TY - JOUR
T1 - Distal Tibial Mononeuropathy from Compression by the Posterior Tibial Artery
T2 - Clinical-Electrophysiological-Ultrasonographic Correlations
AU - Beecher, Grayson
AU - Chompoopong, Pitcha
AU - Litchy, William J.
AU - Boon, Andrea J.
N1 - Publisher Copyright:
© 2023 Lippincott Williams and Wilkins. All rights reserved.
PY - 2023/5/1
Y1 - 2023/5/1
N2 - The tibial nerve is bound tightly to the posterior tibial artery in the tarsal tunnel where expansion capacity is limited. Therefore, the nerve may be vulnerable to, and damaged by chronic pulsatile trauma from an atypically positioned overriding artery, labeled "punched-nerve syndrome". In this article, we present a 49-year-old woman who presented with two months of severe burning pain in the left medial ankle and sole of the foot without antecedent trauma. Neurological examination identified dysesthetic sensation to light touch in the left medial sole of the foot, and both active and passive dorsiflexion worsened the painful paresthesia. Nerve conduction studies demonstrated a reduced left medial plantar mixed nerve action potential amplitude, 50% less than the right. High-resolution ultrasound (HRUS) showed an increased left tibial nerve cross-sectional area of 26 mm2(normal <22.3 mm2) at the level of the ankle with side-to-side difference of 6 mm2(normal <5.7 mm2). The distal tibial nerve and its medial plantar branch were atypically positioned immediately deep to the left posterior tibial artery and abnormally flattened with focal enlargement of the nerve on longitudinal view. Dynamic analysis demonstrated the nerve being compressed with each pulsation of the tibial artery immediately above. Active dorsiflexion of the ankle narrowed the space underneath the flexor retinaculum resulting in further compression of the nerve against the artery. In conclusion, HRUS as an adjunct to electrophysiological studies identified punched-nerve arterial compression as an etiology of tarsal tunnel syndrome.
AB - The tibial nerve is bound tightly to the posterior tibial artery in the tarsal tunnel where expansion capacity is limited. Therefore, the nerve may be vulnerable to, and damaged by chronic pulsatile trauma from an atypically positioned overriding artery, labeled "punched-nerve syndrome". In this article, we present a 49-year-old woman who presented with two months of severe burning pain in the left medial ankle and sole of the foot without antecedent trauma. Neurological examination identified dysesthetic sensation to light touch in the left medial sole of the foot, and both active and passive dorsiflexion worsened the painful paresthesia. Nerve conduction studies demonstrated a reduced left medial plantar mixed nerve action potential amplitude, 50% less than the right. High-resolution ultrasound (HRUS) showed an increased left tibial nerve cross-sectional area of 26 mm2(normal <22.3 mm2) at the level of the ankle with side-to-side difference of 6 mm2(normal <5.7 mm2). The distal tibial nerve and its medial plantar branch were atypically positioned immediately deep to the left posterior tibial artery and abnormally flattened with focal enlargement of the nerve on longitudinal view. Dynamic analysis demonstrated the nerve being compressed with each pulsation of the tibial artery immediately above. Active dorsiflexion of the ankle narrowed the space underneath the flexor retinaculum resulting in further compression of the nerve against the artery. In conclusion, HRUS as an adjunct to electrophysiological studies identified punched-nerve arterial compression as an etiology of tarsal tunnel syndrome.
KW - Medial plantar nerve
KW - Punched nerve syndrome
KW - Tarsal tunnel syndrome
KW - Tibial mononeuropathy
KW - Tibial nerve
KW - Ultrasound
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U2 - 10.1097/WNP.0000000000000983
DO - 10.1097/WNP.0000000000000983
M3 - Article
C2 - 37143210
AN - SCOPUS:85159550357
SN - 0736-0258
VL - 40
SP - E17-E20
JO - Journal of Clinical Neurophysiology
JF - Journal of Clinical Neurophysiology
IS - 4
ER -