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.     

Prospective study of anticardiolipin antibodies in immunized and untreated women with recurrent spontaneous abortions.

OBJECTIVE: To investigate whether active leukocyte immunization increases levels of anticardiolipin antibodies in women with recurrent spontaneous abortions. To assess the impact of anticardiolipin antibodies on pregnancy outcome in these women. DESIGN: Patients who had received various treatments in an ongoing randomized trial were studied prospectively. SETTING: A department of clinical immunology investigating women with recurrent spontaneous abortions from all over Denmark. PATIENTS: Eighty-nine patients with unexplained recurrent spontaneous abortions whose pregnancies had been completed during the course of the trial. INTERVENTIONS: After randomization, 44 patients were actively immunized with husband's or third party leukocytes, and 27 patients received placebo. Eighteen patients received anticoagulation therapy in pregnancy. MAIN OUTCOME MEASURES: Changes in levels of immunoglobulin (Ig)M class and IgG class anticardiolipin antibodies after active immunization. Frequency of new miscarriages in patients who were positive or negative for anticardiolipin antibodies. RESULTS: Neither IgM nor IgG anticardiolipin antibodies changed significantly after active immunization (P greater than 0.2). The interim results of the immunization trial showed a success rate of 68% in the treated group versus 56% in the placebo group (not significantly different). Relative risk of miscarriage in anticardiolipin antibody-positive patients compared with anticardiolipin antibody-negative patients was 1.3 (95% confidence interval 0.7 to 2.2; P = 0.4) in the combined study groups. CONCLUSIONS: Patients eligible for active immunization did not exhibit significant changes in anticardiolipin antibody levels subsequent to the treatment. The treatment did not seem to provide any overall benefit with respect to pregnancy outcome. Prospectively, the risk of miscarriage in patients positive for anticardiolipin antibodies was not significantly increased.     

Argon plasma coagulation for radiation proctitis

Radiation proctitis is a well-recognized complication following radiotherapy for pelvic malignancy. This study was designed to compare the efficacy and complications of argon plasma coagulation (APC) using the power setting of 50 W vs. 60 W in a group of patients with radiation proctitis. Forty-two patients were randomized to undergo APC using the electrical power setting of 60 W (23 patients, group A) or 50 W (19 patients, group B). Patients were asked to estimate the severity of major symptoms before and after APC using a scoring system graded 0-4. The score of major symptoms before and after APC, mean duration of the procedure, number of sessions, side effects/complications were noted. Statistical analysis was performed using Fisher's Exact Test and the 2-tailed p value less than 0.05 was considered statistically significant. A significant improvement of major symptoms was noted in all patients treated with APC, irrespective of the wattage we used, apart from the presence and severity of tenesmus. The mean number of treatment sessions to achieve control of bleeding was 1.34 for group A and 1.9 for group B and the mean time of treatment sessions was significantly shorter for group A (15 min vs. 17 min for group B). No significant differences in early side effects and long term complications between the two groups were evidenced. We can conclude that there is no statistical significance concerning efficacy and side effects of APC application between the 60W and 50W power setting, but the number of sessions and duration of the procedure tend to differ significantly. Rectal stenoses have been described only in patients treated with higher power settings.     

Improved cellular and humoral immune responses against Mycobacterium tuberculosis antigens after intramuscular DNA immunisation combined with muscle electroporation

New delivery methods are needed to improve the efficiency of existing DNA vaccines. We have measured the immune response to Mycobacterium tuberculosis antigens following intramuscular DNA injection in combination with or without electroporation. Three to 6-fold increase in the number of antigen specific CD4(+) and CD8(+) T cells, measured by IFN-gamma-producing cells in an ELISPOT assay, was found in mice DNA injected and electroporated compared with non-electroporated mice. Similarly, 5 to 10-fold increase in antigen specific IgG1, IgG2a and IgG2b antibodies were found in an immunoglobulin subclass specific ELISA. A 100-fold reduction in DNA dose could be used without loss of efficiency when immunisation was combined with electroporation. A single injection of 1 microg of antigen 85b (ag85b) plasmid DNA was sufficient to elicit a higher and long lasting level of IgG2a antibodies against antigen 85B (Ag85B) compared to standard BCG vaccination. We conclude that DNA immunisation in combination with electroporation can significantly improve the immunogenicity of plasmid-based DNA vaccines.     

Expression of IGF-II,IGFBP-2, -5, and -6 in meningiomas with different brain invasiveness

Meningiomas show clinical characteristics that vary from very benign to clearly malignant with rapid invasive growth and metastases. This study was undertaken to analyze the expression of members in the insulin-like growth factor (IGF) system in meningiomas showing different degrees of brain invasion. Tissue samples from 16 meningiomas were analyzed for members in the IGF family by mRNA in situ hybridization. The meningiomas comprised three groups: I. Benign meningiomas that did not interfere with the arachnoid plane and showed no edema. II. Benign meningiomas that did not respect the arachnoid plane and tumors that caused edema. III. Aggressive and malignant meningiomas that caused edema and showed brain invasion.IGF-II mRNA was identified in all tumors analyzed, and with a clear increase in expression observed in group III tumors. IGFBP-2 mRNA was detected in equal levels in all tumors. IGFBP-5 mRNA levels were highest in the benign group without edema (I) of meningiomas whereas IGFBP-6 mRNA levels were highest in the group with brain invasion (III). Brain invasiveness in degrees from respect of the arachnoid membrane progressing to frank brain invasion correlated with increases in IGF-II and IGFBP-6 expression. High levels of IGFBP-6 may not inhibit IGF-II actions, which is known to be growth promoting in tumors. Instead, IGFBP-6 appears to have an importance for the characteristics of edema and brain invasion in meningiomas.     

Reactive lymphoid hyperplasia 1 month after LASIK surgery

Purpose This study was conducted to investigate a case of reactive lymphoid hyperplasia following laser assisted in situ keratomileusis (LASIK). Methods A 31-year-old man who underwent LASIK presented 1 month later with a fleshy conjunctival (plical) tumor in the left eye. An excision biopsy of the tumor was performed. Results Histopathology of the excised tumor revealed reactive lymphoid hyperplasia. Discussion Conjunctival lymphomas can masquerade as chronic conjunctivitis and can be preceded by reactive lymphoid hyperplasia. It is important to identify and differentiate these tumors. This report describes the unusual occurrence of a lymphoid conjunctival tumor after LASIK eye surgery.     

The EAS temperament questionnaire--factor structure, age trends, reliability, and stability in a Norwegian sample

A population-based sample of Norwegian children aged 18 months (N = 921), 30 months (N = 784), and 50 months (N = 737) was examined with the EAS Temperament Survey (Buss & Plomin, 1984). The factor structure, psychometric properties, and stability estimates of the instrument were assessed. A cross-validation of the temperament factors of Emotionality, Activity, and Shyness show that the covariance structure conforms with the three scales described by Rowe and Plomin (1977) and Boer and Westenberg (1994). When items from the experimental scale of Sociability were included in the analysis, a four-factor solution confirmed the separate usability of this scale as well. The factor structure does not seem to vary substantially with the age of the children. The scores on the four temperament scales show high stability from one time of measurement to the next. Although no strong gender differences were found, there were significant age trends. Emotionality and Shyness increased from 18 to 50 months, while Activity and Sociability decreased. The study confirmed the structure and stability of the EAS over 3 years among young children, providing support for its use with children as young as 18 months.     

Delayed cell death related to acute cerebral blood flow changes following subarachnoid hemorrhage in the rat brain

OBJECT: The authors tested the hypotheses that subarachnoid hemorrhage (SAH) leads to delayed cell death with the participation of apoptotic-like mechanisms and is influenced by the degree of acute decrease in the cerebral blood flow (CBF) following hemorrhage. METHODS: Subarachnoid hemorrhage was induced in rats by endovascular perforation of the internal carotid artery or injection of blood into the prechiasmatic cistern. Cerebral blood flow was measured using laser Doppler flowmetry for 60 minutes. Brain sections stained with terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) showed DNA fragmentation at 2 and 7 days after both methods of inducing SAH in one third to two thirds of the surviving animals in the different experimental groups. More than 80% of the TUNEL-positive cells were neuron-specific nuclear protein-positive (neurons), but immunoreactivity to glial fibrillary acidic protein (astrocytes) and transferrin (oligodendrocytes) were markedly decreased in TUNEL-positive areas. Most of the TUNEL-positive cells displayed chromatin condensation and/or blebs and immunostained for increased Bax; approximately 50% of them were immunoreactive to cleaved caspase-3 and a few to Bcl-2. The duration of the acute CBF decrease below 30% of the baseline level was related to the degree of TUNEL staining. CONCLUSIONS: Subarachnoid hemorrhage resulted in delayed cell death in a large proportion, but not all, of the surviving animals. The acute CBF decrease was related to the degree of subsequent cell death. These findings indicated the relevance of apoptotic-like pathways. There appears to be a temporal therapeutic window during which adequate treatment might reduce the final damage following SAH.