Atypical presentations of conus medullaris and filum terminale myxopapillary ependymomas

Out of 27 cases of spinal ependymomas seen during a 21 year period (1978-1999), we observed three out of 12 myxopapillary tumours of the conus medullaris and filum terminale with atypical presentations. All the three cases presented with subarachnoid haemorrhage and intracranial hypertension. In addition, the second patient developed persistently low CSF sugar, while the third patient developed hydrocephalus, acute autonomic crisis and SIADH. Although subarachnoid haemorrhage (SAH), intracranial hypertension and hydrocephalus were previously scarcely reported in the literature, the low CSF sugar, acute autonomic crisis and SIADH were never reported singly or in combination. Up to our best knowledge, this is the first report that clearly outlines all these atypical manifestations in this particularly interesting neoplasm. Hence, the above challenging clinical presentations should be borne in mind with cryptic presentations of lower spinal cord and filum terminale ependymomas. A proposal of the mechanism of their production is suggested.

Paraparesis due to pressure erosion of the thoracic spine by an aortic aneurysm: remission of symptoms following resection of the aneurysm and vertebral reconstruction

BACKGROUND

There are only a few descriptions in the literature of thoraco-abdominal aortic aneurysms responsible for erosion of the vertebral column and compression of the spinal cord. This case is therefore presented to provide an opportunity to discuss the pathomechanic aspects and to demonstrate the feasibility of total surgical repair by an interdisciplinary approach.

METHODS

A thoraco-abdominal aortic aneurysm caused extensive erosion of vertebral bodies T5-8, leading to invasion of the spinal canal and compression of the cord. The clinical signs were paraparesis and chronic thoracolumbar pain. In a combined operation the aneurysm was replaced by a Dacron prosthesis. Corpectomy of T5-8 was carried out and a titanium mesh cage filled with autogenous bone tissue was inserted. The vertebral column was stabilized using dorsal and lateral instrumentation.

FINDINGS

Clinical and imaging follow-up after three years showed remission of the patient's severe paraparesis and chronic pain and long-term technical success of the vertebral and aortic reconstruction.

INTERPRETATION

Complete thoraco-abdominal aortic replacement and spinal column repair can be successfully accomplished with good clinical and neurological long-term results.

Phrenic paresis and respiratory insufficiency associated with cervical spondylotic myelopathy

Cervical spondylotic myelopathy is a common disease caused by chronic segmental compression of the spinal cord. Despite the fact that the columns of the nuclei of the phrenic nerve are located between the 3rd and 5th cervical nerve segments, phrenic nerve paresis is not usually clinically significant. We present one case of cervical spondylotic myelopathy with bilateral phrenic paresis in whom magnetic resonance imaging and surgical findings confirmed intrinsic cord disease as being the cause of this syndrome. This case report suggests that one pathophysiology of clinical phrenic nerve paresis may be segmental damage to the anterior horns caused by cervical spondylosis.

Effects of antithrombin III on spinal cord-evoked potentials and functional recovery after spinal cord injury in rats

STUDY DESIGN

From the view of motor function, spinal cord-evoked potentials, and histology, we evaluated the effects of antithrombin III on a spinal cord injury resulting in incomplete paraplegia.

OBJECTIVES

To investigate the effect of antithrombin III on the recovery process after acute incomplete rat spinal cord injury.

SUMMARY OF BACKGROUND DATA

Antithrombin III is used for treating disseminated intravascular coagulation by its anticoagulant effect and is also reported to reduce organ damage by the release of prostaglandin I2 from endothelial cells, induced by antithrombin III. Therefore, antithrombin III has potential as a therapeutic agent for spinal cord damage.

METHODS

The spinal cord injury was induced by placing a 25 g weight on the dorsal surface of the spinal cord at the 10th thoracic spine level for 20 minutes. Antithrombin III (250 U/kg) was administered intravenously 5 minutes before the compression, whereas 2 mL of physiologic saline solution was administered to the control group. We recorded the spinal cord-evoked potentials at the T13 level after stimulation of the brain and C7 level. For 12 weeks after the injury, we observed the recovery course of waveform and motor function. The recovery of motor function was evaluated by using inclined table and modified Tarlov scores. We also examined the histology of the compressed site in the spinal cord.

RESULTS

There were statistically significant differences in the motor recovery process between the two groups. Evoked potentials of the antithrombin III group recovered earlier than those of the control group. Histologically, hemorrhage and tissue defects in the spinal cord were less in the antithrombin III group.

CONCLUSION

Because antithrombin III facilitated the recovery of behavior and evoked potentials, these findings suggest that antithrombin III may have a positive effect on the recovery of incomplete spinal cord injury.

Treatment and prognosis of patients with paraplegia or quadriplegia because of metastatic spinal cord compression in prostate cancer

Metastatic spinal cord compression (MSCC) is a serious complication of metastatic prostate cancer (PCa). This study retrospectively evaluated patients who presented with paraplegia or quadriplegia because of MSCC of PCa. Of 847 patients with PCa who were treated between 1989 and 1998, 26 (3.1%) demonstrated paraplegia or quadriplegia because of MSCC. Characteristics, treatment efficacy, and prognosis of these patients were analyzed. In total, 15 cases became paraplegic despite androgen ablation therapy (Group I). Average time to paraplegia from initial hormonal treatment was 34 months. Out of nine cases who underwent radiation therapy (RT) to spinal lesions with/without chemotherapy, one patient became ambulatory. However, this patient subsequently had recurrent compression. Two cases had remission of paralysis. Two cases underwent laminectomy plus RT and in one case paralysis improved. MSCC was the first indication of PCa in 11 cases (Group II). Two cases underwent laminectomy plus hormone therapy and nine cases underwent hormone therapy alone. Four patients became ambulatory and two cases showed improved motor capacity. Average interval from paraplegia to death was 7.4 months in Group I and 27.1 months in Group II. However, there was no statistical difference in these two groups on disease-specific survival from the start of initial treatment. It is difficult to recover the ability to walk if paraplegia or quadriplegia occurs in PCa patients although decompression surgery plus hormone therapy seemed to impair the prognosis. Stage M1 patients with paraplegia had survival rates as good as stage M1 patients without paralysis. This should encourage an aggressive treatment approach. However, for patients with hormone-independent disease there seems to be no effective treatment and prognosis is poor.

Palliation of metastatic bone pain: single fraction versus multifraction radiotherapy--a systematic review of randomised trials

Recent randomised studies have reported that single fraction radiotherapy is as effective as multifraction radiotherapy in relieving pain caused by bone metastasis. However, there are concerns about the higher re-treatment rates and the efficacy of preventing future complications, such as pathological fracture and spinal cord compression, by single fraction radiotherapy. A systematic review of randomised studies, examining the effectiveness of single fraction radiotherapy versus multiple fraction radiotherapy for metastatic bone pain relief and prevention of bone complications, was conducted to help answer this controversy. Randomised studies comparing single fraction radiotherapy with multifraction radiotherapy on metastatic bone pain were identified. The analyses were performed using intention-to-treat principle. The results were pooled using meta-analysis to estimate the effect of treatment on pain response, re-treatment rate, pathological fracture rate and spinal cord compression rate. Twelve trials involving 3621 sites were included in the meta-analysis. The overall pain-response rates for single fraction radiotherapy and multifraction radiotherapy were 60% (1080/1814) and 59% (1060/1807), respectively, giving an odds ratio (OR) of 1.03 (95% confidence interval [CI] 0.90-1.19), indicating no difference between the two radiotherapy schedules. There was also no difference in complete pain response rates for single fraction radiotherapy (34% [508/1476]) and multifraction radiotherapy (32% [475/1473]), with an OR of 1.10 (950% CI 0.94-1.30). Patients treated by single fraction radiotherapy had a higher re-treatment rate, with 21.5% (267/1240) requiring re-treatment compared with 7.4% (91/1236) of patients in the multifraction radiotherapy arm (OR 3.44 [95% CI 2.67-4.43]). The pathological fracture rate was also higher in single fraction radiotherapy arm patients. Three per cent (37/1240) of patients treated by single fraction radiotherapy developed pathological fracture compared with 1.6% (20/1236) for those treated by multifraction radiotherapy (OR 1.82 [95% CI 1.06-3.11]). The spinal cord compression rates were similar for both arms (OR 1.41 [95% CI 0.72-2.75]). Single fraction radiotherapy was as effective as multifraction radiotherapy in relieving metastatic bone pain. However, the re-treatment rate and pathological fracture rate were higher after single fraction radiotherapy. Studies with quality of life and health economic end points are warranted to find out the optimal treatment option.

[Micturition dysfunction triggered by spinal intramedullary neurocysticercosis]

INTRODUCTION

Neurocysticercosis is the most common parasitic disease of the human nervous system. This case report describes the rare intramedullary form of spinal neurocysticercosis.

CASE REPORT

A 26-year-old male patient demonstrated sinistral brachialgia, arm paralysis and progressive disturbance of micturition with a weak urine stream and persisting residual urine. The cervical MRI revealed a large intramedullary space-occupying lesion in the spinal cord, which was excised. Histologically, parasitic structures were detected and the lesion classified as neurocysticercosis. Retrospectively, more detailed evaluation of the patient's medical history disclosed a number of subtle early neurological symptoms of the disease. The infection was probably acquired during a stay in South America 20 years earlier. The MRI revealed additional multiple small intramedullary lesions and a large lesion in the area of the conus medullaris, which could not be excised. The clinical course was partially dramatic and eventually resulted--apart from small neurological deficits--in complete failure of micturition due to a hyposensible, hypercontractile and instable detrusor muscle. In order for the patient to empty his bladder, sterile single catheterization under anticholinergic medication became necessary.

CONCLUSIONS

Diagnosis of neurocysticercosis on clinical grounds is difficult, especially in regions like Europe, where the disease is very rare. In patients with non-specific neurological symptoms, and radiological indication of an intraspinal tumor, a history of stays in endemic regions even a long time ago, neurocysticercosis should be considered in the differential diagnosis as a possible cause.

Ischemic preconditioning does not improve neurological recovery after spinal cord compression injury in the rat

Ischemic preconditioning (IPC) has been defined as the endogenous cellular protective mechanism evoked by brief ischemic periods. IPC renders the tissue of the central nervous system more resistant to subsequent lethal ischemic insults, and similar protective effect of IPC has been observed after experimental traumatic brain injury. Spinal cord trauma differs from cerebral trauma in that the secondary processes are damaging mostly the white matter. In the present study, we have tested the hypothesis that a transient non-lethal ischemic insult would improve outcomes after subsequent traumatic spinal cord injury (SCI). In the IPC group, 5-min spinal cord ischemia has been induced by aortic occlusion combined with hypotension. Forty-eight hours after IPC, moderate spinal cord injury has been induced by epidural balloon inflation at T8 level. Control group underwent identical surgical procedures without ischemia followed by SCI after 48 h. During the 4-week survival, locomotor performance of all rats was repeatedly tested and evaluated according to BBB scale. After 4 weeks, the animals were perfusion-fixed for histopathology, and morphometric analyses were performed in order to quantify the extent of the spinal cord lesion. All animals were completely paraplegic after SCI, and showed partial neurological recovery during their survival period. No significant differences were detected either in neurological scores or in morphometric measurements after 4 weeks' survival. These results indicate that in contrary to cerebral trauma, IPC does not improve the outcome after SCI.

[The importance of a complete diagnostic workup in patients with nontraumatic (partial) paraplegia]

In two women, aged 86 and 56 years, respectively, who suffered from back pain and loss of strength, and in a 55-year-old man who lost sensation and strength in his left leg, spinal-cord compression in connection with vertebral destruction was seen on radiological examination. When spinal-cord compression is the result of a local malignant tumour, the therapy often entails emergency radiotherapy. In the first two patients, histological examination revealed a solitary plasmocytoma and curative high-dose radiotherapy was applied. The third patient also had a lung tumour and received low-dose palliative radiotherapy to the vertebrae, as a metastasis was suspected. Later, however, histopathologic examination of the vertebral lesion revealed osteomyelitis due to Listeria monocytogenes and the lung tumour was diagnosed as a pT2N0M0 broncho-alveolar carcinoma which was surgically removed. When a patient is referred with a nontraumatic spinal-cord injury, it is important to complete the radiological and histological examinations before starting emergency radiotherapy in order to prevent an inadequate or even incorrect treatment.

[Bladder dysfunction due to spinal cord compression. Treatment modes and results]

Bladder dysfunction is often observed in cases of spinal compression and is commonly caused by spinal tumors, trauma, or degenerative spine disease. Microsurgical decompression is the most important therapy. The earlier microsurgery is performed, the better the chances are for recovery of bladder function.

Significance of bone marrow examination in the diagnostic process of paraspinal mass in children: a case report

Spinal cord compression is a rare but serious complication of non-Hodgkin lymphoma or leukemia. Biopsy of the mass with or without laminectomy would be necessary for diagnosis in patients presenting with isolated paraspinal mass in the absence of other overt clinical symptoms or findings or laboratory abnormalities that would specifically suggest leukemia or lymphoma. The authors describe a 6-year-old girl with symptoms of spinal cord compression due to a paraspinal mass who had undergone surgical intervention; she was later shown to have acute B-cell lymphoblastic leukemia. A bone marrow aspiration should be considered in such patients to avoid unnecessary surgical intervention.

Anterior decompression for cervical spondylotic myelopathy

Cervical spondylotic myelopathy is a clinical entity that manifests itself due to compression and ischemia of the spinal cord. The goal of treatment is to decompress the spinal cord and stabilize the spine in neutral, anatomical position. Since the obstruction and compression of the cord are localized in front of the cord, it is obvious that an anterior surgical approach is the preferred one. The different surgical procedures, complications, and outcome are discussed here.

Autonomic dysreflexia after spinal cord transection or compression in 129Sv, C57BL, and Wallerian degeneration slow mutant mice

To study plasticity of central autonomic circuits that develops after spinal cord injury (SCI), we have characterized a mouse model of autonomic dysreflexia. Autonomic dysreflexia is a condition in which episodic hypertension occurs after injuries above the midthoracic segments of the spinal cord. As synaptic plasticity may be triggered by axonal degeneration, we investigated whether autonomic dysreflexia is reduced in mice when axonal degeneration is delayed after SCI. We subjected three strains of mice, Wld(S), C57BL, and 129Sv, to either spinal cord transection (SCT) or severe clip-compression injury (CCI). The Wld(S) mouse is a well-characterized mutant that exhibits delayed Wallerian degeneration. The CCI model is an injury paradigm in which significant the axonal degeneration is due to secondary events and therefore delayed relative to the time of the initial injury. We herein demonstrate that the incidence of autonomic dysreflexia is reduced in Wld(S) mice after SCT and in all mice after CCI. To determine if differences in afferent arbor sprouting could explain our observations, we assessed changes in the afferent arbor in each mouse strain after both SCT and CCI. We show that independent of the type of injury, 129Sv mice but not C57BL or Wld(S) mice demonstrated an increased small-diameter CGRP-immunoreactive afferent arbor after SCI. Our work thus suggests a role for Wallerian degeneration in the development of autonomic dysreflexia and demonstrates that the choice of mouse strain and injury model has important consequences to the generalizations that may be drawn from studies of SCI in mice.

Thoracolumbar spinal cord compression due to vertebral process degenerative joint disease in a family of Shiloh Shepherd dogs

Five young Shiloh Shepherd Dogs (4 males and 1 female) related by a common sire were studied because of progressive pelvic limb weakness and incoordination. All dogs had a spastic paraparesis and pelvic limb ataxia consistent with an upper motor neuron and general proprioceptive lesion between spinal cord segments T3 and L3. Proliferative lesions involving one or more of the articular processes from the 11th thoracic vertebrae to the 2nd lumbar vertebra were observed on radiographs of the thoracolumbar vertebrae. Dorsal compression of the spinal cord was identified during imaging studies at these sites. Abnormalities of the synovial joints and bony proliferation of the involved articular processes were identified at postmortem examination in 2 dogs. The articular processes and associated vertebral arches protruded into the vertebral canal, indenting the dorsal surface of the spinalcord. Degenerative joint disease (DJD) was identified histologically. A compressive myelopathy was diagnosed in the spinal cord. These dogs were affected by a compressive myelopathy as a consequence of vertebral process DJD that likely has a geneticcomponent. The DJD could have been caused by a primary vertebral malformation or an injury to the processes at a young age causing malarticulation.

Hydatid disease of the spine in South African children

We present three patients with neurologic complications of the spine from hydatid disease. The first was a 6-year-old girl with lower limb paralysis evolving over 2 weeks. Neuroimaging revealed a cystic mass compressing the spinal cord at the level of T8 and extending from the vertebral body. She underwent surgical decompression. Histopathologic examination confirmed hydatid disease. At 6-month follow-up, functional improvement had occurred with full ambulation. She continues on long-term albendazole therapy. Two other patients are described, one with primary spinal disease and the other with cerebral disease and secondary seeding to the spine. Spinal hydatid disease is a rarity, even more so in children. Although secondary disease, primarily affecting bone, carries a poorer long-term outlook, the first patient made a dramatic recovery and has raised therapeutic dilemmas as to the total duration of continuing albendazole therapy. The literature documents some 37 reports, mostly in adults. Considering the frequency of hydatid disease in South Africa, the incidence in our population could be under-recorded. Unless the clinician includes spinal hydatid disease, in endemic areas, as part of the differential list for paralysis and considers performing neuroimaging, this potentially treatable diagnosis will be missed.

Laminectomy and posterior cervical plating for multilevel cervical spondylotic myelopathy and ossification of the posterior longitudinal ligament: effects on cervical alignment, spinal cord compression, and neurological outcome

OBJECTIVE

Multilevel anterior decompressive procedures for cervical spondylotic myelopathy or ossification of the posterior longitudinal ligament may be associated with a high incidence of neurological morbidity, construct failure, and pseudoarthrosis. We theorized that laminectomy and stabilization of the cervical spine with lateral mass plates would obviate the disadvantages of anterior decompression, prevent the development of kyphotic deformity frequently seen after uninstrumented laminectomy, decompress the spinal cord, and produce neurological results equal or superior to those achieved by multilevel anterior procedures.

METHODS

We retrospectively reviewed the records of 38 patients who underwent laminectomy and lateral mass plating for cervical spondylotic myelopathy or ossification of the posterior longitudinal ligament between January 1994 and November 2001. Seventy-six percent of patients had spondylosis, 18% had ossification of the posterior longitudinal ligament, and 5% had both. Clinical presentation included upper extremity sensory complaints (89%), gait difficulty (70%), and hand use deterioration (67%). Spasticity was present in 83%, and weakness of one or more muscle groups was seen in 79%. Spinal cord signal abnormality on sagittal T2-weighted magnetic resonance imaging (MRI) was seen in 68%. Neurological evaluation was performed using a modification of the Japanese Orthopedic Association Scale for functional assessment of myelopathy, the Cooper Scale for separate evaluation of upper and lower extremity motor function, and a five-point scale for evaluation of strength in individual muscle groups. Lateral cervical spine x-rays were analyzed using a curvature index to determine maintenance of alignment. Each surgically decompressed level was graded on a four-point scale using axial MRI to assess the adequacy of decompression. Late follow-up was conducted by telephone interview.

RESULTS

Laminectomy was performed at a mean 4.6 levels. Follow-up was obtained at a mean of 30.2 months after the procedure. The score on the modified Japanese Orthopedic Association scale improved in 97% of patients from a mean of 12.9 preoperatively to 15.58 postoperatively (P < 0.0001). In the upper extremities, function measured by the Cooper Scale improved from 1.8 to 0.7 (P < 0.0001), and in the lower extremities, function improved from 1.0 to 0.4 (P < 0.0002). There was a statistically significant improvement in strength in the triceps (P < 0.0001), iliopsoas (P < 0.0002), and hand intrinsic muscles (P < 0.0001). X-rays obtained at a mean of 5.9 months after surgery revealed no change in spinal alignment as measured by the curvature index. There was a decrease in the mean preoperative compression grade from 2.46 preoperatively to 0.16 postoperatively (P < 0.0001). There was no correlation between neurological outcome and the presence of spinal cord signal change on T2-weighted MRI scans, patient age, duration of symptoms, or preoperative medical comorbidity.

CONCLUSION

Multilevel laminectomy and instrumentation with lateral mass plates is associated with minimal morbidity, provides excellent decompression of the spinal cord (as visualized on MRI), produces immediate stability of the cervical spine, prevents kyphotic deformity, and precludes further development of spondylosis at fused levels. Neurological outcome is equal or superior to multilevel anterior procedures and prevents spinal deformity associated with laminoplasty or noninstrumented laminectomy.

Recurrent central cord syndrome at the level of a solid cervical vertebral fusion

STUDY DESIGN

A case of a solid cervical vertebral fusion that failed to protect against recurrent central cord syndrome at the same spinal level is described.

OBJECTIVES

To alert clinicians to the potential for incomplete spinal cord lesions at the same level as cervical vertebral fusions.

SUMMARY OF BACKGROUND DATA

The clinical symptomatology of central cord syndrome is discussed and the advantages of T2-weighted magnetic resonance imaging in such cases is considered. No prior reports of central cord syndrome occurring directly posterior to a solidly fused disc segment were found in the literature.

METHODS

The clinical and T2-weighted magnetic resonance imaging features associated with central cord syndrome are presented. The traumatized region developed immediately posterior to the site of an anterior cervical diskectomy and uncovertebral osteophytectomy between the fourth and fifth cervical vertebrae with bone grafting that had been performed more than 3 years earlier.

RESULTS

Symptoms of the central cord syndrome resolved over the course of 4 months with no other intervention other than the use of a Philadelphia cervical collar. Five years later, the patient remained symptom free.

CONCLUSION

This case illustrates that clinicians must be aware of the potential occurrence of central cord syndrome in patients with solidly fused cervical segments, and that cervical fusion does not necessarily protect against future incomplete spinal cord injury, such as central cord syndrome, at the level of the fusion.

Pain and debility associated with spinal compression fractures

Approximately twenty percent of women will suffer a compression fracture sometime in their later years. Almost always the result of postmenopausal osteoporosis, they create dramatic and lasting consequences that lead to pain, reduced physiologic function and increased frailty. Recognition and treatment of compression fractures is an important step in maintaining an acceptable level of comfort and an optimal functional ability.

Diffusion-weighted MRI of the cervical spinal cord using a single-shot fast spin-echo technique: findings in normal subjects and in myelomalacia

We have implemented a new diffusion-weighted MRI (DWI) sequence based on the single-shot fast spin-echo technique. We hypothesised that this would add information to conventional MRI for diagnosis of lesions of the cervical spinal cord. DWI was performed using a technique in which echo collection after the application of motion-probing gradients was done in the same manner as in the single-shot fast spin-echo technique. We first imaged six healthy volunteers to demonstrate the cervical spinal cord using the sequence. Then we applied the sequence to 12 patients with cervical myelomalacia due to chronic cord compression. The spinal cord was well seen in all subjects without the distortion associated with echo-planar DWI. In the patients, lesions appeared as areas of low- or isointense signal on DWI. Calculated apparent diffusion coefficients of the lesions (3.30+/-0.38x10(-3) mm(2)/s) were significantly higher than those of normal volunteers (2.26+/-0.08x10(-3) mm(2)/s). Increased diffusion in areas of cervical myelomalacia, suggesting irreversible damage, can be detected using this technique.

Acute phase effects of ATP-MgCl2 on experimental spinal cord injury

The purpose of this study was to study the acute phase effects of adenosine triphosphate (ATP)-MgCl2 on experimental spinal cord clip compression injury. Spinal cord clip compression injury was performed on 36 albino Wistar rats. The rats were divided into five groups. T4-T8 total laminectomy was performed on all rats. Group 1: sham-operated group. Group 2: clip compression group. In group 3, ATP-MgCl2 (100 micro mol/kg) was given 2 min before the "clip compression injury." In group 4, ATP-MgCl2 (100 micro mol/kg) was given 5 min after the clip compression injury. In group 5, ATP MgCl2 (100 micro mol/kg) was administered 8 h after the injury. The spinal cords were excised for a length of 2 cm and deep frozen at -76 degrees C. Tissue malondialdehyde (MDA) levels were used to determine the effects of ATP-MgCl2 on spinal cord lipid peroxidation. In the groups in which ATP MgCl2 was administered after the clip compression injury (groups 4 and 5), the decrease in spinal cord MDA levels was statistically significant when compared with those of the injury group (group 2). Although MDA levels of group 4 were lower than those of group 5, this difference was not statistically significant. Administration of the ATP-MgCl2 before the clip compression injury (in group 3) did not have a statistically significant effect on lipid peroxidation when compared with the injury group (group 2). In this study, we found that ATP-MgCl2 has decreased lipid peroxidation in spinal cord injury and protected the spinal cord from secondary injury after the trauma. We concluded that ATP-MgCl2 may be used in the treatment of spinal cord injuries in conjunction with the other treatment modalities, but further investigations are mandatory.

Sustained spinal cord compression: part II: effect of methylprednisolone on regional blood flow and recovery of somatosensory evoked potentials

BACKGROUND

The efficacy of methylprednisolone in the treatment of traumatic spinal cord injury is controversial. We examined the effect of methylprednisolone on regional spinal cord blood flow and attempted to determine whether recovery of electrophysiological function is dependent on reperfusion, either during sustained spinal cord compression or after decompression.

METHODS

The effects of methylprednisolone therapy on recovery of somatosensory evoked potentials and on spinal cord blood flow were examined in a canine model of dynamic spinal cord compression. Methylprednisolone (30 mg/kg intravenous loading dose followed by 5.4 mg/kg/hr intravenous infusion) or saline solution was administered to thirty-six beagles (eighteen in each group) five minutes after cessation of dynamic spinal cord compression and loss of all somatosensory evoked potentials. After ninety minutes of sustained compression, the spinal cords were decompressed. Somatosensory evoked potentials and spinal cord blood flow were evaluated throughout the period of sustained compression and for three hours after decompression.

RESULTS

Seven dogs treated with methylprednisolone and none treated with saline solution recovered measurable somatosensory evoked potentials during sustained compression. After decompression, three more dogs treated with methylprednisolone and seven dogs treated with saline solution recovered somatosensory evoked potentials. Four dogs treated with methylprednisolone lost their previously measurable somatosensory evoked potentials. In the methylprednisolone group, spinal cord blood flow was significantly higher (p < 0.05) in the dogs that had recovered somatosensory evoked potentials than it was in the dogs that had not. Reperfusion blood flow was significantly higher (p < 0.05) in the saline-solution group than it was in the methylprednisolone group. Spinal cord blood flow in the saline-solution group returned to baseline levels within five minutes after decompression. It did not return to baseline levels in the dogs treated with methylprednisolone.

CONCLUSIONS

The methylprednisolone administered in this study did not provide a large or significant lasting benefit with regard to neurological preservation or restoration. Methylprednisolone may reduce regional spinal cord blood flow through mechanisms affecting normal autoregulatory blood-flow function.

Sustained spinal cord compression: part I: time-dependent effect on long-term pathophysiology

BACKGROUND

The objective of this study is to determine whether there is a relationship between the duration of sustained spinal cord compression and the extent of spinal cord injury and the capacity for functional recovery after decompression.

METHODS

Sixteen dogs underwent sustained spinal cord compression for thirty or 180 minutes. The cords were compressed with use of a loading device with a hydraulic piston. A pressure transducer was attached to the surface of the piston, which transmitted real-time spinal cord interface pressures to a data-acquisition system. Somatosensory evoked potentials were monitored during a sixty-minute recovery period as well as at twenty-eight days after the injury. Functional motor recovery was judged throughout a twenty-six-day period after the injury with use of a battery of motor tasks. The volume of the lesion and damage to the tissue were assessed with both magnetic resonance imaging and histological analysis.

RESULTS

Sustained spinal cord compression was associated with a gradual decline in interface pressure. Despite this, there was continuous decline in the amplitude of the somatosensory evoked potentials, which did not return until the cord was decompressed. Within one hour after the decompression, the dogs in the thirty-minute-compression group had recovery of somatosensory evoked potentials, but no animal had such recovery in the 180-minute group. Recovery of the somatosensory evoked potentials in the thirty-minute group was sustained over the twenty-eight days after the injury. Motor tests demonstrated rapid recovery of hindlimb motor function in the thirty-minute group, but there was considerable impairment in the 180-minute group. Within two weeks after the injury, balance, cadence, stair-climbing, and the ability to walk up an inclined plane were significantly better in the thirty-minute group than in the 180-minute group. The longer duration of compression produced lesions of significantly greater volume, which corresponded to the long-term functional outcome.

CONCLUSIONS

The relatively rapid viscoelastic relaxation of the spinal cord during the early phase of sustained cord compression suggests that there are mechanisms of secondary injury that are linked to tissue displacement. Longer periods of displacement allow propagation of the secondary injury process, resulting in a lack of recovery of somatosensory evoked potentials, limited functional recovery, and more extensive tissue damage.

Successful treatment of Candida albicans osteomyelitis of the spine with fluconazole and surgical debridement: case report

A 65-year old diabetic male presented with progressive bone destruction of thoracic spine (T-11&12) with cord compression. Candida albicans was isolated from aspirated materials pre-and intra-operative. Two weeks of fluconazole was given prior to surgical debridement, and fixation of the lesion. C. albicans isolated pre-and 2-weeks after fluconazole treatment were DNA-typed using AP-PCR. MIC was 2-4 mg/l in all isolates tested. The pre-and post treatment isolates had two DNA patterns, indicating the existence of two different strains. Surgical treatment was necessary for patient recovery.

Analysis of the spastic gait caused by cervical compression myelopathy

We evaluated the spastic gait of patients with cervical myelopathy with a three-dimensional gait analysis system. Fifteen patients with cervical myelopathy (S group) were investigated. The results obtained were compared with those of normal volunteers (N group). The S group exhibited significant reduction of gait velocity and step length (p < 0.01). In the knee flexion-extension curve, two peaks were observed in the N group. In the S1 group (symptomatic period <1 year), the anterior peak was not smooth, whereas in the S2 group (symptomatic period >1 year), no peak was observed. The pelvis tilted to the side of the standing leg in the N group. However, in the S1 group, this tilting was much less pronounced, and in some patients tilting toward the nonsupporting leg was observed. In the S2 group, the pelvis again tilting toward the supporting side was observed.

Neutralizing intraspinal nerve growth factor with a trkA-IgG fusion protein blocks the development of autonomic dysreflexia in a clip-compression model of spinal cord injury

Increased intraspinal nerve growth factor (NGF) after spinal cord injury (SCI) is detrimental to the autonomic nervous system. Autonomic dysreflexia is a debilitating condition characterized by episodic hypertension, intense headache, and sweating. Experimentally, it is associated with aberrant primary afferent sprouting in the dorsal horn that is nerve growth factor (NGF)-dependent. Therapeutic strategies that neutralize NGF may ameliorate initial apoptotic cellular responses to the injury and aberrant afferent plasticity that occurs weeks after the injury. Subsequently, the development of autonomic disorders may be suppressed. We constructed a protein including the extracellular portion of trkA fused to the Fc portion of human IgG and expressed it using a baculovirus system. Binding of our trkA-IgG fusion protein was specific for NGF with a K(d) = 4.26 x 10(-11) M and blocked NGF-dependent neuritogenesis in PC-12 cells. We hypothesized that binding of NGF in the injured cord by our trkA-IgG fusion protein would diminish autonomic dysreflexia. Severe, high thoracic SCI was induced with clip compression and the rats were treated with intrathecal infusions (4 microg/day) of trkA-IgG or control IgG. At 14 days post-SCI, the magnitude of autonomic dysreflexia was assessed. Colon distension increased mean arterial pressure (MAP) in control rats by 46 +/- 2 from 96 +/- 5 mmHg. In contrast, MAP of rats treated with trkA-IgG increased by only 30 +/- 2 mmHg. Likewise, the MAP response to cutaneous stimulation was also reduced in rats treated with trkA-IgG (20 +/- 1 vs. 29 +/- 2). In contrast, trkA-IgG treatment had no effect on heart rate responses during colon distension or cutaneous stimulation. These results indicate that treatment with trkA-IgG to block NGF suppresses the development of autonomic dysreflexia after a clinically relevant spinal cord injury.

Late neurological deterioration 30 years following conservative treatment of a lower cervical spine fracture--a case report

A today 44 years old man suffered from a compression and subluxation fracture of C 4 and C 5 vertebral body during a swimming accident in 1971. The primary therapy was conservative and the patient was rehabilitated. Since 1997 the patient showed a slowly progressive right hemiparesis with signs of cervical myelopathy. The diagnostic procedures revealed a severe deformity of the cervical spine with myelon compression. We performed an operation with replacement of C4 and C5 and dorsal stabilization at the same time. This very impressive case shows the risk of a late and slowly onset of myelopathic deterioration while latent bony instability persist post traumatic. The authors think in agreement with the actual literature that the early operative stabilization of instable fractures of the lower cervical spine is inevitable. According to the grade of neurological and bony damage the operation should not be performed later than 8-12 hours after injury.

Role of radiotherapy in the treatment of motor dysfunction due to metastatic spinal cord compression: comparison of three different fractionation schedules

PURPOSE

The optimum fractionation schedule for radiotherapy (RT) of metastatic spinal cord compression (MSCC) is still debated in the literature. Several reports have compared different fractionation schedules for pain relief. To our knowledge, this retrospective analysis is the first to compare three different schedules for functional outcome.

METHODS AND MATERIALS

For posttreatment functional and ambulatory outcome, three schedules, 30 Gy in 10 fractions (n = 93), 37.5 Gy in 15 fractions (n = 80), and 40 Gy in 20 fractions (n = 74), were compared. Motor function was evaluated by a 6-point scale before and at the end of RT and 3, 6, and 12 months later. A multivariate analysis was performed for functional outcome, including fractionation schedule and the three relevant prognostic factors (primary tumor type, time of developing motor deficits before RT, and ambulatory status).

RESULTS

No significant difference was observed for posttreatment motor function or ambulatory rates among the three schedules. According to the multivariate analysis, the radiation schedule had no significant impact on functional outcome (p = 0.223) in contrast to the three prognostic factors (p <0.001, p <0.001, and p = 0.012).

CONCLUSION

The three fractionation schedules were comparable for functional outcome. The least time-consuming schedule (30 Gy in 10 fractions) should be considered for patients with a markedly reduced life expectancy.

Cervical cord tethering and congenital mirror movements: is it an association rather than a coincidence?

Two unusual cases of cervical cord tethering associated with mirror movements of the hands are presented. A brief discussion of the literature pertaining to mirror movements is included. It is concluded that the association of cervical cord tethering and mirror movements can be more than a coincidence.

A lethal pulmonary embolism during percutaneous vertebroplasty

IMPLICATIONS

This case report describes a fatal cardiac arrest during percutaneous vertebroplasty. This serves to remind us that life threatening intraoperative pulmonary embolism may occur in this minimal invasive procedure. Surgical precautions and invasive cardiovascular monitoring may be required in high-risk patients.

Retropulsion of intervertebral discs associated with traumatic hyperextension of the cervical spine and absence of vertebral fracture: an uncommon mechanism of spinal cord injury

STUDY DESIGN

Case report of a 68-year-old male who sustained cervical trauma following a bodysurfing accident.

OBJECTIVE

To describe the pathology of a relatively uncommon mechanism of injury involving extradural cord compression associated with traumatic disc protrusion and herniation, following a cervical hyperextension injury in which there was no vertebral fracture or residual subluxation.

SETTING

Department of Neuropathology, Royal Perth Hospital, West Australia.

METHOD

Postmortem pathology report.

RESULTS

Evidence of multiple ruptures of anterior longitudinal ligament with posterior intervertebral disc herniation and three discrete foci of central cord hemorrhage.

CONCLUSION

Observations are consistent with cervical extension injury and an injury vector that involves intense axial loading sufficient to cause multiple disc failures, disc herniation and retropulsion leading to extradural disc compression and cord hemorrhage.

Electroporation-mediated pain-killer gene therapy for mononeuropathic rats

The relatively low expression levels achieved from transferred genes have limited the application of nonviral vectors for gene transfer into the spinal cord in vivo. Thus, the aim of this study was to evaluate the efficacy of electroporation-mediated pro-opiomelanocortin (POMC) gene therapy for neuropathic pain using an animal model of chronic constrictive injury (CCI). Firstly, the optimal pulse characteristics (voltage, pulse duration, number of shocks) were investigated for in vivo electroporation-mediated gene transfer into the spinal cord. The electroporation process makes use of plasmid DNA, which expresses the POMC gene. Expression levels were evaluated in this study by Western blot. We conclude that the optimal conditions for electroporation are a pulse voltage of 200 V, 75-ms duration, 925-ms interval, for five iterations. Secondly, electroporation treatment for neuropathic pain was attempted on CCI rats using plasmid DNA that expresses the POMC gene. Intrathecal administrations of the POMC vector elevated spinal beta-endorphin levels, as manifested in a significantly elevated pain threshold for the CCI limbs. This result suggests that gene therapy for neuropathic pain using this novel technique is very efficacious, and thus shows promise for further clinical trials.

[Psychological predictors of rehabilitation efficiency of patients with radiculopathy after neurosurgical correction of compression diskogenic syndrome]

Sixty four osteochondrosis patients after neurosurgical correction of the compression syndrome were examined psychologically before and after the course of rehabilitation. It was established that considerable relief of pain in the course of physiotherapy was seen in patients who, before the treatment, had less severe impairment of the psychological status, no significant symptoms of hypochondria, anxiety, depression. Psychologically unfavourable predictors of low efficiency of physiotherapy were psychic tension, excitability, low stress resistance, pessimism, high anxiety, intrapersonality conflicts.

Cervical myelopathy due to a "tight dural canal in flexion" with a posterior epidural cavity

A 41-year-old man noticed weakness and atrophy in his right hand and forearm resembling the non-progressive juvenile muscular atrophy of unilateral upper extremity (Hirayama's disease). MRI showed an abnormal cavity in the posterior epidural space which appeared on neck flexion communicating with the subarachnoid space in addition to the flattening of the lower cervical spinal cord on neck flexion. When evaluating atypical cases of Hirayama's disease, the pathomechanism demonstrated in the present case should be taken into consideration.

Secondary chronic respiratory acidosis in a dog following the cervical cord compression by an intradural glioma

An intradural tumor in the upper cervical region was found in a dog with quadriparesis and chronic respiratory acidosis. Surgical removal of the tumor in the atlas and intraoperative radiotherapy were attempted. The tumor was histologically diagnosed as a neural glioma. A preoperative acid-base disturbance was dramatically improved after surgery. The clinical changes appeared in this case suggest that compression of the spinal cord at this region may cause paralysis of the respiratory muscles and secondarily result in chronic respiratory acidosis following the respiratory insufficiency.

Cervical amyotrophy caused by hypertrophy of the posterior longitudinal ligament

STUDY DESIGN

A case report.

OBJECTIVES

To report a case of cervical amyotrophy caused by hypertrophy of the posterior longitudinal ligament (HPLL).

SETTING

Department of Neurological Surgery, Aichi Medical University, Aichi, Japan.

METHODS

The patient had severe muscular atrophy in the deltoid and triceps with slight localized hypesthesia in the C5 area and severely unstable gait due to diminished vibration sense in the knees and ankles. Magnetic resonance imaging (MRI) showed expanded cord compression from C4 to C6 with intramedullary high-signal intensity due to HPLL. Transverse image MRI was useful to identify the HPLL.

RESULTS

Resection of HPLL was achieved by an anterior approach. Histological findings of the surgical specimens showed thickening of the ligamentous tissue with proliferation of chondrocytes.

CONCLUSIONS

HPLL should be included as a causative pathology of cervical spondylotic amyotrophy. Careful neurological examination including sensory examination of the lower limbs should be performed to avoid confusion with motor neuron disease.

Thoracic vertebral osteophyte-causing myelopathy: early diagnosis and treatment

STUDY DESIGN

A case report is described.

OBJECTIVE

To highlight an unusual cause of thoracic myelopathy.

METHODS

Clinical evaluation of 63-year-old male revealed myelopathy. Thoracic cord compression from a solitary projection of a facetal joint osteophyte at the T9-T10 level was documented on magnetic resonance imaging scans and computed tomography scans.

RESULTS

The osteophyte was successfully excised.

CONCLUSIONS

Thoracic cord compression can be caused by various space-occupying lesions, and a high index of suspicion will lead to diagnosis before neurologic deficit is clinically expressed. Magnetic resonance imaging scans and computed tomography scans both demonstrate the osteophyte, and expedient surgery avoids the progression of the neurologic deficit.

Cervical kyphosis: predictive factors for progression of kyphosis and myelopathy

STUDY DESIGN

A retrospective study of 13 patients with cervical kyphosis. The authors propose new methods of measuring spinal cord compression and predicting the progression of kyphosis.

OBJECTIVES

To ascertain predictive factors for progression of cervical kyphosis and myelopathy.

SUMMARY OF BACKGROUND DATA

Cervical kyphosis may be congenital, result from decompression surgery, or occur as a posttraumatic deformity. Although there is the potential for progressive deformity and the development of myelopathy in all these situations, there are few previous reports of predictive factors for progression of cervical kyphosis and myelopathy in patients with cervical kyphosis.

METHODS

The authors studied radiographs and magnetic resonance imaging scans of 13 patients with cervical kyphosis, including 9 who had been operated on and had postsurgical secondary kyphosis, and 4 with idiopathic kyphosis without any of the above causes. Compression of the spinal cord at the apex of the cervical kyphosis was evaluated by magnetic resonance imaging of the ratio between the anteroposterior diameter of the medulla-pons junction and the spinal cord at the apex.

RESULTS

The mean ratio between the anteroposterior diameter of the medulla-pons junction and the spinal cord at the apex in five patients in whom myelopathy did not develop was 0.37, and was 0.21 in the patients in whom myelopathy developed. Progression of cervical kyphosis was associated with osteophyte formation at the anterior aspect of the vertebral body.

CONCLUSION

A ratio below 0.3 between the anteroposterior diameter of the medulla-pons junction and the spinal cord at the apex was a risk factor for cervical myelopathy. One of the most predictable risk factors of progression of the cervical kyphosis was osteophyte formation at the anterior aspect of the vertebral body.

Myelopathy caused by ossification of ligamentum flavum

STUDY DESIGN

Retrospective study of seven cases of ossification of ligamentum flavum from two urban hospitals in a Chinese population.

OBJECTIVES

To inspect the epidemiology, clinical presentation, pathology, and treatment outcome in these Chinese patients with ossification of ligamentum flavum.

SUMMARY OF BACKGROUND DATA

Ossification of ligamentum flavum involving the lower thoracic region is relatively common in the Japanese population. It is usually presented with myelopathy of progressive nature.

MATERIALS AND METHODS

Five patients were male and two were female. The mean age was 52 years (range 41-73 years). Diagnosis was made by CT scan, MRI, and subsequent histology. Six patients have been treated by laminectomy and one by laminoplasty. The average follow-up duration is 34 months (range 26-44 months). The outcome is evaluated by Japanese Orthopaedics Association (JOA) score.

RESULTS

The average time of presentation from the onset of symptoms was 9 months (range 3-12 months). Most of the patients presented with lower limb numbness and gait disturbance. One case was presented after a minor trauma. Mean JOA score was 4.8 (range 2-7, of 11). The lower thoracic level was the most frequently involved region. One case was associated with ossification of the posterior longitudinal ligament. Two patients had transient postoperative neurologic deterioration, which improved subsequently. Mean percentage of recovery after surgery in terms of JOA score is 65% (25-100%), with a mean final JOA score of 7.8.

CONCLUSION

Ossification of ligamentum flavum is an uncommon cause of myelopathy in the Chinese population. It can present acutely after minor trauma. Posterior decompression, especially with en bloc dissection of laminae, gives satisfactory results.

Brachytelephalangic chondrodysplasia punctata with marked cervical stenosis and cord compression: report of two cases

Severe cervical spine stenosis with cord compression has not been well documented in brachytelephalangic chondrodysplasia punctata. We report two boys with phenotypic features of brachytelephalangic chondrodysplasia punctata who had severe cervical spine stenosis secondary to dysplastic cervical vertebrae, and discuss the significance of this association and its relation to the phenotypically similar Binder phenotype.