scholarly journals Repeated buffered acidic saline infusion in the human masseter muscle as a putative experimental pain model

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sofia Louca Jounger ◽  
Niklas Eriksson ◽  
Helena Lindskog ◽  
Anna Oscarsson ◽  
Vivian Simonsson ◽  
...  
Keyword(s):  
Pain Intensity ◽  
Muscle Pain ◽  
Saline Solution ◽  
Isotonic Saline ◽  
Mouth Opening ◽  
Saline Infusion ◽  
Controlled Study ◽  
Solution Ph ◽  
Pressure Pain Thresholds ◽  
Masseter Muscles

Abstract This study investigated if repeated buffered acidic saline infusions into the masseter muscles induced muscle pain and mechanical sensitization. Fourteen healthy men participated in this double-blind, randomized, and placebo-controlled study. Two repeated infusions (day 1 and 3) were given in the masseter muscles with either a buffered acidic saline solution (pH 5.2) or an isotonic saline solution (pH 6) as control. After 10 days of wash-out, the experiment was repeated with the other substance. Pressure pain thresholds (PPT), pain intensity, maximum unassisted mouth opening (MUO), and pain drawings were assessed before, directly following, and after each infusion at 5, 15, and 30 min and on day 4 and 7. Fatigue and pain intensity were assessed after a one-minute chewing test 30 min after infusions and day 4 and 7. Acidic saline induced higher pain intensity than control day 3 up to 5 min after infusions, but did not affect PPT. The chewing test did not evoke higher fatigue during chewing or MUO or after acidic saline infusion compared to control. Repeated acidic saline infusions in the masseter muscles induced a short-lasting muscle pain without mechanical hyperalgesia or functional pain. Hence, this model might not be superior to already existing experimental muscle pain models.

The Relationship Between Corticomotor Reorganization and Acute Pain Severity: A Randomized, Controlled Study Using Rapid Transcranial Magnetic Stimulation Mapping

Pain Medicine ◽  
2020 ◽  
Author(s):  
Rocco Cavaleri ◽  
Lucy S Chipchase ◽  
Simon J Summers ◽  
Jane Chalmers ◽  
Siobhan M Schabrun
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Pain Intensity ◽  
Acute Pain ◽  
Symptom Severity ◽  
Magnetic Stimulation ◽  
Isotonic Saline ◽  
Point Estimation ◽  
Controlled Study ◽  
Peripheral Sensitization ◽  
Pressure Pain Thresholds

Abstract Objective Although acute pain has been shown to reduce corticomotor excitability, it remains unknown whether this response resolves over time or is related to symptom severity. Furthermore, acute pain research has relied upon data acquired from the cranial “hotspot,” which do not provide valuable information regarding reorganization, such as changes to the distribution of a painful muscle’s representation within M1. Using a novel, rapid transcranial magnetic stimulation (TMS) mapping method, this study aimed to 1) explore the temporal profile and variability of corticomotor reorganization in response to acute pain and 2) determine whether individual patterns of corticomotor reorganization are associated with differences in pain, sensitivity, and somatosensory organization. Methods Corticomotor (TMS maps), pain processing (pain intensity, pressure pain thresholds), and somatosensory (two-point discrimination, two-point estimation) outcomes were taken at baseline, immediately after injection (hypertonic [n = 20] or isotonic saline [n = 20]), and at pain resolution. Follow-up measures were recorded every 15 minutes until 90 minutes after injection. Results Corticomotor reorganization persisted at least 90 minutes after pain resolution. Corticomotor depression was associated with lower pain intensity than was corticomotor facilitation (r = 0.47 [P = 0.04]). These effects were not related to somatosensory reorganization or peripheral sensitization mechanisms. Conclusions Individual patterns of corticomotor reorganization during acute pain appear to be related to symptom severity, with early corticomotor depression possibly reflecting a protective response. These findings hold important implications for the management and potential prevention of pain chronicity. However, further research is required to determine whether these adaptations relate to long-term outcomes in clinical populations.

scholarly journals Sterile water; a novel and promising human experimental muscle pain model

2020 ◽  
Author(s):  
Sofia Louca Jounger ◽  
Johanna Svedenlöf ◽  
Reija Elenius ◽  
Christoffer Källkrans ◽  
Emil Scheid ◽  
...  
Keyword(s):  
Pain Intensity ◽  
Hypertonic Saline ◽  
Intramuscular Injection ◽  
Isotonic Saline ◽  
Controlled Study ◽  
Sterile Water ◽  
Pain Model ◽  
Pain Drawing ◽  
Pressure Pain Thresholds ◽  
Pain Duration

Abstract Background Intramuscular injection of hypertonic saline evokes pain with similar characteristics as clinical myalgia and is thus, considered a valid human experimental model. The aim of this study was to investigate if intramuscular injection of sterile water can be used as a human experimental pain model by comparing it with hypertonic and isotonic saline, and to analyze if the effects differ between men and women. Methods This randomized double blind and placebo-controlled study included 15 healthy women and 15 healthy age-matched men (mean (SD) age of 23.6 (2.4) years). The study comprised of three separate sessions, with at least one week of wash out between each session. Sterile water (i.e. the test-substance), hypertonic saline (active control), and isotonic saline (passive control) were injected intramuscularly into one of the masseter muscles in a randomized order. Pain intensity (VAS) was assessed every 15 th s after the injection and pain duration (s) as well as pain drawing area (au) were recorded. Pressure pain thresholds (kPa) were assessed every 5 min after injection during 30 min. Results All substances evoked pain ( P < 0001), but sterile water and hypertonic saline induced pain with higher intensity ( P < 0.001), longer duration ( P < 0.001), and larger pain drawing area ( P < 0.001) than isotonic saline. The pain intensity was higher for hypertonic saline than sterile water 45-165 s after injection ( P < 0.015), but there were no significant differences between them regarding maximum pain intensity, pain duration or pain drawing area. There was no significant difference in PPT values with time or between substances. The pain duration was longer in the men compared to the women for all substances ( P < 0.006), while the pain drawing area was larger in women after injection of hypertonic saline ( P < 0.003), but not after injection of the other substances. No other sex differences were found. Conclusion Injection of sterile water had similar effects as hypertonic saline on pain variables, but no effect on PPT. Hence, the model mimics clinical myalgia and may offer a novel and simpler alternative to hypertonic saline injections.

scholarly journals Enhanced Therapeutic Alliance Modulates Pain Intensity and Muscle Pain Sensitivity in Patients With Chronic Low Back Pain: An Experimental Controlled Study

2014 ◽  
Vol 94 (4) ◽  
pp. 477-489 ◽  
Author(s):  
Jorge Fuentes ◽  
Susan Armijo-Olivo ◽  
Martha Funabashi ◽  
Maxi Miciak ◽  
Bruce Dick ◽  
...  
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Physical Therapy ◽  
Therapeutic Alliance ◽  
Pain Intensity ◽  
Muscle Pain ◽  
Pain Sensitivity ◽  
Controlled Study ◽  
Low Back ◽  
Mean Differences

Background Physical therapy influences chronic pain by means of the specific ingredient of an intervention as well as contextual factors including the setting and therapeutic alliance (TA) between provider and patient. Objective The purpose of this study was to compare the effect of enhanced versus limited TA on pain intensity and muscle pain sensitivity in patients with chronic low back pain (CLBP) receiving either active or sham interferential current therapy (IFC). Design An experimental controlled study with repeated measures was conducted. Participants were randomly divided into 4 groups: (1) AL (n=30), which included the application of active IFC combined with a limited TA; (2) SL (n=29), which received sham IFC combined with a limited TA; (3) AE (n=29), which received active IFC combined with an enhanced TA; and (4) SE (n=29), which received sham IFC combined with an enhanced TA. Methods One hundred seventeen individuals with CLBP received a single session of active or sham IFC. Measurements included pain intensity as assessed with a numerical rating scale (PI-NRS) and muscle pain sensitivity as assessed via pressure pain threshold (PPT). Results Mean differences on the PI-NRS were 1.83 cm (95% CI=14.3–20.3), 1.03 cm (95% CI=6.6–12.7), 3.13 cm (95% CI=27.2–33.3), and 2.22 cm (95% CI=18.9–25.0) for the AL, SL, AE, and SE groups, respectively. Mean differences on PPTs were 1.2 kg (95% CI=0.7–1.6), 0.3 kg (95% CI=0.2–0.8), 2.0 kg (95% CI=1.6–2.5), and 1.7 kg (95% CI=1.3–2.1), for the AL, SL, AE, and SE groups, respectively. Limitations The study protocol aimed to test the immediate effect of the TA within a clinical laboratory setting. Conclusions The context in which physical therapy interventions are offered has the potential to dramatically improve therapeutic effects. Enhanced TA combined with active IFC appears to lead to clinically meaningful improvements in outcomes when treating patients with CLBP.

Hypertonic Saline Solution in Children with Adenoidal Hyperytrophy: Preliminary Evidence

2007 ◽  
Vol 5 (3) ◽  
pp. 159-163 ◽  
Author(s):  
G. Ciprandi ◽  
A. Varricchio ◽  
M. Capasso ◽  
A.M. Varricchio ◽  
A. de Lucia ◽  
...  
Keyword(s):  
Saline Solution ◽  
Isotonic Saline ◽  
Preliminary Evidence ◽  
Endoscopic Examination ◽  
Inflammatory Activity ◽  
Controlled Study ◽  
Hypertonic Solution ◽  
Hypertonic Saline Solution ◽  
Preliminary Study ◽  
Anti Inflammatory

Adenoidal hypertrophy (AH) is a frequent problem in children. A preliminary study evidenced that intranasal hypertonic solutions may exert an anti-inflammatory activity. The aim of the study is to evaluate the effect of intranasal hypertonic or isotonic solutions in children affected with AH. For this purpose, 78 children with AH were evaluated in a randomised and controlled study. Inclusion criteria for the study required that each patient had to have a III or IV degree of AH on the initial endoscopic examination. Children were treated with intranasal hypertonic or isotonic saline solution for 8 weeks. After treatment, endoscopy was performed to evaluate AH degree. Hypertonic treatment was associated with significant (p<0.05) reduction of AH degree. There was a consistent reduction of children with III degree of AH. No adverse events were reported. This preliminary study demonstrates that an 8-week treatment with intranasal hypertonic solution is associated with significant reduction of AH. Therefore, this study evidences that hypertonic solution may exert an anti-inflammatory activity and is safe.

Intranasal Flunisolide Treatment in Children with Adenoidal Hypertrophy

2007 ◽  
Vol 20 (4) ◽  
pp. 833-836 ◽  
Author(s):  
G. Ciprandi ◽  
A. Varricchio ◽  
M. Capasso ◽  
A.M. Varricchio ◽  
A. De Lucia ◽  
...  
Keyword(s):  
Saline Solution ◽  
Isotonic Saline ◽  
Endoscopic Examination ◽  
Controlled Study ◽  
Indications For Surgery ◽  
Inclusion Criteria ◽  
Intranasal Corticosteroids ◽  
Adenoidal Hypertrophy ◽  
Preliminary Study ◽  
Study Inclusion

Adenoidal hypertrophy (AH) represents one of the most frequent indications for surgery in children and it has been proposed that treatment with intranasal corticosteroids can decrease the size of AH. Therefore, the aim of the study is to evaluate the effect of the use of intranasal flunisolide among children affected by AH. 178 children with AH were evaluated in this randomised and controlled study. Inclusion criteria for the study required that each patient had to have a HI or IV degree of AH on the initial endoscopic examination. Children were treated with intranasal flunisolide or isotonic saline solution for 8 weeks. After treatment, endoscopy was performed to re-evaluate AH degree. Flunisolide treatment was associated with significant (p<0.04) reduction of AH degree. There was moreover a consistent reduction of children (46 out of 58) proposed to adenoidectomy. No clinically important adverse events were reported. In conclusion, this preliminary study demonstrates that an 8-week treatment with intranasal flunisolide is significantly associated with reduction of AH, thus preventing the recurrence to adenoidectomy, and is safe.

Hypoalgesia after exercises with painful vs. non-painful muscles in healthy subjects – a randomized cross-over study

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Simon Hansen ◽  
Kristian Kjær Petersen ◽  
Emilie Sloth ◽  
Line Appelon Manum ◽  
Anita Kjær McDonald ◽  
...  
Keyword(s):  
Pain Intensity ◽  
Hypertonic Saline ◽  
Rating Scales ◽  
Isotonic Saline ◽  
Thigh Muscle ◽  
Exercise Session ◽  
Pressure Pain Thresholds ◽  
Exercise Induced ◽  
The Right ◽  
Pain At Rest

Abstract Objectives Exercise-induced hypoalgesia (EIH) is a decrease in the pain sensitivity after exercise. Individuals with chronic pain show less EIH after one exercise session compared with pain-free individuals possibly due to pain in exercising muscles. The primary aim of this randomized controlled cross-over study was to compare the EIH response at the exercising thigh muscle following exercises performed with painful vs. non-painful muscles. Secondary aims were to explore if a reduced EIH response was confined to the painful muscle, and whether the muscle pain intensity and the EIH responses were negatively associated. Methods In two sessions, 34 pain-free participants received a painful (hypertonic saline, 5.8%) injection and a control (isotonic saline, 0.9%) injection in the right thigh muscle before performing a 3 min isometric wall squat exercise. Pressure pain thresholds (PPTs) were assessed at both thighs and the left neck/shoulder at baseline, after injections and after exercise. Pain intensities in the thighs were rated on numerical rating scales (NRS: 0–10). Results Hypertonic saline induced moderate thigh pain at rest (NRS: 4.6 ± 2.1) compared to the control injection (NRS: 0.3 ± 0.4; p<0.001). EIH at the thighs and neck/shoulder were not different between sessions (Injected thigh: 0 kPa; 95% CI: −51 to 52; Contralateral thigh: −6 kPa; 95% CI: −42 to 30; neck/shoulder: 19 kPa; 95% CI: −6 to 44). No significant associations between pain intensity ratings immediately after the Painful injection and EIH responses at any assessment sites were found (right thigh: β=0.08, 95% CI: −12.95 to 20.64, p=0.64, left thigh: β=−0.33, 95% CI: −27.86 to 0.44, p=0.06; neck/shoulder: β=−0.18, 95% CI: −15.11 to 4.96, p=0.31). Conclusions Pain in the area of an exercising muscle did not reduce local or systemic EIH responses. Trial registration number NCT04354948.

Effect of adjunctive sodium hyaluronate versus surfactant nasal irrigation on mucociliary clearance in allergic rhinitis: a single-blind, randomised, controlled study

2021 ◽  
pp. 1-4
Author(s):  
E Ocak ◽  
S Mulazimoglu ◽  
D Kocaoz ◽  
E Mirici ◽  
E Dagli ◽  
...  
Keyword(s):  
Allergic Rhinitis ◽  
Mucociliary Clearance ◽  
Isotonic Saline ◽  
Sodium Hyaluronate ◽  
Controlled Study ◽  
Control Group ◽  
Clearance Time ◽  
Nasal Irrigation ◽  
Persistent Allergic Rhinitis ◽  
Randomised Controlled

Abstract Objective To investigate the effects of nasal irrigation with sodium hyaluronate and surfactant solutions on mucociliary clearance time in patients with mild persistent allergic rhinitis. Methods A total of 120 patients diagnosed with mild persistent allergic rhinitis were enrolled in this prospective study. The patients were allocated randomly to the surfactant, sodium hyaluronate or isotonic saline (as a control) nasal irrigation group. The mucociliary clearance times and improvements in mucociliary clearance times were compared. Results Improvements in mean mucociliary clearance time were significantly greater in the surfactant and sodium hyaluronate groups than in the control group (p < 0.01). The mean post-treatment mucociliary clearance time of the surfactant group was significantly lower than that of the control (p < 0.001) and sodium hyaluronate groups (p = 0.03). Conclusion Surfactant and sodium hyaluronate nasal irrigation solutions may both be used as adjunctive treatments for allergic rhinitis. Surfactant nasal irrigation resulted in better mucociliary clearance times.

scholarly journals Lidocaine coinfusion alleviates vascular pain induced by hypertonic saline infusion: a randomized, placebo-controlled trial

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Zhiping Song ◽  
Shibiao Chen ◽  
Yang Zhang ◽  
Xiaoyun Shi ◽  
Na Zhao ◽  
...  
Keyword(s):  
Hypertonic Saline ◽  
Saline Solution ◽  
Time Slot ◽  
Controlled Trial ◽  
Saline Infusion ◽  
Clinical Trial Registry ◽  
Hypertonic Saline Solution ◽  
Vas Scores ◽  
Vascular Pain ◽  
Hypertonic Saline Infusion

Abstract Background Hypertonic saline solution has been frequently utilized in clinical practice. However, due to the nonphysiological osmolality, hypertonic saline infusion usually induces local vascular pain. We conducted this study to evaluate the effect of lidocaine coinfusion for alleviating vascular pain induced by hypertonic saline. Methods One hundred and six patients undergoing hypertonic saline volume preloading prior to spinal anesthesia were randomly allocated to two groups of 53 each. Group L received a 1 mg/kg lidocaine bolus followed by infusion of 2 mg/kg/h through the same IV line during hypertonic saline infusion; Group C received a bolus and infusion of normal saline of equivalent volume. Visual analogue scale (VAS) scores of vascular pain were recorded every 4 min. Results The vascular pain severity in Group L was significantly lower than that in Group C for each time slot (P < 0.05). The overall incidence of vascular pain during hypertonic saline infusion in Group L was 48.0%, which was significantly lower than the incidence (79.6%) in Group C (P < 0.05). Conclusion Lidocaine coinfusion could effectively alleviate vascular pain induced by hypertonic saline infusion. Trial registration Chinese Clinical Trial Registry, number: ChiCTR1900023753. Registered on 10 June 2019.

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