Experimental data on age-related changes in pain perception have so far been contradictory. It has appeared that the type of pain induction method is critical in this context, with sensitivity to heat pain being decreased whereas sensitivity to pressure pain may be even enhanced in the elderly. Furthermore, it has been shown that temporal summation of heat pain is more pronounced in the elderly but it has remained unclear whether age differences in temporal summation are also evident when using other pain induction methods. No studies on age-related changes in spatial summation of pain have so far been conducted. The aim of the present study was to provide a comprehensive survey on age-related changes in pain perception, i.e. in somatosensory thresholds (warmth, cold, vibration), pain thresholds (heat, pressure) and spatial and temporal summation of heat and pressure pain. We investigated 20 young (mean age 27.1 years) and 20 elderly (mean age 71.6 years) subjects. Our results confirmed and extended previous findings by showing that somatosensory thresholds for non-noxious stimuli increase with age whereas pressure pain thresholds decrease and heat pain thresholds show no age-related changes. Apart from an enhanced temporal summation of heat pain, pain summation was not found to be critically affected by age. The results of the present study provide evidence for stimulus-specific changes in pain perception in the elderly, with deep tissue (muscle) nociception being affected differently by age than superficial tissue (skin) nociception. Summation mechanisms contribute only moderately to age changes in pain perception.

Hyperactivity of N-methyl D-aspartate (NMDA) receptors may be one of the factors in the maintenance of persistent stump and phantom limb pain. Ketamine (bolus at 0.1 mg/kg/5 min followed by an infusion of 7 micrograms/kg/min) was administered intravenously to 11 patients with established stump and phantom limb pain in a double-blind saline-controlled study. All 11 patients responded with a decrease in the rating of stump and phantom limb pain assessed by visual analogue scale (VAS) and McGill Pain Questionnaire (MPQ). Ketamine increased pressure-pain thresholds significantly. Wind-up like pain (pain evoked by repeatedly tapping the dysaesthetic skin area) was reduced significantly by ketamine. In contrast, no effect was seen on pain evoked by repeated thermal stimuli. Side effects were observed in nine patients. The results support the notion that stump and phantom pain are generated by activity in afferent fibres activated by mechanical but not by thermal stimuli and that the NMDA receptor is involved in the maintenance of postamputation pain states. NMDA receptor antagonists may have a potential in the treatment of stump and phantom limb pain.

This study examined the sensory abnormalities in an unselected, consecutive group of patients with central post-stroke pain (CPSP) surviving more than 1 year after stroke. The sensory examination included clinical examination and quantitative measures with detection and pain thresholds to heat and cold stimuli, argon laser, von Frey hair and determination of stimulus-response function in the 10-45 degrees C range. Sensory examination was in 11 identified CPSP patients (5 female, 6 male; aged 43-80 years) carried out in the painful area using the contralateral homologue area as reference. Pain rating was performed using the McGill Pain Questionnaire and a VAS scale. All patients had ischemic (MRI verified) infarction. Of the 11 patients with supratentorial lesions, 5 had thalamic lesions; in addition, 7 patients had lesions in the brain stem/cerebellum. Median present spontaneous pain intensity on the VAS scale was 3.3 (range: 0-7.7). All patients had pain in the body part with sensory abnormalities, which in 8 patients extended the area with pain. Warm detection threshold was higher in the pain area in all patients, and all except 1 patient had increased cold detection threshold. Cold and heat pain thresholds were raised as well, but to a lesser degree. Sensibility to touch (von Frey hairs) and pain (argon laser) were changed in only 4 and 3 patients, respectively. A stimulus-response curve in the 10-45 degrees C range showed different patterns compared to the non-affected side. A cold allodynia in the 10-45 degrees C range was present in the painful area in 6 (56%) of the patients. The results support the theory that damage to the spino-thalamo-cortical pathway is a necessary condition in CPSP. It is proposed that the spontaneous pain in CPSP is linked to hyperexitability or spontaneous discharges in thalamic or cortical neurons that have lost part of their normal input.

Ten patients (4 female, 6 male) aged 34-67 years suffering from peripheral neuropathic pain participated in a double-blind placebo-controlled study where ketamine or magnesium chloride were administered by a 10 min bolus infusion (ketamine: 0.84 mumol/kg = 0.2 mg/kg, magnesium: 0.16 mmol/kg) followed by a continuous infusion (ketamine: 1.3 mumol/kg/h = 0.3 mg/kg/h, magnesium: 0.16 mmol/kg/h). Ongoing pain determined by VAS score, area of touch-evoked allodynia, detection and pain thresholds to mechanical and thermal stimuli were measured before and during drug infusion. Ketamine produced a significant reduction of spontaneous pain (57%) and of the area of allodynia (33%). Magnesium chloride reduced pain (29%) and area of allodynia (18%) insignificantly. Following ketamine there was a significant correlation between the reduction in ongoing pain and reduction in area of touch-evoked allodynia. Detection and pain thresholds to mechanical and thermal stimuli were not significantly changed by the drugs. These findings suggest that both ongoing pain and touch-evoked pain (allodynia) in neuropathic pain are inter-related phenomena, which may be mediated by the same mechanism and involving a N-methyl-D-aspartate receptor.

Objective: To determine the effect of a shared care programme on the attitudes of newly referred cancer patients towards the healthcare system and their health related quality of life and performance status, and to assess patients' reports on contacts with their general practitioner (GP). Setting: Department of Oncology at Aarhus University Hospital and general practices. Design: Randomised controlled trial in which patients completed questionnaires at three time points. The shared care programme included transfer of knowledge from the oncologist to the GP, improved communication between the parties, and active patient involvement. Participants: 248 consecutive cancer patients recently referred to the department. Main outcome measures: Patients' attitudes towards the healthcare services, their health related quality of life, performance status, and reports on contacts with their GPs. Results: The shared care programme had a positive effect on patient evaluation of cooperation between the primary and secondary healthcare sectors. The effect was particularly significant in men and in younger patients (18-49 years) who felt they received more care from the GP and were left less in limbo. Young patients in the intervention group rated the GP's knowledge of disease and treatment significantly higher than young patients in the control group. The number of contacts with the GP was significantly higher in the intervention group. The EORTC quality of life questionnaire and performance status showed no significant differences between the two groups. Conclusions: An intersectoral shared care programme in which GPs and patients are actively involved has a positive influence on patients' attitudes towards the healthcare system. Young patients and men particularly benefit from the programme. P atients with cancer may feel uncertain about what is going to happen when they are referred to hospital and they may experience psychological morbidity and dissatisfaction with the provision of information and care.1 They have stressed the importance of the following aspects in their contact with the healthcare service: doctors' technical competence, communication skills, continuity of care, family care, and financial circumstances.2 Most patients with cancer are treated as outpatients and may therefore feel left alone at crucial moments. At such times they often consult their general practitioner (GP) for further advice, information, and repetition of information. These contacts place the GP in a key position in which s/he may have problems due to lack of specific knowledge of cancer and lack of collaboration with the oncologists. [3][4][5] This situation occurs frequently and may be remedied by sharing the care between GPs and oncologists.Shared care has been defined as "care [which] applies when the responsibility for the health care of the patient is shared between individuals or teams who are part of separate organisations, or where substantial organisational boundaries exist".6 It implies personal communication and organised trans...

We have compared the analgesic efficacy of the racemic mixture and the stereoisomer (S+) of the NMDA antagonist ketamine. In a double-blind, three-way crossover, placebo-controlled study, we assessed the following: pain evoked by small/large area pressure stimuli, pain detection threshold and pain ratings to small/large area of heat stimuli, pain detection threshold and pain rating to heat stimuli of brief/long duration, summation pain threshold and pain ratings to repeated heat/electrical stimuli, side effects and reaction time. Plasma concentrations of 350 ng ml-1 for ketamine (racemic) and 180 ng ml-1 for ketamine (S+) were tried. We found that ketamine (racemic) prolonged the reaction time more than ketamine (S+). Both drugs affected pain caused by repeated stimuli or stimuli of long duration equally or more than a single stimulus of short duration. They also affected pain evoked from large areas equally or more than pain evoked from small areas. The (S+)-isomer was approximately twice as potent as the racemic mixture of ketamine in inhibiting central summation.

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Inhibition of the MA-shuttle during ischaemia and early reperfusion is proposed as a mechanism to reduce IR injury.