The perception threshold counterpart to dynamic and static mechanical allodynia assessed using von Frey filaments in peripheral neuropathic pain patients

2011 ◽  
Vol 2 (1) ◽  
pp. 9-16 ◽  
Author(s):  
Åsa H. Landerholm ◽  
Per T. Hansson
Keyword(s):  
Neuropathic Pain ◽  
Nerve Block ◽  
Mechanical Allodynia ◽  
Threshold Level ◽  
Mechanical Stimulus ◽  
Perception Threshold ◽  
Static Mechanical ◽  
Continuous Nerve Block ◽  
C Fibre ◽  
Myelinated Fibres

AbstractBackground and aimPain due to a usually non-painful mechanical stimulus, mechanical allodynia, is an oppressive symptom in subgroups of patients with neuropathic pain. Dynamic mechanical allodynia (DMA) is evoked by a normally innocuous light moving mechanical stimulus on the skin and static mechanical allodynia (SMA) by a sustained, normally innocuous pressure against the skin. DMA is claimed to be mediated by myelinated fibres and SMA by C-fibres. Also A-delta fibres have been implicated in the static subtype. A low intensity vertically applied stimulus of 1 second (s) is expected to activate predominantly rapidly adapting A-beta mechanoreceptors thus recruiting the same peripheral substrate as a horizontally moving brush on top of the skin. In patients with SMA we assumed an activation of Cbut also A-delta fibres from a static 10 s von Frey filament stimulus. The aim was to investigate if DMA and SMA could be assessed at perception threshold level using short or longer lasting usually non-painful von Frey filament prodding of the neuropathic skin.Patients and methodsEighteen patients with painful unilateral partial peripheral traumatic nerve injury suffering from SMA (n= 9) and/or DMA (n= 18) in a limb were studied. A compression/ischemia-induced (differential) nerve block in conjunction with repeated quantitative sensory testing of A-delta and C-fibre function using cold and warm stimuli was used to assess which nerve fibre population that contributes to pain at perception threshold level using 1 s (vF1) and 10 s (vF10) von Frey filament stimulation of the skin.ResultsThe main outcome was the finding that elevation of vF1 and vF10 occurred simultaneously and significantly prior to an increase in the perception level to cold or warmth during the continuous nerve block. Single patients demonstrated a slight decrease in cold perception levels at the time of elevation of vF1 or vF10 and a possible contribution to mechanical allodynia from A-delta-fibres can therefore not completely be ruled out although the recorded alterations were minor. None of the patients reported an elevation of the perception level to warmth at the time of elevation of vF1 or vF10 excluding contribution from C-fibres. Further, only patients with clinically established SMA (n= 9) reported continuous pain to a sustained 10 s von Frey filament stimulation (vF10). Patients with only DMA (n= 9) reported pain merely for the initial 1–3 s of the total stimulus duration of 10 s and for a few seconds after the filament was lifted from the skin.ConclusionsThese findings support the role of A-beta fibres as peripheral mediators of both vF1 and vF10 although different receptor organs may be involved, i.e., rapidly (RA) and slowly (SA-I) adapting mechanoreceptors.ImplicationsTechniques to quantify the different allodynias at perception threshold level deserve further attention as possible adjuncts to suprathreshold stimuli in intervention studies aimed at modifying these stimulus-evoked phenomena.

scholarly journals Static mechanical allodynia in post-surgical neuropathic pain after breast cancer treatments

2020 ◽  
Vol 20 (4) ◽  
pp. 683-691
Author(s):  
Laura Mustonen ◽  
Tommi Aho ◽  
Hanna Harno ◽  
Eija Kalso
Keyword(s):  
Breast Cancer ◽  
Neuropathic Pain ◽  
Psychological Factors ◽  
Mechanical Allodynia ◽  
Cold Pressor Test ◽  
Pain Tolerance ◽  
Cancer Surgery ◽  
Breast Cancer Surgery ◽  
Cold Pain ◽  
Static Mechanical

AbstractObjectivesStatic mechanical allodynia (SMA), i. e., pain caused by normally non-painful static pressure, is a prevalent manifestation of neuropathic pain (NP). Although SMA may significantly affect the patient’s daily life, it is less well studied in the clinical context. We aimed to characterize SMA in women with chronic post-surgical NP (CPSNP) after breast cancer surgery. Our objective was to improve understanding of the clinical picture of this prevalent pain condition. This is a substudy of a previously published larger cohort of patients with intercostobrachial nerve injury after breast cancer surgery (Mustonen et al. Pain. 2019;160:246–56).MethodsWe studied SMA in 132 patients with CPSNP after breast cancer surgery. The presence, location, and intensity of SMA were assessed at clinical sensory examination. The patients gave self-reports of pain with the Brief Pain Inventory (BPI). We studied the association of SMA to type of surgery, oncological treatments, BMI, other pains, and psychological factors. General pain sensitivity was assessed by the cold pressor test.ResultsSMA was prevalent (84%) in this cohort whereas other forms of allodynia were scarce (6%). Moderate-to-severe SMA was frequently observed even in patients who reported mild pain in BPI. Breast and the side of chest were the most common locations of SMA. SMA was associated with breast surgery type, but not with psychological factors. Severe SMA, but not self-reported pain, was associated with lower cold pain tolerance.ConclusionsSMA is prevalent in post-surgical NP after breast cancer surgery and it may represent a distinct NP phenotype. High intensities of SMA may signal the presence of central sensitization.ImplicationsSMA should be considered when examining and treating patients with post-surgical NP after breast cancer surgery.

Abnormalities of mechanoreceptors in a rat model of neuropathic pain: possible involvement in mediating mechanical allodynia

1993 ◽  
Vol 70 (2) ◽  
pp. 522-528 ◽  
Author(s):  
H. S. Na ◽  
J. W. Leem ◽  
J. M. Chung
Keyword(s):  
Neuropathic Pain ◽  
Mechanical Allodynia ◽  
Mechanical Stimulus ◽  
Mechanical Stimuli ◽  
Cutaneous Mechanoreceptors ◽  
Systemic Injection ◽  
Response Characteristics ◽  
Neuropathic Pain Model ◽  
Neuropathic Foot ◽  
Unusual Type

1. Peripheral nerve injury sometimes leads to the development of neuropathic pain. One of the symptoms of such neuropathic pain is mechanical allodynia, pain in response to normally innocuous mechanical stimuli. We hypothesized that sympathetically driven dysfunction of cutaneous mechanoreceptors is responsible for signaling mechanical allodynia. The present study was undertaken to identify the types of sensory receptors that potentially mediate mechanical allodynia, with the use of a rat neuropathic pain model we have developed. 2. One week to 10 days after tight ligations of the L5 and L6 spinal nerves on one side, the rats fully developed behavioral signs of mechanical allodynia on the affected hindlimb. Various cutaneous mechanoreceptors originating from the neuropathic foot were examined by single-fiber recordings from the L4 dorsal root. 3. Although no particular abnormalities were found in other types of cutaneous mechanoreceptors, an unusual type of mechanoreceptor was found to be innervating the neuropathic foot. The response characteristics of this type of receptor resemble those of rapidly adapting mechanoreceptors (RAs), but with low and irregular static discharges during a maintained mechanical stimulus. We termed this unusual type as a "modified rapidly adapting" mechanoreceptor (MRA). 4. The response characteristics of MRAs change to those of typical RAs after a systemic injection of phentolamine, an alpha-adrenergic receptor blocker. 5. We conclude that many RAs become abnormal under the influence of sympathetic efferents in neuropathic pain, so that their response patterns change to those of MRAs. We propose that this abnormality is responsible for signaling the mechanical allodynia that can be seen in neuropathic pain states such as causalgia.

The Effect of Blocking of Antidromic Impulses by Capsaicin on Mechanical Allodynia in a Rat Model of Peripheral Neuropathic Pain

2004 ◽  
Vol 17 (1) ◽  
pp. 5 ◽  
Author(s):  
Jin Woo Shin ◽  
Kyung Don Hahm ◽  
Joong Woo Leem ◽  
Chul Hoo Park ◽  
Seung Woo Ku ◽  
...  
Keyword(s):  
Neuropathic Pain ◽  
Rat Model ◽  
Mechanical Allodynia ◽  
Peripheral Neuropathic Pain

scholarly journals FRI0382 EFFECTS OF GENICULAR NERVE BLOCK IN PATIENTS WITH KNEE OSTEOARTHRITIS WHO HAVE NEUROPATHIC OR NOCICEPTIVE PAIN

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 788.2-789
Author(s):  
B. Tas ◽  
P. Akpinar ◽  
I. Aktas ◽  
F. Unlu Ozkan ◽  
I. B. Kurucu
Keyword(s):  
Neuropathic Pain ◽  
Knee Osteoarthritis ◽  
Nerve Block ◽  
Intractable Pain ◽  
Ultrasound Guided ◽  
Lidocaine Group ◽  
Knee Oa ◽  
Significant Difference ◽  
Genicular Artery ◽  
Saline Solutions

Background:Genicular nerve block (GNB) is a safe and effective therapeutic procedure for intractable pain associated with chronic knee osteoarthritis (OA)(1). There is increasing support for the neuropathic component to the knee OA pain. Investigators proposed that targeting treatment to the underlying pain mechanism can improve pain management in knee OA (2). There is a debate on injectable solutions used in nerve blocks (3).Objectives:To investigate the analgesic and functional effects of USG-guided GNB in patients with chronic knee OA (with/without neuropathic pain) and to evaluate the efficacy of the anesthetic and non-anesthetic solutions used.Methods:Ninety patients with chronic knee OA between the ages of 50-80 were divided into two groups with and without neuropathic pain according to painDETECT questionnaire (4). The groups were randomized into three subgroups to either the lidocaine group (n=30) or dextrose group (n=29) or saline solutions (n=31). After the ultrasound-guided GNB, quadriceps isometric strengthening exercises and cryotherapy were recommended to the patients. Visual analog scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Lequesne-algofunctional Index were assessed at baseline and at 1 week, 1 and 3 months later after the procedure.Results:Statistically significant improvement was observed in all groups with or without neuropathic pain according to VAS values at the 1stweek, 1stmonth and 3rdmonth compared to baseline (p<0.05). Statistically significant improvement was observed in all groups with neuropathic pain according to painDETECT values at the 1stweek, 1stmonth and 3rdmonth compared to baseline (p<0.05). There was a statistically significant improvement in the groups without neuropathic pain which received dextrose and saline solutions, according to painDETECT values, but not in the group which received lidocain at the 1stweek, 1stmonth and 3rdmonth compared to baseline (p>0.05). There was a statistically significant improvement in all groups with or without neuropathic pain according to WOMAC and Lequesne total scores at the 1stweek, 1stmonth and 3rdmonth compared to baseline (p<0.05).Conclusion:We conclude that in patients with chronic knee OA (with/without neuropathic pain), the use of GNB with USG is an analgesic method which provides short to medium term analgesia and functional recovery and has no serious side effects. The lack of significant difference between the anesthetic and non-anesthetic solutions used in the GNB suggests that this may be a central effect rather than a symptom of peripheral nerve dysfunction. It suggests that injection may have an indirect effect through nociceptive processing and changes in neuroplastic mechanisms in the brain. In addition, we can say that regular exercise program contributes to improved physical function with the decrease in pain.References:[1]Kim DH et al. Ultrasound-guided genicular nerve block for knee osteoarthritis: a double-blind, randomized controlled trial of local anesthetic alone or in combination with corticosteroid. Pain Physician 2018;21:41-51.[2]Thakur M et.al. Osteoarthritis pain: nociceptive or neuropathic?. Nat Rev Rheumatol 2014:10(6):374.[3]Lam SKH et al. Transition from deep regional blocks toward deep nerve hydrodissection in the upper body and torso: method description and results from a retrospective chart review. BioMed Research International Volume 2017;7920438.[4]Hochman JR et al. Neuropathic pain symptoms in a community knee OA cohort. Osteoarthritis Cartilage. 2011 Jun;19(6):647-54.Fig. 1:Ultrasound- guided identification of GNB target sites. Doppler mode. White arrows indicate genicular arteries.A.Superior medial genicular artery.B.Inferior medial genicular artery.C.Superior lateral genicular artery.Disclosure of Interests:None declared

scholarly journals Tongluo Zhitong Prescription Alleviates Allodynia, Hyperalgesia, and Dyskinesia in the Chronic Constriction Injury Model of Rats

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Zhiyong Wang ◽  
Jianwei Wang ◽  
Lihua Qin ◽  
Weiguang Zhang
Keyword(s):  
Neuropathic Pain ◽  
Mechanical Allodynia ◽  
Chronic Constriction Injury ◽  
Catgut Suture ◽  
Cold Allodynia ◽  
Injury Model ◽  
Neuropathic Pain Model ◽  
Gait Function ◽  
Chronic Constriction Injury Model ◽  
Heat Hyperalgesia

Neuropathic pain is common in clinical practice. Exploration of new drug therapeutics has always been carried out for more satisfactory effects and fewer side-effects. In the present study, we aimed to investigate effects of Tongluo Zhitong Prescription (TZP), a compounded Chinese medicine description, on neuropathic pain model of rats with chronic constriction injury (CCI). The CCI model was established by loosely ligating sciatic nerve with catgut suture, proximal to its trifurcation. The static and dynamic allodynia, heat hyperalgesia, mechanical allodynia, cold allodynia, and gait were assessed. Our results showed that TZP alleviated CCI-induced static and dynamic allodynia, suppressed heat hyperalgesia and cold and mechanical allodynia, and improved gait function. These results suggest that TZP could alleviate neuropathic pain. Further experiments are needed to explore its mechanisms.

Comparison of Continuous Nerve Block Versus Patient-Controlled Analgesia for Postoperative Pain and Outcome After Talar and Calcaneal Fractures

2014 ◽  
Vol 35 (11) ◽  
pp. 1116-1121 ◽  
Author(s):  
Willem E. Luiten ◽  
Tim Schepers ◽  
Jan S. Luitse ◽  
J. Carel Goslings ◽  
Jeroen Hermanides ◽  
...  
Keyword(s):  
Postoperative Pain ◽  
Nerve Block ◽  
Patient Controlled Analgesia ◽  
Calcaneal Fractures ◽  
Continuous Nerve Block

scholarly journals Plasticity-Related PKMζSignaling in the Insular Cortex Is Involved in the Modulation of Neuropathic Pain after Nerve Injury

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Jeongsoo Han ◽  
Minjee Kwon ◽  
Myeounghoon Cha ◽  
Motomasa Tanioka ◽  
Seong-Karp Hong ◽  
...  
Keyword(s):  
Chronic Pain ◽  
Neuropathic Pain ◽  
Nerve Injury ◽  
Neural Plasticity ◽  
Mechanical Allodynia ◽  
Insular Cortex ◽  
Long Term Potentiation ◽  
Inhibitory Peptide ◽  
Term Potentiation ◽  
Potential Applications

The insular cortex (IC) is associated with important functions linked with pain and emotions. According to recent reports, neural plasticity in the brain including the IC can be induced by nerve injury and may contribute to chronic pain. Continuous active kinase, protein kinase Mζ(PKMζ), has been known to maintain the long-term potentiation. This study was conducted to determine the role of PKMζin the IC, which may be involved in the modulation of neuropathic pain. Mechanical allodynia test and immunohistochemistry (IHC) of zif268, an activity-dependent transcription factor required for neuronal plasticity, were performed after nerve injury. Afterζ-pseudosubstrate inhibitory peptide (ZIP, a selective inhibitor of PKMζ) injection, mechanical allodynia test and immunoblotting of PKMζ, phospho-PKMζ(p-PKMζ), and GluR1 and GluR2 were observed. IHC demonstrated that zif268 expression significantly increased in the IC after nerve injury. Mechanical allodynia was significantly decreased by ZIP microinjection into the IC. The analgesic effect lasted for 12 hours. Moreover, the levels of GluR1, GluR2, and p-PKMζwere decreased after ZIP microinjection. These results suggest that peripheral nerve injury induces neural plasticity related to PKMζand that ZIP has potential applications for relieving chronic pain.

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