Lars Korsholm

Magnetic resonance imaging and low back pain in adults: a diagnostic imaging study of 40-year-old men and women.

Study Design. Cross-sectional cohort study of a general population. Objective. To investigate “abnormal” lumbar spine magnetic resonance imaging (MRI) findings, and their prevalence and associations with low back pain (LBP). Summary of Background Data. The clinical relevance of various “abnormal” findings in the lumbar spine is unclear. Distinguishing between inevitable age-related findings and degenerative findings with deleterious consequences is a challenge. Methods. Lumbar spine MRI was obtained in 412, 40-year-old individuals. Predefined “abnormal” MRI findings were interpreted without any knowledge of patient symptoms. Associations between MRI abnormalities and LBP were calculated using odds ratios. The “overall picture” of each MRI finding was established on the basis of the frequencies, diagnostic values, and the strength and consistency of associations. Results. Most “abnormal” MRI findings were found at the lowest lumbar levels. Irregular nucleus shape and reduced disc height were common (>50% of individuals). Relatively common (25% to 50%) were hypointense disc signal, anular tears, high intensity zones, disc protrusions, endplate changes, zygapophyseal joint degeneration, asymmetry, and foraminal stenosis. Nerve root compromise, Modic changes, central spinal stenosis, and anterolisthesis/retrolisthesis were rare (<25%). Most strongly associated with LBP were Modic changes and anterolisthesis (odds ratios >4). Significantly positive associations with all LBP variables were seen for hypointense disc signals, reduced disc height, and Modic changes. All disc “abnormalities” except protrusion were moderately associated with LBP during the past year. Conclusion. Most degenerative disc “abnormalities” were moderately associated with LBP. The strongest associations were noted for Modic changes and anterolisthesis. Further studies are needed to define clinical relevance.

Responsiveness and minimal clinically important difference for pain and disability instruments in low back pain patients

BackgroundThe choice of an evaluative instrument has been hampered by the lack of head-to-head comparisons of responsiveness and the minimal clinically important difference (MCID) in subpopulations of low back pain (LBP). The objective of this study was to concurrently compare responsiveness and MCID for commonly used pain scales and functional instruments in four subpopulations of LBP patients.MethodsThe Danish versions of the Oswestry Disability Index (ODI), the 23-item Roland Morris Disability Questionnaire (RMQ), the physical function and bodily pain subscales of the SF36, the Low Back Pain Rating Scale (LBPRS) and a numerical rating scale for pain (0–10) were completed by 191 patients from the primary and secondary sectors of the Danish health care system. Clinical change was estimated using a 7-point transition question and a numeric rating scale for importance. Responsiveness was operationalised using standardardised response mean (SRM), area under the receiver operating characteristic curve (ROC), and cut-point analysis. Subpopulation analyses were carried out on primary and secondary sector patients with LBP only or leg pain +/- LBP.ResultsRMQ was the most responsive instrument in primary and secondary sector patients with LBP only (SRM = 0.5–1.4; ROC = 0.75–0.94) whereas ODI and RMQ showed almost similar responsiveness in primary and secondary sector patients with leg pain (ODI: SRM = 0.4–0.9; ROC = 0.76–0.89; RMQ: SRM = 0.3–0.9; ROC = 0.72–0.88). In improved patients, the RMQ was more responsive in primary and secondary sector patients and LBP only patients (SRM = 1.3–1.7) while the RMQ and ODI were equally responsive in leg pain patients (SRM = 1.3 and 1.2 respectively). All pain measures demonstrated almost equal responsiveness. The MCID increased with increasing baseline score in primary sector and LBP only patients but was only marginally affected by patient entry point and pain location. The MCID of the percentage change score remained constant for the ODI (51%) and RMQ (38%) specifically and differed in the subpopulations.ConclusionRMQ is suitable for measuring change in LBP only patients and both ODI and RMQ are suitable for leg pain patients irrespectively of patient entry point. The MCID is baseline score dependent but only in certain subpopulations. Relative change measured using the ODI and RMQ was not affected by baseline score when patients quantified an important improvement.

Modic changes and their associations with clinical findings

It is believed that disc degeneration (DD) is, in general, only mildly associated with low back pain (LBP). MRI-identified Modic changes (MC), probably a late stage of DD, are relatively strongly associated with LBP but it is not known if people with MC also have a specific clinical profile. The purpose of this study was to investigate if the clinical findings differ in people with Modic changes (MC) as compared to those with only degenerative disc findings or none at all. In a population-based sample of 412 40-year-old Danes, information was collected independently with MRI, questionnaires and clinical examination. Three subgroups of people were created: those with both DD and MC, those with only DD, and those with neither DD nor MC. The clinical pattern was investigated for each subgroup in order to test the assumption that the clinical picture differs in the three groups. It was expected that people with both DD and MC would have a more pronounced clinical profile than those with only DD who, in turn, would differ from those with neither of these two MRI findings. Our findings were generally in concordance with our expectations. MC constitutes the crucial element in the degenerative process around the disc in relation to LBP, history, and clinical findings. People with DD and no MC only vaguely differ from those without. People with LBP and MC may deserve to be diagnosed as having specific LBP.

Are MRI-defined fat infiltrations in the multifidus muscles associated with low back pain?

BackgroundBecause training of the lumbar muscles is a commonly recommended intervention in low back pain (LBP), it is important to clarify whether lumbar muscle atrophy is related to LBP. Fat infiltration seems to be a late stage of muscular degeneration, and can be measured in a non-invasive manner using magnetic resonance imaging. The purpose of this study was to investigate if fat infiltration in the lumbar multifidus muscles (LMM) is associated with LBP in adults and adolescents.MethodsIn total, 412 adults (40-year-olds) and 442 adolescents (13-year-olds) from the general Danish population participated in this cross-sectional cohort study. People with LBP were identified through questionnaires. Using MRI, fat infiltration of the LMM was visually graded as none, slight or severe. Odds ratios were calculated for both age groups, taking into account sex, body composition and leisure time physical activity for both groups, and physical workload (in adults only) or daily bicycling (in adolescents only).ResultsFat infiltration was noted in 81% of the adults but only 14% of the adolescents. In the adults, severe fat infiltration was strongly associated with ever having had LBP (OR 9.2; 95% CI 2.0–43.2), and with having LBP in the past year (OR 4.1; 1.5–11.2), but there was no such association in adolescents. None of the investigated moderating factors had an obvious effect on the OR in the adults.ConclusionFat infiltration in the LMM is strongly associated with LBP in adults only. However, it will be necessary to quantify these measurements objectively and to investigate the direction of this link longitudinally in order to determine if the abnormal muscle is the cause of LBP or vice versa.

The pattern of chromosome-specific variations in telomere length in humans is determined by inherited, telomere-near factors and is maintained throughout life

In this study the telomere length distribution on individual chromosome arms in humans has been characterized. Using fluorescent in situ hybridisation (FISH) followed by computer-assisted analysis of digital images, we show that the distribution of telomere length on individual chromosome arms is not random, but that humans have a common telomere profile. This profile exists in both lymphocytes, amniocytes and fibroblasts, and is conserved during life until about the age of 100. We find that the length of the telomeres generally follows the length of the chromosomes and that the chromosome specific differences in telomere length are determined by factors located very distally on the chromosome arms. In addition to the common profile, we also find that each individual has specific characteristics. Based on analysis of both monozygotic and dizygotic twins, we find that these characteristics are partly inherited. For each chromosome, age-related chromosome loss correlates negatively with telomere length. This suggests that decrease in telomere length may be an element in age-related genome instability.

Tracking of objectively measured physical activity from childhood to adolescence: The European youth heart study

A number of studies have investigated tracking of physical activity from childhood to adolescence and, in general, these studies have been based on methods with some degree of subjectivity (e.g., questionnaires). The aim of the present study was to evaluate tracking of physical activity from childhood to adolescence using accelerometry, taking into account major sources of variation in physical activity. Both a crude and an adjusted model was fitted, and, in the adjusted model, analyses were corrected for seasonal variation, within‐week variation, activity registration during night time sleep, within instrumental measurement error, and day‐to‐day variation in physical activity. In all, 208 subjects were included in the crude analyses. Stability coefficients estimated from the crude model were low (i.e., 0.18 and 0.19 for boys and girls, respectively) and only borderline significant. However, in the adjusted model highly significant stability coefficients of 0.53 and 0.48 for boys and girls, respectively, were observed. It was concluded that physical activity behavior tends to track moderately from childhood to adolescence.

Peri-Conceptional A1C and Risk of Serious Adverse Pregnancy Outcome in 933 Women With Type 1 Diabetes

OBJECTIVE To study the association between peri-conceptional A1C and serious adverse pregnancy outcome (congenital malformations and perinatal mortality). RESEARCH DESIGN AND METHODS Prospective data were collected in 933 singleton pregnancies complicated by type 1 diabetes. RESULTS The risk of serious adverse outcome at different A1C levels was compared with the background population. The risk was significantly higher when peri-conceptional A1C exceeded 6.9%, and the risk tended to increase gradually with increasing A1C. Women with A1C exceeding 10.4% had a very high risk of 16%. Congenital malformation rate increased significantly at A1C above 10.4%, whereas perinatal mortality was increased even at A1C below 6.9%. CONCLUSIONS These results support recent guidelines of preconceptional A1C levels <7% in women with type 1 diabetes.

Risk factors in developing pregnancy-related pelvic girdle pain.

Background. In this prospective epidemiologic cohort study the aim was to identify possible risk factors for developing four different syndromes of pelvic girdle pain during pregnancy. Methods. Over a one‐year period a total of 2,269 consecutive pregnant women – at week 33 of gestation – responded to a structured questionnaire and underwent a thorough physical examination. Women who at baseline reported daily pain from pelvic joints and had corresponding objective findings were allocated, according to symptoms, into one of four classification groups, and followed up with questionnaires and physical examinations up to two years after delivery. Results. Multivariate analysis could distinguish the four pelvic pain sub groups from the “Pelvic healthy” group with respect to 13 of 24 variables. The pelvic girdle syndrome group revealed a history of previous low back pain, trauma of the back or pelvis, multiparae, had a relatively higher weight, a higher level of self reported stress and of job At a higher risk of developing symphysiolysis were women who were multiparae, had a relatively higher weight, and were smokers. If a woman had vocational training or a professional education, was stressed, had a poorer experience of previous delivery, had previous low back pain, trauma of back, or previous salpingitis, she had an increased risk of developing one‐sided sacroiliac syndrome. The risk factors for developing double‐sided sacroiliac syndrome were previous low back pain and trauma of the back or pelvis, multiparae, poorer relationship with spouse, and less job satisfaction. Conclusions. This study demonstrates no single dominant risk factor for developing pelvic girdle pain in pregnancy, but reveals a set of physical and psychosocial factors. The risk factors for developing pelvic girdle pain in general are: history of previous low back pain, trauma of the back or pelvis, multivariate, higher level of stress, and low job satisfaction.

Sources of variation in habitual physical activity of children and adolescents: the European youth heart study

The present study examined the influence of gender, maturity state, seasonality, type of measurement day and socioeconomic status (SES) on habitual physical activity in 8–10‐year‐old children and 14–16‐year‐old adolescents (n=1318). Physical activity was assessed objectively by accelerometry. The results showed a significant effect of the type of measurement day on physical activity with a general pattern of lower activity levels in weekends compared with weekdays. Furthermore, higher physical activity levels were observed during the months of spring/summer compared with the months of autumn/winter for the 8–10‐year‐olds, whereas no significant effect of months was observed for the 14–16‐year‐olds, possibly due to exam preparations and lack of physical activity registration during the months of summer for this cohort. SES was unrelated to physical activity in the 8–10‐year‐olds, whereas an inverse association was observed in the 14–16‐year‐olds. However, a post hoc analysis provided strong evidence that this latter result was biased by the accelerometers inability to pick up bicycling activities. Finally, boys were more physically active compared with girls, and maturity state was unrelated to physical activity. The results could prove useful for working out strategies to prevent inactivity and for adjusting for temporal sources of variation in physical activity in future studies.

Neck collar, "act-as-usual" or active mobilization for whiplash injury? A randomized parallel-group trial.

Study Design. Randomized, parallel-group trial. Objective. To compare the effect of 3 early intervention strategies following whiplash injury. Summary of Background Data. Long-lasting pain and disability, known as chronic whiplash-associated disorder (WAD), may develop after a forced flexion-extension trauma to the cervical spine. It is unclear whether this, in some cases disabling, condition can be prevented by early intervention. Active interventions have been recommended but have not been compared with information only. Methods. Participants were recruited from emergency units and general practitioners within 10 days after a whiplash injury and randomized to: 1) immobilization of the cervical spine in a rigid collar followed by active mobilization, 2) advice to “act-as-usual,” or 3) an active mobilization program (Mechanical Diagnosis and Therapy). Follow-up was carried out after 3, 6, and 12 months postinjury. Treatment effect was measured in terms of headache and neck pain intensity (0–10), disability, and work capability. Results. A total of 458 participants were included. At the 1-year follow-up, 48% of participants reported considerable neck pain, 53% disability, and 14% were still sick listed at 1 year follow-up. No significant differences were observed between the 3 interventions group. Conclusion. Immobilization, “act-as-usual,” and mobilization had similar effects regarding prevention of pain, disability, and work capability 1 year after a whiplash injury.