Surgical treatment of sural nerve entrapment aided by imaging- and electrography-based diagnosis: illustrative case

Abstract

BACKGROUND The sural nerve (SN) is a cutaneous sensory nerve that innervates the posterolateral side of the distal third of the leg and lateral side of the foot. The SN has wide variation in its course and is fixed to the subcutaneous tissue and superficial fascia. Idiopathic spontaneous SN neuropathy is rarely surgically treated because of the difficulty in detecting SN entrapment. OBSERVATIONS Herein, the authors present a rare case of surgically treated spontaneous SN neuropathy. A 67-year-old male patient presented with right foot pain for several years. Magnetic resonance imaging and ultrasonography showed SN entrapment slightly proximal and posterior to the lateral malleolus. A nerve conduction study showed SN disturbance. After undergoing neurolysis, the patient’s foot pain was alleviated. LESSONS Idiopathic SN neuropathy can be treated surgically when SN entrapment is detected with comprehensive evaluation methods.

Letter to the Editor. Before surgical sural nerve neurolysis, study neighboring sensory nerves

“…TO THE EDITOR: We read with interest the article by Matsubara et al 1 who reported on a 67-year-old male diagnosed with right sural nerve entrapment at the level behind the right lateral malleolus, confirmed by magnetic resonance imaging (MRI) and sensory nerve conduction studies ( Matsubara M, Yagi K, Hemmi S, et al Surgical treatment of sural nerve entrapment aided by imaging- and electrography-based diagnosis: illustrative case. J Neurosurg Case Lessons .…”

“…The patient underwent surgical neurolysis, which resulted in significant pain reduction over a follow-up period of 10 months. 1 The study is impressive but has limitations that should be discussed.…”

“…We disagree that fourth and fifth toe pain is associated with sural nerve lesion. 1 The pain modality in the fourth and fifth toes is usually conducted via the superficial peroneal nerve. 2 Therefore, we should know whether there was a slowing in conduction velocity or a reduction in sensory nerve action potential (SNAP) amplitude of the superficial peroneal nerve.…”