PMC7411456_01
Nerve conduction studies in 2010 (a) indicating F-wave hyperexcitability in the tibial nerve with reduced minimal latency of 41.2 ms, a polyphasic appearance, and persistence. Nerve conduction studies in 2015 (b) showing a normalized minimal latency of 48.2 ms.
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fig1
Nerve conduction studies indicated F-wave hyperexcitability in the tibial nerve (see Figure 1) but were misinterpreted as normal.
Thermoregulatory Sweat Test. Skin areas in yellow indicate reduced or absent sweat output consistent with small fiber neuropathy.
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fig2
Test. The Thermoregulatory Sweat Test revealed sweating abnormalities with hypohidrosis in the areas of worst pain, specifically the lateral aspects of the legs, thighs, and arms, consistent with small fiber neuropathy (see Figure 2).
Needle electromyogram showing spontaneous activity in the right abductor pollicis brevis muscle with fasciculations, fibrillations, and complex repetitive discharge at 90-120 Hz.
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fig3
However, needle EMG revealed abnormal spontaneous activity in the form of fibrillation potentials, complex repetitive discharges, and myotonic discharges in the abductor pollicis brevis and extensor digitorum brevis muscles (Figure 3).