Magnus Peterson

A randomized controlled trial of exercise versus wait-list in chronic tennis elbow (lateral epicondylosis)

Abstract Background. Chronic tennis elbow (lateral epicondylosis) is a common disorder. Like other chronic soft-tissue pain conditions it is often difficult to treat successfully. The effects of exercise have been discussed, but no convincing evidence has been put forward so far, and a simple protocol for exercise is lacking. Aims of the study. This study is a randomized, controlled, clinical trial of the effect of exercise versus expectation (wait-list) on pain, muscle strength, function, and quality of life in patients with long-standing lateral epicondylosis. Methods. Eighty-one subjects with tennis elbow lasting for more than 3 months were randomly allocated to an exercise group (n = 40) or a reference group (n = 41). The exercise group performed daily exercise, with weekly load increase, for 3 months. The reference group was wait-listed, but otherwise followed in the same way. Outcome measures were pain during maximum voluntary muscle contraction (Cozens test) and pain during maximum muscle elongation with a load (modified Empty-can-test); muscle strength was measured with a Chatillon MSE 100 hand-held dynamometer, and the Disability of the Arm, Shoulder and Hand (DASH) and the Gothenburg Quality of Life questionnaires. Results. The exercise group had greater and faster regression of pain, both during muscle contraction and muscle elongation, than the reference group (p = 0.0005 and p = 0.0016, respectively). There was a non-significant muscle strength difference between the groups, but no differences regarding DASH scores or quality of life measures. Conclusions. Exercise appears to be superior to expectation in reducing pain in chronic lateral epicondylosis.

A randomized controlled trial of eccentric vs. concentric graded exercise in chronic tennis elbow (lateral elbow tendinopathy)

Objective: To analyse treatment effects of eccentric vs. concentric graded exercise in chronic tennis elbow. Design: Randomized controlled trial. Setting: Primary care in Uppsala County, Sweden. Subjects: A total of 120 subjects with tennis elbow lasting more than three months were recruited from primary care and by advertisement. Intervention: Eccentric (n = 60) or concentric exercise (n = 60), by lowering or lifting a weight, at home daily, for three months with gradually increasing load. Main measures: Pain during muscle contraction and muscle elongation, as well as strength, was assessed at baseline and after one, two, three, six, and 12 months. Function and quality of life was assessed at baseline and after three, six and 12 months. Results: The eccentric exercise group had faster regression of pain, with an average of 10% higher responder rate at all levels of pain reduction, both during muscle contraction and elongation, (p < 0.0001 and p = 0.006, respectively). Significant differences were found in Cox’s analysis from two months onwards (HR 0.78, 95% confidence interval (CI) 0.63–0.96, p < 0.02). This represents an absolute pain reduction of 10% in the eccentric vs. the concentric group and a number-needed-to-treat of 10. The eccentric group also had a greater increase of muscle strength than the concentric (p < 0.02). The differences persisted throughout the follow-up period. There were no significant differences between the groups regarding function or quality of life measures. Conclusion: Eccentric graded exercise reduced pain and increased muscle strength in chronic tennis elbow more effectively than concentric graded exercise.

Treatment practice in chronic epicondylitis : A survey among general practitioners and physiotherapists in Uppsala County, Sweden

Objective. To investigate treatment practice among general practitioners (GPs) and physiotherapists (PTs) in chronic epicondylitis of 3 months’ duration or more. Design. Postal survey. Setting and subjects. All 129 GPs and all 77 PTs at 35 primary health care centres in Uppsala County, Sweden, received the questionnaire. Main outcome measures. Proportion of responders using various treatments (five specified alternatives + open question). Results. The questionnaire was answered by 70% of the GPs and 61% of the PTs. Ergonomic counselling, stretching, and orthotic devices were common, and used to a similar extent by GPs and PTs. Acupuncture was also common, but less so among GPs than PTs. Transcutaneous electric nerve stimulation was used by relatively few GPs and PTs. The open question revealed that dynamic exercise, particularly eccentric, was used by most PTs but only one GP. A majority of GPs prescribed sick leave and anti-inflammatory treatment with an NSAID or cortisone injections. Conclusion. A large number of treatment methods in chronic epicondylitis were reported, none of which is properly evidence-based and some of which are even known to be ineffective. There is a need for randomized controlled studies of potentially effective treatments in this condition.

Adverse childhood experiences influence development of pain during pregnancy

To investigate the association between adverse childhood experiences (ACE) and pain with onset during pregnancy.

PET-scan shows peripherally increased neurokinin 1 receptor availability in chronic tennis elbow: visualizing neurogenic inflammation?

In response to pain, neurokinin 1 (NK1) receptor availability is altered in the central nervous system. The NK1 receptor and its primary agonist, substance P, also play a crucial role in peripheral tissue in response to pain, as part of neurogenic inflammation. However, little is known about alterations in NK1 receptor availability in peripheral tissue in chronic pain conditions and very few studies have been performed on human beings. Ten subjects with chronic tennis elbow were therefore examined by positron emission tomography (PET) with the NK1 specific radioligand [11C]GR205171 before and after treatment with graded exercise. The radioligand signal intensity was higher in the affected arm as compared with the unaffected arm, measured as differences between the arms in volume of voxels and signal intensity of this volume above a reference threshold set as 2.5 SD above mean signal intensity of the unaffected arm before treatment. In the eight subjects examined after treatment, pain ratings decreased in all subjects but signal intensity decreased in five and increased in three. In conclusion, NK1 receptors may be activated, or up-regulated in the peripheral, painful tissue of a chronic pain condition. This up-regulation does, however, have moderate correlation to pain ratings. The increased NK1 receptor availability is interpreted as part of ongoing neurogenic inflammation and may have correlation to the pathogenesis of chronic tennis elbow. Trial Registration ClinicalTrials.gov NCT00888225 http://clinicaltrials.gov/

Referred pain patterns provoked on intra-pelvic structures among women with and without chronic pelvic pain : a descriptive study

Objectives To describe referred pain patterns provoked from intra-pelvic structures in women with chronic pelvic pain (CPP) persisting after childbirth with the purpose to improve diagnostics and give implications for treatment. Materials and Methods In this descriptive and comparative study 36 parous women with CPP were recruited from a physiotherapy department waiting list and by advertisements in newspapers. A control group of 29 parous women without CPP was consecutively assessed for eligibility from a midwifery surgery. Inclusion criterion for CPP was: moderate pain in the sacral region persisting at least six months after childbirth confirmed by pelvic pain provocation tests. Exclusion criteria in groups with and without CPP were: persistent back or pelvic pain with onset prior to pregnancy, previous back surgery and positive neurological signs. Pain was provoked by palpation of 13 predetermined intra-pelvic anatomical landmarks. The referred pain distribution was expressed in pain drawings and described in pain maps and calculated referred pain areas. Results Pain provoked by palpation of the posterior intra-pelvic landmarks was mostly referred to the sacral region and pain provoked by palpation of the ischial and pubic bones was mostly referred to the groin and pubic regions, with or without pain referred down the ipsilateral leg. The average pain distribution area provoked by palpation of all 13 anatomical landmarks was 30.3 mm² (19.2 to 53.7) in women with CPP as compared to 3.2 mm² (1.0 to 5.1) in women without CPP, p< 0.0001. Conclusions Referred pain patterns provoked from intra-pelvic landmarks in women with CPP are consistent with sclerotomal sensory innervation. Magnification of referred pain patterns indicates allodynia and central sensitization. The results suggest that pain mapping can be used to evaluate and confirm the pain experience among women with CPP and contribute to diagnosis.

Association between HbA1c and peripheral neuropathy in a 10-year follow-up study of people with normal glucose tolerance, impaired glucose tolerance and Type 2 diabetes

To explore the association between HbA1c and sural nerve function in a group of people with normal glucose tolerance, impaired glucose tolerance or Type 2 diabetes.

Reduced Corneal Nerve Fiber Density in Type 2 Diabetes by Wide-Area Mosaic Analysis

Purpose To determine if corneal subbasal nerve plexus (SBP) parameters derived from wide-area depth-corrected mosaic images are associated with type 2 diabetes. Methods One hundred sixty-three mosaics were produced from eyes of 82 subjects by laser-scanning in vivo confocal microscopy (IVCM). Subjects were of the same age, without (43 subjects) or with type 2 diabetes (39 subjects). Mosaic corneal nerve fiber length density (mCNFL) and apical whorl corneal nerve fiber length density (wCNFL) were quantified and related to the presence and duration of diabetes (short duration < 10 years and long duration ≥ 10 years). Results In mosaics with a mean size of 6 mm2 in subjects aged 69.1 ± 1.2 years, mCNFL in type 2 diabetes was reduced relative to nondiabetic subjects (13.1 ± 4.2 vs. 15.0 ± 3.2 mm/mm2, P = 0.018). Also reduced relative to nondiabetic subjects was mCNFL in both short-duration (14.0 ± 4.0 mm/mm2, 3.2 ± 3.9 years since diagnosis) and long-duration diabetes (12.7 ± 4.2 mm/mm2, 15.4 ± 4.2 years since diagnosis; ANOVA P = 0.023). Lower mCNFL was associated with presence of diabetes (P = 0.032) and increased hemoglobin A1c (HbA1c) levels (P = 0.047). By contrast, wCNFL was unaffected by diabetes or HbA1c (P > 0.05). Global SBP patterns revealed marked degeneration of secondary nerve fiber branches outside the whorl region in long-duration diabetes. Conclusions Wide-area mosaic images provide reference values for mCNFL and wCNFL and reveal a progressive degeneration of the SBP with increasing duration of type 2 diabetes.

Visualization of painful inflammation in patients with pain after traumatic ankle sprain using [ 11 C]-D-deprenyl PET/CT

Graphical Abstract Abstract Background and aims Positron emission tomography (PET) with the radioligand [11C]-D-deprenyl has shown increased signal at location of pain in patients with rheumatoid arthritis and chronic whiplash injury. The binding site of [11C]-D-deprenyl in peripheral tissues is suggested to be mitochondrial monoamine oxidase in cells engaged in post-traumatic inflammation and tissue repair processes. The association between [11C]-D-deprenyl uptake and the transition from acute to chronic pain remain unknown. Further imaging studies of musculoskeletal pain at the molecular level would benefit from establishing a clinical model in a common and well-defined injury in otherwise healthy and drug-naive subjects. The aim of this study was to investigate if [11C]-D-deprenyl uptake would be acutely elevated in unilateral ankle sprain and if tracer uptake would be reduced as a function of healing, and correlated with pain localizations and pain experience. Methods Eight otherwise healthy patients with unilateral ankle sprain were recruited at the emergency department. All underwent [11 C]-D-deprenyl PET/CT in the acute phase, at one month and 6-14 months after injury. Results Acute [11C]-D-deprenyl uptake at the injury site was a factor of 10.7 (range 2.9-37.3) higher than the intact ankle. During healing, [11C]-D-deprenyl uptake decreased, but did not normalize until after 11 months. Patients experiencing persistent pain had prolonged [11C]-D-deprenyl uptake in painful locations. Conclusions and implications The data provide further support that [11C]-D-deprenyl PET can visualize, quantify and follow processes in peripheral tissue that may relate to soft tissue injuries, inflammation and associated nociceptive signaling. Such an objective correlate would represent a progress in pain research, as well as in clinical pain diagnostics and management.

Wide-field corneal subbasal nerve plexus mosaics in age-controlled healthy and type 2 diabetes populations

A dense nerve plexus in the clear outer window of the eye, the cornea, can be imaged in vivo to enable non-invasive monitoring of peripheral nerve degeneration in diabetes. However, a limited field of view of corneal nerves, operator-dependent image quality, and subjective image sampling methods have led to difficulty in establishing robust diagnostic measures relating to the progression of diabetes and its complications. Here, we use machine-based algorithms to provide wide-area mosaics of the cornea’s subbasal nerve plexus (SBP) also accounting for depth (axial) fluctuation of the plexus. Degradation of the SBP with age has been mitigated as a confounding factor by providing a dataset comprising healthy and type 2 diabetes subjects of the same age. To maximize reuse, the dataset includes bilateral eye data, associated clinical parameters, and machine-generated SBP nerve density values obtained through automatic segmentation and nerve tracing algorithms. The dataset can be used to examine nerve degradation patterns to develop tools to non-invasively monitor diabetes progression while avoiding narrow-field imaging and image selection biases.