Sural neuropathy
Updates to Article Attributes
Sural neuropathy or sural nerve entrapment can be the result of nerve compression or traction injury of the sural nerve a purepurely sensory branch usually formed by a conjunction of branches from the tibial nerve and common peroneal nerves thatnerve that supplies the the lateral aspect of the ankle and the foot to the base of the fifth toe 1,2.
Epidemiology
Associations
Sural nerve entrapment is usallyusually associated with traumatic injuries 1-3.
Diagnosis
The diagnosis is usually made on clinical grounds and difficult and can be confirmed with electrodiagnostic tests aslike nerve conduction studies and/or small fibre testing. Differential diagnosis as common peroneal nerve, tibial nerve entrapment and radiculopathy need toshould be ruled out.ref A A diagnostic sural nerve block might beis another option to confirm the diagnosis. Imaging studies such as MRI might help to identify the location of the entrapment and provide clues with regard toabout the aetiology 1.
Clinical presentation
PesentingPresenting symptoms include pain and paraesthesia along the lateral aspect of the foot and ankle including the base of the fifth toe 1,3 which might be exacerbated by plantar flexion and/or inversion of the foot 2. Chronic calf pain exacerbated by physical activity is another symptom 2. A positive Tinel sign or point tenderness at the entrapment site might be another clinical clue.
Pathology
Sural nerve neuropathy can be a result of an acute traumaictraumatic injury at different sites, chronic compression due to tendon dislocation or entrapment within a scar 4 or as a consequence of a traction injury with secondary fibrosis 2,3.
Aetiology
The cause areis usually related to a traumatic injury affecting the sural nerve including 1-4:
- direct contusion
- distal fibular fracture, talar, calcaneal or cuboid fracture
- fracture
of the baseof the fifth metatarsalbonebase - severe lateral ankle sprain
- gastrocnemius injury
-
Achilles tendinopathy or
peroneal tendinopathyperoneus tendon injury - space-occupying lesions
- iatrogenic injury (surgery)
Location
Sural neuropathy due to a direct traumatic event can happen at multiple different sites along the course 1-3. A common location at the level of the fifth metatarsal base where it bifurcates into its medial and lateral terminal branches 2,3. Another potential site would be the lateral aspect of the calf where the sural nerve leaves the crural fascia 5.
Radiographic features
Ultrasound
In the calf, the sural nerve can be visualized on top of the gasrocnemiusgastrocnemius muscle at a midcalf level and descends with the small saphenous vein 6,7. Further distally it can be seen between the Achilles tendon and the peroneal muscles and below or posterior to the peroneal tendons and superficial to the peroneal retinacula and the calacaneofibularcalcaneofibular ligament at the level of the calcaneus 6,7.
In sural nerve neuropathy, the nerve might be thickened and hypoechoic with partial or complete loss of its normal fascicular pattern 7. Local compression with the ultrasound probe might reproduce pain and ultrasound can be utilized for the guidance of a diagnostic nerve block 7.
MRI
MRI might visualize displacement or compression of the sural nerve due to traumatic injury or space-occupying lesion 2. Since the sural nerve is pure sensory there will not be any denervation changes 2.
Radiology report
The radiology report should include a description of the following 6:
- abnormal appearance of the sural nerve and location
- neuroma formation
- associated underlying pathology
Treatment and prognosis
Management includes conservative measures including physiotherapy, local anaesthetics, nonsteroidal anti-inflammatory non-steroidal drugs. Surgery might be required for the removal of space occupying-occupying lesions and involves decompression and neurolysis 5.
History and etymology
Some of the first reported cases of sural nerve neuropathy were described by R Pringle and colleagues in 1974 5,8.
Differential diagnosis
The differential diagnosis of superficial sural nerve entrapment includes:ref
-<p><strong>Sural neuropathy </strong>or<strong> sural nerve entrapment </strong>can be the result of nerve compression or traction injury of the sural nerve a pure sensory branch usually formed by a conjunction of branches from the tibial nerve and common peroneal nerves that supplies the the lateral aspect of the ankle and the foot to the base of the fifth toe <sup>1,2</sup>.</p><h4>Epidemiology</h4><h5>Associations</h5><p>Sural nerve entrapment is usally associated with traumatic injuries <sup>1-3</sup>.</p><h4>Diagnosis</h4><p>The diagnosis is usually made on clinical grounds and difficult and can be confirmed with electrodiagnostic tests as nerve conduction studies and/or small fibre testing. Differential diagnosis as common peroneal nerve, tibial nerve entrapment and radiculopathy need to be ruled out <sup>ref</sup>. A diagnostic sural nerve block might be another option to confirm the diagnosis. Imaging studies such as MRI might help to identify the location of the entrapment and provide clues with regard to the aetiology <sup>1</sup>.</p><h4>Clinical presentation</h4><p>Pesenting symptoms include pain and paraesthesia along the lateral aspect of the foot and ankle including the base of the fifth toe <sup>1,3</sup> which might be exacerbated by plantar flexion and/or inversion of the foot <sup>2</sup>. Chronic calf pain exacerbated by physical activity is another symptom <sup>2</sup>. A positive Tinel sign or point tenderness at the entrapment site might be another clinical clue.</p><h4>Pathology</h4><p>Sural nerve neuropathy can be a result of an acute traumaic injury at different sites, chronic compression due to tendon dislocation or entrapment within a scar <sup>4</sup> or as a consequence of a traction injury with secondary fibrosis <sup>2,3</sup>.</p><h5>Aetiology</h5><p>The cause are usually related to a traumatic injury affecting the sural nerve including <sup>1-4</sup>:</p><p>direct contusion</p><p>distal fibular fracture</p><p>talar, calcaneal or cuboid fracture</p><p>fracture of the base of the fifth metatarsal bone</p><p>severe lateral ankle sprain</p><p>gastrocnemius injury</p><p>Achilles or peroneal tendinopathy</p><p>space-occupying lesions</p><p>iatrogenic injury (surgery)</p><h5>Location</h5><p>Sural neuropathy due to a direct traumatic event can happen at multiple different sites along the course <sup>1-3</sup>. A common location at the level of the fifth metatarsal base where it bifurcates into its medial and lateral terminal branches <sup>2,3</sup>. Another potential site would be the lateral aspect of the calf where the sural nerve leaves the crural fascia <sup>5</sup>.</p><h4>Radiographic features</h4><h5>Ultrasound</h5><p>In the calf the sural nerve can be visualized on top of the gasrocnemius muscle at a midcalf level and descends with the small saphenous vein <sup>6,7</sup>. Further distally it can be seen between the Achilles tendon and the peroneal muscles and below or posterior to the peroneal tendons and superficial to the peroneal retinacula and the calacaneofibular ligament at the level of the calcaneus <sup>6,7</sup>.</p><p>In sural nerve neuropathy the nerve might be thickened and hypoechoic with partial or complete loss of its normal fascicular pattern <sup>7</sup>. Local compression with the ultrasound probe might reproduce pain and ultrasound can be utilized for guidance of a diagnostic nerve block <sup>7</sup>.</p><p> </p><h5>MRI</h5><p>MRI might visualize displacement or compression of the sural nerve due to traumatic injury or space-occupying lesion <sup>2</sup>. Since the sural nerve is pure sensory there will not be any denervation changes <sup>2</sup>.</p><h4>Radiology report</h4><p>The radiology report should include a description of the following <sup>6</sup>:</p><p>abnormal appearance of the sural nerve and location</p><p>neuroma formation</p><p>associated underlying pathology</p><h4>Treatment and prognosis</h4><p>Management includes conservative measures including physiotherapy, local anaesthetics, anti-inflammatory non-steroidal drugs. Surgery might be required for removal of space occupying lesions and involves decompression and neurolysis <sup>5</sup>.</p><h4>History and etymology</h4><p>Some of the first reported cases of sural nerve neuropathy were described by R Pringle and colleagues in 1974 <sup>5,8</sup>.</p><h4>Differential diagnosis</h4><p>The differential diagnosis of superficial sural nerve entrapment includes <sup>ref</sup>:</p><p>common peroneal nerve entrapment</p><p>deep peroneal nerve entrapment</p><p>peripheral nerve sheath tumour</p><p>radiculopathy</p>- +<p><strong>Sural neuropathy </strong>or<strong> sural nerve entrapment </strong>can be the result of nerve compression or traction injury of the <a href="/articles/sural-nerve">sural nerve</a> a purely sensory branch usually formed by a conjunction of branches from the <a href="/articles/tibial-nerve">tibial nerve</a> and <a href="/articles/common-peroneal-nerve">common peroneal nerve</a> that supplies the lateral aspect of the <a href="/articles/ankle-joint-2">ankle</a> and the <a href="/articles/foot">foot</a> to the base of the fifth toe <sup>1,2</sup>.</p><h4>Epidemiology</h4><h5>Associations</h5><p>Sural nerve entrapment is usually associated with <a href="/articles/trauma">traumatic injuries</a> <sup>1-3</sup>.</p><h4>Diagnosis</h4><p>The diagnosis is usually made on clinical grounds and difficult and can be confirmed with electrodiagnostic tests like nerve conduction studies and/or small fibre testing. Differential diagnosis as common peroneal nerve, tibial nerve entrapment and radiculopathy should be ruled out. A diagnostic sural nerve block is another option to confirm the diagnosis. Imaging studies such as MRI might help to identify the location of the entrapment and provide clues about the aetiology <sup>1</sup>.</p><h4>Clinical presentation</h4><p>Presenting symptoms include pain and paraesthesia along the lateral aspect of the foot and ankle including the base of the fifth toe <sup>1,3</sup> which might be exacerbated by plantar flexion and/or inversion of the foot <sup>2</sup>. Chronic calf pain exacerbated by physical activity is another symptom <sup>2</sup>. A positive <a href="/articles/tinel-sign">Tinel sign</a> or point tenderness at the entrapment site might be another clinical clue.</p><h4>Pathology</h4><p>Sural nerve neuropathy can be a result of an acute traumatic injury at different sites, chronic compression due to tendon dislocation or entrapment within a scar <sup>4</sup> or as a consequence of a traction injury with secondary fibrosis <sup>2,3</sup>.</p><h5>Aetiology</h5><p>The cause is usually related to a traumatic injury affecting the sural nerve including <sup>1-4</sup>:</p><ul>
- +<li>direct contusion</li>
- +<li>
- +<a href="/articles/aoota-classification-of-malleolar-fractures">distal fibular fracture</a>, <a href="/articles/talar-fractures">talar</a>, <a href="/articles/calcaneal-fracture">calcaneal</a> or cuboid fracture</li>
- +<li>fracture of the fifth metatarsal base</li>
- +<li>severe <a href="/articles/lateral-ankle-sprain">lateral ankle sprain</a>
- +</li>
- +<li>gastrocnemius injury</li>
- +<li>
- +<a href="/articles/achilles-tendinopathy">Achilles tendinopathy</a> or <a href="/articles/peroneus-tendon-injury-1">peroneus tendon injury</a>
- +</li>
- +<li>space-occupying lesions</li>
- +<li>iatrogenic injury (surgery)</li>
- +</ul><h5>Location</h5><p>Sural neuropathy due to a direct traumatic event can happen at multiple different sites along the course <sup>1-3</sup>. A common location at the level of the fifth metatarsal base where it bifurcates into its medial and lateral terminal branches <sup>2,3</sup>. Another potential site would be the lateral aspect of the calf where the sural nerve leaves the crural fascia <sup>5</sup>.</p><h4>Radiographic features</h4><h5>Ultrasound</h5><p>In the calf, the sural nerve can be visualized on top of the <a href="/articles/gastrocnemius-muscle">gastrocnemius muscle</a> at a midcalf level and descends with the <a href="/articles/small-saphenous-vein">small saphenous vein</a> <sup>6,7</sup>. Further distally it can be seen between the <a href="/articles/calcaneal-tendon-1">Achilles tendon</a> and the <a href="/articles/peroneus-longus-muscle">peroneal muscles</a> and below or posterior to the peroneal tendons and superficial to the <a href="/articles/peroneal-retinaculum">peroneal retinacula</a> and the <a href="/articles/calcaneofibular-ligament">calcaneofibular ligament</a> at the level of the <a href="/articles/calcaneus">calcaneus</a> <sup>6,7</sup>.</p><p>In sural nerve neuropathy, the nerve might be thickened and hypoechoic with partial or complete loss of its normal fascicular pattern <sup>7</sup>. Local compression with the ultrasound probe might reproduce pain and ultrasound can be utilized for the guidance of a diagnostic nerve block <sup>7</sup>.</p><h5>MRI</h5><p>MRI might visualize displacement or compression of the sural nerve due to traumatic injury or space-occupying lesion <sup>2</sup>. Since the sural nerve is pure sensory there will not be any denervation changes <sup>2</sup>.</p><h4>Radiology report</h4><p>The radiology report should include a description of the following <sup>6</sup>:</p><ul>
- +<li>abnormal appearance of the sural nerve and location</li>
- +<li>neuroma formation</li>
- +<li>associated underlying pathology</li>
- +</ul><h4>Treatment and prognosis</h4><p>Management includes conservative measures including physiotherapy, local anaesthetics, <a href="/articles/non-steroidal-anti-inflammatory-drugs">nonsteroidal anti-inflammatory drugs</a>. Surgery might be required for the removal of space-occupying lesions and involves decompression and neurolysis <sup>5</sup>.</p><h4>History and etymology</h4><p>Some of the first reported cases of sural nerve neuropathy were described by R Pringle and colleagues in 1974 <sup>5,8</sup>.</p><h4>Differential diagnosis</h4><p>The differential diagnosis of superficial sural nerve entrapment includes:</p><ul>
- +<li><a href="/articles/common-peroneal-neuropathy">common peroneal nerve entrapment</a></li>
- +<li><a href="/articles/deep-peroneal-nerve-entrapment">deep peroneal nerve entrapment</a></li>
- +<li><a href="/articles/peripheral-nerve-sheath-tumours">peripheral nerve sheath tumour</a></li>
- +<li>radiculopathy</li>
- +</ul>
References changed:
- 1. Donovan A, Rosenberg Z, Cavalcanti C. MR Imaging of Entrapment Neuropathies of the Lower Extremity. Radiographics. 2010;30(4):1001-19. <a href="https://doi.org/10.1148/rg.304095188">doi:10.1148/rg.304095188</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/20631365">Pubmed</a>
- 2. Beltran L, Bencardino J, Ghazikhanian V, Beltran J. Entrapment Neuropathies III: Lower Limb. Semin Musculoskelet Radiol. 2010;14(05):501-11. <a href="https://doi.org/10.1055/s-0030-1268070">doi:10.1055/s-0030-1268070</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/21072728">Pubmed</a>
- 3. Delfaut E, Demondion X, Bieganski A, Thiron M, Mestdagh H, Cotten A. Imaging of Foot and Ankle Nerve Entrapment Syndromes: From Well-Demonstrated to Unfamiliar Sites. Radiographics. 2003;23(3):613-23. <a href="https://doi.org/10.1148/rg.233025053">doi:10.1148/rg.233025053</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/12740464">Pubmed</a>
- 4. Paraskevas G, Natsis K, Tzika M, Ioannidis O. Fascial Entrapment of the Sural Nerve and Its Clinical Relevance. Anat Cell Biol. 2014;47(2):144. <a href="https://doi.org/10.5115/acb.2014.47.2.144">doi:10.5115/acb.2014.47.2.144</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/24987554">Pubmed</a>
- 5. Kowalska B, Indywidualna Specjalistyczna Praktyka Lekarska Berta Kowalska, Kraków, Polska, Sudoł‑Szopińska I, Zakład Diagnostyki Obrazowej, Instytut Reumatologii w Warszawie oraz Zakład Diagnostyki Obrazowej, II Wydział Lekarski WUM, Warszawa, Polska. Ultrasound Assessment of Selected Peripheral Nerves Pathologies. Part II: Entrapment Neuropathies of the Lower Limb. J Ultrason. 2012;12(51):463-71. <a href="https://doi.org/10.15557/jou.2012.0033">doi:10.15557/jou.2012.0033</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/26673938">Pubmed</a>
- 6. Bianchi S, Droz L, Lups Deplaine C, Dubois-Ferriere V, Delmi M. Ultrasonography of the Sural Nerve: Normal and Pathologic Appearances. J Ultrasound Med. 2017;37(5):1257-65. <a href="https://doi.org/10.1002/jum.14444">doi:10.1002/jum.14444</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/29027686">Pubmed</a>
- 8. Pringle R, Protheroe K, Mukherjee S. Entrapment Neuropathy of the Sural Nerve. J Bone Joint Surg Br. 1974;56B(3):465-8. - <a href="https://www.ncbi.nlm.nih.gov/pubmed/4417790">Pubmed</a>
- 7. Chang K, Mezian K, Naňka O et al. Ultrasound Imaging for the Cutaneous Nerves of the Extremities and Relevant Entrapment Syndromes: From Anatomy to Clinical Implications. JCM. 2018;7(11):457. <a href="https://doi.org/10.3390/jcm7110457">doi:10.3390/jcm7110457</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/30469370">Pubmed</a>
Tags changed:
- cases
Systems changed:
- Musculoskeletal