NCT06503523

The Effects of Performing a Motor Imagery Task on Cortical Excitability During Acute Experimental Muscle Pain and Acute Itch

Investigation of the Neurophysiological and Psychological Aspects of Itch

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 30 (estimated)
• Sponsor: Aalborg University · Academic / Other
• Sex: All
• Age: 18 Years – 60 Years
• Healthy volunteers: Accepted

Summary

The aim of this project is to determine the effects of performing a motor imagery task on cortical excitability during acute experimental muscle pain (induced by hypertonic saline), acute histaminergic itch (induced by histamine), and non-histaminergic itch stimulation (triggered by Cowhage). We hypothesize that motor imagery will counteract the alterations in cortical excitability observed during experimental muscle pain and both itch models.

Detailed description

Itch and pain share many similarities and dissimilarities in terms of the mechanisms and molecules involved. Many studies have been conducted to explain all the neurophysiological aspects involved in the pain process, and cortical adaptations have been provoked in healthy individuals using experimental pain models. Unfortunately, all these aspects still need to be clarified regarding itch. Has been previously demonstrated that motor imagery can counteracted the pain-induced decrease in corticospinal excitability observed during acute pain, and it has also been proposed as a potential intervention for individuals with pain to restore maladaptive neuroplasticity. However, whether motor imagery can similarly counteract the itch-induced cortical changes remains unclear. Therefore, the aim of this project is to investigate whether motor imagery would counteract the reduction in cortical excitability during acute itch, similar to the effects observed in the context of acute pain.

Conditions

• Itch
• Pain

Interventions

Type	Name	Description
OTHER	Hypertonic Saline	A bolus injection of hypertonic saline (7% NaCl) will be administered to the FDI muscle using a 1 mL syringe with a disposable needle (27G), and the volume of the bolus will be 0.1 mL
OTHER	Histamine	A small drop of histamine dihydrochloride will be applied to a previously determined area on the volar forearm, followed by a prick through the drop
OTHER	Cowhage	This insertion is conducted by forceps using a stereomicroscope, and 30-35 spicules are gently rubbed into a 1 cm diameter skin area.
DEVICE	Transcranial magnetic stimulation (TMS)	Transcranial magnetic stimulation (TMS) will be used to evoke motor-evoked potentials (MEPs) in the muscle of interest and cortical responses (TMSevoked potentials - TEPs) in the motor cortex with a figure-eight-shaped cone coil.

Timeline

• Start date: 2024-10-01
• Primary completion: 2025-12-31
• Completion: 2026-12-31
• First posted: 2024-07-16
• Last updated: 2024-11-22

Locations

2 sites across 1 country: Denmark