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Biomedical subjects

P Hansson

Publications and source records attributed to P Hansson.

At least 19 recordsLinked to original sources
PubMed2006

EFNS guidelines on pharmacological treatment of neuropathic pain.

Neuropathic pain treatment remains unsatisfactory despite a substantial increase in the number of trials. This EFNS Task Force aimed at evaluating the existing evidence about the pharmacological treatment of neuropathic pain. Studies were identified using first the Cochrane Database then Medline. Trials were classified according to the aetiological condition. All class I and II controlled trials (according to EFNS classification of evidence) were assessed, but lower-class studies were considered in conditions that had no top level studies. Only treatments feasible in an outpatient setting were evaluated. Effects on pain symptoms/signs, quality of life and comorbidities were particularly searched for. Most of the randomized controlled trials included patients with postherpetic neuralgia (PHN) and painful polyneuropathies (PPN) mainly caused by diabetes. These trials provide level A evidence for the efficacy of tricyclic antidepressants, gabapentin, pregabalin and opioids, with a large number of class I trials, followed by topical lidocaine (in PHN) and the newer antidepressants venlafaxine and duloxetine (in PPN). A small number of controlled trials were performed in central pain, trigeminal neuralgia, other peripheral neuropathic pain states and multiple-aetiology neuropathic pains. The main peripheral pain conditions respond similarly well to tricyclic antidepressants, gabapentin, and pregabalin, but some conditions, such as HIV-associated polyneuropathy, are more refractory. There are too few studies on central pain, combination therapy, and head-to-head comparison. For future trials, we recommend to assess quality of life and pain symptoms or signs with standardized tools.

AIDS-Associated Nephropathy↗
PubMed2005

Considerable differences between methods for plasma D-dimer in the diagnosis of venous thrombosis: increased positive prediction using elevated discriminatory limits.

Four analytical methods for plasma D-dimer have been compared in a group of 82 consecutive patients with suspected venous thrombosis, 22 of whom subsequently received a positive clinical diagnosis. Differences in diagnostic power between methods were observed. In three of the four methods tested, the use of elevated discriminatory limits (rather than conventional 95-percentile upper reference limits) resulted in stronger positive predictive values for thromboembolism. We suggest that this approach may result in better diagnostic performance of the D-dimer method.

Adult↗
PubMed2004

Mixed micelles of fluorocarbon and hydrocarbon surfactants. A small angle neutron scattering study.

Mixtures of the partly fluorinated cationic surfactant HFDePC (N-(1, 1,2,2-tetrahydroperfluorodecanyl)-pyridinium chloride and deuterated headgroup) with C16TAC, hexadecyl-trimethylammonium chloride, have been investigated using small angle neutron scattering with contrast matching. Earlier results from this system suggested that a demixing occurred, into two coexisting populations of micelles, hydrocarbon-rich and fluorocarbon-rich, respectively. The present results could be explained by one type of mixed micelles with an inhomogeneous distribution of fluorinated and hydrogenated surfactants within the micelles although a demixing cannot be definitely excluded.

Journal Article↗
PubMed2004

Post-stroke pain case study: clinical characteristics, therapeutic options and long-term follow-up.

Central post-stroke pain (CPSP) is a syndrome characterized by sensory disturbances and neuropathic pain. In 40%-60% of CPSP patients, the onset of central pain following a stroke occurs more than 1 month after the stroke, creating a source of diagnostic uncertainty or significant delay in treatment since healthcare providers familiar with CPSP may no longer be caring for the patient when the symptoms occur. In addition to chronic pain, the presence of somatosensory abnormalities is the most important diagnostic corollary of CPSP. Neuropathic or central pain has been estimated to occur in up to 8% of patients after a stroke, and about 18% of stroke patients with a somatosensory disturbance will develop CPSP. Although largely a matter of conjecture, it is generally agreed that damage to spinothalamic sensory pathways plays a significant role in the pathogenesis of CPSP. A comprehensive examination of the patient for sensory deficits is essential before treatment can be initiated. Functional disturbances such as depression, anxiety and sleep disturbances are significant comorbid conditions associated with CPSP; the physician should incorporate an assessment of these potential comorbidities into the examination. Treatment options for CPSP are limited; at present, amitriptyline is the drug of first choice. Other drugs including antidepressants, anticonvulsants, antiarrhythmics, opioids and N-methyl-d-aspartate antagonists may provide relief for some patients who do not respond to amitriptyline. Included in this review is a case study outlining the challenges of managing the patient with CPSP.

Adult↗
PubMed2001

Phosphatidylethanol in post-mortem blood as a marker of previous heavy drinking.

Phosphatidylethanol (PEth) is an ethanol-phospholipid adduct, formed via non-oxidative metabolism of ethanol. PEth was measured in femoral blood from 85 consecutive forensic autopsies and was detected in 35 of the cases at concentrations ranging from 0.8 to 22.0 micromol/l. Of the PEth positive cases, 12 did not have significant levels of ethanol in the blood. Two cases (both suicides involving hanging) had detectable ethanol, but no PEth present in the blood. We conclude that measurements of PEth provide indications of previous alcohol abuse in cases where this may not otherwise be evident.

Adult↗
PubMed2000

Antiretroviral therapy may improve sensory function in HIV-infected patients: a pilot study.

OBJECTIVE: To evaluate thermal and nociceptive function in a prospective, longitudinal study of 49 consecutive HIV-1-infected patients before and at 1, 4, and 8 months after initiation of highly active antiretroviral therapy. METHODS: Quantitative assessments of thermal perception thresholds for warmth (dWT), cold (dCT), and heat pain (HPT) were performed. CD4+ cell levels in blood and HIV-1 RNA levels in plasma were determined. Depending on the virologic response to treatment, the patients were divided into two groups: responders (37 of 49, 76%) and nonresponders (12 of 49, 24%). RESULTS: Before treatment, impairment of dWT was found in 26 of 49 patients, of dCT in 33 of 49 patients, and of HPT in 19 of 49 patients. Improvements of perception thresholds for dWT (p < 0.0001), dCT (p < 0.001), and HPT (p < 0.01) were observed after 8 months of treatment in the responder group but not in the nonresponders. Within the responder group, improved thermal perception thresholds was associated with higher pretreatment CD4+ levels than in patients without improvement. CONCLUSIONS: Virologically successful antiretroviral combination therapy of HIV-1-infected patients has a capacity to improve function of the thermal and nociceptive systems, especially in patients with less advanced immunodeficiency.

Adult↗
PubMed2000

Normalization rate and cellular localization of phosphatidylethanol in whole blood from chronic alcoholics.

Phosphatidylethanol (PEth) is an abnormal phospholipid which is formed in the presence of ethanol, via the action of phospholipase D (PLD). PEth in blood is a potential marker of alcohol abuse. The present study was made to determine the compartmentalization and the elimination rate of PEth in human whole blood. PEth was assayed by an improved HPLC technique, with evaporative light-scattering detection. Blood from six alcoholic males was separated into different blood cell fractions. The PEth concentration in whole blood was 2.5+/-0.9 and 1.9+/-1.1 micromol/l in erythrocytes. Only one subject had detectable PEth in the mononuclear cells. Fifteen patients (13 men, two women) with chronic alcoholism, were followed as inpatients, after admission to an alcohol detoxification clinic. PEth, carbohydrate-deficient transferrin (CDT) and gamma-glutamyltransferase (GGT) were measured on days 1, 3, 5 and 7 after admission. Linear regression analysis of logarithmic PEth values in individuals, with measurable PEth at day 1, gave a good fit (P<0.001) with the one-compartment elimination model. The half-life was calculated as 4.0+/-0.7 days. A weak significance (P<0.05) was observed in the correlation of PEth at day 1 and half-life values of the same subjects.

Alcoholism↗
PubMed2000

The influence of pain intensity on somatosensory perception in patients suffering from subacute/chronic lateral epicondylalgia.

A confounding factor in the analysis of chronic pain patients is the finding of signs of somatosensory disturbances not only in neuropathic pain patients but also in a subgroup of patients with musculoskeletal pain. The purpose was to investigate if patients suffering from subacute/chronic lateral epicondylalgia demonstrated altered sensibility, and if this was affected by pain intensity. At the start of the experiment, quantitative sensory testing (QST) (thermal, pressure pain, touch) was performed in the local pain area and in the area of pain referral. QST was repeated following pain provocation (weight lifting). A local anaesthetic was then injected into the lateral epicondyle and QST was repeated in the area of pain referral. The contralateral arm was assessed, treated and injected in the same way. At the baseline assessment there was no difference in sensibility between sides, with the exception of a significantly lowered threshold to noxious heat (p<0.04) in the area of pain referral, present during the whole experiment. In the affected arm only, weight lifting resulted in significantly increased pain intensity in the local (p<0.01) and referred (p<0.01) pain areas, respectively. Repeated muscle contractions resulted in altered somatosensory functions in both the affected arm and the unaffected arm, consequently not dependent on ongoing pain in the assessed area. Tactile perception thresholds increased significantly following pain provocation in the area of pain referral (p<0.04) only and normalized following injection of local anaesthetic (p<0.02), indicating that the sensitivity to light touch was altered by the nociceptive input from the affected arm.

Adult↗
PubMed2000

Injection of hypertonic saline into musculus infraspinatus resulted in referred pain and sensory disturbances in the ipsilateral upper arm.

A confounding factor in the analysis of chronic pain patients is the finding of somatosensory disturbances not only in neuropathic pain patients, but also in a subgroup of patients with musculoskeletal pain. The purpose of the study was to examine if referred pain, induced by intramuscular injections of hypertonic saline (5% NaCl) into the left musculus infraspinatus, resulted in somatosensory alterations. Thermal sensitivity, pressure pain sensitivity, as well as low threshold mechanoreceptive function, were assessed in the referred pain area and the homologous contralateral site before, during and following the injections. In 10 out of 12 subjects the procedure induced only referred pain localized in the dorsolateral part of the ipsilateral proximal upper arm. In this referred pain area there was a significantly decreased sensitivity to light touch, as tested with von Frey filaments, during the pain period and the post-injection period compared to the contralateral side (p<0.004 and p<0.009, respectively). A trend for thermal hypoaesthesia, which was only demonstrable in the sum of warm and cold thresholds, was found in the referred pain area, but not contralaterally, during the pain period compared to the pre-injection period. Significantly increased sensitivity to threshold and suprathreshold heat pain was found bilaterally during post-injection assessments (p<0.02 and p<0.006, respectively). There were no statistically significant changes in sensitivity to innocuous thermal stimuli when assessing the two percepts separately, or to pressure pain or brush-evoked touch. In conclusion, intramuscular injections of hypertonic saline resulted in referred pain and tactile hypoaesthesia in the referred pain area.

Adult↗
PubMed1999

A PET activation study of dynamic mechanical allodynia in patients with mononeuropathy.

The objective of this study was to investigate the central processing of dynamic mechanical allodynia in patients with mononeuropathy. Regional cerebral blood flow, as an indicator of neuronal activity, was measured with positron emission tomography. Paired comparisons were made between three different states; rest, allodynia during brushing the painful skin area, and brushing of the homologous contralateral area. Bilateral activations were observed in the primary somatosensory cortex (S1) and the secondary somatosensory cortex (S2) during allodynia compared to rest. The S1 activation contralateral to the site of the stimulus was more expressed during allodynia than during innocuous touch. Significant activations of the contralateral posterior parietal cortex, the periaqueductal gray (PAG), the thalamus bilaterally and motor areas were also observed in the allodynic state compared to both non-allodynic states. In the anterior cingulate cortex (ACC) there was only a suggested activation when the allodynic state was compared with the non-allodynic states. In order to account for the individual variability in the intensity of allodynia and ongoing spontaneous pain, rCBF was regressed on the individually reported pain intensity, and significant covariations were observed in the ACC and the right anterior insula. Significantly decreased regional blood flow was observed bilaterally in the medial and lateral temporal lobe as well as in the occipital and posterior cingulate cortices when the allodynic state was compared to the non-painful conditions. This finding is consistent with previous studies suggesting attentional modulation and a central coping strategy for known and expected painful stimuli. Involvement of the medial pain system has previously been reported in patients with mononeuropathy during ongoing spontaneous pain. This study reveals a bilateral activation of the lateral pain system as well as involvement of the medial pain system during dynamic mechanical allodynia in patients with mononeuropathy.

Adult↗
PubMed1999

Pain in ambulatory HIV-infected patients with and without intravenous drug use.

The prevalence of pain in 211 HIV-infected patients with and without intravenous drug use was assessed and the prognostic information inherent in pain reporting was evaluated, using a questionnaire on pain and HIV-related symptoms combined with data on disease classification, route of HIV transmission, CD4+ lymphocyte counts in blood (CD4) and mortality rates at 15 months after completing the questionnaire. The pain prevalence was significantly higher among intravenous drug users (IDUs) compared with non-IDUs [76/89 (85%) vs 87/122 (71%);p<0.05], especially among the patients classified as asymptomatic [43/53 (81%) vs 35/59 (59%);p = 0.01]. No significant difference was found among AIDS patients. In non-IDUs, a strong correlation was found between HIV disease stages according to the Centers for Disease Control classification (CDC) and pain prevalence (CDC A: 59%vs B: 74%vs C: 96%, p<0.001), and between the number of concurrent pain sites and both the CD4 levels (no pains: CD4 0.26 x 10(9)/l vs 1-2 pain sites: CD4 0.22 vs>2 pain sites: CD4 0.09;r = 0.35, p<0.001), and the mortality rate [no pains: 2/35 (6%) vs 1-2 pain sites: 8/45 (18%) vs> 2 pain sites: 12/42 (29%), p<0.01]. In IDUs, no such correlations were found. Our data demonstrates differences in the development, prevalence and prognostic value of pain among HIV-infected patients, with and without intravenous drug use, clearly indicating the need to differentiate risk groups in pain related studies. Copyright 1999 European Federation of Chapters of the International Association for the Study of Pain.

Journal Article↗
PubMed1999

Pressure pain thresholds in different tissues in one body region. The influence of skin sensitivity in pressure algometry.

This study aimed at determining whether there are differences in pressure pain sensitivity in different tissues in the same body region when systematically assessed, before and after skin hypoesthesia. Pressure pain thresholds (PPTs) were assessed bilaterally in 15 healthy females at the bony part of the epicondylus lateralis humeri, at the belly of m. extensor carpi ulnaris and at m. brachioradialis where the superficial radial nerve branches pass underneath ("muscle/nerve" site). Following a double blind design, a local anaesthetic cream (EMLA) or a control cream was applied to the skin and PPTs were reassessed. The PPT was significantly (p < 0.001) lower at the "muscle/nerve" site than at the bony and "pure" muscle sites. The PPTs over the bony and "pure" muscle sites did not differ. There was no significant difference when PPTs were compared before and after application of EMLA cream. However, PPTs after control cream were lower (p < 0.001) over all examined areas than those obtained prior to cream application. Thus, EMLA cream increased PPTs compared to control sites in all examined areas (p < 0.001). Under the given circumstances, skin pressure pain sensitivity was demonstrated to influence the PPT.

Adult↗
PubMed1999

Somatosensory status after pedicled or free TRAM flap surgery: a retrospective study.

The transverse rectus abdominis musculocutaneous (TRAM) flap is widely used in autologous breast reconstructions. In transferring tissue as a pedicled or free flap, alterations in sensibility are unavoidable. This study evaluated somatosensory function in the reconstructed breast at least 2 years after pedicled or free TRAM flap surgery. Thirteen patients who had a pedicled TRAM flap and 13 patients who had a free TRAM flap participated in the study. The patients completed a questionnaire regarding subjective sensibility and their general opinion of the reconstructed breast. Somatosensory examinations to study the sensations of touch, warmth, cold, and pain were performed using nonquantitative and quantitative techniques. An age-matched control group of eight women who had never had breast surgery was also examined because the majority of the women who had breast reconstruction also had a mammaplasty performed on the contralateral breast, which disqualified it as a control. The majority of the patients reported that the reconstructed breast felt like a real breast. However, sensibility to touch, warmth, cold, and pain was decreased in the study groups compared with the control group. No clinically significant differences existed in sensibility between the pedicled and free TRAM flap groups.

Adult↗
PubMed1998

Effects of calcitonin gene-related peptide-(8-37) on withdrawal responses in rats with inflammation.

The present study was performed to explore the effect of subcutaneous injection of carrageenan into the rat plantar region on hindpaw edema formation and the latency of hindpaw withdrawal to presumed nociceptive stimulation. Subcutaneous injection of carrageenan into the left hindpaw induced a significant increase in the volume of the left hindpaw, leaving the right side unaffected. In addition, we found a bilateral decrease in hindpaw withdrawal latency to heat and mechanical, but not to cold stimulation. The decreased bilateral hindpaw withdrawal latency to heat stimulation lasted for 14 days after carrageenan injection. The decreased bilateral hindpaw withdrawal latency to mechanical stimulation lasted for 2 days after the injection, then reversed and increased from day 3 to 14. Intrathecal injection of either 10 nmol of calcitonin gene-related peptide 8-37 or 26.6 nmol of morphine induced significant bilateral increases in hindpaw withdrawal latency, which were more pronounced with the morphine. The results show that experimentally induced unilateral hindpaw inflammation induces a bilateral decrease in hindpaw withdrawal latencies to presumed nociceptive stimulation while the sensory systems for heat and mechanical stimulation were differently affected after carrageenan injection.

Analgesics, Opioid↗
PubMed1998

[Pain analysis is vital in rheumatic diseases. The pain is often the patient's worst problem].

The article consists of a synthesis of a rheumatic pain symposium held at the annual meeting of the Swedish Medical Association in 1996. Various aspects of pain in rheumatic diseases were discussed, such as physiological, neurohumoral and neurogenic mechanisms, sensory stimulation treatment, differentiation of mechanical and inflammatory pain, quality enhancement by improved cooperation between primary and tertiary care facilities, pharmacological treatment with (centrally and peripherally acting) opioids, selective cyclo-oxygenase inhibitors, and NMDA (N-methyl-D-aspartate) receptor antagonists. The aim of the symposium, with its focus on the manifest pain problem, was to improve our knowledge and skill in the understanding and treatment of this large patient category. For patients with rheumatic disorders exacerbated by pain problems, as for other patients, a pain diagnosis is of fundamental importance. This can be achieved by analysis of the social, psychological, physiological and medical factors contributing to the cause and degree of pain and to pain behaviour, and of the extent to which the pain may be nociceptive (i.e., inflammatory, mechanical, or ischaemic in origin), neurogenic or idiopathic. Pain analysis should be followed by individualised treatment focused on the patient's most crucial problems, thus enhancing the prospect of optimal treatment outcome.

Analgesia↗