TY - JOUR
T1 - Prospective pre-operative 3-T MR neurography peripheral nerve mapping of upper extremity amputations implanted with FAST-LIFE electrode interfaces of robotic hands
T2 - technical report
AU - Mogharrabi, Bayan
AU - Cheng, Jonathan
AU - Ratakonda, Raghu
AU - Keefer, Edward
AU - Chhabra, Avneesh
N1 - Funding Information:
Jonathan Cheng and Edward Keefer are both co-owners of Nerves Incorporated which conducted this research sponsored by the DARPA HAPTIX (Hand Proprioceptive and Touch Interfaces) program under the US federal BRAIN initiative.
Publisher Copyright:
© 2022, The Author(s), under exclusive licence to International Skeletal Society (ISS).
PY - 2022/11
Y1 - 2022/11
N2 - Background and purpose: Fascicular targeting of longitudinal intrafascicular electrode (FAST-LIFE) interface enables hand dexterity with exogenous electrical microstimulation for sensory restoration, custom neural recording hardware, and deep learning–based artificial intelligence for motor intent decoding. The purpose of this technical report from a prospective pilot study was to illustrate magnetic resonance neurography (MRN) mapping of hand and nerve anatomy in amputees and incremental value of MRN over electrophysiology findings in pre-surgical planning of FAST-LIFE interface (robotic hand) patients. Materials and methods: After obtaining informed consent, patients with upper extremity amputations underwent pre-operative 3-T MRN, X-rays, and electrophysiology. MRN findings were correlated with electrophysiology reports. Descriptive statistics were performed. Results: Five patients of ages 21–59 years exhibited 3/5 partial hand amputations, and 2/5 transradial amputations on X-rays. The median and ulnar nerve end bulb neuromas measured 10.1 ± 3.04 mm (range: 5.5–14 mm, median: 10.5 mm) and 10.9 ± 7.64 mm (2–22 mm, 9.75 mm), respectively. The ADC of median and ulnar nerves were increased at 1.64 ± 0.1 × 10−3 mm2/s (range: 1.5–1.8, median: 1.64 × 10−3 mm2/s) and 1.70 ± 0.17 × 10−3 mm2/s (1.49–1.98 × 10−3 mm2/s, 1.65 × 10−3 mm2/s), respectively. Other identified lesions were neuromas of superficial branch of the radial nerve and anterior interosseous nerve. On electrophysiology, 2/5 reports were unremarkable, 2/5 showed mixed motor-sensory neuropathies of median and ulnar nerves along with radial sensory neuropathy, and 1/5 showed sensory neuropathy of lateral cutaneous nerve of the forearm. All patients regained naturalistic sensations and motor control of digits. Conclusion: 3-T MRN allows excellent demonstration of forearm and hand nerve anatomy, altered diffusion characteristics, and their neuromas despite unremarkable electrophysiology for pre-surgical planning of the FAST-LIFE (robotic hand) interfaces.
AB - Background and purpose: Fascicular targeting of longitudinal intrafascicular electrode (FAST-LIFE) interface enables hand dexterity with exogenous electrical microstimulation for sensory restoration, custom neural recording hardware, and deep learning–based artificial intelligence for motor intent decoding. The purpose of this technical report from a prospective pilot study was to illustrate magnetic resonance neurography (MRN) mapping of hand and nerve anatomy in amputees and incremental value of MRN over electrophysiology findings in pre-surgical planning of FAST-LIFE interface (robotic hand) patients. Materials and methods: After obtaining informed consent, patients with upper extremity amputations underwent pre-operative 3-T MRN, X-rays, and electrophysiology. MRN findings were correlated with electrophysiology reports. Descriptive statistics were performed. Results: Five patients of ages 21–59 years exhibited 3/5 partial hand amputations, and 2/5 transradial amputations on X-rays. The median and ulnar nerve end bulb neuromas measured 10.1 ± 3.04 mm (range: 5.5–14 mm, median: 10.5 mm) and 10.9 ± 7.64 mm (2–22 mm, 9.75 mm), respectively. The ADC of median and ulnar nerves were increased at 1.64 ± 0.1 × 10−3 mm2/s (range: 1.5–1.8, median: 1.64 × 10−3 mm2/s) and 1.70 ± 0.17 × 10−3 mm2/s (1.49–1.98 × 10−3 mm2/s, 1.65 × 10−3 mm2/s), respectively. Other identified lesions were neuromas of superficial branch of the radial nerve and anterior interosseous nerve. On electrophysiology, 2/5 reports were unremarkable, 2/5 showed mixed motor-sensory neuropathies of median and ulnar nerves along with radial sensory neuropathy, and 1/5 showed sensory neuropathy of lateral cutaneous nerve of the forearm. All patients regained naturalistic sensations and motor control of digits. Conclusion: 3-T MRN allows excellent demonstration of forearm and hand nerve anatomy, altered diffusion characteristics, and their neuromas despite unremarkable electrophysiology for pre-surgical planning of the FAST-LIFE (robotic hand) interfaces.
KW - FAST-LIFE
KW - MR neurography
KW - MRN
KW - Neuroma
KW - Upper extremity amputation
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UR - http://www.scopus.com/inward/citedby.url?scp=85131061903&partnerID=8YFLogxK
U2 - 10.1007/s00256-022-04079-5
DO - 10.1007/s00256-022-04079-5
M3 - Article
C2 - 35635556
AN - SCOPUS:85131061903
SN - 0364-2348
VL - 51
SP - 2185
EP - 2193
JO - Skeletal radiology
JF - Skeletal radiology
IS - 11
ER -