Localizing and Assessing Amputee Pain with Intense Focused Ultrasound
Abstract
In order to study the differential sensitivity of peripheral pain generators in the residual limb of two classes of amputees, we use our existing research-grade image-guided intense focused ultrasound (ig-iFU) system to stimulate those pain generators. Targets for iFU stimulation include neuromas, intact nerves, TMR (targeted muscle reinnervation) sites, and patient-identified sensitive areas. We have successful stimulated intact and transected nerves in our amputee patients and intact volunteers. We have observed significant differences in how the different groups respond to iFU stimulation and how the threshold value of iFU intensity necessary to generate sensations relates to different factors such as overall pain score, neuropathic pain, and the presence of phantom feelings and pain. While the distribution of iFU intensity threshold values do not differ in a statistically significant fashion from one another, their difference in dependency on the presence/absence of neuropathic pain is quite striking, and of clinical significance. Specifically, standard amputation can produce neuropathic, transected nerves much more sensitive to external stimulation (iFU here) than their non-neuropathic counterparts. In contrast, the presence/absence of neuropathic pain does not produce unusually sensitive transected nerves for TMR patients. Also, standard amputation much more often produced central sensitization both ipsilateral and contralateral to the amputation; not so for TMR. These observations strongly favor the TMR procedure as the transection procedure of choice for amputees.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2021
- Accession Number
- AD1203276
Entities
People
- Pierre D. Mourad
Organizations
- University of Washington