Editor's key points † The effect of high-intensity focused ultrasound was measured in rats with diabetic neuropathy to assess its potential for pain relief. † High-intensity focused ultrasound temporarily blocked compound and sensory action potentials and compound muscle action potentials without damaging nerves. † High-intensity focused ultrasound may have potential for reversibly blocking sensory nerves and providing pain relief.Background. Nerve conduction block using high-intensity focused ultrasound (HIFU) has been conducted with nerves of mixed fibres in normal animal models. This study tested the feasibility and safety of HIFU for sensory nerve conduction block in diabetic neuropathic nerves to determine its potential for pain relief.

Measurements of ultrasonic attenuation in the sciatic nerves of rats were performed to verify the feasibility of ultrasound diagnosis of peripheral neuropathy and to avoid damage to the nerves caused by overheating in pain management applications. A rat model of diabetic peripheral neuropathy was established. The proximal-segment and middle-segment sciatic nerves of control and neuropathic rats were dissected for the attenuation measurement. Two commercial ultrasound transducers and a self-developed experimental platform were used in the measurements. Using H&E staining and transmission electron (TE) microscopy, morphological analysis of the control and neuropathic nerves was performed to determine the relationship between attenuation and the histology of the nerves. The experimental results showed that the attenuation coefficients of the control, second-week, fourth-week, and eighth-week neuropathic nerves were -6.68 ± 0.50, -5.61 ± 0.34, -6.27 ± 0.40, and -7.10 ± 0.35 dB/cm at 2.68 MHz, respectively. The respective values at 7.50 MHz were -14.96 ± 0.79, -12.65 ± 0.28, -13.98 ± 1.07, and -16.00 ± 0.54 dB/cm. The changes in the attenuation coefficients were significantly different among the second-week, fourth-week, and eighth-week DN nerves. Additionally, the ultrasonic attenuation coefficient of the rat sciatic nerve was fourfold that of the cat brain and cow liver and twofold that of human muscle.

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