title: High-intensity focused ultrasound attenuates neural responses of sciatic nerves isolated from normal or neuropathic rats.
abstract: Patients with diabetic neuropathy often have neuropathic pain. The purpose of our work was to investigate the effects of high-intensity focused ultrasound (HIFU) on the conduction block of normal and neuropathic nerves for soothing pain. Adult male Sprague-Dawley rats were used, and diabetes was induced by streptozotocin injection. Diabetic neuropathy was evaluated with animal behavior tests. Sciatic nerves of both control and neuropathic rats were dissected from the starting point of the sciatic nerve to the point where the sural nerve ends near the ankle. The nerves were stored in Ringer's solution. The in vitro nerve was placed on a self-developed experimental platform for HIFU exposure. Stimulation and recording of the compound action potentials (CAPs) and sensory action potentials (SAPs) were performed. Control and neuropathic nerves exposed or not exposed to HIFU were submitted to histologic analysis. For the control and neuropathic nerves, suppression of CAPs and SAPs started 2 min post-HIFU treatment. Maximum suppression of SAPs was 34.4 ± 3.2% for the control rats and 11.6 ± 2.0% and 9.8 ± 3.0% for rats 4 wk post-injection and 8 wk post-injection, respectively. Time to full recovery was 25, 70 and 80 min, respectively. Histologic analysis revealed that the nerves in which CAPs and SAPs did not fully recover were damaged thermally or mechanically by HIFU. It is feasible to reversibly block nerves with appropriate HIFU treatment. Diabetic nerves were less suppressed by HIFU and were more vulnerable to permanent damage.
authors.affiliation: Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Zhunan, Taiwan.
authors.forename: Yee-Fun
authors.initials: YF
authors.lastname: Lee
authors.affiliation: Department of Neurology, National Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: Chou-Ching
authors.initials: CC
authors.lastname: Lin
authors.affiliation: Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Zhunan, Taiwan.
authors.forename: Jung-Sung
authors.initials: JS
authors.lastname: Cheng
authors.affiliation: Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Zhunan, Taiwan. Electronic address: gschen@nhri.org.tw.
authors.forename: Gin-Shin
authors.initials: GS
authors.lastname: Chen
mesh_terms: D000818:Animals; D003928:Diabetic Nephropathies / Q000139:chemically induced / Q000503:physiopathology* / Q000601:surgery*; D057086:High-Intensity Focused Ultrasound Ablation; D008297:Male; D009407:Nerve Block / Q000379:methods; D009431:Neural Conduction; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000187:drug effects / Q000503:physiopathology* / Q000601:surgery; D020426:Sciatic Neuropathy / Q000139:chemically induced / Q000503:physiopathology* / Q000601:surgery*; D013311:Streptozocin; D016896:Treatment Outcome
chemical_list: D013311:Streptozocin
keywords: Conduction block; Diabetic neuropathy; High-intensity focused ultrasound; Rat; Sciatic nerve