PMC10205977_01
Schematic of TMR procedures and sensory testing. (A) Schematic of the case participant presenting with a short trans-humeral amputation after a targeted muscle reinnervation surgery. The radial nerve was transferred to the nerve branch of the clavicular head of the pectoralis major. The musculocutaneous nerve was transferred to the nerve branch that innervated the superior half of the sternal head of the pectoralis major. The median nerve was transferred to the nerve branch that innervated the inferior half of the sternal head of the pectoralis major. Lastly, the ulnar nerve was transferred to the lateral thoracic nerve which innervated the serratus anterior. Subcutaneous fat was not removed secondary to the patient's low body fat content. (B) The grid used to palpate the reinnervation sites. This grid along with anatomical landmarks clavical, sternum, axilla, and mamilla were used to reduce variability and increase consistency of palpation sites between data collection days. (C) Phantom limb therapy occurred every day for 3-months. Data collection sessions were conducted every 2-weeks over the 3-month period. (D) Palmar and dorsal side of the hand. The subject pointed to the area of the hand or arm where he felt the sensory sensation when a stimulus was produced by palpating the reinnervation sites. (E) Sensitivity profile of the probe over the sensorimotor cortex used in this study. Log sensitivity index values closer to zero (red) reflect greater sensitivity for acquiring signals in that region. Image created using AtlasViewer (v2.12.4). The location of the detectors (blue), the sources (red), and the channels (yellow lines) are shown for the subject.
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fig1
The subject underwent a TMR procedure after the damage control procedure through a distinct surgical site proximal to the traumatic amputation where the four main nerves of the brachial plexus after the divergence of the axillary nerve were transferred to various nerves of chest wall muscles (Figure 1A). The subject performed the phantom limb therapy every day at home for a total of 3 months and returned to the lab for data collections every 2 weeks (Figure 1C). Sensory mapping data were collected by palpating in a grid orientation (Figure 1B) over the pectoralis major and serratus anterior muscles to increase reproducibility between sessions. The subject would then point to the drawing of the hand (Figure 1D) or on the researcher's hand or arm where he felt the sensation. The cap was positioned to cover the sensorimotor area (Figure 1E).