Pain tolerance after stroke: The Tromsø study

Background

Stroke lesions might alter pain processing and modulation by affecting the widely distributed network of brain regions involved. We aimed to compare pain tolerance in stroke survivors and stroke-free persons in the general population, with and without chronic pain.

Methods

We included all participants of the sixth and seventh wave of the population-based Tromsø Study who had been tested with the cold pressor test (hand in cold water bath, 3°C, maximum time 106 s in the sixth wave and 120 s in the seventh) and who had information on previous stroke status and covariates. Data on stroke status were obtained from the Tromsø Study Cardiovascular Disease Register and the Norwegian Stroke Register. Cox regression models were fitted using stroke prior to study attendance as the independent variable, cold pressor endurance time as time variable and hand withdrawal from cold water as event. Statistical adjustments were made for age, sex, diabetes, hypertension, hyperlipidaemia, body mass index and smoking.

Results

In total 21,837 participants were included, 311 of them with previous stroke. Stroke was associated with decreased cold pain tolerance time, with 28% increased hazard of hand withdrawal (hazard ratio [HR] 1.28, 95% CI 1.10–1.50). The effect was similar in participants with (HR 1.28, 95% CI 0.99–1.66) and without chronic pain (HR 1.29, 95% CI 1.04–1.59).

Conclusions

Stroke survivors, with and without chronic pain, had lower cold pressor pain tolerance, with possible clinical implications for pain in this group.

Significance

We found lower pain tolerance in participants with previous stroke compared to stroke-free participants of a large, population-based study. The association was present both in those with and without chronic pain. The results may warrant increased awareness by health professionals towards pain experienced by stroke patients in response to injuries, diseases and procedures.     

Mitochondria and autophagy in adult stem cells: proliferate or differentiate

Journal of Muscle Research and Cell Motility - Adult stem cells are undifferentiated cells that are found in many different tissues after development. They are responsible for regenerating and...     

Sex differences in muscular load among house painters performing identical work tasks

Purpose

The present study aimed to estimate possible differences in upper body muscular load between male and female house painters performing identical work tasks. Sex-related differences in muscular load may help explain why women, in general, have more musculoskeletal complaints than men.

Methods

In a laboratory setting, 16 male and 16 female house painters performed nine standardised work tasks common to house painters. Unilateral electromyography (EMG) recordings were obtained from the supraspinatus muscle by intramuscular electrodes and from the trapezius, extensor and flexor carpi radialis muscles by surface electrodes. Relative muscular loads in %EMG_max as well as exerted force in Newton, based on ramp calibrations, were assessed. Sex differences were tested using a mixed model approach.

Results

Women worked at about 50 % higher relative muscular loads than men in the supraspinatus and forearm muscles at all percentiles and in all tasks. Women exerted about 30 % less force in the trapezius muscle at the 50th percentile.

Conclusions

Female house painters had a higher relative muscular load than their male colleagues without exerting more force. The effects of a higher relative muscular load accumulated over years of work may in part explain why musculoskeletal complaints in the upper body occur more frequently among women than men.     

Profiles of orofacial dysfunction in different diagnostic groups using the Nordic Orofacial Test (NOT-S)—A review

Objective. The Nordic Orofacial Test-Screening (NOT-S) was developed as a comprehensive method to assess orofacial function. Results from the screening protocol have been presented in 11 international publications to date. This study reviewed these publications in order to compile NOT-S screening data and create profiles of orofacial dysfunction that characterize various age groups and disorders. Materials and methods. NOT-S results of nine reports meeting the inclusion criteria were reviewed. Seven of these studies not only provided data on the mean and range of total NOT-S scores, but also on the most common domains of orofacial dysfunction (highest rate of individuals with dysfunction scores), allowing the construction of orofacial dysfunction profiles based on the prevalence of dysfunction in each domain of NOT-S. Results. The compiled data comprised 669 individuals, which included healthy control subjects (n = 333) and various patient groups (n = 336). All studies reported differences between individuals with diagnosed disorders and healthy control subjects. The NOT-S data could measure treatment effects and provided dysfunction profiles characterizing the patterns of orofacial dysfunction in various diagnoses. Conclusions. This review corroborates previous results that the NOT-S differentiates well between patients and healthy controls and can also show changes in individuals after treatment. NOT-S could be used as a standard instrument to assess orofacial dysfunction, evaluate the outcomes of oral habilitation and rehabilitation and improve comparability in clinical practice and research.     

Effects of a training programme for elderly people on mineral content of the heel bone

Physical inactivity can cause rapid bone loss. Different forms of physical activity are recommended for osteoporosis. The scientific background for such recommendations, however, is usually weak.This study was performed to evaluate whether it is possible to influence bone mineral content in elderly people by regular exercise. A total of 15 women with a mean age of 72 yr took part in a study in which they were given 1 h of training twice a week for 9 mth. Physically inactive patients from an outpatient geriatric unit served as a control group. They were matched in age and did not suffer from diseases that affect the locomotor system.After 10 mth of training no significant increase in bone mineral content, measured in the heel bone, could be found among the participants in the training group. Bone mineral content in the trained subjects was however, significantly higher after this training period than in the control group. The decrease in bone mineral content in the control group was almost the same as in a representative group of the population aged 70 to 79 yr.The cause of the decreased loss of bone mineral content in the physically-active subjects in the study could not be determined, but some contributing factors are discussed. Thus, it appears that physical activity diminishes bone loss due to age and that physical training has a positive effect on bone mineral content compared to that of nonactive controls of the same age. As there are no negative side effects, it has advantages over other forms of therapy, such as pharmacological treatment.     

An analysis of epidemiological data in HLA-typed diabetic children

Summary To clarify the heterogeneity of Type 1 (insulin-dependent) diabetes mellitus, differences between patients with different HLA risk antigens were investigated with regard to sex, age at diagnosis, season of year and calendar year at diagnosis of the disease. The study consisted of 293 HLA-typed patients from the Department of Paediatrics, University of Oulu, Oulu, Finland. HLA-Dw2 was extremely rare among diabetic patients, whereas Dw3 and Dw4 were associated with increased risk in this as in other series. Male patients more often had the HLA-A1 antigen than females. On comparison of the Dw3 positive patients, boys more frequently had the combination A1,B8 than girls. A1,B8-positive patients were more often diagnosed during the warm months, in the late summer and autumn. Patients with both Dw3 and Dw4 were younger at diagnosis when compared with the rest of the patients. The results support the concept of heterogeneity in the pathogenesis of Type 1 diabetes associated with HLA-linked genetic determinants.     

Accumulation of lipid in muscular arteries of short-term diabetic rats

Summary Lipid accumulation in muscular (pulmonary, coronary and tibial) arteries and elastic (aorta and pulmonary) arteries of streptozotocin diabetic (65 mg/kg) rats was studied with an electron microscope. Arterial tissue specimens taken 4 days after the induction of diabetes showed lipid deposits in smooth muscle cells in the muscular arteries of 9 out of 24 diabetic rats, but in none of the 17 control rats. Histochemically the lipid was identified as triacylglycerol. Lipid accumulation was not seen in the elastic arteries of either diabetic or control rats. The diabetic animals with lipid deposits had slightly but significantly higher plasma glucose concentrations (p<0.02), higher non-esterified fatty acids levels (p<0.01), and lower concentrations of plasma insulin (p<0.02) than those without arterial deposits. The amount of lipid deposited in the arteries was closely related to the plasma non-esterified fatty acid level, which was in the ranges 0.8–1.1 mmol/l in diabetic rats without deposits, and 1.1–2.4 mmol/l in those with deposits. The findings suggest that lipid accumulation in smooth muscle cells of muscular arteries during acute diabetes could result from the high plasma non-esterified fatty acid concentrations.