Clinical Neurology and Neurosurgery 151 (2016) 6–8 Contents lists available at ScienceDirect Clinical Neurology and Neurosurgery journal homepage: www.elsevier.com/locate/clineuro Case Report Tibialis anterior muscle herniation with superficial peroneal nerve involvement: Ultrasound role for diagnosis and treatment Ilaria Paolasso a , Chiara Cambise b , Daniele Coraci a,c , Filippo M. Del Tedesco b , Carmen Erra b , Eduardo Fernandez b , Luca Padua (Prof.) a,b,* a Don Carlo Gnocchi ONLUS Foundation, Milan, Italy b Department of Geriatrics, Neurosciences and Orthopaedics, Università Cattolica del Sacro Cuore, Rome, Italy c Board of Physical Medicine and Rehabilitation, Department of Orthopaedic Science, “Sapienza” University, Rome, Italy a r t i c l e i n f o Article history: Received 16 June 2016 Received in revised form 10 August 2016 Accepted 30 September 2016 Keywords: Muscle herniation Nerve Ultrasound Rehabilitation Surgery a b s t r a c t Ultrasound is helpful to identify nerve suffering cause. We report a case of pain at leg associated with burning paresthesia. Ultrasound found tibialis muscle herniation, close to superficial fibular nerve. The morphological alteration was supposed to be the cause of symptoms. Neurolysis, based on ultrasono- graphic findings, allowed symptoms relief. © 2016 Elsevier B.V. All rights reserved. 1. Introduction Muscle herniation is defined as a portion of muscle through acquired or congenital fascial layer defects [1]. Tibialis anterior muscle herniation is the most common, because its fascia is the most vulnerable to trauma. Herniations of peroneus longus, brevis and gastrocnemius muscles have also been described. Even upper limbs can be involved, but less frequently. Although this condi- tion is especially an esthetic problem, with palpable subcutaneous soft tissue mass, it can lead to spontaneous pain, cramp or local tenderness [2]. Potentially, neuropathic symptoms due to nerve damage may occur. Patients are usually adolescent or young adults; occupational and sporting activities, trauma, chronic compartment syndrome and weakness in the overlying fascia due to perforating vessels are implicated as causes. Because of the common subcuta- neous palpable mass, patients and physicians are often concerned the mass is a tumor. The swelling usually appears or enlarges when the affected muscle is contracted or patient is standing up [3]. Muscle herniation diagnosis is usual clinical, but Ultrasound (US) * Corresponding author at: Don Carlo Gnocchi ONLUS Foundation, Piazzale Morandi 6, 20121, Milan, Italy. E-mail addresses: luca.padua@unicatt.it, segreteriascientifica.padua@rm.unicatt.it (L. Padua). or Magnetic Resonance (MR) are often used to confirm diagnosis and guide treatment. US is useful for peripheral nervous system assessment and for evaluation of surrounding structures (bone, muscles, etc.) which sometimes may present anatomical variations [4]. In literature an incidence approaching 50% of muscle hernias in chronic leg-compartment syndromes is reported. Most frequently these hernias can be found in the anterolateral distal half of the leg. Chronic leg-compartment syndromes are characterized by recurrent symptoms of pain and paresthesia. Entrapment of the superficial fibular nerve (SFN) is relatively rare, Henry first described the condition in 1945 calling it “mononeuralgia in the superficial peroneal nerve”. Mechanical and dynamic causes are involved. The main symptom is usually the presence of pain in the distribution of the nerve, sometimes with sensory abnormalities. Pain occasionally radiates up into the thigh. Sometimes the pain is similar to sciatica, even if the signs do not indicate that it originates on the back. A paper by Canella et al. demonstrated the ability of high-resolution ultrasound to follow the course of the SPN and its anatomic variability [5]. 2. Case report A 54-year-old woman was referred to our neurophysiological lab because of a 5-years history of right lateral leg pain associ- http://dx.doi.org/10.1016/j.clineuro.2016.09.019 0303-8467/© 2016 Elsevier B.V. All rights reserved.