Search results for "Hyperalgesia"
showing 10 items of 78 documents
AMPK phosphorylation modulates pain by activation of NLRP3 inflammasome
2016
et al.
Transthyretin familial amyloid polyneuropathy (TTR‐FAP): Parameters for early diagnosis
2017
Abstract Background Familial transthyretin amyloidosis is a life‐threatening disease presenting with sensorimotor and autonomic polyneuropathy. Delayed diagnosis has a detrimental effect on treatment and prognosis. To facilitate diagnosis, we analyzed data patterns of patients with transthyretin familial amyloid polyneuropathy (TTR‐FAP) and compared them to polyneuropathies of different etiology for clinical and electrophysiological discriminators. Methods Twenty‐four patients with TTR‐FAP and 48 patients with diabetic polyneuropathy (dPNP) were investigated (neurological impairment score NIS; neurological disability score NDS) in a cross‐sectional design. Both groups were matched for gende…
Complex regional pain syndrome:intradermal injection of phenylephrine evokes pain and hyperalgesia in a subgroup of patients with upregulated α1-adre…
2018
The aim of this study was to determine whether upregulated cutaneous expression of α1-adrenoceptors (α1-AR) is a source of pain in patients with complex regional pain syndrome (CRPS). Immunohistochemistry was used to identify α1-AR on nerve fibres and other targets in the affected and contralateral skin of 90 patients, and in skin samples from 38 pain-free controls. The distribution of α1-AR was compared between patients and controls, and among subgroups of patients defined by CRPS duration, limb temperature asymmetry, and diagnostic subtype (CRPS I vs CRPS II). In addition, α1-AR expression was investigated in relation to pain and pinprick hyperalgesia evoked by intradermal injection of th…
Secondary tactile hypoesthesia: a novel type of pain-induced somatosensory plasticity in human subjects
2004
Quantitative sensory testing revealed that pain induced by intracutaneous capsaicin injection elicited secondary hyperalgesia coexisting with secondary tactile hypoesthesia. Mapping the areas of altered mechanical sensations adjacent to the capsaicin injection disclosed that the area of secondary hyperalgesia was always nested in a larger area of secondary hypoesthesia easily detected as numbness by most subjects. Psychometric functions revealed a twofold rightward shift of tactile detection (hypoesthesia), which coexisted with a more than fourfold leftward shift of pricking pain detection (hyperalgesia) in the same skin area. As a mechanism we propose a functional switch at the spinal leve…
The Endogenous Opioid System Is Not Involved in Modulation of Opioid-Induced Hyperalgesia
2009
Abstract Some recent studies suggested a role of the endogenous opioid system in modulating opioid-induced hyperalgesia (OIH). In order to test this hypothesis, we conducted a prospective randomized, placebo-controlled, 2-way crossover study in healthy human volunteers. We utilized a well-established model of inducing OIH after a brief exposure to the μ-opioid agonist remifentanil using intradermal electrical stimulation. Patients were exposed to a randomized 90-minute infusion of remifentanil or saline placebo during 2 separate occasions. Development of OIH was quantified using changes in the average radius of the area of secondary hyperalgesia generated by electrical pain stimulation. A 2…
TNF-α in CRPS and 'normal' trauma--significant differences between tissue and serum.
2011
Posttraumatic TNF-alpha signaling may be one of the factors responsible for pain and hyperalgesia in complex regional pain syndromes (CRPS). In order to further specify the role of TNF-alpha we investigated tissue (skin) and serum concentrations in three different patient groups: patients with osteoarthritis and planned surgery, with acute traumatic upper limb bone fracture waiting for surgery, and with CRPS I. Thirty patients (10 in each group) were recruited. Mean CRPS duration was 36.1 ± 8.1 weeks (range 8- 90 weeks). Skin punch biopsies were taken at the beginning of the surgery in osteoarthritis and fracture patients and from the affected side in CRPS patients. Blood samples were taken…
Interaction of hyperalgesia and sensory loss in complex regional pain syndrome type I (CRPS I).
2008
Background: Sensory abnormalities are a key feature of Complex Regional Pain Syndrome (CRPS). In order to characterise these changes in patients suffering from acute or chronic CRPS I, we used Quantitative Sensory Testing (QST) in comparison to an age and gender matched control group. Methods: 61 patients presenting with CRPS I of the upper extremity and 56 healthy subjects were prospectively assessed using QST. The patients’ warm and cold detection thresholds (WDT; CDT), the heat and cold pain thresholds (HPT; CPT) and the occurrence of paradoxical heat sensation (PHS) were observed. Results: In acute CRPS I, patients showed warm and cold hyperalgesia, indicated by significant changes in H…
Roles of capsaicin-insensitive nociceptors in cutaneous pain and secondary hyperalgesia.
2001
Polymodal nociceptors respond to mechanical, thermal and chemical stimuli. Whereas sensitivities to heat and to the irritant substance capsaicin have recently been linked via the properties of the vanilloid receptor type 1 receptor ion channel, sensitivity to noxious mechanical stimuli such as the pinpricks used in clinical neurology seems to be unrelated. We investigated the peripheral neural basis of pinprick pain using quantitative psychophysical techniques combined with selective conduction block by nerve compression and selective desensitization by topical capsaicin treatment. Complete A-fibre block by compression of the superficial radial nerve (criterion: loss of first pain sensation…
Hypnotic hypo- and hyperalgesia: divergent effects on pain ratings and pain-related cerebral potentials.
1993
Pain ratings and pain-related cerebral potentials in response to noxious stimuli were investigated under hypnotic hypo- or hyperalgesia. Out of a sample of 50 subjects the 10 most highly hypnotizable were selected using the Stanford Hypnotic Susceptibility Scale. Phasic pain was induced by brief electrical stimuli intracutaneously applied to the subject's left middle finger. The subjects took part in three experimental sessions. The first session was without hypnosis for familiarization with the experimental surroundings. In the two other sessions, the subjects were hypnotized and given a suggestion of analgesia or hyperalgesia with respect to pain sensation in the left hand. The sequence o…
The efficacy of acupuncture in human pain models: A randomized, controlled, double-blinded study
2012
Acupuncture is frequently used to treat pain, although data supporting the analgesic efficacy from placebo-controlled studies is sparse. In order to get evidence for acupuncture analgesia we performed a study with 2 well-recognized experimental human pain models - the cold-pressor (CP) test and intradermal capsaicin injection. Fifty healthy men were included. Our study compared Traditional Chinese Medicine-based acupuncture to sham acupuncture with Streitberger placebo needles in a randomized, controlled, double-blinded trial. The primary endpoint was the reduction of mean pain intensity during 3minutes of CP test or of mean pain intensity within 10minutes after capsaicin injection. Seconda…