Regional spinal cord blood flow measurements (r.S.C.B.F.) in spinal cord acute compression caused by an epidural balloon

Our study was carried out in 34 rabbits which were divided into three groups (A, B, C). In group A (10 animals), a mid-laminectomy of the first lumbar (L1) vertebra was performed and the circulation in the exposed spinal cord segment was examined using both procedures, the videomicroscopy as well as the r.S.C.B.F. measurement (by intraarterial-5th radicular injection of 2.5 mic133 Xe). In group B (10 rabbits) after the performance of L1 vertebra mid-laminectomy, a teflon catheter was introduced through T11-T12 (thoracic) intervertebral foramina and 0.5 ml of metrizamide sodium was injected through the balloon producing, thus, a 36 +/- 1% stenosis in the diameter of the corresponding spinal canal level. Using the procedures described above as well as light microscopy it was shown that, during the period of the 4 hours the experiment lasted, the circulatory disturbances of spinal cord were still reversible. On the contrary, in group C (14 rabbits) where 0.8 ml of metriz amide sodium was injected through the balloon catheter producing, thus, a 52 +/- 1% stenosis in the corresponding spinal canal level, the spinal cord disturbances proved irreversible after the 4-hour period of the experiment's duration.     

Autonomic hyperreflexia. A serious complication of radiological procedures in patients with cervical or upper thoracic spinal cord lesions

Autonomic hyperreflexia is a reflex response to visceral distension which occurs only in patients with spinal cord lesions above T6. The marked hypertension, which is an integral part of this reflex, may lead to severe morbidity, or even death. The mechanism whereby interruption of the sympathetic outflow from the spinal cord results in autonomic hyperreflexia is described, as well as the clinical signs and symptoms associated with this condition. The value of autonomic hyperreflexia as a clinical indicator of complications in patients with spinal cord lesions is stressed. The diagnosis and treatment of autonomic hyperreflexia which has occurred as a complication of radiological procedures are discussed.     

Guanethidine sulfate in the prevention of autonomic hyperreflexia.

Autonomic hyperreflexia constitutes the only medical emergency seen in spinal cord injury patients. Uncontrolled hypertension and bradycardia can result in seizures and death. The acute treatment of the syndrome has ranged from medical ganglionic blockers to topical anesthetic agents to surgical procedures. The oral use of 10 mg. guanethidine sulfate 3 times daily successfully prevented the major symptoms of the syndrome in 200 spinal cord injury patients with lesions above T5. Toxicity has been mild and the drug is recommended until the patients are voiding and are capable of self-care.     

Enterogenous cyst of the spinal cord terminal cone. Clinical and radiological aspects (CT and MRI)

Enterogeneous cyst of the spinal cord are rare. They are the result of a dysembriogenetic error occurred in the third week of the embryo life. The cervical tract, followed by the caudal tract of the spinal cord, are their favourite sites. This work describes a case of neuroenteric cyst localized in the terminal cone of the spinal cord; CT and myelographic findings point to a generic cystic lesion; MR shows a sharp edge lesion, hypointense at T1 and hyperintense at T2, with signal uniformity similar to C.S.F. MR also allows the evaluation of any CSF pulsation in the cystic lesion and, in the presence of a cystic neoplasm, any signal changes in the adjacent parenchyma.     

Ultra-early MRI showing no abnormality in a fall victim presenting with tetraparesis

STUDY DESIGN: Case report. SETTING: Department of Neurosurgery, Sapporo Azabu Neurosurgical Hospital and Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan. CASE REPORT: A patient presented to us with complete C4 tetraplegia after a 3-m fall. MRI performed 120 min after his fall showed spinal canal stenosis due to disk protrusion at the C3/4 level without spinal cord signal changes on T1- and T2-weighted images. He underwent laminoplasty between C2 and C6. Intraoperative ultrasound, performed 6 h after his fall, disclosed a hyperechoic lesion at the C3/4 level of the cervical cord; postoperative T2-weighted MRI, obtained at 8 h after his fall, showed high intensity at the same level. CONCLUSION: In patients with cerebral infarction, approximately 6 h between the insult and the acquisition of T2-weighted MRI are required to detect signal changes. We postulate that the time course on MRI scans obtained immediately after spinal cord injury is similar in patients with spinal cord injury and cerebral infarction and suggest that the absence of spinal cord abnormalities in the ultra-early post-injury stage is not always predictive of a good prognosis.     

臂丛神经根性撕脱伤前根椎管内植入手术入路探讨

目的通过对臂丛神经根部及椎管内结构的显微外科解剖学研究,寻找臂丛神经前根再植入脊髓的最佳手术入路。方法在成人19例38侧颈胸段尸体标本上,显露臂丛神经并追踪至椎间孔,切除椎弓,切开硬脊膜,暴露脊髓及臂丛神经根,对臂丛神经根走行、长度及周围相关骨性结构,各脊髓节段与对应椎间盘相对位置和椎动脉与臂丛神经的关系进行观测。结果脊髓节段与椎间盘的对应关系为：C_(5-7)脊髓节段对应C_(3-4)、C_(4-5)、C_(5-6)椎间盘,C_8、T_1脊髓节段对应C_6、C_7椎体,根据解剖学结果寻找出侧前方、椎间孔扩大侧方、侧后方、侧-后方联合四条可行的手术入路。结论侧前方及侧方入路是臂从神经前根再植入脊髓的最佳入路,侧后方及侧-后方联合入路再植入脊髓的位点差,但其难度和危险小。     

Advanced Chiari malformation type I with marked spinal cord atrophy. Case report

The authors discuss the results obtained in patients who underwent foramen magnum decompression for longstanding advanced Chiari I malformation in which marked spinal cord atrophy was present. This 50-year-old woman presented with progressive quadriparesis and sensory disorders. Magnetic resonance imaging revealed the descent of cerebellar tonsils and medulla associated with remarkable C1-L2 spinal cord atrophy. After a C-1 laminectomy-based foramen magnum decompression, arachnoid dissection and duraplasty were undertaken. These procedures resulted in remarkable neurological improvement, even after 40 years of clinical progression. Spinal cord atrophy may be caused by chronic pressure of entrapped cerebrospinal fluid in the spinal canal.     

Posttraumatic syringomyelia developing soon after spinal cord injury. A case report

We report a case of posttraumatic syringomyelia (PTS) that developed 10 months after spinal cord injury (SCI), A 46-year-old man was involved in a motorcycle accident, in which he received a severe spinal cord injury due to a burst fracture at the T6 level. The patient underwent posterior fixation without decompression at another hospital, and was transferred to our hospital for rehabilitation. Ten months after the SCI, he complained of back and neck pain caused by bending his head backward. MRI showed syringomyelia shaped like a cone extending from the T6 to the C6 level, enlarged by cerebrospinal fluid (CSF) flow toward the syringomyelia at the T6 level. Pain was relieved by syringosubarachnoid shunt implantation and the syrinx disappeared after the operation. PTS emerging 10 months after spinal cord injury is relatively rare. From the radiological and operative findings, PTS was enlarged by the CSF flow, which was hindered at the T6 level by compression of the vertebral body to the spinal cord. In cases of SCI in patients who undergo posterior fixation with insufficient decompression, close attention to PTS is required in the postoperative follow-up.     

Stab wounds of the spinal cord by a kitchen knife: report of a case

A case of spinal cord injury due to stab wounds by a kitchen knife is presented. A 41-year-old male was hospitalized because of spinal cord injury resulting from stab wounds inflicted with a kitchen knife in the posterior cervical area. Neurological examination on admission showed paraplegia, disappearance of deep tendon reflex in both lower extremities, sensory disturbance below T1 level, left Horner's syndrome and urinary disturbance. In addition to these symptoms cerebrospinal fluid was leaking from the wounds. An emergency operation was performed. After laminectomy of C7 and T1, we found that the spinal cord was almost completely split at C7/T1 level. Dural plasty was performed. Neurologically, sensory disturbance was slightly improved at 4 months after the injury. Initial MRI (TR: 200 msec, TE: 20 msec) revealed high intensity at C7/T1 level which was damaged by the kitchen knife. MRI 5 months after the injury revealed low intensity on T1 weighted imaged, high intensity on T2 and proton weighted image. The occurrence of the spinal cord injury due to stab wounds by a kitchen knife is very rare in Japan. MRI is useful in the diagnosis of stab wounds of the spinal cord.     

Non-dysraphic intramedullary spinal cord lipoma. A case report

Non-dysraphic spinal cord lipomas are rare benign lesions, accounting for approximately 1% of all spinal cord tumors. Patients usually present with long histories of disability followed by rapid progression of their symptoms. Presenting symptoms include spinal pain, dysesthesic sensory changes, gait difficulties, weakness, and incontinence. Magnetic resonance imaging is the examination of choice. The T1- and T2-weighted images show increased and decreased signal intensity, respectively. The goal of intervention is decompression and generous debulking following by duraplasty. Early diagnosis of spinal cord lipomas and early surgery is advanced prior to irreversible disease progression. One new case of true non-dysraphic cervicodorsal spinal cord lipoma is reported.     

Left atrial-inferior vena cava bypass achieves retroperfusion of the porcine spinal cord: morphologic and preliminary physiologic studies

BACKGROUND: Spinal cord injury remains a devastating complication after procedures on the descending thoracic aorta. A new model for retrograde perfusion of the spinal cord during aortic cross-clamping was evaluated for its potential role in preventing spinal cord injury after thoraco-abdominal aortic surgery. METHODS: Retrograde perfusion of the spinal cord was established in juvenile pigs using partial bypass from the left atrium to the isolated inferior vena cava. Flow was maintained for a 60-min period of aortic occlusion. Morphologic studies of spinal cord blood flow were obtained using injection of a dilute barium-gelatin-chromatin dye solution. Physiologic cooling of the spinal cord was achieved using varying degrees of hypothermic retroperfusion. RESULTS: Five animals underwent a 30-min period of retroperfusion followed by dye injection. Dye was identified in spinal cord venules and capillaries, most heavily concentrated in the lumbar and lower thoracic cord. Thirteen animals underwent a 60-min period of normothermic (37 degrees C), mild hypothermic (27 degrees C), moderate hypothermic (17 degrees C), or deep hypothermic (7 degrees C) retroperfusion; mean spinal cord temperatures were 35.2, 32.2, 28.0, and 24.4 degrees C, respectively. CONCLUSIONS: Retrograde perfusion of the porcine spinal cord using a left atrial to inferior vena cava partial bypass circuit can be accomplished and can be used with hypothermic perfusate to produce cooling of the spinal cord. This new technique warrants further investigation into spinal cord protection and potential application for operations on the descending thoracic aorta.     

Morphometric effects of acute shortening of the spine: the kinking and the sliding of the cord,response of the spinal nerves

Spinal shortening is performed for a wide spectrum of diseases. This study was designed to investigate the morphologic effects of shortening on the spinal cord, to enlighten the amount and direction of the sliding of the cord, the alteration of the angles of the roots, and to identify the appropriate laminectomy length. Total vertebrectomy of T12 was applied to ten sheep models after spinal instrumentation. Gradual shortening was applied to five sheep; then, the degree and direction of the sliding of the spinal cord and the angles of the adjacent roots were measured. On five other sheep, additional sagittal sectioning was performed via excision of the pedicles. Measurements were taken at different laminectomy lengths to record kinking of the spinal cord with gradual shortening. The mean sliding of the spinal cord was 9 mm cranially and 7.8 mm caudally. T11 spinal nerves became more vertical caudally, and T12 spinal nerves achieved an ascending position with gradual shortening. Both T11 and T12 spinal nerves were sharply bent in the foramen and on the pedicle of T13, respectively. In full-length shortening, the mean kink of the spine in the sagittal plane was 92.4° for two levels of hemi-laminectomies, 24.6° for complete laminectomy of T11 with hemilaminectomy of T13, and 20.2° for two levels of complete laminectomies. The slippage of the cord is dominant in the earlier stages and kinking is dominant in later stages of shortening. Increasing the laminectomy length by only a half or one level prevents excessive kinking and compressions at the upper and lower margins of the laminectomy. In the later stages of shortening, the spinal nerves near the vertebrectomy site are at risk because of the sharp bending of the nerves. This study describes the mechanism of the sliding and kinking of the cord due to gradual shortening of the spine, which might be useful in spinal surgery procedures. It also states that it is possible to avoid excessive kinking by planning the appropriate technique of laminectomy style in full-length shortening. This study has been approved by Institutional Review Board by sentence number 1150 on 26 April 2006.     

Spinal sensory and motor tract activation after epidural electrical stimulation in the cat

Somatosensory evoked potentials (SEPs) after peripheral nerve stimulation and motor evoked potentials (MEPs) after transcranial stimulation have been routinely used as monitors of the viability of pathways in the posterior and anterior spinal cord, respectively, in patients undergoing spinal cord surgery. To assess total spinal cord function, both of these procedures must be performed simultaneously, which is both cumbersome and technically difficult. The objectives of this study were to demonstrate both sensory and motor spinal tract activation after epidural electrical stimulation of the cat spinal cord. Thirty-seven adult mongrel cats were anesthetized with ketamine, intubated, and maintained with Ethrane and nitrous oxide. Stimulating electrodes were placed over the right dorsolateral spinal cord epidurally at T7 after a laminectomy. Recording electrodes were placed over the right L3 spinal cord epidurally, on the right L7 dorsal and ventral nerve roots, on the right and left sciatic nerves in the popliteal fossa, and in the right gastrocnemius muscle. After epidural stimulation of the spinal cord at T11, distinct reproducible potentials were recorded at each site. Activity in the L7 dorsal root implicated activation of spinal sensory tracts. Activity in the L7 ventral root and in the gastrocnemius implicated activation of spinal motoneurons.(ABSTRACT TRUNCATED AT 250 WORDS)     

The optimal radiologic method for assessing spinal canal compromise and cord compression in patients with cervical spinal cord injury. Part II: Results of a multicenter study

STUDY DESIGN: A multicenter, retrospective study using computed tomographic and magnetic resonance imaging data to establish quantitative, reliable criteria of canal compromise and cord compression in patients with cervical spinal cord injury. OBJECTIVES: To develop and validate a radiologic assessment tool of spinal canal compromise and cord compression in cervical spinal cord injury for use in clinical trials. SUMMARY OF BACKGROUND DATA: There are few quantitative, reliable criteria for radiologic measurement of cervical spinal canal compromise or cord compression after acute spinal cord injury. METHODS: The study included 71 patients (55 men, 16 women; mean age, 39.7 +/- 18.7 years) with acute cervical spinal cord injury. Causes of spinal cord injury included motor vehicle accidents (n = 36), falls (n = 20), water-related injuries (n = 8), sports (n = 5), assault (n = 1), and farm accidents (n = 1). Canal compromise was measured on computed tomographic scan and T1- and T2-weighted magnetic resonance imaging, and cord compression at the level of maximum injury was measured on T1- and T2-weighted magnetic resonance imaging. All films were assessed by two independent observers. RESULTS: There was a strong correlation of canal compromise and/or cord compression measurements between axial and midsagittal computed tomography, and between axial and midsagittal T2-weighted magnetic resonance imaging. Spinal canal compromise assessed by computed tomography showed a significant although moderate correlation with spinal cord compression assessed by T1- and T2-weighted magnetic resonance imaging. Virtually all patients with canal compromise of 25% or more on computed tomographic scan had evidence of some degree of cord compression on magnetic resonance imaging, but a large number of patients with less than 25% canal compromise on computed tomographic scan also had evidence on magnetic resonance imaging of cord compression. CONCLUSIONS: In patients with cervical spinal cord injury, the midsagittal T1- and T2-weighted magnetic resonance imaging provides an objective, quantifiable, and reliable assessment of spinal cord compression that cannot be adequately assessed by computed tomography alone.     

Treatment of severe double spinal cord injuries

This is a case report describing an injury--sustained by a 25-year-old man during a car accident, and characterized by fracture dislocation of the spine at the level of C7 and T4 accompanied by pulmonary contusion. He had an incomplete spinal cord lesion at the level of C7 and a complete lesion at the level of T4 (T4 ASIA A). Imaging of the spine showed three column fractures with ventral spinal cord compression at both levels. Discussants of this case comment on the concept of acute treatment of severe double spinal cord injuries, and present their chosen way of management in this particular case.     

Capillary hemangioma of the spinal cord. A new case

A 49-year-old man presented with a 8-month history of gait and sphincter disturbances. Examination revealed a spastic paraplegia predominant on the left limb, associated with decreased tactile sensitivity below T10. MRI showed a right posterolateral intramedullary lesion with an isosignal on T1-weighted images and a mild hypersignal on T2-weighted images, with an intense contrast enhancement; the spinal cord presented with an hypersignal on T2-weighted images. At operation, a vascular tumor presented at the spinal cord surface, was well demarcated from the parenchyma and was easily removed. Microscopic examination showed a capillary hemangioma. Three months later the patient exhibited a motor improvement with a right spasticity, deficits in proprioception, without sphincter abnormalities. A new MRI showed the disappearance of the hemangioma and of the preoperative spinal cord hypersignal. Capillary hemangiomas are unusual on nerves or roots. Cases found in the spinal cord are extremely rare: to our knowledge, 5 cases have been reported. On MRI, they are easily distinguished from cavernous hemangiomas, but microscopic examination is necessary to distinguish them from hemangioreticulomas. The postoperative prognosis is generally good. However, a report of a multiple location case, on roots and spinal cord, suggests the need for long follow-up.     

Spinal cord and brain stem anomalies in scoliosis. MR screening of 26 cases

The spinal cord and brain were examined with magnetic resonance (MR) in 26 patients with idiopathic scoliosis to study the prevalence of spinal cord and brainstem anomalies. Two patients had small centrally located spinal cord syrinxes, one at C6-C8 and the other at T6-T8, without association with any brainstem or cerebellar deformity. The lowest position of the cerebellar tonsils was 0.5 cm below the foramen magnum, which was also seen in 2 other patients. Scoliosis associated with syringomyelia may be more common than previously thought, and may be wrongly classified as idiopathic. A neurogenic cause of scoliosis should always be considered, and at least in atypical cases be excluded by MR imaging of the spinal cord. MR should be mandatory before bracing or operative correction of scoliosis.     

Thoracic spinal cord compression by a gouty tophus. Case report. Review of the literature

An unusual case of thoracic spinal cord compression caused by extradural tophaceous deposits is reported in a 59-year-old female with a long-standing history of gout involving the metatarsophalangeal joints. T1 and T2 magnetic resonance images of the spine illustrated an extradural hyperintense signal extending from T2 to T9. A decompressive laminectomy disclosed a white caseum-like material in the extradural space, together with a small organized hematoma. Histologic examination showed areas of amorphous substance containing urate crystals surrounded by inflammatory cells, which was diagnosed as a gouty tophus. The patient made an uneventful recovery after surgery. Fifteen similar cases of the literature are reviewed. Although spinal involvement by gout seems relatively common, a compression of the spinal cord or of the cauda equina in gout patients seems exceptional. The diagnosis should be considered in patients showing a relevant history of gout, but spinal cord compromise may also represent the initial manifestation of the disease.     

Influence of hypotension and nerve root section on the ability to mobilize the spinal cord during spine surgery. An experimental study in a pig model

Background contextThe correction of severe spinal deformities by an isolated posterior approach often involves cord manipulation together with hypotensive anesthesia. To date, the efficiency of methods to increase the tolerance of the cord to displacement and the influence of hypotension on this tolerance is yet to be assessed.PurposeThe objective of this study was to determine the limits of cord displacement before the disappearance of neurophysiologic signals. The influence of the type of force applied, the section of the roots, and the induced hypotension on the cord's tolerance to displacement was also assessed.Study designExperimental study using a domestic pig model.Outcome measuresSuccessive records of cord-to-cord motor evoked potentials were obtained during displacement maneuvers. Displacing forces were released immediately after the absence of neurophysiologic signals.MethodsSurgical procedures were performed under conventional general anesthesia. The spinal cord and nerve roots from T6 to T10 levels were exposed by excision of the posterior elements, allowing for free cord movement. Three groups were established according to the method of spinal cord displacement: the separation (Group 1, n=5), the root stump pull (Group 2, n=5), and the torsion groups (Group 3, n=5). An electromechanical external device was used to apply the displacing forces. The three displacement tests were repeated after sectioning the adjacent nerve roots. The experiments were first carried out under normotension and afterward under induced hypotension.ResultsIn Group 1, evoked potential disappeared with a displacement of 10.1±1.6 mm with unharmed roots and 15.3±4.7 mm after the sectioning of four adjacent roots (p<.01). After induced hypotension, potentials were lost at 4.0±1.2 mm (p<.01). In Group 2, the absence of potentials occurred at 20.0±4.3 mm and increased to 23.5±2.1 mm (p<.05) after cutting the two contralateral roots. Under hypotensive conditions, the loss of neurophysiologic signals was detected at 5.3±1.2 mm (p<.01). In Group 3, the cord allowed torsion of 95.3±.2° that increased to 112.4±7.1° if the contralateral roots were cut. Under hypotension, the loss of potentials was found at 20±6.2° (p<.01).ConclusionsIn this experimental model, it was possible to displace the thoracic spinal cord by a distance superior to the spinal cord width without suffering neurophysiologic changes. The limits of cord displacement increase when the adjacent nerve roots are sacrificed. Induced hypotension had a dramatic effect on the tolerance of the spinal cord for displacement. This work has an important clinical significance because induced hypotension during specific spine surgery procedures requiring spinal cord manipulation in humans may increase the risk of neurologic spinal cord injury.     

C9、CD59在大鼠急性脊髓损伤组织中的表达

目的探讨补体系统固有成分C9及补体调节因子CD59在大鼠急性脊髓损伤组织中的表达。方法采用改良Allen重物打击法制成SD大鼠脊髓急性损伤模型,观察各组伤后12h、1、3、5、7d各时间点脊髓损伤组织的变性坏死、中性粒细胞浸润情况及C9、CD59阳性反应物的表达部位及时程。结果伤后12h损伤组织中开始有C9、CD59阳性表达,在伤后3d达到高峰,之后表达逐渐减少,伤后1周趋于稳定,随时间延长存在动态变化过程,且与脊髓损伤组织的变性坏死、中性粒细胞浸润程度相一致。结论在急性脊髓损伤组织中有补体固有成分C9及补体调节因子CD59的表达,补体系统参与了继发性脊髓损伤。