Yes. The patient’s signs and symptoms suggest involvement of a specific peripheral nerve of the right sacral plexus, the tibial nerve, while sparing other nerves of the plexus (e.g., the common fibular (peroneal) nerve and more proximal nerves of the plexus). Numbness, tingling, and burning (hyperpathic) pain involving the plantar aspect of the right foot and toes, with variable, inconsistent spread up the posterior, distal aspect of the calf, plus the weakness of ankle plantar flexion, inversion of the foot, and flexion of the toes, suggest a lesion of the right tibial nerve.

Her right tibial mononeuropathy appears to be localized to the middle of the popliteal fossa above its branches to the gastrocnemius and soleus muscles, since those muscles, as well as the muscles of the deep posterior compartment of the leg, are involved by the pathologic process.

The most likely pathological process in this setting is a compression or pressure neuropathy; although the specific mechanism of compression is not clear from the patient’s history. However, as mentioned in other similar cases, mononeuropathies can also be caused by amyloid or tumor infiltration and ischemic, infectious, or inflammatory processes such as diabetes, leprosy, sarcoidosis, vasculitis, and autoimmune diseases.