Correlation of lower extremity functional scale and electrodiagnostic findings in sciatic neuropathy patients

Abstract

Introduction Sciatic nerve has an essential role in sensorimotor innervation of the lower extremities. This study explored the association between electrophysiological findings and lower extremity function in patients with sciatic neuropathy. Materials and Methods This retrospective study analyzed the electrophysiological data of 41 patients with sciatic neuropathy who underwent evaluation between January 2023 and August 2024. Lower extremity function was evaluated with the Lower Extremity Functional Scale (LEFS), while neuropathic pain was assessed using the Douleur Neuropathique 4 (DN4) questionnaire. Results The median LEFS score was 29, reflecting significant functional impairment, while 95.1% of patients exhibited neuropathic pain based on DN4 scores. LEFS scores showed a significant correlation with the compound muscle action potential (CMAP) amplitudes of the abductor hallucis brevis (Spearman rho: 0.52, p < 0.001) and extensor digitorum brevis (Spearman rho: 0.32, p = 0.04) muscles. Conclusion This study provides novel evidence on the critical role of posterior tibial and peroneal nerve dysfunction in lower extremity impairment in sciatic neuropathy patients. The stronger correlation of LEFS with posterior tibial nerve function underscores its importance in high-effort activities. We propose that electrophysiological findings may facilitate a more objective evaluation of functional impairment in sciatic neuropathy patients and aid in the development of targeted rehabilitation strategies.

Keywords

• Sciatic neuropathy
• lower extremity
• neuropathic pain
• electromyography
• nerve conduction studies

Siyatik sinir nöropatisi olan hastalarda elektrofizyolojik bulgular ile alt ekstremite fonksiyonel ölçeğinin korelasyonu

Öz

Amaç Alt ekstremitelerin sensorimotor innervasyonunun sağlanmasında siyatik sinirin önemli bir rolü vardır. Bu çalışma, siyatik nöropatili hastalarda elektrofizyolojik bulgular ile alt ekstremite fonksiyonları arasındaki ilişkiyi araştırmayı amaçlamaktadır. Gereç ve Yöntem Bu retrospektif çalışmada, Ocak 2023 - Ağustos 2024 tarihleri arasında değerlendirilmiş 41 siyatik nöropati hastasının elektrofizyolojik verileri analiz edilmiştir. Alt ekstremite fonksiyonları Alt Ekstremite Fonksiyonel Ölçeği ile değerlendirilirken, nöropatik ağrı varlığı ve şiddeti Douleur Neuropathique 4 (DN4) anketi ile ölçülmüştür. Bulgular Alt ekstremite fonksiyonel ölçeği medyan skoru 29 olup hastalardaki ciddi fonksiyonel kaybı göstermektedir. DN4 ölçeğine göre hastaların %95.1’inde nöropatik ağrı saptanmıştır. Alt ekstremite fonksiyonel ölçeği skorları ile abductor hallucis brevis (Spearman rho: 0.52, p < 0.001) ve extensor digitorum brevis (Spearman rho: 0.32, p = 0.04) kaslarından kaydedilen bileşik kas aksiyon potansiyeli amplitüdü arasında anlamlı bir korelasyon saptanmıştır. Sonuç Bulgularımız, siyatik nöropati hastalarında posterior tibial ve peroneal sinirlerin disfonksiyonunun alt ekstremite fonksiyon kaybındaki kritik rolünü ortaya koymaktadır. Alt ekstremite fonksiyonel ölçeği skorları ile posterior tibial sinir fonksiyonunun daha güçlü bir korelasyon göstermesi, bu sinirin alt ekstremitenin efor gerektiren aktivitelerindeki önemini göstermektedir. Siyatik nöropati hastalarında elektrofizyolojik bulgular, fonksiyonel kaybın daha objektif bir şekilde değerlendirilmesine katkı sağlayabilir ve hedefe yönelik rehabilitasyon stratejilerinin geliştirilmesine yardımcı olabilir.

Anahtar Kelimeler

• Siyatik sinir nöropatisi
• nöropatik ağrı
• elektromiyografi
• sinir iletim çalışması

Kaynakça

1. 1.Distad BJ, Weiss MD. Clinical and Electrodiagnostic Features of Sciatic Neuropathies. Phys Med Rehabil Clin N Am: 2013;24:107–120. [Crossref]
2. 2.Hayat G, Calvin JS. Electrodiagnostic Assessment of Uncommon Mononeuropathies. Neurol Clin: 2021;39:957–981. [Crossref]
3. 3.Yildiz FG, Uzuncakmak‑Uyanik H, Aghamirzayeva K et al. Electrodiagnostic Features of Sciatic Neuropathy: Six‑year Referral Center Experience. Neurol Sci Neurophysiol: 2023;40:145–151. [Crossref]
4. 4.Yuen EC, So YT, Olney RK. The electrophysiologic features of sciatic neuropathy in 100 patients. Muscle Nerve: 1995;18:414–420. [Crossref]
5. 5.Cherian RP, Li Y. Clinical and Electrodiagnostic Features Of Nontraumatic Sciatic Neuropathy. Muscle and Nerve: 2019;59:309–314. [Crossref]
6. 6.Fidanci H, Öztürk I. The relationship between nerve conduction studies and neuropathic pain in sciatic nerve injury due to intramuscular injection. Korean J Pain: 2021;34:124–131. [Crossref]
7. 7.Yuen EC, Olney RK, So YT. Sciatic neuropathy: clinical and prognostic features in 73 patients. Neurology: 1994;44:1669–1674. [Crossref]
8. 8.Binkley JM, Stratford PW, Lott SA, et al. The Lower Extremity Functional Scale (LEFS): Scale development, measurement properties, and clinical application. Phys Ther: 1999;79:371–383. [Crossref]

9. 9.Mehta SP, Fulton A, Quach C, et al. Measurement Properties of the Lower Extremity Functional Scale: A Systematic Review. J Orthop Sports Phys Ther: 2016;46:200–216. [Crossref]
10. 10.Citaker S, Kafa N, Hazar Kanik Z, et al. Translation, cross-cultural adaptation and validation of the Turkish version of the Lower Extremity Functional Scale on patients with knee injuries. Arch Orthop Trauma Surg: 2016;136:389–395. [Crossref]
11. 11.Walsh J, Rabey MI, Hall TM. Agreement and correlation between the self-report leeds assessment of neuropathic symptoms and signs and Douleur Neuropathique 4 Questions neuropathic pain screening tools in subjects with low back-related leg pain. J Manipulative Physiol Ther: 2012;35:196–202. [Crossref]
12. 12.Unal-Cevik I, Sarioglu-Ay S, Evcik D. A comparison of the DN4 and LANSS questionnaires in the assessment of neuropathic pain: validity and reliability of the Turkish version of DN4. J pain: 2010;11:1129–1135. [Crossref]
13. 13.Halil AC, Gul BM, Rumeysa P, et al. Neuropathic pain and mood disorders in earthquake survivors with peripheral nerve injuries. Ideggyogy Sz: 2024;77:97–102. [Crossref]
14. 14.Fidanci H, Öztürk I, Köylüoğlu AC, et al. The needle electromyography findings in the neurophysiological classification of ulnar neuropathy at the elbow. Turkish J Med Sci: 2020;50:804–810. [Crossref]
15. 15.Fidanci H, Öztürk İ, Köylüoğlu AC, et al. Bilateral Nerve Conduction Studies Must Be Considered in the Diagnosis of Sciatic Nerve Injury Due to Intramuscular Injection. Neurol Sci Neurophysiol: 2020;37.
16. 16.Maqbool W, Sheikh S, Ahmed A. Clinical, electrophysiological, and prognostic study of postinjection sciatic nerve injury: An avoidable cause of loss of limb in the peripheral medical service. Ann Indian Acad Neurol: 2009;12:116–119. [Crossref]
17. 17.Preston DC, Shapiro B. Electromyography and neuromuscular disorders clinical-electrophysiologic-ultrasound correlations [Internet]. 4th editio. Amsterdam: Elsevier; 2020
18. 18.Stratford PW, Kennedy D, Pagura SMC, et al. The relationship between self-report and performance-related measures: questioning the content validity of timed tests. Arthritis Rheum: 2003;49:535–540. [Crossref]
19. 19.Bromberg MB. The motor unit and quantitative electromyography. Muscle Nerve: 2020;61:131–142. [Crossref]
20. 20.Rubin DI. Normal and abnormal voluntary activity. Handb Clin Neurol: 2019;160:281–301. [Crossref]
21. 21.Abraham A, Drory VE, Fainmesser Y, et al. Muscle thickness measured by ultrasound is reduced in neuromuscular disorders and correlates with clinical and electrophysiological findings. Muscle Nerve: 2019;60:687–692. [Crossref]
22. 22.Bäumer P, Weiler M, Bendszus M, et al. Somatotopic fascicular organization of the human sciatic nerve demonstrated by MR neurography. Neurology: 2015;84:1782–1787. [Crossref]