Felsenthal G, Butler D H, Shear M S
Department of Rehabilitation Medicine of Sinai Hospital, Baltimore, MD.
Arch Phys Med Rehabil. 1992 Jan;73(1):64-9.
Tarsal tunnel syndrome is a commonly considered compression of the tibial nerve and its plantar divisions as the nerve curves behind the medial malleolus underneath the flexor retinaculum. Motor, sensory, and/or mixed-nerve conduction studies are used to confirm or exclude the presence of compression of the posterior tibial nerve and its plantar divisions. In previous studies, stimulation has been done either proximal to the tunnel or distally in the sole of the feet or in the toes. Thus, differentiation between compression of the nerve within the proximal tarsal tunnel, as distinguished from compression of the plantar nerves in the distal tarsal tunnel or distal to the tunnel, has not been feasible. In addition, onset latency is frequently difficult to measure, and peak latencies have not been reported for the motor-evoked action potential. This study reports across-tarsal-tunnel latencies and amplitude decrements for both the medial and the lateral plantar nerves. For the medial plantar nerve with active electrodes placed over the medial head of the flexor pollicis brevis, the calculated mean + 2SD across tunnel onset latency is 3.2msec, peak latency is 2.9msec, and amplitude decrement is 29.3%. For the lateral plantar division, the calculated across-tunnel onset latency is 3.2msec, peak latency is 2.9msec, and amplitude decrement is 27.2%. Medial plantar nerve latency distal to the tarsal tunnel for the mean + 2SD is 5.9msec to onset and 9.5msec to peak, and the lateral plantar nerve latency is onset 5.9msec and peak 9.7msec.
跗管综合征通常被认为是当胫神经及其足底分支在屈肌支持带下方、内踝后方弯曲时受到压迫。运动、感觉和/或混合神经传导研究用于确认或排除胫后神经及其足底分支是否存在压迫。在以往的研究中，刺激是在隧道近端或足底或脚趾远端进行的。因此，区分近端跗管内神经的压迫与远端跗管或隧道远端足底神经的压迫是不可行的。此外，起始潜伏期常常难以测量，且运动诱发电位的峰值潜伏期尚未见报道。本研究报告了内侧和外侧足底神经的跨跗管潜伏期和波幅递减情况。对于将活动电极置于拇短屈肌内侧头上方的内侧足底神经，计算得出的跨隧道起始潜伏期平均 + 2标准差为3.2毫秒，峰值潜伏期为2.9毫秒，波幅递减为29.3%。对于外侧足底分支，计算得出的跨隧道起始潜伏期为3.2毫秒，峰值潜伏期为2.9毫秒，波幅递减为27.2%。跗管远端内侧足底神经的潜伏期平均 + 2标准差为起始5.9毫秒、峰值9.5毫秒，外侧足底神经潜伏期为起始5.9毫秒、峰值9.7毫秒。
