Phosphoglycerate mutase 5 facilitates mitochondrial dysfunction and neuroinflammation in spinal tissues after spinal cord injury.

Spinal cord injury (SCI) is a high incidence worldwide that causes a heavy physical and psychological burden to patients. It is urgent to further reveal the pathological mechanism and effective treatment of SCI. Mitochondrial dysfunction plays an important role in the disease progression of SCI. As a mitochondrial membrane protein, phosphoglycerate mutase 5 (PGAM5) is mainly involved in mitochondrial function and mitosis to modulate cellular physiological functions, but the roles of PGAM5 in spinal tissues remain to be unreported after SCI. The purpose of this study was to evaluate the role of PGAM5 in SCI mice and its relationship with neuroinflammation. The results showed that the mitochondrial membrane protein PGAM5 was involved in microglia activation after SCI, and PGAM5 deletion could improve mitochondrial dysfunction (including abnormal mtDNA, ATP synthases, and ATP levels, Cyt C expression, and ROS and rGSH levels) in spinal cord tissue after SCI, Arg1/iNOS mRNA level, iNOS expression, and pro-inflammatory cytokines TNF-α, IL-1ß, and IL-18 levels. In vitro, H2O2 increased TNF-α, IL-1ß, and IL-18 levels in BV2 cells, and PGAM5-sh and Nrf2 activators significantly reversed H2O2-induced iNOS expression and proinflammatory cytokine production. Furthermore, IP/Western blotting results revealed that PGAM5-sh treatment significantly reduced the interaction of PGAM5 with Nrf2 and enhanced the nuclear translocation of Nrf2 in BV2 cells. The data suggested that PGAM5 was involved in the cascade of oxidative stress and inflammatory response in microglia via facilitating the expression level of Nrf2 in the nucleus after SCI. It provided a reference for clarifying the pathological mechanism and therapeutic target of SCI.

Anterior Cervical Decompression and Fusion Surgery for Cervical Spondylosis with Concomitant Tinnitus: A Multicenter Prospective Cohort Study.

OBJECTIVE: Cervical spondylosis is often accompanied by tinnitus. Up to now, there is a lack of large samples and prospective studies to investigate the effect of anterior cervical decompression and fusion (ACDF) on tinnitus associate with cervical spondylosis. To this end, we performed a prospective cohort study to assess the effectiveness of ACDF on the relief of tinnitus. METHODS: This was a multicenter, prospective, cohort clinical study. Between August 2017 and August 2018, 174 patients with cervical spondylosis accompanied by tinnitus were enrolled, with a follow-up of 12 months. Among the 174 patients, 142 received anterior cervical surgery (surgery group) and 32 received conservative treatment (conservative group). The primary end point was the mean change in scores on the tinnitus functional index (TFI). The secondary end points included tinnitus loudness, modified Japanese orthopaedic association scores (mJOA) for spinal cord function, and visual analogue scale (VAS) for neck pain. All the above indexes were measured before treatments and at 1, 3, 6, and 12 months after treatments. One-way analysis of variance and paired samples t-test was adopted for statistical analysis. RESULTS: The TFI score was reduced immediately after cervical decompression surgery (from 54.7 ± 15.6 to 32.3 ± 12.5, P < 0.001) and this was sustained at 12 months (P < 0.001). The TFI score of the conservative group also decreased (from 53.9 ± 16.8 to 45.2 ± 13.6, P < 0.001), but the effect was not maintained at 12 months (P = 0.069). There was a significant improvement in tinnitus loudness (from 5.2 ± 1.6 to 2.6 ± 1.9, P < 0.001), mJOA (from 12.0 ± 1.6 to 14.2 ± 1.6, P < 0.001), and VAS for neck pain (from 58.5 ± 9.6 to 22.0 ± 16.4, P < 0.001) in the surgical group. Improvements in the surgical group were statistically significantly greater than that in the conservative group (P < 0.001). CONCLUSION: This study indicates that anterior cervical surgery can relieve tinnitus in patients with cervical spondylosis and that tinnitus is an accompanying manifestation of cervical spondylosis.

Anterior cervical decompression and fusion surgery for cervicogenic headache: A multicenter prospective cohort study.

Background: Cervicogenic headache (CEH) has long been recognized as a referred pain deriving from pathological changes in the upper cervical nerves. However, previous clinical studies found that anterior lower cervical discectomy for the treatment of cervical myelopathy and/or radiculopathy can also help relieve associated headaches. To date, there is still a lack of large sample and prospective study to investigate the effect of anterior cervical decompression and fusion (ACDF) on CEH associated with cervical spondylosis. Methods: A total of 656 patients with cervical radiculopathy and/or myelopathy were enrolled in three spinal centers. Among them, 221 patients who were diagnosed with CEH were collected in this study, and 204 completed a 1-year follow-up. The primary endpoint was headache intensity during a 12-month follow-up period measured by the numeric pain rating scale (NPRS). The secondary outcome measures included headache frequency, headache duration, and the neck disability index (NDI). Results: Among all 204 patients with CEH who completed a 1-year follow-up, 166 received anterior cervical surgery (surgery group) and 38 received conservative treatment (conservative group). There were statistically significant lower NPRS in the surgical group during follow-up. Between-group differences showed that NPRS in the surgery group was significantly greater improvement at 1 month (2.8, 95% CI: 2.0, 3.6), 3 months (2.6, 95% CI: 1.8, 3.4), 6 months (2.4, 95% CI: 1.6, 3.2), and 12 months (1.5, 95% CI: 0.7, 2.4) (p < 0.05 for all). There were statistically significant lower NDI, less frequent headaches, and lower headache duration in the surgery group during follow-up (p < 0.05 for all). Conclusion: This study indicates that ACDF can effectively relieve CEH associated with cervical myelopathy and/or radiculopathy.

Application of a new anatomic hook-rod-pedicle screw system in young patients with lumbar spondylolysis: A pilot study.

BACKGROUND: The pedicle screw-laminar hook system has strong fixation and is conducive to bone graft fusion for lumbar spondylolysis. However, the current pedicle screw-laminar hook fixation system is not specifically designed for lumbar spondylolysis. AIM: To investigate the clinical effects of a new anatomical hook-rod-pedicle screw system in the treatment of lumbar spondylolysis in young adults. METHODS: We designed a new anatomic hook-rod-pedicle screw system for young patients with lumbar spondylolysis. The isthmus and the corresponding pedicle screw entry point were exposed through the intermuscular approach. Autogenous iliac bone graft was obtained to bridge the isthmus defect, and then the anatomic hook-rod-pedicle screw system was used to fix the isthmus in 15 young patients. RESULTS: At 24 mo follow-up, the visual analogue scale score of low back pain decreased from 6.73 ± 0.88 to 0.73 ± 0.59, and the Oswestry disability index score decreased from 58.20 ± 8.99 to 7.87 ± 4.97. Computed tomography showed bilateral isthmic bone healing in 14 cases and unilateral isthmic bone healing in 1 case. Magnetic resonance imaging showed that the lumbar disc signal of diseased segment and adjacent segments had no change compared with that before surgery. The pain visual analogue scale score of the donor site was 0.20 ± 0.41 at the last follow-up. According to the Modified Macnab score, the excellent and good rate was 100%. CONCLUSION: The application of this new anatomical hook-rod-pedicle screw system to treat young patients with lumbar spondylolysis has the advantages of less trauma, a simple operation and satisfactory clinical effects.

Entinostat Improves Motor Function and Neuronal Damage Via Downregulating NLRP3 Inflammasome Activation After Spinal Cord Injury.

Background: Spinal cord injury (SCI), a major public health problem, has no effective treatment. A large number of studies have confirmed that histone deacetylases (HDACs) are involved in the physiologic processes that occur following SCI. We tried to uncover the potential neuroprotective role of entinostat (a class I HDAC inhibitor) in SCI. Methods: We conducted a study on a preclinical mouse model of SCI and OGD-induced neuronal damage to present the role of entinostat by the analysis of motor function, histopathologic damage, local NLRP3 inflammasome activation, and neuronal damage. Results: The results showed that entinostat suppressed HDAC activation (including HDAC1 and HDAC3 expression), improved the grip strength and BMS score, spinal edema, cell death, and local NLRP3 inflammasome activation in the spinal cord following SCI. Furthermore, entinostat significantly increased OGD-inhibited neuronal activity and decreased PI-positive cells, HDAC activation, caspase-1 activation, IL-1ß and IL-18 levels, and NLRP3 expression. Conclusion: In summary, we first documented that entinostat improved the motor function, histopathologic damage, and local inflammatory response and NLRP3 inflammasome activation in the spinal cord following SCI and also presented the neuroprotective role of OGD-induced neuronal damage via the NLRP3 inflammasome. Thus, our study has the potential to reveal the interaction between the HDAC and NLRP3 inflammasome in the pathologic process as well as SCI and further promote the clinical indications of HDACi entinostat and clinical treatment for the inflammatory response after SCI.

Surgical treatment of four segment lumbar spondylolysis: A case report.

BACKGROUND: Four-level lumbar spondylolysis is extremely rare. So far, only 1 case has been reported in the literature. CASE SUMMARY: A 19-year-old man presented with severe back pain irresponsive to conservative therapies for 2 years. Lumbar radiographs and two-dimensional computed tomography scan showed four segment lumbar spondylolysis on both sides of L2-L5. Lumbar magnetic resonance imaging showed normal signal in all lumbar discs. Because daily activities were severely limited, surgery was recommended for the case. The patient underwent four-level bilateral isthmic repair at L2-L5. During surgery, L2-L5 isthmi were curetted bilaterally, freshened, and then grafted with autologous iliac bone that was bridged and compressed with a pedicular screw connected to a sub-laminar hook by a short rod. The symptoms of back pain almost disappeared. He has been followed-up for 96 mo, and his symptoms have never recurred. Fusion was found in all repaired isthmi 14 mo after surgery according to evaluation of lumbar radiography and computed tomography scan. CONCLUSION: We report here 1 case of four-level lumbar spondylolysis that was treated successfully with direct isthmic repair.

Cervical Intervertebral Disc Degeneration Contributes to Dizziness: A Clinical and Immunohistochemical Study.

OBJECTIVES: Dizziness often happens in patients with chronic neck pain with only cervical disc degeneration but without cervical radiculopathy or myelopathy. We prospectively selected a series of patients who showed cervical disc degeneration with concomitant chronic neck pain and intractable dizziness who did not respond to conservative treatment to test a new diagnostic method for this dizziness, to analyze the results of anterior cervical discectomy and fusion (ACDF) surgery based on the test, and to explore its pathogenesis. METHODS: Seventy-seven patients who had a transient neck pain and dizziness relief after injection of bupivacaine into a suspected disc were included in the study. In total, 52 underwent ACDF as surgery group, and 25 refused surgery and accepted conservative treatments as conservative group from June, 2015 to October, 2016 with subsequent follow-up to 1 year. The outcomes were visual analogue scale for neck pain, Neck Disability Index, and intensity and frequency of dizziness. During ACDF, the 72 specimens of degenerative cervical discs were collected to determine the innervation in degenerative cervical discs immunohistochemically. RESULTS: After surgery, the patients experienced a significant reduction in neck pain and dizziness. Symptomatic relief in surgery group was obviously better than conservative group at each time point of follow-up (P = 0.001). Ruffini corpuscles and substance P-positive free nerve fibers were obviously increased in the number and deeply ingrown into the inner degenerative cervical discs. CONCLUSIONS: Current clinical and immunohistochemical studies strongly suggest that chronic neck pain and intractable dizziness in this series of patients stem from the degenerative cervical discs.

Cervical Decompression Surgery for Cervical Spondylotic Myelopathy and Concomitant Hypertension: A Multicenter Prospective Cohort Study.

STUDY DESIGN: We performed decompression surgery or conservative treatments on 135 cervical spondylotic myelopathy (CSM) patients with concomitant hypertension and did follow-up assessments up to 1 year to examine the change of blood pressure, spinal cord function, and cervical pain. OBJECTIVE: The aim of this study was to determine whether concomitant hypertension is relieved after decompression surgery, and whether it is related to the improvement of spinal cord function or cervical pain. SUMMARY OF BACKGROUND DATA: In clinical practice, we often found that some patients with CSM have concomitant hypertension. Interestingly, after CSM was treated successfully by decompression surgery, some patients' high blood pressure returned to normal range even without oral medications. METHODS: We enrolled 135 CSM patients with hypertension, 103 of whom received decompression surgery, and remaining 32 patients accepted conservative treatments. We did follow-up assessments at 3, 6, and 12 months. The primary endpoints were changes of blood pressure, and secondary endpoints were changes of modified Japanese Orthopedic Association (mJOA) score and cervical pain visual analogue scale (VAS). Spearman correlation coefficients were calculated between changes in systolic blood pressure (SBP) and mJOA scores, VAS scores. RESULTS: In patients with decompression surgery, the significant decrease in both SBP and diastolic blood pressure (DBP) that was seen 3 months and sustained through subsequent visit at 12 months. Paired-samples t test showed that both SBP and DBP were significantly lower than baseline blood pressure at all time points after procedure (P < 0.001). Significant correlation was found between the improvement rates of mJOA score and changes in SBP (r = -0.579, P < 0.001). But the correlation between changes in VAS score and changes in SBP was not significant (r = 0.58, P = 0.571). CONCLUSION: Cervical decompression surgery could reduce concomitant high blood pressure in CSM patients, indicating a significant association between the decrease in blood pressure and the improvement of spinal cord function. LEVEL OF EVIDENCE: 2.

Mechanoreceptors in Diseased Cervical Intervertebral Disc and Vertigo.

STUDY DESIGN: We collected the samples of cervical intervertebral discs from patients with vertigo to examine the distribution and types of mechanoreceptors in diseased cervical disc. OBJECTIVE: The aim of this study was to determine whether mechanoreceptors are distributed more abundantly in cervical discs from patients with cervical spondylosis, and whether they are related to vertigo. SUMMARY OF BACKGROUND DATA: Previous limited studies have found that normal cervical intervertebral discs are supplied with mechanoreceptors that have been considered responsible for proprioceptive functions. Several clinical studies have indicated that the patients with cervical spondylosis manifested significantly impaired postural control and subjective balance disturbance. METHODS: We collected 77 samples of cervical discs from 62 cervical spondylosis patients without vertigo, 61 samples from 54 patients with vertigo, and 40 control samples from 8 cadaveric donors to investigate distribution of mechanoreceptors containing neurofilament (NF200) and S-100 protein immunoreactive nerve endings. RESULTS: The immunohistochemical investigation revealed that the most frequently encountered mechanoreceptors were the Ruffini corpuscles in all groups of cervical disc samples. They were obviously increased in the number and deeply ingrown into inner annulus fibrosus and even into nucleus pulposus in the diseased cervical discs from patients with vertigo in comparison with the discs from patients without vertigo and control discs. Only three Golgi endings were seen in the three samples from patients with vertigo. No Pacinian corpuscles were found in any samples of cervical discs. CONCLUSION: The diseased cervical discs from patients with vertigo had more abundant distribution of Ruffini corpuscles than other discs. A positive association between the increased number and ingrowth of Ruffini corpuscles in the diseased cervical disc and the incidence of vertigo in the patients with cervical spondylosis was found, which may indicate a key role of Ruffini corpuscles in the pathogenesis of vertigo of cervical origin. LEVEL OF EVIDENCE: 1.

Differences of Sagittal Lumbosacral Parameters between Patients with Lumbar Spondylolysis and Normal Adults.

BACKGROUND: Recent studies have suggested an association between elevated pelvic incidence (PI) and the development of lumbar spondylolysis. However, there is still lack of investigation for Han Chinese people concerning the normal range of spinopelvic parameters and relationship between abnormal sagittal parameters and lumbar diseases. The objective of the study was to investigate sagittal lumbosacral parameters of adult lumbar spondylolysis patients in Han Chinese population. METHODS: A total of 52 adult patients with symptomatic lumbar spondylolysis treated in the General Hospital of Armed Police Force (Beijing, China) were identified as the spondylolysis group. All the 52 patients were divided into two subgroups, Subgroup A: 36 patients with simple lumbar spondylolysis, and Subgroup B: 16 patients with lumbar spondylolysis accompanying with mild lumbar spondylolisthesis (slip percentage <30%). Altogether 207 healthy adults were chosen as the control group. All patients and the control group took lumbosacral lateral radiographs. Seven sagittal lumbosacral parameters, including PI, pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), L5 incidence, L5 slope, and sacral table angle (STA), were measured in the lateral radiographs. All the parameters aforementioned were compared between the two subgroups and between the spondylolysis group and the control group with independent-sample t- test. RESULTS: There were no statistically significant differences of all seven sagittal lumbosacral parameters between Subgroup A and Subgroup B. PI, PT, SS, and LL were higher (P < 0.05) in the spondylolysis group than those in the control group, but STA was lower (P < 0.001) in the spondylolysis group. CONCLUSIONS: Current study results suggest that increased PI and decreased STA may play important roles in the pathology of lumbar spondylolysis in Han Chinese population.

Surgical Management of 3-Level Lumbar Spondylolyses.

Three-level lumbar spondylolyses are extremely rare. So far, only 11 cases were reported in the literature. Treatment of multilevel spondylolyses has not been consistent. Conservative treatment is commonly considered first in most patients, but those who remain symptomatic may benefit from operative treatment. We report here 3 cases of 3-level lumbar spondylolyses that were treated successfully with direct isthmic repair in 2 cases and a combined surgery of isthmic repair and interbody fusion in 1 case. Our clinical results indicated that direct defect repair using the screw-hook technique is a simple and safe procedure for the motion segment with normal disc. If the involved disc shows degenerative change, fusion surgery should be consideredSurgical treatment of multilevel spondylolyses varies between fusion, direct isthmic repair, and combined management associating 2 procedures at different levels. The success of management of the 3 patients with 3-level spondylolyses depends on the choice of appropriate treatment for every patient.

Cervical spondylosis and hypertension: a clinical study of 2 cases.

Cervical spondylosis and hypertension are all common diseases, but the relationship between them has never been studied. Patients with cervical spondylosis are often accompanied with vertigo. Anterior cervical discectomy and fusion is an effective method of treatment for cervical spondylosis with cervical vertigo that is unresponsive to conservative therapy. We report 2 patients of cervical spondylosis with concomitant cervical vertigo and hypertension who were treated successfully with anterior cervical discectomy and fusion. Stimulation of sympathetic nerve fibers in pathologically degenerative disc could produce sympathetic excitation, and induce a sympathetic reflex to cause cervical vertigo and hypertension. In addition, chronic neck pain could contribute to hypertension development through sympathetic arousal and failure of normal homeostatic pain regulatory mechanisms. Cervical spondylosis may be one of the causes of secondary hypertension. Early treatment for resolution of symptoms of cervical spondylosis may have a beneficial impact on cardiovascular disease risk in patients with cervical spondylosis.

Minimum 5-year follow-up study on the effects of the Wallis dynamic stabilization system in the treatment of lumbar degenerative disease.

BACKGROUND: Short-term outcomes of the Wallis system in the treatment of lumbar degenerative disease (LDD) have been shown to be effective, whereas there is a paucity of studies on the mid-long-term effects of the treatment of the Wallis system. This study was to evaluate the mid-long-term effects of the Wallis dynamic stabilization system in the treatment of LDD. METHODS: A total of 26 patients who received the treatment of the Wallis system between February 2008 and January 2009 were included in the study, with 14 patients (Group 1) with L4/5 disc herniation and 12 patients (Group 2) with L5/S1 disc herniation and L4/5 intervertebral disc degeneration (IDD). Visual analog scale (VAS) and Oswestry Disability Index (ODI) were used to evaluate the clinical outcomes and lumbar X-rays and MRI were obtained to observe imaging changes before and after operation. RESULTS: The mean follow-up period was (63.50±2.12) months. The mean ODI and VAS scores decreased obviously three months and five years after operation (P < 0.05). In Groups 1 and 2, L4/5 Cobb angle and range of motion (ROM) decreased and L4/5 posterior disc height increased at the last follow-up (P < 0.05). There were no statistically significant changes in L4/5 anterior disc height and L3/4 University of California at Los Angeles grading before and after operation. There was no statistically significant change in Pfirrmann grading system of L4/5 IDD in Group 2 before and after operation. Adjacent segment degeneration at the last follow-up was found in two patients (2/26, 7.69%) and Modic changes in L4/5 endplates were detected in one patient (1/26, 3.85%). CONCLUSIONS: The mid-long-term effects of the Wallis system in the treatment of LDD were satisfied. The Wallis system, as a dynamic stabilization system, which can preserve some ROM of the fixed segment, sustain the lumbar stabilization, and prevent adjacent segment disease and fixed segment degeneration, is an effective instrument to treat LDD.

Prospective clinical study on natural history of discogenic low back pain at 4 years of follow-up.

BACKGROUND: To accurately assess the effect of any therapy for treating discogenic low back pain, the natural history of such pain should be known beforehand. However, until now, no pathological characteristic could be used to predict the disease course of low back pain. OBJECTIVE: To better instruct the clinical treatment of discogenic low back pain, a prospective clinical study was performed to observe the natural history of the disease. STUDY DESIGN: A prospective clinical study during a 4-year follow-up period. SETTING: The study was performed at a spinal center in China. METHODS: A total of 279 patients with chronic low back pain were included from June 2006 through October 2007. Using discography, 156 patients (56%) were diagnosed to have discogenic back pain. A 101-point numerical rating scale (NRS) was used to assess the back pain symptoms and the Oswestry Disability Index (ODI) was used to assess lumbar function. RESULTS: Of the 156 patients, 131 (84%) completed the study at 4-year follow-up. At the end of follow-up, 17 patients (13.0%) had their low back pain symptoms alleviated and lumbar function improved; 10 patients (7.6%) were slightly improved; 16 patients (12.2%) had their symptoms aggravated; and 88 patients (67.2%) experienced the same pain and disability as before. Although the average NRS and ODI scores obtained during the 4-year follow-up study gradually decreased, statistical significances were found in such changes (P < 0.05,and P < 0.05, respectively); however, the improvement rates of both pain (7.6%) and disability (5.2%) were very low. LIMITATIONS: The shortcoming of this study is its relatively small sample size. CONCLUSION: The present study indicated that the natural history of discogenic low back pain was chronic but persistent, and that the pain and disability in most patients did not improve over time.

Diagnosis and surgical treatment of back pain originating from endplate.

Twenty-one patients with back pain originating from the endplate injuries were selected to explore the methods of diagnosis and surgical treatment. All patients underwent examinations using radiography, CT, and MR imaging. Pain level of disc was determined through discography in each patient. The principal outcome judgments were pain and disability, and the efficacy of surgical treatment was assessed through the use of the visual analog scale (VAS) for pain and the Oswestry disability index (ODI) for functional recovery. All 21 patients with a diagnosis of back pain originating from endplate injuries according to discography were treated with anterior or posterior fusion surgery. The mean follow-up period was 3 years and 5 months (range, 2-6 years). Of the 21 patients, 20 (20/21) reported a disappearance or marked alleviation of low back pain and experienced a definite improvement in physical function. Statistically significant and clinically meaningful improvements in the VAS and ODI scores were obtained after treatment in the patients with chronic low back pain originating from the endplate injuries (P = 0.0001). The study suggests that discography and fusion surgery may be very effective methods for the diagnosis and treatment, respectively, of chronic back pain originating from the endplate injuries.

Expression and role of connective tissue growth factor in painful disc fibrosis and degeneration.

STUDY DESIGN: We collected the specimens of lumbar intervertebral discs from patients with discogenic low back pain, to study the histopathological features and connective tissue growth factor (CTGF) expressions. OBJECTIVE: To study the expression and role of CTGF in fibrosis and degeneration of painful disc tissue. SUMMARY OF BACKGROUND DATA: Previous studies have demonstrated that degenerative disc commonly showed fibrosis in histology. CTGF, a downstream effector mediated by transforming growth factor-beta1 (TGF-beta1), is commonly related to tissue fibrosis. We do not know whether CTGF is expressed in painful disc, and related to painful disc degeneration and fibrosis. METHODS: This study included 43 lumbar intervertebral disc specimens from 28 patients with discogenic low back pain obtained during posterior lumbar interbody fusion and 16 asymptomatic degenerative discs from patients without low back pain. Further, 8 normal discs were included as controls. Their histopathological features were studied, and the expression of CTGF was assessed using immunohistochemistry. RESULTS: Histologic examination revealed that the painful discs showed chronic inflammatory reaction with blood vessel infiltration in varying degrees. The anulus fibrosus had lost its normal lamellar architecture, and instead, disorganization, disruption, and crossed fusion were observed. Normal fibroblasts were replaced by chondrocytes in the anulus fibrosus. The nucleus pulposus showed marked fibrosis, blood vessel infiltration, and inflammatory granulation tissue formation. Immunohistochemical staining demonstrated strong CTGF expression in the painful discs, weak expression in the asymptomatic degenerative disc, and no expression in the control discs. CONCLUSION: The painful degenerative disc is significantly different from the asymptomatic degenerative disc with regard to histopathological findings. The strong CTGF expression in the painful disc may be related to disc fibrosis and degeneration.

[A special type of discogenic low back pain: normal signal intensity of magnetic resonance imaging with abnormal discography].

OBJECTIVE: To report a group of special patients showing a normal signal intensity of MRI with a positive discography and discuss its pathogenesis and clinical significance. METHODS: From August 2003 to November 2008, 288 patients with chronic low back pain were treated. Of these patients, 12 showed a normal intensity signal of MRI in lumbar intervertebral discs with a positive discography. There were 7 males and 5 females aged 20 - 44 years with an average of 29.6 years. The duration of disease was 8 months to 3 years with an average of 1.8 years. Dallas CT grading method was used for assessing the degree of annular disruption. RESULTS: Of these 12 patients, 33 lumbar discs underwent discography. Twelve discs in 12 patients showed annular disruption and low back pain reproduction. Among 12 painful discs, 3 showed grade 2 annular disruption and 9 showed grade 3 annular disruption. CONCLUSION: Patients who are refractory to conservative care and have normal signal intensity in lumbar disc MRI and who are suggested as discogenic origin and might need further treatment such as minimal invasive surgery or lumbar interbody fusion should still be examined by discography.

[Natural history and prognosis of discogenic low back pain].

OBJECTIVE: To understand the natural history and prognosis of patients with discogenic low back pain so as to offer a better guide on its clinical treatment. METHODS: From December 2003 to November 2004, we consecutively hospitalized 72 patients with discogenic low back pain diagnosed by lumbar discography. These patients were randomized into two groups. One group (n = 36) received an intradiscal methylene blue (MB) injection immediately after discography while another group (n = 36) received a placebo. Both Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) were used to assess the back pain symptoms and the lumbar function respectively during a 4-year follow-up period. RESULTS: In total, 32 of 36 patients who received a placebo injection underwent a 4-year follow-up. Of these patients, 4 cases (12.5%) had their low back pain symptoms alleviated, 1 case (3.1%) slightly improved, 3 cases (9.4%) aggravated and 22 cases (68.8%) had no change in symptoms. According to VAS and ODI scores taken at different time points, these two scores gradually decreased over time; however, no statistical significances were found (VAS: F = 3.049, P > 0.05; ODI: F = 2. 272, P > 0.05). CONCLUSION: The disease course of discogenic low back pain is chronic and persistent so that its symptoms show no improvement over time.