The impact of tarsal tunnel syndrome to cold sensation in the pedal extremities

Abstract Objective Tarsal tunnel syndrome (TTS) is an entrapment neuropathy of the posterior tibial nerve in the tarsal tunnel. It is not known whether vascular or neuropathic factors are implicated in the etiology of a cold sensation experienced by patients. Therefore we studied the cold sensation in the pedal extremities of patients who did or did not undergo TTS surgery. Patients and Methods Our study population was comprised of 20 patients with TTS (38 feet); one foot was affected in 2- and both feet in 18 patients. We acquired the toe-brachial pressure index (TBI) to evaluate perfusion of the sole and toe perfusion under 4 conditions: In the at-rest position (condition 1), in the at-rest position with compression of the foot dorsal artery (FDA) (condition 2), in the Kinoshita foot position (condition 3), and in the Kinoshita foot position with FDA compression (condition 4). Patients who reported abatement in the cold sensation during surgery underwent intraoperative re-occlusion of the tibial artery to check for the return of the cold sensation. Results The TBI for conditions 1 and 3 averaged 0.82 ± 0.09 and 0.81 ± 0.11, respectively; for conditions 2 and 4 it averaged 0.70±0.11 and 0.71±0.09. Among the 16 operated patients, the cold sensation in 7 feet improved intraoperatively; transient re-occlusion of the tibial artery did not result in the reappearance of the cold sensation. Conclusion Our findings suggest that the cold sensation in the feet of our TTS patients was associated with neuropathic- rather than vascular factors.