Psychological correlates of pain behavior in patients with chronic low back pain

Pain behaviors that are excessive for the degree of known physical disease are common in patients with chronic low back pain and are frequently assumed to arise from a comorbid depressive illness. Although some studies have confirmed an association between depression and excessive pain behavior, methodologic problems (such as the use of depression ratings that also recorded symptoms attributable to physical disease) make interpretation of this finding difficult. We recruited 54 consecutive patients with chronic (>6 months) low back pain from a hospital clinic. Subjects completed self-rated assessments of anxiety and depression (Hospital Anxiety and Depression Scale) designed to be minimally affected by physical symptoms, along with assessments of disability (ODQ), pain (visual analogue scale), pain behavior (Waddell checklist), and physical impairment. Seventeen subjects (31%) exhibited excessive pain behavior. Overall, they were no more depressed or anxious than the remainder, although men with excessive pain behavior showed a trend toward being more depressed. Patients with excessive pain behavior were more disabled (self-rated and observer-rated), reported greater pain, and were more likely to be female and to have pain of shorter duration. Pain behavior did not correlate with anxiety or depression, but correlated with measures of disability and pain intensity. Factor analysis revealed that physical disability, pain intensity, and pain behavior loaded heavily on the first factor. Anxiety and depression loaded together on a separate factor. We conclude that pain behaviors were not related to anxiety or depression in our group, although gender differences between groups could have contributed to our negative findings. Pain behaviors may influence other physical measures. Further studies are required to investigate the relation between depression and pain behavior while controlling for gender differences.     

Screening of lower back pain, low back pain clinic. The clinical experience

Acute low back pain is a common complaint with high prevalence in society. Orthopaedic and specialist spinal services may be overwhelmed by large numbers of patients with low back pain who do not require investigation or surgical intervention. This phenomenon has led to the establishment of back pain screening clinics as a system of triage for those with acute low back pain. In March 2001, a back pain screening clinic was established in the Adelaide and Meath Hospitals incorporating the National Children's hospital. Six hundred and sixty-five patients were seen in the first year of this clinic. Of these, only ninety-six required referral to the orthopaedic spinal clinic. Just twenty-nine of these patients required surgical intervention. The introduction of this service resulted in a reduction in the waiting periods for the specialised spine clinic. We conclude that back pain screening clinics result in a clinical and economical improvement in the care of those suffering from acute low back pain. This is achieved by the systematic and efficient assessment, treatment and referral of patients afflicted with acute low back pain.     

Prognostic indicators in low back pain

Nearly four per cent of the population over the age of 15 years in a Danish general practice reported episodes of low back pain at least once a year. A one-year follow-up of 72 patients provided data regarding symptoms, length of absence from work, use of analgesics and bed rest. An indication of the prognosis was reached by relating these data to the history (including occupation), symptoms and signs noted at the initial interview. The following factors indicated a long or relapsing course:

1. More than three previous episodes of low back pain.

2. Gradual onset of symptoms.

3. Pain referred distal to the femur.

4. More than four weeks' delay in reporting symptoms.

Other factors of prognostic significance were difficulty in moving, onset in relation to work, absence from work, positive straight leg raising test and unilateral pain in the loin.

     

Chronic low back pain and depression

It is not clear whether the psychological disturbances associated with chronic low back pain are the cause or the result of the chronicity. It is also not clear whether increasing duration of low back pain is associated with depression. Three groups of patients (N = 148), with recent (0-6 months), relatively longstanding (6-24 months) and chronic (more than 24 months) low back pain were given the MMPI, Multiple Affect Adjective Check List (MAACL), State Trait Anxiety Inventory (STAI) and Low Back Pain Questionnaire (LBPQ). Increasing chronicity is associated with significant increases on MMPI Hs, D, HY, PT and MA scales, and on STAI Trait Anxiety scale. These results suggest that chronicity leads to the development of psychopathological characteristics and that these characteristics include a heightened awareness of somatic functioning and the vegetative aspects of the depressive syndrome, but that there is no increase in depressive mood or in the perception of the pain itself.     

Chronic low back pain and depression

In an attempt to clarify the relationship between chronic low back pain and depression, the authors studied the incidence of depression, alcoholism, and chronic back pain in first-degree relatives of chronic pain patients with and without depression. A higher incidence of recurrent unipolar depression was found in those relatives of patients with depression than without depression. These findings raise questions about the concept of chronic low back pain simply as a variant of depression and they suggest that the occurrence of major depression together with chronic back pain might relate to genetic vulnerability to depression.     

Patterns of H-reflex abnormality in patients with low back pain.

H-reflex was studied in 43 patients with low back pain (including 20 patients with neurological deficit corresponding to S1 radix and 23 patients without deficit) and 20 control subjects. Among patients with neurological deficit the abnormality consisted of absent H-reflex (7 patients), increased H-latency (3 patients), reduced H/M maximal amplitude ratio (5 patients) or a combination of the latter two (2 patients). The H/M ratio was significantly reduced in this group as compared to control subjects and between affected and unaffected sides. Abnormal H-reflex correlated well with ankle jerk hypo- or areflexia, S1 sensory deficit and lumbar myelographic/CT abnormality. In 23 patients without deficit, increased H-latency and/or reduced H/M ratio was observed in 4 cases. Enhanced H/M ratio was noted in only 2 patients of this group. Use of H/M ratio seems to increase the sensitivity of H-reflex in the diagnosis of S1 radiculopathy.     

Transdermal fentanyl for chronic low back pain

Purpose

Chronic low back pain is a common clinical problem. As medication, non-steroidal anti-inflammatory drugs are generally used; however, they are sometimes non-effective. Recently, opioids have been used for the treatment of chronic low back pain, and since 2010, transdermal fentanyl has been used to treat chronic non-cancer pain in Japan. The purpose of the current study was to examine the efficacy of transdermal fentanyl in the treatment of chronic low back pain.

Materials and Methods

This study included patients (n=62) that suffered from chronic low back pain and were non-responsive to non-steroidal anti-inflammatory drugs. Their conditions consisted of non-specific low back pain, multiple back operations, and specific low back pain awaiting surgery. Patients were given transdermal fentanyl for chronic low back pain. Scores of the visual analogue scale and the Oswestry Disability Index, as well as adverse events were evaluated before and after therapy.

Results

Overall, visual analogue scale scores and Oswestry Disability Index scores improved significantly after treatment. Transdermal fentanyl (12.5 to 50 µg/h) was effective in reducing low back pain in 45 of 62 patients; however, it was not effective in 17 patients. Patients who experienced the most improvement were those with specific low back pain awaiting surgery. Adverse events were seen in 40% of patients (constipation, 29%; nausea, 24%; itching, 24%).

Conclusion

Disability Index scores in 73% of patients, especially those with specific low back pain awaiting surgery; however, it did not decrease pain in 27% of patients, including patients with non-specific low back pain or multiple back operations.     

椎间盘源性下腰痛的组织病理学变化

背景：椎间盘源性下腰痛是一种椎间盘外周部基本保持完整,而内部各种病理(退变、终板损伤、炎症等)刺激椎间盘内疼痛感受器引起的功能丧失性下腰痛,并且不伴有根性症状,无神经或节段过度活动的放射学证据。 目的：综述了椎间盘源性下腰痛病理变化、临床诊断的特异性、敏感性和安全性以及各种诊断方法存在的争议观点。 方法：应用计算机检索中国期刊全文数据库、PubMed 数据库、EMBASE数据库1970/2010 有关椎间盘源性下腰痛诊断的文献,排除重复性研究。 结果与结论：共保留42篇文献归纳总结。目前临床上根据椎间盘源性下腰痛的病理变化有多种诊断方法,包括物理检查的中心化趋势和骨震动测试,MRI上的黑间盘、高密度区、Modic 改变,椎间盘超声检查,血清学中的高敏感性C-反应蛋白和椎间盘造影。其中腰椎间盘造影有较高的敏感性和特异性,是目前首选的诊断方法。     

下腰疼痛的生物力学分析

背景:下腰痛是人类极容易发生的疾病,原因复杂,发生机制依然不能完全阐明。目的:针对下背疼痛起因做一详细的力学分析。方法:藉由生物力学原理,应用计算软件Matlab与图像软件Photoshop对L4及两侧的小关节进行3D力学模拟。分析不同体质量的人在不同弯腰角度、提取不同重物时,L3-L4椎间盘所承受的滑脱力,以及在不同程度椎间盘退化的情形下,应力转移至关节囊的百分比。结果与结论:①L4因弯腰搬动物品时所受的压力会随着弯腰的角度增加而呈非线性递减,弯腰角度越大L4所受压力越小;当弯腰搬取物品时,L4所承受的压力与人体质量或物品质量呈正比;②当人弯腰达75°时,由于环状应力的产生可使腰大肌所承受的力可达体质量的20倍,来回反复做相同的动作就会使肌肉疲劳,进而对其造成损伤;椎间盘的退化也会将原先正常作用在周边组织的应力放大4倍左右,而对这些组织造成应力伤害。