Alleviation Effects and Mechanisms of Low‐intensity Focused Ultrasound on Pain Triggered by Soft Tissue Injury

Abstract

Objectives-Pain caused by soft tissue injury (STI) is always intractable and will eventually result in physical and psychological problems. This experiment aimed to assess the efficacy and mechanisms of low-intensity focused ultrasound (LIFU) for pain-related STI.Methods-Rabbits (n = 30) with STI were given fixed treatment for 20 seconds and then mobile treatment for 60 seconds daily for 10 consecutive days by an LIFU device with a power output of 5 to 6 W and a frequency of 0.8 MHz. To evaluate the degree of pain, the levels of β-endorphin in serum were measured by an enzyme-linked immunosorbent assay before and 5 to 10 minutes after the 1st, 3rd, 7th, and 10th treatments. The pain threshold was measured by an electronic analgesy meter on the 1st, 3rd, 7th, 10th, 17th, and 24th days after the start of the treatment. To investigate inflammation, prostaglandin E 2 , interleukin-1β, and 5-hydroxytryptamine levels were detected by an enzyme-linked immunosorbent assay, and nuclear factor κB messenger RNA levels were determined by a real-time quantitative polymerase chain reaction at the same time as the pain threshold was tested.Results-Compared with non-LIFU groups, β-endorphin levels and pain thresholds were significantly increased (P < .05), whereas nuclear factor-κB messenger RNA, prostaglandin E 2 , interleukin-1β, and 5-hydroxytryptamine levels were significantly reduced (P < .05) after LIFU treatment in rabbits with STI.Conclusions-Low-intensity focused ultrasound can alleviate pain induced by STI and could have further clinical applications.

Transcranial Focused Ultrasound Neuromodulation: A Review of the Excitatory and Inhibitory Effects on Brain Activity in Human and Animals

“…Recent investigations on the interactions between sound pressure waves and brain tissue suggest that ultrasound primarily exerts its modulatory effects through mechanical action on cell membranes, notably affecting ion channel gating ( Kubanek et al, 2016 ). Liang et al (2020) explored the efficacy and mechanisms of tFUS in treating pain caused by soft tissue injury. Low-intensity focused ultrasound relieved pain, and the mechanism could be attributed to decreasing the release of analgesic substances from the nerve and reducing local inflammatory factors ( Liang et al, 2020 ).…”

“… Liang et al (2020) explored the efficacy and mechanisms of tFUS in treating pain caused by soft tissue injury. Low-intensity focused ultrasound relieved pain, and the mechanism could be attributed to decreasing the release of analgesic substances from the nerve and reducing local inflammatory factors ( Liang et al, 2020 ). Na Pang et al (2021) demonstrated that transcranial ultrasound stimulation was effective in modulating the learning behaviors of mice and the expression of apoptosis, oxidative stress, and inflammation.…”

Potential Application of Low‐Intensity Focused Ultrasound in Rapidly Relieving Delayed‐Onset Muscle Soreness Induced by High‐Intensity Exercise

“…17 Previous studies have confirmed that LIFU has a significant pain relief effect on soft tissue injuries. 17 Therefore, we believe LIFU has potential application value in relieving DOMS after high-intensity exercise.…”

“…However, the clinical efficacy of traditional ultrasound treatment has not been well proved, which may be due to insufficient ultrasound dose in the injured area 16 . Low‐intensity focused ultrasound (LIFU) was designed to focus the ultrasonic beams on the target area without damaging the acoustic channels 17 . Previous studies have confirmed that LIFU has a significant pain relief effect on soft tissue injuries 17 .…”

“…Low‐intensity focused ultrasound (LIFU) was designed to focus the ultrasonic beams on the target area without damaging the acoustic channels 17 . Previous studies have confirmed that LIFU has a significant pain relief effect on soft tissue injuries 17 . Therefore, we believe LIFU has potential application value in relieving DOMS after high‐intensity exercise.…”