A study of computer-assisted tomography. II. Comparison of metrizamide myelography and computed tomography in the diagnosis of herniated lumbar disc and spinal stenosis

One hundred twenty-two patients with surgically confirmed pathology consisting of either herniated lumbar disc, spinal stenosis, or both were included in this investigation. For each of these patients, preoperative metrizamide myelography and computerized tomography were performed. Each myelogram and CT scan was read blindly so that the neuroradiologist interpreting the study had no knowledge of the patient's surgical pathology, clinical examination, nor any knowledge of the interpretation of the other preoperative test. A painstaking attempt was made to describe precisely both the exact nature of the preoperative myelogram and CT scan interpretations. The correlations between the preoperative interpretation of each test and the observed surgical findings then were analyzed statistically. Based upon this analysis, myelography was found to be more accurate than computed tomography in the diagnosis of herniated lumbar disc (83% vs. 72%). In the diagnosis of spinal stenosis, myelography was slightly more accurate than computed tomography (93% vs. 89%). Based upon the results of this study, the authors conclude that metrizamide myelography is more accurate than computed tomography in the diagnosis of both herniated lumbar disc and spinal stenosis and remains the diagnostic study of choice for these conditions. Furthermore, metrizamide myelography gives the added advantage of visualizing the thoracolumbar junction and, thus, affords the opportunity to diagnose occult spinal tumors.     

Computed tomography scanning after chymopapain injection for herniated nucleus pulposus. A prospective study

Fifty consecutive patients treated with chymopapain injection for a clinical and radiographic diagnosis of herniated nucleus pulposus were evaluated prospectively. All patients had a prechymopapain computed tomography (CT) scan and a three-month postinjection CT scan. In addition, ten patients (20%) had a six-month postinjection CT scan. All scans were interpreted blindly. Only six patients (12%) had obvious changes in the size of the disc when preinjection and three-month postinjection CT scans were compared. By six months, however, seven of ten patients (70%) had obvious changes in their CT scan. Seven patients (14%) were considered chymopapain treatment failures and were later treated with surgical discectomy. Only two of these seven patients (30%) had obvious changes in their three-month CT scan. Chymopapain injection did not alter the size of the herniated portion of the disc during the first three months after chymopapain injection. A decision to operate for presumed chymopapain failure should therefore be based on clinical grounds, rather than on the three-month CT appearance of the herniated disc.     

Computed tomography in the diagnosis of a herniated disk at the L5-S1 level

Six patients with a normal myelogram were found to have evidence of a herniated nucleus pulposus (HNP) at the L5-S1 level on computed tomography (CT) scan. In all six patients, the presence of the herniated disk was confirmed at surgery. Five of the six herniations were lateral. The authors found no patients with an abnormal myelogram and a normal CT at the L5-S1 level in a technically good study. The sensitivity of the CT in diagnosing an HNP at the L5-S1 interspace is greater than with myelography if images in the exact plane of the disk can be obtained.     

Percutaneous laser disc decompression. A new therapeutic modality.

The authors present a new advance in the treatment of herniated disc disease using percutaneous Nd:YAG laser to vaporize a small portion of nucleus pulposus, thereby decompressing the disc. In vitro and in vivo animal data are presented. Three hundred seventy-seven magnetic resonance imaging or computed tomography scan-documented, herniated, nonsequestered lumbar intervertebral discs with corresponding clinical findings in 333 patients were so treated in an outpatient setting. The longest follow-up was 62 months, with a mean of 26 months. According to the Macnab criteria, there was a good to fair response in 261 patients (78.4%), and a poor response in 72 (21.6%); 166 patients experienced relief of pain during the procedure. One-third of repeat magnetic resonance imaging scans at 4-6 months postlaser treatment showed modest to moderate decrease of disc herniation.     

Lumbar disc herniation regression after successful epidural steroid injection

In some lumbar disc herniation patients, noninvasive measures fail, necessitating more aggressive treatment, such as epidural steroid injections or surgery. This study sought to determine whether improvement in patients who receive epidural steroid injections is related to regression of herniated nucleus pulposus or whether such patients' symptoms decrease because of the steroid effect in the presence of continued herniated nucleus pulposus. Two nonoperatively treated patient cohorts were followed who had follow-up MRI. Specifically, 38 other patients who improved without invasive treatment within 6 weeks after the onset of their symptoms were compared with 20 patients who improved with epidural steroid injections. Results found that both groups had similar initial and follow-up herniated nucleus pulposus size and outcomes. The epidural steroid injection group had fewer sequestered or extruded herniations that resorbed, and most were of lower hydration. In conclusion, epidural steroid injections do not alter ultimate herniated nucleus pulposus regression. Patients in whom the disc herniation has less hydration may have prolonged symptoms, but many improve with epidural steroid injections.     

Cost-effectiveness analysis of extended conservative therapy versus surgical intervention in the management of herniated lumbar intervertebral disc.

The management of herniated lumbar intervertebral disc for patients not responding to an initial trial of conservative therapy is generally surgical. Little is known about the effect of continued conservative therapy on patients who have not improved or have deteriorated within the first 3 months. This study assessed which form of treatment, surgical or continued conservative therapy, is more cost-effective once an adequate trial of conservative therapy has failed. The study is a retrospective chart review of 55 white male truck drivers who presented with acutely herniated nucleus pulposus between 1985 and 1989. Twenty-five patients underwent surgery, and 30 underwent continued conservative therapy after initial rehabilitation. No significant difference was found in outcome (80% good or fair in both the surgical and conservative groups) or costs ($55,000 +/- $1,000/case during a 5-year period), hence no difference in the cost-effectiveness between the two treatment modalities (each $63,000 +/- $2,000/adjusted outcome). Conservatively treated patients, however, missed significantly more work. It was concluded that, for a patient not responding to the initial trial of conservative therapy, the option to undergo continued conservative treatment should be made available.     

Nonoperative treatment of herniated lumbar intervertebral disc with radiculopathy. An outcome study

The functional outcome of patients with lumbar herniated nucleus pulposus without significant stenosis was analyzed in a retrospective cohort study. Inclusion criteria were as follows: 1) a chief complaint of leg pain, primarily; 2) a positive straight leg raising (SLR) at less than 60 degrees reproducing the leg pain; 3) a computed tomography (CT) scan demonstrating a herniated nucleus pulposus without significant stenosis by a radiologist's reading, which was also confirmed by the authors; 4) a positive electromyogram (EMG) demonstrating evidence of radiculopathy; and 5) response to a follow-up questionnaire. All patients had undergone an aggressive physical rehabilitation program consisting of back school and stabilization exercise training. Of a total of 347 consecutively identified patients, 64 patients with an average follow-up time of 31.1 months met the inclusion criteria and constituted the study population. They were sent questionnaires that inquired about activity level, pain level, work status, and further medical care. The patients with neurologic loss, extruded discs, and those seeking a second opinion regarding surgery were identified and subgrouped. Results for the total group included 90% good or excellent outcome with a 92% return to work rate. For the subgroups with extruded discs and second opinions, 87% and 83% had good or excellent outcomes, respectively, all (100%) of whom returned to work. Sick leave time for these subgroups was 2.9 months (+/- 1.4 months) and 3.4 months (+/- 1.7 months), respectively. These results compared favorably with previously published surgical studies. Four of six patients who required surgery were found to have stenosis at operation.(ABSTRACT TRUNCATED AT 250 WORDS)     

"Lumbar intervertebral disk-induced sciatica" diagnostic error in extensive extra- and intrapelvic lipoma

PURPOSE: The aim of this study is to demonstrate the importance of the differential diagnosis of sciatica. Radiculopathy in the lower extremity of an adult usually originates from a herniated nucleus pulposus. In this paper an extraspinal cause of sciatica due to a pelvic tumor is reported, which is initially often not recognized. METHODS AND RESULTS: A 67-year old woman suffered from sciatica. After one year of unsuccessful conservative treatment and beginning weakness of hip flexion a computed tomography of the pelvis revealed a giant lipoma with compression of the lumbosacral plexus. CONCLUSIONS: The results of this case illustrate the problem of over-rating CT-findings of the lumbar intervertebral disks in patients with sciatica. Extraspinal tumorous causes of radiculopathy are rare, but should be considered if the therapeutical measures are resistant to treatment. Computed tomography and magnetic resonance imaging are most useful in confirming a retroperitoneal tumor causing lumbosacral radiculopathy.     

Automated percutaneous lumbar nucleotomy

Surgical Principles The disc space is evacuated with the help of a percutaneously inserted Nucleotome® Probe. The herniated nucleus pulposus material is suctioned through an opening in the probe, cut off with a cutting device and aspirated through the probe. The automated percutaneus nucleotomy can be performed in patients with small or medium sized encapsulated herniated lumbar discs, when conservative treatment failed and prior to considering a lumbar discoidectomy.     

Foraminal and extraforaminal lumbar disc herniation: diagnosis and treatment

During a 1-year period from December 1, 1984, through November 30, 1985, a total of 174 patients underwent lumbar discectomy for herniated nucleus pulposus. Eighteen (10.3%) were diagnosed as having foraminal or extraforaminal disc herniations. Sixteen patients are included in this study. All patients were evaluated with computed tomography, metrizamide myelography, discography, and discography-enhanced computed tomography (disco-CT). Accurate diagnosis of foraminal or extraforaminal herniation was made with disco-CT in 15 of 16 cases (93.8%), compared with discography alone (37.5%), computed tomography alone, and/or myelography-enhanced computed tomography (50%) and myelography alone (12.5%). Surgical treatment with bilateral hemilaminectomy, partial medial facetectomy, and partial internal foraminotomy, if needed, followed by discectomy is very effective and the favored surgical management for nerve root decompression in most all cases.     

Improvement of preoperative foot drop after lumbar surgery

Foot drop is a common and debilitating finding in patients with lumbar spinal disorders. Recovery of function after surgical treatment of the underlying disorder is not well documented in the literature. The purpose of this retrospective study was to analyze the prognosis of preoperative foot drop after lumbar surgery in 55 patients with foot drop and herniated nucleus pulposus and/or lumbar spinal stenosis. Preoperative dorsiflexion motor strength improved measurably in 98%, and 71% had full recovery of strength. All patients had associated neurologic findings and 71% experienced complete resolution. No statistically significant relationship was found between the extent of recovery and age, diagnosis (herniated nucleus pulposus lumbar spinal stenosis), duration of symptoms, or severity of preoperative weakness. In our series, the prognosis of preoperative foot drop and associated neurologic deficits treated by lumbar spine surgery was excellent.     

Presence and distribution of antigen-antibody complexes in the herniated nucleus pulposus.

STUDY DESIGN: Herniated tissue was studied by immunohistochemistry in eight patients with lumbar disc herniation. The results were compared with those of control subjects. OBJECTIVE: To assess the presence and distribution of possible antigen-antibody complexes in herniated disc tissue. SUMMARY OF BACKGROUND DATA: It has been suggested that the nucleus pulposus may be recognized as a foreign-body by the immune system and that this will lead to secondary nerve root disturbance. Such immunologic events should be initiated by binding of antibodies to a specific antigen in the disc tissue. However, the presence of antigen-antibody complexes in the herniated disc tissue has not been assessed. METHODS: Amplification of the peroxidase reaction produced in avidin-biotin-peroxidase complex immunostaining by diaminobenzidine was used to visualize antigen-antibody complexes in the herniated tissue. The authors used herniated tissue from eight patients with lumbar disc herniation and nucleus pulposus from five control subjects with nonlumbar disc herniation. Thin paraffin sections, prefixed in 4% paraformaldehyde, were incubated with anti-human IgG antibody to allow visualization of antigen-antibody complexes in the specimens. RESULTS: A brown deposit, indicating antigen-antibody complexes, could be observed in the pericellular capsule in herniated disc tissue but not in control discs or in the residual discs of the herniation patients. CONCLUSION: Antigen-antibody complexes seem to be commonly present in herniated disc tissue, but not in healthy discs. However, the pathophysiologic and clinical significance of this observation has to be elucidated further.     

皮层躯体感觉诱发电位在监测腰神经根损伤中作用的研究

目的：利用大鼠髓核突出动物模型。探索皮层躯体感觉诱发电位（CSEP）的波幅和潜伏期变化是否与神经根性疼痛有关系。方法：取大鼠自体尾部的髓核无压迫下放置在L4和L5神经根上，制成髓核突出动物模型。分别在术后3d,1,2及4周观察大鼠术侧肢体机械刺激敏感性和热刺激敏感性和热刺激敏感性的变化，并引出大鼠后肢CSEP，观察术侧肢体CSEP的变化。结果：在无明显机械压迫的情况下，大鼠腰神经根上植入自体髓核可产生痛觉过敏，CSEP波幅增高。结论：髓核自身是引起腰腿痛的重要原因，CSEP波幅的增高与神经根性疼痛有一定相关性。     

Sequential dynamics of monocyte chemotactic protein-1 expression in herniated nucleus pulposus resorption

We previously demonstrated that the granulation tissues of herniated nucleus pulposus are composed of a marked infiltration of macrophages that strongly express monocyte chemotactic protein-1. Monocyte chemotactic protein-1 is a chemotactic cytokine that contributes to the activation and recruitment of macrophages. Relatively little is known about its role in the resorption process of herniated nucleus pulposus. To clarify the sequential dynamics of expression of monocyte chemotactic protein-1 in the granulation tissues of herniated nucleus pulposus, we introduced a rat autologous transplantation model of nuclear materials onto its lumbar dura mater and performed immunohistological analysis and competitive polymerase chain reaction assay using the grafted samples. Immunohistological analysis demonstrated that the majority of infiltrating mononuclear cells expressed monocyte chemotactic protein-1. Monocyte chemotactic protein-1 mRNA was expressed in the first 3 weeks after the procedure and was significantly and maximally upregulated at 1 week. To determine whether human recombinant monocyte chemotactic protein-1 facilitates the resorption process of herniated nucleus pulposus, we introduced another model of autologous transplantation, wherein the nuclear materials were grafted to the abdominal subcutaneous tissues and recombinant monocyte chemotactic protein-1 was subsequently applied to these materials. When monocyte chemotactic protein-1 was injected into the murine nucleus pulposus tissues, they reduced in size more rapidly than in the control group. These findings suggest that monocyte chemotactic protein-1 plays an important role in the recruitment of macrophages in the early phase of the resorption process of herniated nucleus pulposus and that its application may physiologically facilitate the resorption process of the nucleus pulposus.     

The use of lumbar extension in the evaluation and treatment of patients with acute herniated nucleus pulposus. A preliminary report

Many patients with acute herniated nucleus pulposus can be expected to resolve their conditions with conservative management. To date, however, no reliable sign has been described in the literature that can predict which patient will respond. This report shows that the ability to achieve normal lumbar extension represents such a sign. Of 67 patients who met the criteria for inclusion in the study, 35 patients were treated without operation; 97% were able to achieve normal lumbar extension within three days of admission to the hospital. Thirty-two patients underwent laminotomy and discectomy because they failed to improve with conservative measures. Of these patients, only two (6%) were able to achieve normal lumbar extension preoperatively. Furthermore, some of these patients responded so dramatically to extension therapy that the use of extension exercises as a therapeutic modality is recommended.     

临床症状体征与影像学检查分离的腰椎间盘突出症的发生机制研究进展

临床会出现少数症状体征与影像学检查结果不相符的腰椎间盘突出症患者,而单纯用传统的突出髓核直接机械压迫刺激神经根的理论不能解释这种反常的腰椎间盘突出症。腰椎间盘髓核的突出与患者临床症状体征的出现受多因素、多环节的影响,脊神经根的间接性机械压迫与神经根牵张效应为主要因素,而反常症状体征的产生往往与突出的髓核自身位置的迁移、神经系统对信息的传递以及髓核与硬膜囊或神经根的相互作用密切相关。此外,突出的髓核组织所继发的局部微循环、炎症改变,相应节段的骨质增生退变和腰椎应力姿势改变诱发此类反常腰椎间盘突出症患者出现多样性的症状体征。同时,一些患者还存在神经或椎体的先天性发育异常,并可能出现影像学检查上的误诊或漏诊。突出髓核对硬膜囊以及周围神经根之间的确切相互作用机制及其继发的局部病理生理、生物力学改变,病变责任节段的确定以及如何克服影像学检查的局限性需进一步研究。     

The effect of age on inflammatory responses and nerve root injuries after lumbar disc herniation: an experimental study in a canine model

STUDY DESIGN: An experimental investigation on the effect of age on pathologic events surrounding the herniated disc and at the adjacent nerve root. OBJECTIVES: To investigate the role of age on the inflammatory responses and nerve root damage surrounding a sequestered lumbar disc fragment using a dog model. SUMMARY OF BACKGROUND DATA: Lumbar disc herniation is manifested in patients by variable clinical findings, natural history, and resorption phenomena in which the variability is particularly noted among patients with different ages. There are no previous reports on the effect of age on pathologic events induced by the herniated disc. METHODS: Six beagle dogs, including two animals of each age group of 6, 12, and 24 months (human equivalent ages of 10, 15, and 24 years), were used in this study. The dogs underwent L4-L5, L5-L6, and L6-L7 laminotomy and discectomy under general anesthesia. An autologous intervertebral disc from the tail was divided into anulus fibrosus and nucleus pulposus fragments. The anulus fibrosus and nucleus pulposus fragments were placed in the anterolateral epidural space of L5-L6 and L6-L7, respectively. The L4-L5 discectomy site served as a control. Dogs were killed at 12 weeks after surgery. The lumbar spine was removed en bloc, and histologic sections were prepared consecutively and examined. RESULTS: In the nucleus pulposus group at L6-L7, neovascularity, and intensive infiltration of lymphocytes, macrophages, and fibroblasts were observed surrounding the nucleus pulposus fragment in the 24-month-old group only. Degenerative changes of the nerve root fibers were observed in the 24-month-old group only. In the control and anulus fibrosus groups at L4-L5 and L5-L6, there were no marked inflammatory reactions in all age groups. The nerve root fibers around the anulus fibrosus were normal in all age groups. CONCLUSIONS: There is an effect of age on the inflammatory response and nerve root injury caused by the herniated disc. The apparent neuroprotective mechanism in the young animal, and the apparent inflammatory and resorption changes of the nucleus pulposus fragment in the older animal are quite intriguing.     

一氧化氮在神经根性疼痛中的作用

目的：探索一氧化氮(NO)在髓核突出所致的神经根性疼痛中的作用。方法：取大鼠自体尾椎髓核无压迫下放置在L4和L5神经根表面，分别在术后3d及1、2、3、4周时观察大鼠后足机械刺激和热刺激敏感性的变化，并用免疫组化方法对移植髓核中的一氧化氮合酶(NOS)进行检测．探索NO在疼痛中的作用：结果：在无明显机械压迫情况下，大鼠腰神经根上放置自体髓核可产生痛觉过敏，移植髓核组织中NOS染色阳性一结论：髓核自身是引起腰腿痛的重要原因，NO可能参与疼痛的产生.     

The alpha2 type IX collagen tryptophan polymorphism is associated with the severity of disc degeneration in younger patients with herniated nucleus pulposus of the lumbar spine

Tryptophan alleles in COL9A2 (Trp2) and COL9A3 (Trp3) have been linked to lumbar disc diseases in the Finnish population. Although such diseases consist of various pathogenetically different conditions, detailed analysis of each has not been well documented. The aim of this study was to clarify whether the collagen IX tryptophan alleles influence the symptomatic degeneration of the lumbar disc in Japanese patients with herniated nucleus pulposus. We performed a prospective study of 84 patients who underwent lumbar discectomy. The degree of disc degeneration was evaluated by magnetic resonance images in relation to the collagen IX genotype. Twenty patients (21.4%) had the Trp2 allele and no patients had the Trp3 allele. Patients under 40 years with the Trp2 allele showed more severe disc degeneration at the surgical level than did those without the Trp2 allele (odds ratio 6.00, P=0.043). In contrast, patients aged 40 years or over did not show significant association between disc degeneration and collagen IX genotype. Our results suggest that the Trp2 allele is an age-dependent risk factor for the severity of disc degeneration in younger patients with symptomatic herniated nucleus pulposus of the lumbar spine.