[Pain in patients with paraplegia]. / Schmerzen bei Patienten mit Querschnittlähmung.

Chronic pain is one of the most reported health problems in patients suffering from spinal cord injuries and is described by the patients as one of the most burdensome sequelae of paraplegia. Various types of pain, such as nociceptive, neuropathic and other types of pain can occur. In addition, multiple pathophysiological mechanisms based on the biopsychosocial pain model play a role in the origins of the pain. These aspects necessitate a multimodal pain management approach in this patient group. This article presents an overview of the occurrence, importance and pathophysiology of chronic pain following spinal cord injury as well as diagnostic and therapeutic approaches.

Usefulness of laser-evoked potentials and quantitative sensory testing in the diagnosis of neuropathic spinal cord injury pain: a multiple case study.

STUDY DESIGN: A retrospective study. OBJECTIVES: The aim of this study was to investigate the contribution of laser-evoked potentials (LEPs) and quantitative sensory testing (QST) to the diagnosis of neuropathic pain in patients with spinal cord injury (SCI) and inconclusive magnetic resonance imaging (MRI) findings. SETTING: A multidisciplinary pain center. METHODS: QST (DFNS protocol) and Tm-YAG-laser stimulation of the skin were applied within the pain site corresponding with dermatomes of altered sensation. Available MRI scans were reviewed. RESULTS: Thirteen individuals (50±16 years) with SCI were examined. In four cases with no detectable neural lesion on MRI, all QST but three LEP were abnormal. In four patients with poorly defined spinal lesion on MRI, all QST but three LEP only were abnormal. In four cases where pain was not matching adequately with MRI lesions, all patients had abnormal LEP and QST. In one patient showing a spinal cord atrophy, LEP was normal but QST was abnormal. Findings supported the diagnoses at-level (n=5) and below-level (n=8) SCI pain. Spinothalamic tract function assessed by LEP was normal in three cases, but QST was abnormal in all cases. CONCLUSIONS: As QST is a psychophysical examination depending on patient cooperation, we suggest that the combination of QST and LEP might be a valuable diagnostic tool to detect lesions of the somatosensory system in a subgroup of patients with neuropathic spinal cord injury pain and inconclusive MRI findings.

Prevalence and associated factors of pain in the Swiss spinal cord injury population.

STUDY DESIGN: Population-based, cross-sectional. OBJECTIVES: To determine pain prevalence and identify factors associated with chronic pain in individuals with spinal cord injury (SCI) living in Switzerland. SETTING: Swiss SCI Cohort Study (SwiSCI). METHODS: Pain characteristics were assessed using an adapted version of the International SCI Pain Basic Data Set, adding one item of the SCI Secondary Conditions Scale to address chronic pain. Pain prevalence was calculated using stratification over demographic, SCI-related and socioeconomic characteristics; odds ratios (adjusted for non-response) for determinants of severity of chronic pain were calculated using stereotype logistic regressions. RESULTS: Pain (in the past week) was reported by 68.9% and chronic pain by 73.5% (significant 36.9%) of all participants (N=1549; 28% female). Most frequently reported pain type was musculoskeletal (71.1%). Back/spine was the most frequently reported pain location (54.6%). Contrasting the 'significant' to the 'none/mild' category of chronic pain, adjusted odds ratios were 1.54 (95% CI: 1.18-2.01; P<0.01) for women (vs men); 6.64 (95% CI: 3.37-11.67; P<0.001) for the oldest age group 61+ (vs youngest (16-30)); 3.41 (95% CI: 2.07-5.62; P<0.001) in individuals reporting severe financial hardship (vs no financial hardship). Individuals reporting specific SCI-related health conditions were 1.41-2.92 (P<0.05) times more likely to report chronic pain as 'significant' rather than 'none/mild' compared with those without the respective condition. CONCLUSIONS: Pain is highly prevalent in individuals with SCI living in Switzerland. Considered at risk for chronic pain are women, older individuals and individuals with financial hardship and specific secondary health conditions. Longitudinal studies are necessary to identify predictors for the development of pain and its chronification.

Short lasting transient effects of a capsaicin 8% patch on nociceptor activation in humans.

BACKGROUND: At high concentration, the TRPV-1 agonist capsaicin de-sensitizes nociceptors and reduces the intra-epidermal nerve density. METHODS: We investigated the effects of a 5 × 10 cm capsaicin 8% patch on C- and A-delta-nociceptor activation in ten healthy subjects before and at days 1-3-7-21 after patch application. Thermal thresholds, infrared thulium-YAG laser-evoked potentials (LEP) and heat pain (numeric rating scale, NRS, 0-10), electrically induced pain (10 pulses, 1.5-fold pain threshold intensity, five randomized series of 5-10-20-50-100 Hz), and axon-reflex flare (laser Doppler imaging) were recorded. RESULTS: Thermal hypoesthesia developed upon capsaicin 8% treatment. Warmth detection thresholds increased at day 1-3, heat pain thresholds were increased by about 2.6 °C after day 3, and laser-evoked heat pain remained significantly reduced for 7 days. Axon-reflex flare responses (days 1-3), but not supra-threshold electrically induced pain were significantly reduced by the capsaicin patch. CONCLUSIONS: Axonal nociceptor function assessed by electrical excitability tests supplements threshold tests of nociceptive endings. The differential analgesic effects of 8% capsaicin patches may be attributed to the kinetics of capsaicin and the different depth of nociceptive nerve fibres, yet, the time course does not match the long-lasting analgesia observed in neuropathic pain patients treated with the same patch. WHAT DOES THIS STUDY ADD?: Axonal nociceptor function assessed by supra-threshold electrical excitability tests did not coincide with capsaicin-induced transduction changes supplementing threshold measures of terminal nociceptor endings. Threshold measurements do not reflect the sustained effect of pain relief seen in neuropathic pain patients. Capsaicin-sensitive nociceptors responsible for spontaneous pain are either not specifically tested with currently available sensory stimulation protocols or have higher capsaicin sensitivity or slower recovery under neuropathic conditions.

Pain assessment according to the International Spinal Cord Injury Pain classification in patients with spinal cord injury referred to a multidisciplinary pain center.

STUDY DESIGN: This is a retrospective study. OBJECTIVES: The aim of this study was to investigate the epidemiology of pain types in patients with spinal cord injury (SCI) according to the International Spinal Cord Injury Pain (ISCIP) classification. SETTING: This study was conducted in a multidisciplinary pain center. METHODS: Socio-demographic and clinical data were examined and ISCIP classification was applied. RESULTS: Sixty-six individuals (51±13 years) with SCI had pain, a lesion older than 5 years in 67% and a pain history older than 5 years in 54% of patients. According to the ISCIP classification, nociceptive pain was present in 58% (musculoskeletal pain) and 3% (visceral pain) of the patients. At-level, below-level neuropathic pain and other neuropathic pain were observed, respectively in 53, 42 and 5% of patients. Unknown pain type was found in 8% of patients. Patients with complete lesions showed significantly more frequent neuropathic pain (P=0.021) and more frequent at-level SCI pain (P=0.00) compared with those with incomplete lesions. Patients with paraplegia had more often at-level pain (P=0.00), whereas patients with tetraplegia reported more often below-level pain (P=0.00). Patients had severe pain (mean intensity: 8.2 (±1.6) on a 0 to 10 numerical scale) and showed high grades of pain chronicity. Mild to severe depression and anxiety were present, respectively in 53 and 56% of patients. The health-related quality of life was low. CONCLUSION: The use of the ISCIP classification in a clinical setting is mirroring the very complex pain situation in patients with SCI referred to a multidisciplinary pain center, and it might be an important step for adequate pain therapy.

[Nondermatomal somatosensory deficits in chronic pain patients]. / Nichtdermatomgebundene somatosensorische Defizite bei chronischen Schmerzpatienten.

Nondermatomal somatosensory deficits (NDSDs) are frequently found in chronic pain patients and allude to pain sensitization and pain centralization. In the clinical examination NDSDs are as a rule accompanied by hyposensitivity to touch and heat perception often with a quadrantal or hemibody distribution. The majority of NDSD patients show a trigger episode with a somatic nociceptive trauma in the case history. These somatic findings, however, never fully explain the pain disorder, analogue to the complex regional pain syndrome (CRPS). Most patients with chronic pain disorders as well as those with NDSD often report an antecedent period of high psychobiological stress. The data from functional imaging reveal a complex pattern of a central nervous dysregulation.

Radioguided occult lesion localization (ROLL) for treatment and diagnosis of malignant and premalignant breast lesions combined with sentinel node biopsy: a prospective clinical trial with 100 patients.

UNLABELLED: Advanced breast cancer screening techniques and their availability increased the number of non-palpable breast lesions requiring surgery. Consequently reliable and efficient therapeutic management permitting accurate localization and removal of these occult lesions is essential. AIMS: In our study we evaluated radioguided occult lesion localization (ROLL) for effectiveness of localization, oncological safety and feasibility of concomitant sentinel node biopsy. METHODS: Hundred patients (120 lesions) underwent ROLL and tumour excision with or without sentinel node biopsy after confirmed histopathological findings via intra-tumoral injection of Tc99m-labelled macro-aggregate albumin for ROLL and Tc99m-labelled nanocolloids with periareolar-subdermal injection for simultaneous sentinel node biopsy. RESULTS: Our detection rate for ROLL was 98.3%, respectively, 98.6% for sentinel nodes in cases of concomitant sentinel node biopsy. We had a radical excision rate of 55 out of 69 cases of invasive ductal cancer and 17 out of 26 cases of DCIS to achieve 1mm, respectively, 10 mm tumour-free margins. CONCLUSIONS: Intra-tumoral tracer injection of for ROLL and periareolar-subdermal tracer injection for simultaneous sentinel node biopsy seem to be a sensitive technique. According to our results ROLL is a safe, precise and simple technique permitting definitive therapeutic removal of malignant or premalignant breast lesions. The high detection rate of the sentinel node in cases with concomitant sentinel node biopsy shows that the combination of both procedures is possible and safe. In our opinion ROLL is an excellent therapeutic option after histological confirmation of malignancy or premalignant disease.

Influence of oestrogens on formation of reactive oxygen species in liver microsomes of differently aged male Wistar rats.

Metabolic pathways of oestrogens are the formation of catechol oestrogens (CE; 2- and 4-hydroxy-oestrogens), redox cycling of CE and free radical generation, mediated through cytochrome P450 (P450) oxidase/reductase activity. We checked the oestrogens oestradiol (E2), oestradiol valerate (E2V) and ethinyloestradiol (EE2) for formation of reactive oxygen species in vitro and ex vivo in male Wistar rats in dependence on age. In liver microsomes of 10-, 30-, 60- and 270-day-old rats the influence of E2, E2V and EE2 (10(-7)-10(-3) M) on NADPH-Fe(++)-stimulated lipid peroxidation (LPO), H2O2 generation and lucigenin (LUC) and luminol (LUM) amplified chemiluminescence (CL) was investigated. The same parameters, additionally P450 content and monooxygenase activities were measured in liver 9000 x g supernatants after subchronic administration of the oestrogens (1, 10 mg/kg b. wt. orally). The most important results are the strong inhibitory capacities of the oestrogens in vitro on LPO in the order of E2V < E2 < EE2, most pronounced in 10-, 60- and 270-day-old animals. In microsomes of 30-day-old rats with the highest control LPO the antioxidative effect of the oestrogens was lower. Whereas the H2O2 generation was not changed by E2, enhanced by E2V, but diminished by EE2 in all age groups, CL(LUC) and CL(LUM) were inhibited in the order of E2 < E2V < EE2. Also after subchronical treatment of the rats the antioxidative action of the oestrogens was evident, microsomal LPO was inhibited in the order of E2 < E2V < EE2. All oestrogens inhibited ethylmorphine N-demethylation. But enhanced H2O2 generation and increased CL(LUC) also indicate a formation of reactive oxygen species by these oestrogens. Obviously in vitro the antioxidative phenolic structure of the oestrogens dominates, whereas after in vivo administration the dose- and age-dependent biotransformation produces prooxidative in addition to antioxidative structures.

Consistency of observations of forest tree defoliation in three European countries.

The crown densities of 186 trees of five common European tree species (Norway spruce (Picea abies), silver fir (Abies alba), Scots pine (Pinus sylvestris), oak (Quercus robur) and beech (Fagus sylvatica) were assessed simultaneously by observation teams from France, Germany and the United Kingdom. Major differences in the scores existed, with the maximum difference on any one tree being 45%. Differences tended to be consistent, with the French team scoring more lightly than the German team and the German team more lightly than the UK team. The differences throw into question the value of international comparisons of forest condition, particularly the use of comparative tables of the extent of "forest decline" in individual European countries.