-term follow up and the difficulty in applying this technique in septated cysts. Expansion of the subarachnoid space with resection of scars has better long-term results. Patients in whom a syrinx cavity has caused a kyphotic spinal deformity may need to undergo a procedure in which the kyphotic deformity is corrected to expand the subarachnoid space. Cyst obliteration is an experimental approach that cannot be evaluated at the present time.

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.

Dural band pathology in syringomyelia with Chiari type I malformation

Surgical material taken from the 'outer layer' of thickened dura mater (dural band) at the craniovertebral junction of eight cases of syringomyelia with Chiari type I malformation was histologically examined in comparison with four autopsy cases as controls. The dural band was thickened and there were increased numbers of collagen fibers which showed fiber splitting, hyalinous nodule, calcification and/or ossification. These changes were not observed in the four control cases. Thus, it is suggested that the thickening of the dura mater may be a causative factor of syringomyelia with Chiari type I malformation. In addition, the histology of the thickened dura mater suggests the condition may be a consequence of birth injury in these patients.

The “presyrinx” state: is there a reversible myelopathic condition that may precede syringomyelia?

Object

Alteration of cerebrospinal fluid (CSF) flow has been proposed as an important mechanism leading to the development of syringomyelia. We hypothesize that a “presyrinx” condition due to potentially reversible alteration in normal CSF flow exists and that its appearance may be due to variations in the competence of the central canal of the spinal cord.

Methods

Five patients with clinical evidence of myelopathy, no history of spinal cord trauma, enlargement of the cervical spinal cord with T1 and T2 prolongation but no cavitation, evidence for altered or obstructed CSF flow, and no evidence of intramedullary tumor or a spinal vascular event underwent MR imaging before and after intervention that alleviated obstruction to CSF flow.

Results

Preoperatively, all patients demonstrated enlarged spinal cords and parenchymal T1 and T2 prolongation without cavitation. Results of magnetic resonance (MR) imaging examinations following intervention in all patients showed resolution of cord enlargement and normalization or improvement of cord signal abnormalities. In one patient with severe arachnoid adhesions who initially improved following decompression, late evolution into syringomyelia occurred in association with continued CSF obstruction.

Conclusion

Nontraumatic obstruction of the CSF pathways in the spine may result in spinal cord parenchymal T2 prolongation that is reversible following restoration of patency of CSF pathways. We refer to this MR appearance as the “presyrinx” state and stress the importance of timely intervention to limit progression to syringomyelia.

Arachnoiditis ossificans and syringomyelia: a unique case report

A 62-year-old male presented with progressive quadriparesis. Magnetic resonance imaging of the spine revealed a spinal cord syrinx but failed to detect extensive arachnoiditis ossificans noted on insertion of a syringopleural shunt. A postoperative computed tomography scan clearly demonstrated the abnormality and its extent. We present a rare case of syringomyelia resulting from spinal arachnoiditis ossificans and review the relevant literature.

Surgical results for spinal meningiomas

Among a series of 782 spinal tumors, 130 spinal meningiomas in 117 patients were operated in the Department of Neurosurgery at the Nordstadt Hospital in Hannover, Germany, between 1977 and 1998. Patients were followed postoperatively for up to 13 years (mean 20 +/- 33 months). Comparing the period of 1977 through 1987, before magnetic resonance imaging (MRI) was available, to the period of 1988 to 1998 revealed that the average history until diagnosis shortened by about 6 months during the second decade of this study (24 +/- 33 to 18 +/- 29 months; not significant). Consequently, the preoperative Karnofsky Score increased significantly (59 +/- 15 and 66 +/- 16; p < 0.05). The rates of complete resection and the postoperative neurological outcome, however, remained unchanged. Even though the overall prognosis of neurological deficits is favorable after complete resection of a meningioma, a subset of 18 patients had either en plaque growing or recurrent tumors that were more likely to be removed incompletely and to cause postoperative neurological problems, with a significantly worse Karnofsky Score after 1 year (57 +/- 12 and 77 +/- 12, respectively; p < 0.01) and a significantly higher recurrence rate after 5 years (86.7% and 20.4%, respectively; log rank test p = 0.0014). In conclusion, a favorable postoperative neurological outcome requires complete resection of the spinal meningioma. The advent of MRI has shortened the time until diagnosis and made it possible to perform surgery before severe deficits have occurred, but did not have a major impact on postoperative results. En plaque and recurrent meningiomas remain surgical challenges, as infiltration of surrounding structures and associated arachnoid scarring may render complete resection difficult to achieve.

A critical appraisal of syrinx cavity shunting procedures

OBJECT

This study was conducted to evaluate the results of shunting procedures for syringomyelia.

METHODS

In a follow-up analysis of 42 patients in whom shunts were placed in syringomyelic cavities, the authors have demonstrated that 21 (50%) developed recurrent cyst expansion indicative of shunt failure. Problems were encountered in patients with syringomyelia resulting from hindbrain herniation, spinal trauma, or inflammatory processes. A low-pressure cerebrospinal fluid state occurred in two of 18 patients; infection was also rare (one of 18 patients), but both are potentially devastating complications of shunt procedures. Shunt obstruction, the most common problem, was encountered in 18 patients; spinal cord tethering, seen in three cases, may account for situations in which the patient gradually deteriorated neurologically, despite a functioning shunt.

CONCLUSIONS

Placement of all types of shunts (subarachnoid, syringoperitoneal, and syringopleural) may be followed by significant morbidity requiring one or more additional surgical procedures.

Obliteration of a posttraumatic spinal cord cyst with solid human embryonic spinal cord grafts: first clinical attempt

Cystic lesions of the spinal cord (syringomyelia) may occur after spinal cord injury. Posttraumatic syringomyelia may result in a myelopathy causing symptoms of sensory and motor loss, as well as worsening spasticity, pain, hyperhidrosis, and autonomic dysreflexia. Shunting of the cyst cavity along with untethering of the scarred spinal cord is widely accepted as the treatment of choice. However, the long-term stabilization of the progressive myelopathy caused by a posttraumatic cyst is suboptimal because of arachnoidal rescarring, shunt tube blockage, and cyst reexpansion. A new neurosurgical strategy to overcome the complication of cyst reexpansion was designed. Experimental studies have shown the successful use of embryonic spinal cord grafts, including human grafts, to obliterate induced spinal cord cavities in rats. The authors report the first use of solid human embryonic spinal cord grafts to successfully obliterate 6 cm of a large cyst cavity in a patient becoming myelopathic from a posttraumatic cyst. The grafts are well visualized by MRI to the 7-month postoperative follow-up and cyst obliteration is seen in the region where the grafts were placed.