362 - A unique case of peroneal neuropathy due to non-traumatic rhabdomyolysis with electrodiagnostic evidence of peripheral nerve recovery

Friday, February 23, 2024

5:00 PM – 6:30 PM EDT

Presenting Author(s)

JP

Jordan Petersen, DO

Resident
Corewell Health Taylor
Taylor, Michigan, United States

Co-Author(s)

RH

Ryan Haley, MD

Resident
Corewell Health Taylor
Taylor, Michigan, United States
MM

Melissa Mafiah, MD

Attending Physician
Corewell Health Taylor
Taylor, Michigan, United States

Case Diagnosis: Peroneal neuropathy has many etiologies with varying degrees of recovery. This case reveals a unique clinical course of peroneal neuropathy secondary to acute non-traumatic rhabdomyolysis with electrodiagnostic evidence of peripheral nerve recovery.

Case Description: A 23 yo male with a history of asthma was hospitalized for worsening swelling, pain, and erythema of his right lower extremity (RLE) for three days following a one hour low intensity walk. He was diagnosed with rhabdomyolysis with peak creatine kinase reaching 9302 u/L. CT imaging revealed diffuse edema of RLE subcutaneous tissue from the knee to the ankle most pronounced laterally. There were no clinical signs of compartment syndrome. He developed paresthesias of the dorsum of the foot and progressive monoparesis of the RLE including 0/5 manual muscle testing (MMT) of dorsiflexion, great toe extension, and ankle eversion.

Discussions: NCS/EMG testing was performed 5 weeks following symptom onset. Initial electrodiagnostic testing revealed right peroneal neuropathy with severe axonal loss with acute denervations of right tibialis anterior (TA), extensor hallucis longus (EHL), and peroneus longus (PL) with no motor units seen during recruitment. Peroneal nerve was unable to be recorded from extensor digitorum brevis (EDB), but recording from TA showed significant axonal loss. He began physical therapy and returned for repeat NCS/EMG 8 weeks later. Electrodiagnostic testing redemonstrated right peroneal neuropathy with continued absence of response from EDB and improvement in peroneal nerve amplitude as measured from TA without acute ongoing denervations in RLE muscles. Newly noted large amplitude motor units with reduced recruitment in TA, EHL, and PL were identified. Repeat MMT revealed improvement in dorsiflexion, great toe extension, and ankle eversion.

Conclusions: This case reviews an interesting etiology of peroneal neuropathy and its associated recovery with electrodiagnostic evidence to support.