Sciatica Patients Research Articles

The clinical features of the piriformis syndrome: a systematic review.

Piriformis syndrome, sciatica caused by compression of the sciatic nerve by the piriformis muscle, has been described for over 70 years; yet, it remains controversial. The literature consists mainly of case series and narrative reviews. The objectives of the study were: first, to make the best use of existing evidence to estimate the frequencies of clinical features in patients reported to have PS; second, to identify future research questions. A systematic review was conducted of any study type that reported extractable data relevant to diagnosis. The search included all studies up to 1 March 2008 in four databases: AMED, CINAHL, Embase and Medline. Screening, data extraction and analysis were all performed independently by two reviewers. A total of 55 studies were included: 51 individual and 3 aggregated data studies, and 1 combined study. The most common features found were: buttock pain, external tenderness over the greater sciatic notch, aggravation of the pain through sitting and augmentation of the pain with manoeuvres that increase piriformis muscle tension. Future research could start with comparing the frequencies of these features in sciatica patients with and without disc herniation or spinal stenosis.

Should Sciatica Patients With Workers' Compensation Claims Avoid Disc Surgery?

The Back Letter: April 2010 - Volume 25 - Issue 4 - p 37,42-44 doi: 10.1097/01.BACK.0000370117.79147.d7

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Value of perineural edema/inflammation detected by fat saturation sequences in lumbar magnetic resonance imaging of patients with unilateral sciatica

Routine lumbar spine magnetic resonance imaging (MRI) may not show any evidence of the cause of sciatica in some cases. The relationship between nerve root compression detected on lumbar MRI and sciatica is also sometimes uncertain. To ascertain whether axial (and, when necessary, sagittal and coronal) short-tau inversion recovery or fat-saturated T2-weighted MRI findings can be used to study the level of sciatica in patients with a non-yielding routine MRI examination. A total of 215 patients with unilateral sciatica underwent MRI. All patients were asked to complete pain drawing forms describing their pain dermatomal distributions. Perineural edema/inflammation corresponding to the pain location indicated by the pain drawings was sought on short-tau inversion recovery or fat-saturated T2-weighted images. Routine MRI findings revealed that 110 of the 215 patients had nerve root compromise related to the patients' symptoms. Routine MRI could not ascertain the cause of these symptoms in the remaining 105 patients. In 31 (29.5%) of these 105 patients, short-tau inversion recovery or fat-saturated T2-weighted magnetic resonance images revealed perineural edema/inflammation surrounding the nerve roots related to the pain locations indicated in the pain drawings. Axial (and, when required, sagittal and coronal) short-tau inversion recovery or fat-saturated T2-weighted magnetic resonance images may be helpful for revealing additional findings in cases of unexplained sciatica in standard magnetic resonance imaging. However, the value of this imaging may be not great enough to justify routine use of these additional sequences to study the level of sciatica.

The Warming Acupuncture for Treatment of Sciatica in 30 Cases

To observe the relation between the pain threshold and the therapeutic effects of acupuncture for sciatica. 90 sciatica patients were equally divided at random into the following 3 groups: a warming acupuncture group treated with the needles warmed by burning moxa, a western medicine group administered Nimesulide tablets and a point-injection group with Anisodamine injected. The pain threshold was tested before treatment and after the first, second and third treatment courses. The warming acupuncture therapy showed better therapeutic effects than the other two groups with significant differences in the change of pain threshold and the improvement of clinical symptoms and signs (P<0.01). Acupuncture can relieve the symptoms of sciatica with the increase of pain threshold.

Participation of 5-Hydroxytryptamine in Pain-Related Behavior Induced by Nucleus Pulposus Applied on the Nerve Root in Rats

The role of 5-hydroxytryptamine (5-HT) in sciatica in lumbar disc herniation (LDH) in rats was investigated. We evaluated the effects of exogenous 5-HT applied on the nerve root on pain-related behavior, the release of endogenous 5-HT in plasma, and the expression of 5-HT2A receptors in dorsal root ganglion (DRG) in a rat LDH model. In previous studies, 5-HT2A receptor antagonists improved sciatica in patients with LDH and attenuated pain-related behavior induced by nucleus pulposus applied to the nerve root in rats. Adult female Sprague-Dawley rats were divided into four experimental groups [control group; low-dose (10 microg) 5-HT-group; high-dose (30 microg) 5-HT-group; and autologous nucleus pulposus (NP) and saline group] and each drug was applied to the L5 nerve root. Von Frey tests were used for pain-behavior testing. To assess levels of endogenous 5-HT released in capillaries surrounding inflamed nerve roots, we measured 5-hydroxyindole acetic acid (5-HIAA), a metabolite of 5-HT. Expression of 5-HT2A receptors in the left L5 DRG was examined by immunohistochemical and immunoblotting analyses in the control and NP groups. Mechanical withdrawal thresholds of the high-dose 5-HT and the NP groups were significantly decreased after surgery compared with the control group and recovered after 14 days in the high-dose 5-HT group. 5-HIAA in plasma was increased by nucleus pulposus applied on the nerve root for 7 days after surgery. The expression of 5-HT2A receptors was enhanced in a time-dependent manner by nucleus pulposus. Exogenous 5-HT to the nerve root induced pain-related behavior with short-lasting effects compared with the nucleus pulposus application. 5-HIAA content in plasma and expression of 5-HT2A receptors in DRG neurons increased early time points after the nucleus pulposus application. These results suggest that 5-HT plays a role in the early phase of the chemical pathogenesis of sciatica in LDH in rats.

Is the interleukin-6 haplotype a prognostic factor for sciatica?

Aims We have shown in a cross-sectional setting that an IL6 haplotype (GGGA) is associated with intervertebral disc disease (IDD) characterized by sciatica. The aim of this study was to evaluate the prognostic role of the GGGA haplotype in IDD. Methods DNA from 153 sciatica patients who participated in a randomized controlled trial of periradicular infiltration was analysed for IL6 variations rs1800797 (−596A > G), rs1800796 (−572G > C), rs1800795 (−174G > C), and rs13306435 (+15T > A). The patients recorded back and leg pain intensity and duration, disability by Oswestry Index and back-related sickness absence over a three-year follow-up. Repeated measures and univariate analysis of variance with adjustment for age, gender and physical work load were used in statistical analyses for the last two-years of the follow-up. Results The prevalence of the GGGA haplotype was 9% (14/153). Subjects with the GGGA haplotype did not differ from those without the haplotype with respect to pain intensity, or disability score, but days with back and leg pain and days on sick leave were significantly higher among subjects with the IL6 haplotype after adjustment for occupation ( p = 0.006, 0.001 and 0.002, respectively). An interaction between the IL6 haplotype and physical work load was significant for the duration of back and leg pain and sick leave ( p = 0.038, 0.011 and 0.006, respectively). Conclusions This is the first observation of any prognostic genotype among sciatica patients. The IL6 haplotype GGGA predicted the number of days with back or leg pain and also sickness absence. Subjects with the IL6 haplotype may be more vulnerable when doing physically demanding jobs.

Drug Disease Interactions: Role of Inflammatory Mediators in Pain and Variability in Analgesic Drug Response

Pain has both physical and emotional components. Physical noxious stimuli activate peripheral sensory neurons that, in turn, relay signals to the spinal and supraspinal nuclei. Subsequently, these signals activate areas within the brain associated with pain. Despite considerable knowledge in this area, analgesics may provide pain complete relief in only one out of five patients. Failure to manage pain may be due to a lack of understanding of the neurobiological processing of pain. Factors such as anticipation, anxiety and pain history play roles in the perception of pain. Non-neuronal cells such as those of the immune system influence perception and modulation of pain by the nervous system. In post-dental surgery patients, the severity of the pain and the relief following administration of anti-inflammatory analgesics has been linked to the time course of inflammatory mediators. Similarly, the relief of post-operative pain after abdominal surgery is also associated with a reduction in expression of pro-inflammatory mediators. Administration of anti-cytokines to sciatica patients and subsequent pain relief further emphasizes the role of pro-inflammatory mediators in modulation of pain. Increased expression of inflammatory mediators may also alter response to analgesia. For example, rheumatoid patients with temporal mandibular joint disease with increased expression of interleukins prior to treatment demonstrate inadequate pain relief after administration of anti-TNF-. In addition, pain or its trauma impairs absorption of oral analgesics causing therapeutic failure. Improved analgesic pharmacotherapy may require a better understanding of the involvement of the inflammatory pathways.

(609/Paper 312): Resequencing of the pain candidate gene, GCH1, to identify novel variants potentially responsible for changes in function

GTP-cyclohydrolase (GCH1) is the rate-limiting enzyme for tetrahydrobiopterin (BH4) synthesis and has been shown to regulate pain sensitivity and persistence. Using a candidate gene approach, one haplotype of GCH1 was found to correlate with lower pain in a population of sciatica patients from the Maine Lumbar Spine Study and in two populations of normal subjects tested with experimental pain.1 As no obvious functional polymorphisms were found within this haplotype, we have now partially resequenced this gene to search for a polymorphism that directly alters function.

Dermatomal laser-evoked potentials: a diagnostic approach to the dorsal root. Norm data in healthy volunteers and changes in patients with radiculopathy

We conducted a cross-sectional study of 40 radiculopathy patients in comparison with norm data from healthy subjects using a new electrophysiological method. Early manifestations of dorsal root impairment escape objective diagnosis by conventional somatosensory-evoked potentials due to the overlapping innervation of the affected dermatome by thickly myelinated mechanoreceptive afferents projecting to adjacent intact roots. Evidence suggested less intersegmental overlap for thermonociceptive afferents rendering laser-evoked potentials (LEP) sensitive to monosegmental dorsal root damage. Therefore we used this new method to study acute manifestations of monosegmental dorsal root pathology. Dorsal root function was tested in 12 healthy subjects and 40 sciatica patients by intraindividual interside comparison. Mechanosensibility and thermosensibility were clinically investigated. LEP were induced by moderately painful laser stimuli. The LEP were evaluated by amplitude and latency of the averaged electroencephalogram. Normal interside differences of LEP for amplitude were +/-22% (lower limb) and +/-35% (upper limb) and +/-15 to +/-16% for latency. Twenty-six patients (65%) showed significant LEP changes, mainly amplitude decreases. Six of these patients exhibited latency prolongations. Clinical testing yielded more frequent pathological results for pain compared to mechanosensibility. The study confirmed our preliminary evidence of LEP sensitivity to objectively document dorsal root impairment in patients suffering from acute monosegmental radiculopathy. This result opens the perspective of electrophysiologically differentiating the presence or absence of dorsal root pathology in patients with similar clinical symptoms but possibly different prognoses, which require different therapies.

A Three-Year Follow-up of Lumbar Spine Endplate (Modic) Changes

A longitudinal follow-up of Modic changes on magnetic resonance imaging (MRI). To assess the prevalence and natural course Modic changes over a 3-year follow-up period. Modic changes are bone marrow and endplate lesions visible on MRI. To the authors' knowledge, no follow-up studies on their natural course have been published. The study population consisted of 60 unoperated sciatica patients 23 to 76 years of age. Baseline and 3-year lumbar MR images from L1-L2 through L5-S1 were analyzed independently by 2 radiologists and a consensus reading was performed. At baseline, the prevalence of Modic changes was 23%. Seven discs had mixed Type I/II, and 63 Type II change. Changes typically occurred at L4-L5 and L5-S1, and associated positively with age (P = 0.009). Ten of 70 discs (14%) with Modic changes at baseline displayed another type at 3 years. Furthermore, the nonconverted changes increased significantly in size. The incidence of new Modic changes during the follow-up was 6% (13 of 230). Modic changes are common MRI findings in patients with degenerative lumbar disc disease. We found evidence that Modic Type II changes may be less stable than previously assumed.

Comparison of postural control in unilateral stance between healthy controls and lumbar discectomy patients with and without pain

Previous studies have demonstrated that sciatica patients have poorer postural control than healthy controls and that postural control remains unchanged 3 months after lumbar discectomy in sciatica patients. The aims of the current study were to investigate whether static balance control recovers in pain-free discectomy patients long-term after lumbar discectomy. Next is to determine whether static balance responses of asymptomatic and symptomatic lumbar discectomy patients differed from each other and from healthy controls. In addition, the influence of the extent of disc resection (unilateral/bilateral removal) and the side of operation on static balance control were investigated. Fifteen pain-free lumbar discectomy patients, 23 lumbar discectomy patients with residual pain and 72 controls performed unilateral stance tasks with eyes open and eyes closed on a force plate were taken up for the investigation. Three repetitions of a 10 s unilateral stance test were performed on each leg. Postural sway was determined. Patients were divided into three age groups. In the eyes open condition, there was no significant difference between postural sway of pain-free lumbar discectomy patients and controls (P=0.68), whereas balance of patients with pain was significantly worse than in controls (P=0.003). In the eyes closed condition, the sway in both groups of lumbar discectomy patients was significantly worse than in controls (pain-free P=0.009/painful P<0.001). No significant differences were found in postural sway between patients with unilateral and bilateral disc resection. In unilateral stance on the leg of the operated side, centre of gravity sway was not significantly different in the eyes open condition compared to the eyes closed condition, whereas in stance on the leg of the non-operated side, postural sway was significantly lower in the eyes open condition compared to the eyes closed condition. In both conditions, postural sway in the age group of 50-65 years was significantly higher than in the age groups of 30-39 years (eyes open P=0.005; eyes closed P<0.001) and 40-49 years (eyes open P=0.002; eyes closed P=0.006). There was no significant difference between the age group of 30-39 years and the age group of 40-49 years (P=0.51). As for long-term following lumbar discectomy, there is no complete recovery of postural control. Patients seem to develop visual compensation mechanisms for underlying sensory-motor deficits, which are, however, sufficient in case of pain relief only. Further study is needed to determine the cause of the balance disturbances in lumbar discectomy patients.

Pathophysiology of disk-related sciatica. I.—Evidence supporting a chemical component

Sciatica in patients with disk disease was long ascribed to pressure put on the sciatic nerve root by a herniated disk. However, a role for chemical factors acting in conjunction with this mechanical insult is suggested by a number of clinical observations: disk surgery does not consistently provide pain relief, large disk herniations are not always symptomatic, severe pain may be present in patients without imaging evidence of nerve root compression, the severity of symptoms and neurological signs is not well correlated with the size of the disk herniation, and conservative therapy is often effective. Experimental studies have provided further evidence for a chemical component: disk herniations can undergo spontaneous resorption, the intervertebral disk is immunogenic, and mediators for inflammation have been identified within intervertebral disk tissue. The current pathophysiological theory incriminates proinflammatory substances secreted by the nucleus pulposus (NP). When preexisting or concomitant mechanical injury to a nerve root occurs, these substances can cause nerve root pain. Animal experiments have established that the NP can induce functional and structural nerve root abnormalities in the absence of mechanical compression and that this effect is mediated by substances located at the surface of NP cells. Methylprednisolone, diclofenac, indomethacin, doxycycline, and cyclosporine induce variable inhibition of this effect. Available information points to tumor necrosis factor-α (TNF-α) as the main candidate among substances potentially responsible for nerve root pain. Therefore, trials of TNF-α antagonists in patients with disk-related sciatica are warranted.

Clinical analysis on the treatment of nerve root sciatica by stuck needle method

Fifty-six cases of nerve root sciatica patients were treated by stuck needle method at Ashi and Jiaji points (Ex-B 2) at the waist region, Huantiao (GB 30), Zhibian (BL 54), Weizhong (BL 40), Yanglingquan (GB 34), Chengshan (BL 57) and Kunlun (BL 60) in the diseased region. 40 cases were treated as control by routine even reinforcing-reducing manipulation with above acupoints. The curative effects were 96.4% and 90.0% respectively.

Determinants of lumbar artery occlusion among patients with sciatica: A three-year follow-up with magnetic resonance angiography

We showed previously that chronic Chlamydia pneumoniae infection increases the risk of lumbar artery occlusion. We did not evaluate, however, the effect of other risk factors for cardiovascular diseases in combination with this chronic infection. The purpose of this study was to investigate the combined effect of chronic C. pneumoniae infection and other known determinants of artery occlusion in a population of sciatica patients. Two-dimensional time-of-flight magnetic resonance angiography (MRA) was used to evaluate lumbar arteries at baseline and three years. The arteries on both sides (L1-L4) were evaluated visually and scored as normal, narrowed or occluded. Logistic regression analysis was performed separately for baseline total arterial stenosis and each L1-L4 segmental artery pair, and for incident new stenosis during the follow-up period. The determinants analyzed included age, body mass index (BMI, kg/m(2)), education, gender, and smoking, in addition to presence of chronic C. pneumoniae infection. MRA was obtained at baseline for 147 patients and at 3 years for 134 patients. Sixty-four (47.8%) of 134 patients had new arterial stenosis. Total incidence of new arterial stenosis was distributed quite evenly between the individual segmental levels, varying from 12.7 to 18.6%. BMI was the only predictor of new arterial stenosis (odds ratio (OR) 1.13). A reasonable logistic model could be established only for baseline L4 and total arterial scores. At L4, education was a protective factor (OR 0.07), whereas age (OR for the oldest age group 6.7) and BMI (OR 1.17) were associated with increased risk of occlusion. For total arterial score, chronic C. pneumoniae infection was an independent determinant of arterial occlusion, increasing the risk to almost eightfold. Additionally, BMI (OR 1.16), and age (for the oldest age group OR 11.4) were significant determinants for stenosis. Smoking was not statistically significant. As chronic C. pneumoniae infection was an independent determinant of lumbar artery occlusion, treatments of this chronic infection may have an impact on lumbar diseases. The importance of BMI for new arterial stenosis suggests that weight reduction may also have a beneficial effect in lumbar artery disease.

Spinal Manipulation, Epidural Injections, and Self-Care for Sciatica: A Pilot Study for a Randomized Clinical Trial

Objective To assess the feasibility of recruiting sciatica patients and to evaluate their compliance in preparation for a full-scale randomized clinical trial. We also aimed to determine the responsiveness of key outcome measures. Methods Thirty-two subjects were randomly assigned to spinal manipulation (n=11), epidural steroid injections (n=11), or self-care education (n=10). No between-group comparisons were planned because of the small sample size. Results At week 12 (the end of the treatment phase), the outcome measures indicating the most improvement/change were the Oswestry disability score (mean, 22.9; SD, 19.9; effect size [ES], 1.8), leg pain severity (mean, 2.9; SD, 1.7; ES, 1.7), and if the symptoms were bothersome (mean, 25.2; SD, 16.0; ES, 1.6). Twenty-four patients were either “very satisfied” or “completely satisfied,” and 22 of 32 patients reported 75% or 100% improvement. After 52 weeks, the outcome measure showing the most improvement/change was leg pain severity (mean, 2.3; SD, 2.6; ES, 1.35), followed by the Oswestry disability score (mean, 15.6; SD, 20; ES, 1.2) and if symptoms were bothersome (mean, 18.1; SD, 22.6; ES, 1.1). Eighteen patients were either “very satisfied” or “completely satisfied,” and 15 of 32 patients reported 75% or 100% improvement. Conclusions The results of this pilot study suggest that it is feasible to recruit subacute and chronic sciatica patients and to obtain their compliance for a full-scale randomized clinical.

Relation entre lombosciatique, hernie discale et neuroborréliose : à propos de quatre observations

We report four cases of sciatica in patients with same-level disk herniation confirmed by computed tomography and a final diagnosis of acute radiculitis caused by Borrelia burgdorferi, with a favorable response to ceftriaxone therapy. The neurological manifestations of Lyme disease are protean, and a potential contribution of concomitant disk disease to sciatica can lead to diagnostic wanderings. Disk lesions and infectious conditions that can cause sciatica are discussed. Whether a favorable response to antibiotic therapy should be taken as proof of B. burgdorferi radiculitis deserves discussion. In practice, in a patient with clinical manifestations suggesting disk-related nerve root pain and residing or having traveled to an endemic area, B. burgdorferi infection should be looked for, as both etiologies can coexist.

What do patients think? Results of a mixed methods pilot study assessing sciatica patients' interpretations of satisfaction and improvement

Background Little is known about the issues low back pain patients take into account when deciding their satisfaction with care, the importance placed on such satisfaction, or the factors they consider when assessing their overall improvement. Objective The purpose of this study was to explore these issues and to assess the feasibility of implementing qualitative research methods within a clinical trial. Methods Study participants were volunteers taking part in a randomized clinical pilot study comparing nonsurgical treatments for sciatica. Face-to-face interviews were conducted, transcribed, and analyzed using content analysis. Results All 31 individuals who participated in the pilot study were interviewed. When asked which issues they considered when deciding their satisfaction with care, the most frequently identified themes were change in pain, personnel, and the treatment experience. When assessing their overall improvement, all participants considered whether their pain had changed. In response to the question asking participants which outcomes they considered to be most important, severity of pain and quality of life were most commonly cited. Conclusion This study demonstrated that a “mixed methods” approach using qualitative research methods within a clinical trial is not only feasible but can provide interesting and useful information for trial interpretation and future study design. By providing insight to the multidimensional nature of patients' beliefs and perceptions, this technique may not only shape but also redefine the focus of patient-oriented research and health care for low back pain conditions.

Sciatica, disk herniation, and neuroborreliosis. A report of four cases

We report four cases of sciatica in patients with same-level disk herniation confirmed by computed tomography and a final diagnosis of acute radiculitis caused by Borrelia burgdorferi, with a favorable response to ceftriaxone therapy. The neurological manifestations of Lyme disease are protean, and a potential contribution of concomitant disk disease to sciatica can lead to diagnostic wanderings. Disk lesions and infectious conditions that can cause sciatica are discussed. Whether a favorable response to antibiotic therapy should be taken as proof of B. burgdorferi radiculitis deserves discussion. In practice, in a patient with clinical manifestations suggesting disk-related nerve root pain and residing or having traveled to an endemic area, B. burgdorferi infection should be looked for, as both etiologies can coexist.

Lumbar Paraspinal Muscle Function, Perception of Lumbar Position, and Postural Control in Disc Herniation-Related Back Pain

A follow-up study evaluating postural control, lumbar movement perception, and paraspinal muscle reflexes in disc herniation-related chronic low back pain (LBP) before and after discectomy. To assess the effect of discectomy on postural control, lumbar perception, and reflex activation of paraspinal muscles during sudden upper limb loading. Impaired muscle function, postural control, and lumbar proprioception have been observed in LBP. However, they have not been studied in sciatica patients after surgery. The study included 20 patients selected for an operation for chronic LBP caused by disc herniation and 15 controls without chronic LBP. The paraspinal muscle responses for upper limb loading during unexpected and expected conditions were measured by surface electromyography. The ability to sense lumbar rotation was assessed in a previously validated motorized trunk rotation unit in the seated position. The postural control was measured with a vertical force platform. Pain, disability, and depression scores were recorded. Patients had poorer lumbar perception (P = 0.012) and postural control (P < 0.05) than did healthy controls. The postural control remained unchanged, but lumbar perception (P = 0.054) and the lumbar feed-forward control (P = 0.043) improved after the surgery. The results demonstrate impaired lumbar proprioception and postural control in sciatica patients. During short-term follow-up after operative treatment, postural control does not seem to change, but impaired lumbar proprioception and feed-forward control of paraspinal muscles seem to recover.