Article

The Prolapsed Intervertebral Disc

Authors:
  • Hale O'mana'o Biomedical Research
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Abstract

Study Design: The study compared the presence of the high‐intensity zone on magnetic resonance imaging with the results of awake discography. Objectives: To see if there was a correlation between the results of awake discography and the presence of a high‐intensity zone on magnetic resonance imaging. Summary of Background Data: The evaluation of discogenic pain has proved to be somewhat elusive. Recent studies have indicated the high‐intensity zone as being highly sensitive in the diagnosis of the painful discogenic segment. The present study was designed to investigate whether the presence of a high‐intensity zone is associated with a concordant pain response on awake discography. Methods: Magnetic resonance images were obtained in 29 patients with low back pain with and without radiculopathy. Consecutive patients were considered for surgical intervention after failing to respond to conservative treatment. The presence of a high‐intensity zone was specifically looked for within the posterior anulus. Each patient subsequently underwent awake discography with computed tomography. Computed tomography was classified according to the Dallas Discogram Scale and the presence of a concordant pain response. Chi‐square analysis was used to calculate the presence of a high‐intensity zone versus disc disruption and the correlation of high‐intensity zone and concordant pain response. Results: There was no statistically significant correlation between the presence of a high‐intensity zone and a concordant pain response at any level. The high‐intensity zone was, however, never seen in a morphologically normal disc. Conclusions: Although the high‐intensity zone is present within the posterior anulus of some abnormal discs, it is not necessarily associated with a concordant pain response.

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... The previous studies have proven that the histology-detected AF tear and MRI could be treated as a reliable marker for a sore disk in patients with LBP [12]. There are, however, also controversial results [15], indicating that AF tear by itself may not be enough to cause LBP from degenerative discs. One entirely accepted interpretation of the LBP, causing AF tears, maybe that macromolecules could transport from NP to AF, and nerve fiber can be increased in internal AF or NP [15]. ...
... There are, however, also controversial results [15], indicating that AF tear by itself may not be enough to cause LBP from degenerative discs. One entirely accepted interpretation of the LBP, causing AF tears, maybe that macromolecules could transport from NP to AF, and nerve fiber can be increased in internal AF or NP [15]. ...
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Low back pain (LBP) is a common affliction with numerous causes. Some individuals experience LBP attributed to disc pathology. Disc pathology has been implicated in a plurality of cases of LBP, and some cases are associated with annular fissures (AFs). AFs are weaknesses in the structure that contains the nucleus pulposus and is the site of possible disc herniations. On magnetic resonance imaging (MRI), some AFs manifest as the high-intensity zone (HIZ), otherwise known as an annular enhancement region. In this report, we present three patients with LBP, mild radiculitis, and HIZ who later developed herniated nucleus pulposus (HNP) with extrusion through the HIZ. These cases suggest that HIZ indicates a propensity for the future development of disc extrusion through the weakened tissue at the AF visualized as HIZ on MRI. With a better understanding of the association between AFs and disc herniations with HIZ, clinicians may be able to predict and prevent the pain and disability associated with disc extrusion.
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The high intensity zone (HIZ) was first described by Aprill and Bogduk on lumbar spine magnetic resonance imaging (MRI) studies in 1992. Correlation with lumbar computed tomography (CT) discography showed that the HIZ represents a deep radial tear of the annulus fibrosus, which may be a cause of chronic low back pain. Initial studies comparing the finding of a HIZ on MRI with discography suggested that it may be a highly specific marker of a painful lumbar disc, but later investigators demonstrated that it is also present in asymptomatic individuals. The purpose of this article is to review the literature regarding the lumbar HIZ 20 years after its initial description.
Article
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Article
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Chapter
High-intensity zone (HIZ) is located in the posterior annulus fibrosus of the intervertebral disc on the T2-weighted lumbar magnetic resonance (MR) images. HIZ is described as an indicator of internal disc disruption or tear of annulus fibrosus. Discogenic low back pain (DLBP) with HIZ can be diagnosed with the MR image findings of HIZ in the target disc, provocative discography, and leakage of contrast medium into the fissure of annular tear. DLBP with HIZ can be treated by full-endo thermal annuloplasty (TA) under local anesthesia. The indication of full-endo TA for DLBP is the cases unresponsive to conservative treatment and concordant LBP during discography to the target disc.
Chapter
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Article
Purpose The purpose of this study was to review the current understanding of high-intensity zones (HIZ) in the lumbar spine with particular attention to its imaging phenotype and clinical relevance. Methods A review was conducted of studies related to HIZ. Particular attention was made to imaging phenotypes and classification, and its relationship with discogenic low back pain (LBP). Results The most current classification system of HIZ is based on location (anterior and posterior), morphology (round, fissure, vertical, rim, or giant types), and its appearance on both T1- and T2-weighted magnetic resonance imaging (MRI). HIZ are commonly manifested with disc degeneration. Hence, both conditions share similar risk factors such as the effect of frequent and prolonged disc loading. The clinical significance of HIZ however is not conclusive. Provocative discography is not sensitive (~ 70%) for eliciting a concordant pain response. Population-based studies have conflicting results regarding the prevalence (14–63%) of HIZ and its correlation with LBP. Conclusions HIZ are likely a risk factor for discogenic LBP. However, its etiology and pathophysiology are not well understood. Some clinical studies suggest a link between its occurrence and LBP. However, the results are not consistent as a result of studies which are underpowered and based on heterogeneous study populations, lacking control groups, and without standardized imaging phenotypes. HIZ may be an important pain biomarker that should be further studied. With more modern MRI technology and a detailed classification system, future large-scale population studies will improve our knowledge on its role in the disc degeneration cascade and development of LBP.
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Article
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Background This meta-analysis aimed to assess the correlation between the high-intensity zone (HIZ) of a lumbar MRI and discography. Methods We conducted an electronic search of the PubMed, MEDLINE, Embase, and ScienceDirect databases from their respective inceptions to October 2016 using the following search terms: “low back pain,” “discogenic low back pain,” “HIZ or high-intensity zone,” and “discography”. Relevant journals and conference proceedings were manually searched. Two reviewers independently assessed the quality of the studies, extracted data from the included studies, and analyzed the data. ResultsEleven studies were included. The results of the meta-analysis indicated that outstanding relativity and statistically significant correlations were observed between the HIZ and abnormal disc morphology (OR = 47.79; 95% CI: 17.07 to 133.77; P < 0.00001), HIZ and pain reproduction (OR = 8.65, 95% CI: 6.01 to 15.23, P < 0.00001), and HIZ and abnormal morphology pain reproduction (OR = 11.74, 95% CI: 1.99 to 69.36, P = 0.007). Conclusions The presence of an HIZ on a lumbar MRI T2-weighted image indicates abnormal disc morphology. There is a strong relationship between the HIZ and pain reproduction. The HIZ can be an effective index for prediction of discogenic low back pain.
Chapter
The term discogenic pain refers to pain arising from the disc itself. Discogenic pain is cited as the most common cause of chronic low back pain, accounting for approximately 26–39 % of patients with such pain etiology. Internal disc disruption (IDD) is the most common diagnosis leading to chronic low back pain and one of the major causes of chronic neck pain. Discogenic pain is a significant medical challenge, in terms of its clinical, social, economic, and public health implications. An extensive body of literature suggests that discogenic pain is likely to be multifactorial. The most significant risk factors are genetic inheritance, environmental influences, and lifestyle choices. Although available literature supports hypothesis that the intervertebral disc is an independent chronic pain generator, research related to the epidemiology of discogenic pain is still in its formative stage.
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High intensity zones (HIZ) of the lumbar spine are a phenotype of the intervertebral disc noted on MRI whose clinical relevance has been debated. Traditionally, T2-weighted (T2W) magnetic resonance imaging (MRI) has been utilized to identify HIZ of lumbar discs. However, controversy exists with regards to HIZ morphology, topography, and association with other MRI spinal phenotypes. Moreover, classification of HIZ has not been thoroughly defined in the past and the use of additional imaging parameters (e.g. T1W MRI) to assist in defining this phenotype has not been addressed.A cross-sectional study of 814 (69.8% females) subjects with mean age of 63.6 years from a homogenous Japanese population was performed. T2W and T1W sagittal 1.5T MRI was obtained on all subjects to assess HIZ from L1-S1. We created a morphological and topographical HIZ classification based on disc level, shape type (round, fissure, vertical, rim, and enlarged), location within the disc (posterior, anterior), and signal type on T1W MRI (low, high and iso intensity) in comparison to the typical high intensity on T2W MRI.HIZ was noted in 38.0% of subjects. Of these, the prevalence of posterior, anterior, and both posterior/anterior HIZ in the overall lumbar spine were 47.3%, 42.4%, and 10.4%, respectively. Posterior HIZ was most common, occurring at L4/5 (32.5%) and L5/S1 (47.0%), whereas anterior HIZ was most common at L3/4 (41.8%). T1W iso-intensity type of HIZ was most prevalent (71.8%), followed by T1W high-intensity (21.4%) and T1W low-intensity (6.8%). Of all discs, round types were most prevalent (anterior: 3.6%, posterior: 3.7%) followed by vertical type (posterior: 1.6%). At all affected levels, there was a significant association between HIZ and disc degeneration, disc bulge/protrusion and Modic type II (p
Chapter
The term discogenic pain refers to pain arising from the disc itself. Discogenic pain is cited as the most common cause of chronic low back pain, accounting for approximately 26–39 % of patients with such pain etiology. Internal disc disruption (IDD) is the most common diagnosis leading to chronic low back pain and one of the major causes of chronic neck pain. Discogenic pain is a significant medical challenge, in terms of its clinical, social, economic, and public health implications. An extensive body of literature suggests that discogenic pain is likely to be multifactorial. The most significant risk factors are genetic inheritance, environmental influences, and lifestyle choices. Although available literature supports hypothesis that the intervertebral disc is an independent chronic pain generator, research related to the epidemiology of discogenic pain is still in its formative stage.
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The objective of this study was to investigate the spatial and temporal variations of water content in intervertebral discs during degeneration and repair processes. We hypothesized that the patterns of water content distribution in the discs are related to the intensity patterns observed in T2-weighted MRI images. Water content distributions in the mildly (e.g., 80% viable cells in the disc, 2.3% decrease in disc height) and moderately (e.g., 40% viable cells in the disc, 9.3% decrease in disc height) degenerated discs were predicted using a finite element model. The variation of water content in the degenerated discs treated with three biological therapies [i.e., increasing the cell density in the NP (Case I), increasing glycosaminoglycan synthesis rate in the nucleus pulposus (Case II), and decreasing glycosaminoglycan degradation rate in the nucleus pulposus (Case III)] were also predicted. It was found that two patterns of water content distributions, a horizontal region with lower water content at the mid-axial plane of nucleus pulposus and a spot with higher water content at the posterior region, were shown during the degeneration progress for the disc simulated in this study. These two patterns disappeared after treatment in Case I, but in Case II and Case III. The implication of these patterns for the horizontal gray band and high intensity zone in T2-weighted MRI images was discussed. This study provided new guidance to develop a novel method for diagnosing disc degeneration and assessing outcomes of biological therapies with MRI techniques. This article is protected by copyright. All rights reserved.
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Intervertebral disc (IVD) degeneration is one of the major causes of low back pain (LBP). Due to the complexity of spinal pain syndromes, it is often difficult to determine the extent of the IVD’s contribution to the genesis of spinal pain. Inflammatory response to IVD’ injury has been acknowledged to be important in the process of disc degeneration and may play an important role in pain generation. In this article, the inflammatory mechanisms of LBP will be discussed with special focus on interactions between inflammatory mediators and IVD biomechanics. Tumor necrosis factor-α (TNF-α) is a key mediator of inflammatory reactions in the pathogenesis of degenerative disk disease. The role of TNF-α inhibitors as a potential target of therapeutic interventions in prevention of neuronal damage and neuroprotection in LBP is discussed.
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High-intensity zone (HIZ) was originally described as a high-intensity signal on T2-weighted magnetic resonance (MR) images, located in the posterior annulus fibrosus, clearly separated from the nucleus pulposus. Among symptomatic patients with low back pain, HIZ is present in 28-59% of cases. In morphologically abnormal discs, high sensitivity and specificity of 81% and 79%, respectively, were reported for HIZs and concordant pain during discography. In contrast, another report indicated low rates. Although most papers reported high sensitivity and specificity for this relationship, it remains controversial. Regarding the pathology of HIZs, inflammatory granulation tissues are found at sites showing HIZs. Such inflammatory tissues produce pro-inflammatory cytokines and mediators, which sensitize the nociceptors within the disc and cause pain. An effective treatment for this condition is yet to be established. Recently, minimally invasive surgery using percutaneous endoscopic discectomy (PED) under local anesthesia was introduced. After removal of the degenerated disc material, the HIZ is identified with the endoscope and then coagulated and modulated with a bipolar radio pulse. This technique is called thermal annuloplasty. In conclusion, HIZs is an important sign of painful intervertebral disc disruption, if identified precisely based on factors such as location and intensity. J. Med. Invest. 63: 1-7, February, 2016
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Lumbar disc herniation is one of the most common spinal degenerative disorders which may lead to low back pain (LBP) and radicular leg pain. However, it remains difficult to diagnose a degenerative herniated disc as the LBP generator in clinical practice. The purpose of this study is to explore the characteristic changes of a herniated disc causing LBP on MRI and to clarify the underlying role of inflammatory mediators and annulus fibrous (AF) tears in LBP generation associated with disc herniation. We prospectively collected intervertebral disc specimens and MRI from 57 single-segment disc herniation patients with radiculopathy. All subjects were grouped according to LBP occurrence or disc degeneration severity for the comparison of inflammatory mediators' expression and AF tears occurrence (High Intensity Zone, HIZ, on MRI). LBP incidence under circumstances of different degeneration severity with or without HIZ was further analyzed. Both LBP incidence and Inflammatory mediators expression in moderately degenerated group was higher than mildly and severely degenerative groups. HIZ incidence was higher in moderately and severely degenerated groups. LBP incidence in the patients with both moderately degenerated discs and HIZ was 86.7%, much higher than the rest of the patient population. In conclusion, the high expression of inflammatory mediators with AF tears causes LBP associated with disc herniation. Moderately degenerative disc with HIZ is MRI morphological change of herniated disc causing LBP, which can be applied to diagnose LBP.
Chapter
Low back pain (LBP) is a common complaint, with over 80 % of the population experiencing an episode of LBP during their lives [1]. Recent data from the Centers for Disease Control and Prevention found that 29 % of interviewees had experienced LBP pain at some point during the previous 3 months [2]. Usually, the clinical course is benign and most patients recover within a few months. It has been reported that over 90 % of patients will recover within 3–6 months [1, 3].
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BACKGROUND: Evaluation of vertebral disc under the vertebral body facilitates selection of treatments. Currently, studies of Denis type B fracture intervertebral disc appearance and function in vertebral burst fractures are few. OBJECTIVE: To observe the imaging and histological features of vertebral disc under the vertebral body of Denis type B thoracolumbar burst fracture, to further evaluate the effect of preserving the vertebral disc under the injured vertebral body. METHODS: A total of 18 cases with Denis type B thoracolumbar burst fracture underwent X-ray, CT, and MRI examination. The anterior and posterior margin of intervertebral height under the injured vertebral body were accessed and compared with the normal height of intervertebrae by X-ray. Oner classification was performed based on the outcome of MRI examination. The signal intensity of nucleus pulposus (NP), annulus fibrosus (AF) and cerebrospinal fluid (CSF) on T2WI in sagittal position was measured, respectively. The ratio of signal intensity for NP/CSF and AF/CSF was calculated. The tissue of interested and normal vertebral disc was collected and measured by hematoxylin-eosin staining and alcian blue staining (absorbance value). The outcomes of staining were measured by Norbert Boos score. RESULTS AND CONCLUSION: The anterior and posterior margin of intervertebral height under the injured vertebral body was not significantly different compared with the normal intervertebrae by X-ray (P > 0.05). According to Oner classification, all the vertebral discs under the injured vertebral body of 18 cases were in type I, i.e., the vertebral disc was normal or near-normal, and there were no vertebral disc of type I - V. The signal intensity ratio of AF/CSF, the signal intensity ratio of NF/CSF for the vertebral disc under the injured vertebral body displayed no significant differences compared with the normal ratio of NF/CSF (P > 0.05). Norbert Boos histological score and the absorbance values of alcian blue staining of the interested vertebral disc were similar to the normal one (P > 0.05). The vertebral disc under the injured vertebral body remained no obvious damage, and the structure was examined by X-ray, CT, and MR. Histological analysis shows that the vertebral disc could be preserved.
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In the absence of any scientifically admissible evidence of efficacy or efficiency for revision back surgery, the syndrome of failed back surgeons is described by the following combination of back surgeons' shortcomings: - Lack of scientific basis for proper surgical indications in patients with low back and/or leg pain, with the exception of surgery for severe nerve root pain due to a disc hernia. - Avoidance of attempts to provide evidence of efficacy by scientifically admissible studies. - Too easily influenced by the marketing forces of instrument manufactures and/or wellspoken colleagues with a new method. - Uncritical reading of published uncontrolled case series of various surgical procedures for patients with chronic low back pain. - Disregard for the predictive value of the psychosocial factors. The overwhelming evidence of our failures explains the poor results of revision surgery for Failed Back Surgery Syndrome.
Chapter
Degenerative chronic spondylitic spinal disease is “markedly underrepresented in the literature. The natural history is not known and most forms of conservative care are unproven.”1 In the aggregate, the diagnosis and management of degenerative spinal disease constitutes a considerably larger percentage of the day-to-day practice of neuroradiology than any other disorder. Furthermore, the impact that neuroradiologists can have in guiding appropriate care is greater in this area than any other single area of our specialty. Unfortunately, too often the neuroradiologist has little or no training in the clinical management of spinal disease. Reports are generated in a vacuum with little understanding of the patient’s history or the intended procedure. Without proper communication with clinical colleagues, vague terms such as protrusion, bulge, broad-based herniation, and so on, mean different things to different people. All too commonly, the focus is on disk integrity, rather than on the spinal unit as a whole; including cartilaginous injury, ligamentous or musculotendinous injury, facet joint instability, sacroiliac joint disease, or neural foraminal disease.
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La artrosis de la columna lumbar aparece casi de forma sistematica despues de los 50 anos y altera los medios de union entre las vertebras. Afecta al disco intervertebral y al arco vertebral posterior al mismo tiempo. Puede conducir a la inestabilidad de la articulacion intervertebral y a la estenosis del conducto raquideo. Su evaluacion depende del estudio por imagen y, en primer lugar, de las radiografias. La artrosis lumbar presenta grados variables de una persona a otra. Puede ser asintomatica o producir dolor en la region lumbar o los miembros inferiores. Sin embargo, no hay ningun paralelismo entre la magnitud de las anomalias radiologicas y la de los sintomas. La intensidad de estos y su duracion inducen a completar las radiografias iniciales con estudios por cortes, es decir, tomografia computarizada o resonancia magnetica, o bien por sacorradiculografia. En la mayoria de los casos, con estos metodos se trata de establecer la relacion de la artrosis con el dolor radicular, pero tambien, respecto a algunas imagenes especificas, con la lumbalgia. Debido a que la artrosis es, con mucho, la afeccion mas frecuente de la columna lumbar, es primordial conocer todos sus aspectos semiologicos con el fin de disipar la inquietud de pacientes que, por su edad, estan expuestos a enfermedades menos frecuentes y mas graves.
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To determine abnormal MRI findings in adults hospitalized with acute severe axial LBP. Sixty patients with back pain were divided into 3 groups consisting of 1) 23 adults with acute axial severe LBP who could not sit up or stand up for several days, but had not experienced previous back-related diseases or trauma (group A), 2) 19 adults who had been involved in a minor traffic accident, and had mild symptoms but not limited mobility (group B), and 3) 18 adults with LBP with radicular pain (group C)., Various MRI findings were assessed among the above 3 groups and compared as follows: disc herniation (protrusion, extrusion), lumbar disc degeneration (LDD), annular tear, high intensity zone (HIZ), and endplate changes. THE MRI FINDINGS OF A GROUP WERE AS FOLLOWS: disc herniation (87%), LDD (100%), annular tear (100%), HIZ (61%), and end plate changes (4.4%). The findings of disc herniation, annular tear, HIZ, and LDD were more prevalent in A group than in B group (p<0.01). HIZ findings were more prevalent in A group than in group B or group C (p<0.05). Patients with acute severe axial LBP were more likely to have disc herniation, LDD, annular tear, HIZ. Among LBP groups, there was a significant association of HIZ on MRI with acute severe axial LBP.
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The prevalence, validity and reliability of high-intensity zones in the annulus fibrosus seen on T2-weighted magnetic resonance images of patients with intractable low-back pain were determined. This sign was readily recognized by two independent observers. It occurred in 28% of 500 patients undergoing magnetic resonance imaging for back pain. The presence of a high-intensity zone correlated significantly with the presence of Grade 4 annular disruption and with reproduction of the patient's pain. Its sensitivity as a sign of either annular disruption or pain was modest but its specificity was high, and its positive predictive value for a severely disrupted, symptomatic disc was 86%. This sign is diagnostic of painful internal disc disruption.
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This study was undertaken to determine the correlation between awake discography findings and magnetic resonance imaging in the evaluation of symptomatic lumbar disc disease. The study included 164 consecutive patients who underwent evaluation with discography and magnetic resonance imaging for lumbar disc disease from August 1987 to September 1989. Chronic low-back pain, with or without radicular symptoms, was the presenting complaint in each case. Each patient had previously failed conservative treatment. The average age was 36 (range, 19-66 years). Magnetic resonance images were performed before discography in each case. Discography was performed with patients minimally sedated and under local anesthesia. A lateral approach was used. Magnetic resonance imaging and discography correlated in 90 cases (55%) and differed in 74 (45%). Considering disc levels, discography and magnetic resonance imaging correlated in 371 discs (80%). There were 172 normal discsand 199 abnormal discs. Of the abnormal discs, 151 (76%) reproduced symptoms. In 60 discs (13%), magnetic resonance images showed abnormal findings and the discogram normal findings. Discs levels classified as abnormal on magnetic resonance imaging demonstrated that 108 discs (37%) were asymptomatic. Magnetic resonance imaging showed normal findings and the discogram abnormal findings in 34 discs (7%), of which 21 (5%) recreated exact symptoms and 13 (2%) caused no pain. Magnetic resonance imaging is a static test and discography the only available dynamic test for disc evaluation. Awake discography is a diagnostic study that can determine which abnormal discs are symptomatic via the pain response.
Article
This study presents a large prospective analysis of abnormal magnetic resonance signal patterns in 1,389 lumbar discs in 892 patients with chronic low back pain. Discographic correlations were available at 166 disc levels. Six different signal patterns were identified, and correlations with discograms would suggest that these patterns reflect the differing and progressive changes of lumbar disc degeneration that occur in vivo in patients with low back pain.
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Pain provocation was analyzed in 1477 intervertebral discs in 523 patients subjected to lumbar computed tomography/discography. The relation between pain provocation and the degree of general degeneration and anular disruption assessed according to the Dallas Discogram Description as indices of intradiscal deterioration was investigated. Pain provocation was also evaluated after categorizing the discs by the clinical diagnosis. Pain provocation showed little relation to intradiscal deterioration, whereas a strong relation was found between it and herniated nucleus pulposus. in herniated nucleus pulposus, discs with extraligamentous extrusion or sequestration, large protrusions, maximum protrusion site at the nerve root portion, and herniation routes passing through the central portion of the disc showed a high pain provocation ratio. Pain provocation ratios of discs associated with spinal canal stenosis were extremely low.
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There are no detailed data in literature concerning the histologic nature of the sequestered (extruded) lumbar disc, and on the frequency with which an extruded fragment, a prolapse or a protrusion are found at surgery. A prospective analysis of 100 consecutive cases of sequestered lumbar disc herniation submitted to surgical treatment revealed this group to represent 28.6% of all cases operated on for lumbar disc herniation. Patients (both male and female) with sequestered lumbar discs are significantly older than those with prolapsed (P < 0.01) and protruded (P < 0.001) discs. Single extruded fragments (n = 68) were twice as frequent as multiple ones (n = 32). The general belief that a 'sequestered (extruded) disc' is almost invariably composed of nucleus pulposus is not substantiated by this study: In 54 cases the extruded fragment consisted predominantly of nucleus material, whereas in 44 cases it consisted mainly of end-plate material. Multiple as well as recurrent sequestered fragments almost always consist of end-plate material. These findings may reflect the result of metabolic alterations in the course of disc degeneration.
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Two patients with intervertebral disc herniation appeared to demonstrate abnormally diffuse and intense enhancement of the disc after intravenous administration of gadolinium-DTPA for MRI. Surgery disclosed a dilated epidural venous plexus in one and vascular granulation tissue in the other, associated with the herniated disc material. The mechanism of this "pseudoenhancement" of the disc appears to be a partial volume effect of disc material and the adjacent veins or granulation tissue. Pseudoenhancement of a herniated disc should be included in the differential diagnosis of a diffusely enhancing epidural mass.
Article
Magnetic resonance imaging was used to determine the T2 relaxation times of prepared proteoglycan solutions and of normal human intervertebral disc tissue from the annulus fibrosus (AF) and nucleus pulposus (NP). The collagen, proteoglycan, and water contents of the disc tissue samples were determined by biochemical assays after they were scanned. Correlations among 1/T2, collagen, proteoglycan, and water contents of the tissue samples and among 1/T2, water, and proteoglycan contents of the proteoglycan solutions were calculated. A moderate negative correlation between 1/T2 and water content was noted for the tissue samples, and a very high negative correlation was found between 1/T2 and water content for the proteoglycan solutions. The very high positive correlation between 1/T2 and proteoglycan content of the proteoglycan solutions is probably due to this negative correlation between 1/T2 and water content. There was no significant correlation between 1/T2 and proteoglycan content of the tissues. The moderate positive correlation between 1/T2 and collagen content is probably due to the high negative correlation between collagen content and water content. No significant correlation was found between the collagen and proteoglycan contents of the tissues. Thus it appears that the data confirm previous reports in the literature that the collagen of the disc tissue functions to control its water content.
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Human discs have been demonstrated to contain high levels of phospholipase A2. As the enzyme responsible for the liberation of arachidonic acid from membranes, this enzyme has a theoretical inflammatory potential. Herniated lumbar discs have a higher level of phospholipase A2 than do normal discs. The purpose of this study was to evaluate the inflammatory capability of purified human disc phospholipase A2. Phospholipase A2 extracted and purified from human disc was found to be inflammatory. Its inflammatory capability was directly related to its ability to function enzymatically. When the enzyme was treated with parabromophenacyl bromide (p-BPB) to specifically alkylate the active site histidine and block catalytic activity, the ability of the modified protein to produce edema was markedly reduced. Careful regulation of the activity of this enzyme is important in vivo because its inflammatory potential could result in disc degeneration and nerve injury.
Article
Immunohistochemical studies support earlier reports of a rich nerve supply to the posterior longitudinal ligament, a less developed innervation of the anterior ligament and the outermost annular ring, and a total lack of innervation in deeper parts of the intervertebral disc. Whether this pattern of innervation is altered when the disc becomes severely degenerated is presently uncertain. Recent studies have also revealed neuropeptide-immunoreactive nerves in the outermost parts of the annulus and adjacent peridiscal ligaments. These nerves are probably involved in discogenic back pain, and may become sensitized when disc tissue is injured. This sensitization appears to be coupled to an alteration of neuropeptide pools in the nearby dorsal root ganglion, the important site of neuropeptide production. Direct influences on the dorsal root ganglion, mechanical and/or chemical, may also be important, and may be involved in spinal segment degeneration.
Article
Inflammation of neural elements is frequently mentioned clinically in association with lumbar radiculopathy. Mechanical embarrassment of neural elements by definable structural abnormalities is inadequate as a sole explanation of nerve injury in this condition. The purpose of this study was to demonstrate whether an enzymatic marker for inflammation (phospholipase A2) could be identified in human disc samples removed at surgery for radiculopathy due to lumbar disc disease. Samples were assayed for phospholipase A2 activity. The level of activity in the disc samples was compared with values obtained from other human tissues using the same assay. Specific activity (percent hydrolysis radiolabelled substrate) ranged from 238 to 1,014.5 nmol/min/mg. Mean activity for the human disc material was 568.7 nmol/min/mg, compared with 0.006 nmol/min/mg for human PMN, and 12.1 nmol/min/mg for inflammatory human synovial effusion. The pH and cation-related activity were identical to those demonstrated for phospholipase A2 inflammatory conditions. Human lumbar disc phospholipase A2 activity is from 20- to 100,000-fold more active than any other phospholipase A2 that has been described. As the enzyme responsible for the liberation of arachidonic acid from cell membranes, phospholipase A2 is the rate-limiting step in the production of prostaglandins and leukotrienes. These data establish biochemical evidence of inflammation at the site of lumbar disc herniations.
Article
We performed magnetic resonance imaging on sixty-seven individuals who had never had low-back pain, sciatica, or neurogenic claudication. The scans were interpreted independently by three neuro-radiologists who had no knowledge about the presence or absence of clinical symptoms in the subjects. About one-third of the subjects were found to have a substantial abnormality. Of those who were less than sixty years old, 20 per cent had a herniated nucleus pulposus and one had spinal stenosis. In the group that was sixty years old or older, the findings were abnormal on about 57 per cent of the scans: 36 per cent of the subjects had a herniated nucleus pulposus and 21 per cent had spinal stenosis. There was degeneration or bulging of a disc at at least one lumbar level in 35 per cent of the subjects between twenty and thirty-nine years old and in all but one of the sixty to eighty-year-old subjects. In view of these findings in asymptomatic subjects, we concluded that abnormalities on magnetic resonance images must be strictly correlated with age and any clinical signs and symptoms before operative treatment is contemplated.
Article
Major advances in the techniques of discography since 1968, in conjunction with major strides in the evaluation of pain in recent years, prompted a study in which Holt's work on the specificity of discography was replicated and extended. For the present study, seven patients who had low-back pain and ten volunteers who had been carefully screened, with a questionnaire and a physical examination, to ensure that they had no history of problems with the back, had an injection at three levels, and all sessions were videotaped. After each injection, the participant was interviewed about the pattern and intensity of the pain, and then the discs were imaged with computed tomography. Five raters, who were blind to the condition of the participant, graded each disc as normal or abnormal on the basis of findings on magnetic resonance images that had been made before the injection and computed tomography (discography) were done. There was only one disagreement between the ratings that were made on the basis of the magnetic resonance images and those that were made on the basis of the discograms. Each participant's pain-related response was evaluated independently by two raters who viewed the videotapes of the discography. Inter-rater reliability was 0.99, 0.93, and 0.88 for the evaluation of intensity of the pain, pain-related behavior, and similarity of the pain to pain that the subject had had before the injection. In the asymptomatic individuals, the discogram was interpreted as abnormal for 17 per cent (five) of the thirty discs and for five of the ten subjects.(ABSTRACT TRUNCATED AT 250 WORDS)
Article
To develop histologic criteria that allow distinction of prolapsed from nonprolapsed intervertebral disk material, we reviewed the histologic features of curetted fibrocartilage from 100 consecutive patients having documented disk prolapse into the spinal canal and contrasted our findings to those in 40 intervertebral disks removed at autopsy from 20 patients without prolapse. Neovascularization, occurring at the edges of fibrocartilage fragments, was present in 50% of prolapsed disk specimens and in none of the control autopsy disks (p = 0.0004). Other histologic features sometimes used as evidence of degeneration and/or prolapse (i.e., fibrillation, chondrocyte "cloning," and granular change) were not helpful in distinguishing prolapsed from nonprolapsed control disks. Although this indicator was only 50% sensitive in our series, we propose that edge neovascularization of the fibrocartilage fragments is the only reliable histologic clue that intervertebral disk prolapse has occurred.
Article
MR imaging after IV gadolinium-DTPA administration has demonstrated contrast enhancement in traumatized lumbar intervertebral disks. To characterize the morbid anatomy that correlates with the contrast enhancement, we developed a canine model of traumatized intervertebral disks. Diskectomy was performed with a nucleotome and the spines were imaged biweekly with MR and Gd-DTPA. The spines were studied at necropsy, and their anatomic abnormalities correlated with contrast enhancement detected by MR imaging. Our preliminary results indicate that contrast enhancement occurs where granulation tissue develops in traumatized intervertebral disks.
Article
Extruded lumbar intervertebral disks traditionally have been classified as posterior or central in location. A retrospective review of 250 MR imaging examinations of the lumbar spine that used mid- and high-field imagers revealed 145 positive studies, which included a significant number of extrusions extending anteriorly. With the lateral margin of the neural foramen/pedicle as the boundary, 29.2% of peripheral disk extrusions were anterior and 56.4% were posterior. In addition, a prevalence of 14.4% was found for central disk extrusions, in which there was a rupture of disk material into or through the vertebral body itself. The clinical state of neurogenic spinal radiculopathy accompanying posterior disk extrusion has been well defined; however, uncomplicated anterior and central disk extrusions also may be associated with a definite clinical syndrome. The vertebrogenic symptom complex includes (1) local and referred pain and (2) autonomic reflex dysfunction within the lumbosacral zones of Head. Generalized alterations in viscerosomatic tone potentially may also be observed. The anatomic basis for the mediation of clinical signs and symptoms generated within the disk and paradiskal structures rests with afferent sensory fibers from two primary sources: (1) posterolateral neural branches emanating from the ventral ramus of the somatic spinal root and (2) neural rami projecting directly to the paravertebral autonomic neural plexus. Thus, conscious perception and unconscious effects originating in the vertebral column, although complex, have definite pathways represented in this dual peripheral innervation associated with intimately related and/or parallel central ramifications. It is further proposed that the specific clinical manifestations of the autonomic syndrome are mediated predominantly, if not entirely, within the sympathetic nervous system. The directional differentiation of lumbar disk extrusions by MR, together with a clarification and appreciation of the accompanying clinical somatic and autonomic syndromes, should contribute both to understanding the specific causes as well as to establishing the appropriate treatment of acute and chronic signs and symptoms engendered by many nonspecific disease processes involving the spinal column.
Article
A new classification method for CT/discography was developed. The Dallas discogram description (DDD) related five separate categories of information. Degeneration and annular disruption were regarded as separate phenomena. Additionally, provoked pain response, contrast volume, and miscellaneous information were recorded. Discogram findings of 59 patients with low-back and/or leg pain were graded according to the new method and compared with standard methods using routine anteroposterior and lateral discographic images. Findings from routine discography and CT/discography were graded and correlated with myelographic and plain computerized axial tomography (CAT) scans. This study demonstrated that the contrast-enhanced axial view provided by CT/discography served as a useful projection for demonstrating disc pathology. CT/discography analyzed according to DDD offered a more sensitive discriminator of disc degeneration from annular disruption (disc protrusion/leaking). This evaluation can be recommended as the procedure of choice when revision of spine surgery is considered or when there is an equivocal or negative correlation between clinical information and myelography or CAT scan.
Article
In degenerative lumbar spine disease, recent studies have supported the clinical usefulness of discography, especially when used with computed tomography (CT) scanning. The role and capabilities of magnetic resonance imaging (MRI) scanning are currently evolving and being defined. This study reviews a series of patients with prolonged disabling symptoms who had normal MRI scans and abnormal discography. Discograms and discogram-CT scans may at times allow detection of clinically correlative and significant pathology (usually annular disruptions) not suggested by MRI scanning. This fact should be considered in patients with normal MRI scanning and continuing unexplained symptomatology.
Article
The CT/discographic findings from 225 discs in 91 low-back pain patients were compared to the pain provocation during the injection of contrast into the disc. The radiographic appearance of disc deterioration demonstrating disc degeneration and annular disruption of each disc was classified separately using a fourpoint scale: normal, slight, moderate, or severe. Pain reaction to the discogram at each level was recorded as follows: no pain, dissimilar pain, similar pain, or exact reproduction of the patient's clinical pain. This more precise analysis demonstrated a significant relationship between pain and deterioration of discs. The CT/discogram presents an axial view of the disc that allows a subgrouping of disc deterioration that can discriminate between peripheral deterioration (degeneration) and internal deterioration (disruption). The disruption supposedly occurs earlier and is more likely to be the source of exact pain reproduction.
Article
Sixty-five patients were examined with magnetic resonance imaging (MR) to determine what combination of operator-selectable controls would result in a thorough examination of the intervertebral disks. There were 20 normal subjects, 8 with degenerative lumbar disk disease, 27 with both degeneration and herniation, 5 with stenosis of the spinal canal, and 5 with disk space infection. T2 was significantly longer in the normal nucleus pulposus than in the degenerated disk. Based on plots of in vivo signal intensity vs. repetition time (TR) for various echo times (TE), a sagittal 30-msec. TE and a 0.25-sec. TR were used for anatomical delineation and rapid localization, while sagittal and/or axial 120-msec. TE/3-sec. TR images were used to evaluate the cerebrospinal fluid and disk. Comparison with radiographs, high-resolution CT scans, and myelograms showed that MR was the most sensitive for identification of degeneration and disk space infection, separating the normal nucleus pulposus from the annulus and degenerated disk. Herniation, stenosis of the canal, and scarring can be identified as accurately with MR as with CT or myelography.
Article
Summary Subdermal injections of PGE2 (5 μg) in the rat foot lead to increases in the potentials evoked in sensory nerve branches by the mechanical stimulation of the skin. This sensitization of both A and C fibres complements the previously described hyperalgesic effects of prostaglandins of the E series.
New Hampshire René Schmidt Mannheim, Germany Michael Schneier Marina Del Rey, California Atsushi Seichi Tochigi
  • Luiz Pimenta
  • São Paulo
  • Timothy A Puckett Oklahoma
  • Oklahoma City
  • M Robert
  • Quencer
  • Florida Miami
  • R Glenn
  • Ii Rechtine
  • H Rochester Japan Francis
  • Virginia Shen Charlottesville
  • L Harry
  • Florida Shuffl Ebarger Miami
  • P Dhaval
  • Shukla
  • India Bangalore
  • H Edward
  • Georgia Simmons Buffalo Andrew Simpson Atlanta
  • L Richard
  • Skolasky
  • Maryland Baltimore
  • J Paul
  • Jr Slosar
  • Daly
  • City
Luiz Pimenta São Paulo, Brazil Timothy A. Puckett Oklahoma City, Oklahoma Robert M. Quencer Miami, Florida Glenn R. Rechtine II Rochester, New York Charles A. Reitman Houston, Texas Sally Roberts Shropshire, United Kingdom Peter Robertson Aukland, New Zealand Michel Rossignol Montreal, Canada Jeffrey A. Saal Redwood City, California Joel S. Saal Redwood City, California Koichi Sairyo Tokushima, Japan Harvinder S. Sandhu New York, New York Richard Saunders Lebanon, New Hampshire René Schmidt Mannheim, Germany Michael Schneier Marina Del Rey, California Atsushi Seichi Tochigi, Japan Francis H. Shen Charlottesville, Virginia Harry L. Shuffl ebarger Miami, Florida Dhaval P. Shukla Bangalore, India Edward H. Simmons Buffalo, New York Andrew Simpson Atlanta, Georgia Richard L. Skolasky Baltimore, Maryland Paul J. Slosar, Jr. Daly City, California Gary L. Smidt Lakeville, Minnesota William D. Smith Las Vegas, Nevada Tomislav Smoljanovic Zagreb, Croatia Paul D. Sponseller Baltimore, Maryland Jeffrey Stambough Cincinnati, Ohio Bjorn N. Stromqvist Lund, Sweden Fred Sweet Rockford, Illinois Katsushi Takeshita Tokyo, Japan Eeric Truumees Austin, Texas Dennis Turk Seattle, Washington Judith A. Turner Seattle, Washington Vidyadhar V. Upasani San Diego, California Howard Vernon Ontario, Canada Barrie Vernon-Roberts Adelaide, Australia Tapio Videman Alberta, Canada Michael R. Von Korff Seattle, Washington Robert G. Watkins Los Angeles, California H. Randal Woodward Omaha, Nebraska Karin Wuertz Zurich, Switzerland Hiroshi Yamada Wakayama, Japan Narayan Yoganandan Milwaukee, Wisconsin Kazuo Yonenobu Osaka, Japan Takashi Yurube Hyogo, Japan Yin-gang Zhang Shaanxi, China Michael R. Zindrick Hinsdale, Illinois Dewei Zou Beijing, China BRS-Advisory-Board.indd 1