Objective: Early detection of nerve dysfunction is important in management of diabetic peripheral neuropathy. Our study was aimed at finding the correlation of cross sectional area and Maximum thickness of nerve fascicle with the presence of peripheral neuropathy.

Materials and Methods: 50 patients with type 2 diabetes clinically diagnosed with diabetic peripheral neuropathy were analysed and severity of peripheral neuropathy was determined using Toronto clinical neuropathic score. 45 diabetic patients with no symptoms of peripheral neuropathy and 50 healthy non-diabetic subjects were taken as controls. The cross sectional area and maximum thickness of nerve fascicles of the tibial nerve were calculated 3cm cranial to medial malleolus in both lower limbs.

Results: The mean cross sectional area  (17.01+/-1.31 mm²) and maximum thickness of nerve fascicle (0.61 mm) of the tibial nerve  in patients with peripheral neuropathy compared with both control groups were significantly larger and statistically significant correlation was found with Toronto clinical neuropathic score(p<0.001). the diabetic patients with no signs of peripheral neuropathy had larger mean cross sectional area(10.77+/-1.73 mm²) and maximum thickness of nerve fascicle (0.25mm) than the healthy non-diabetic subjects (7.46+/-1.77mm² and 0.20 mm respectively).

Conclusion: The cross sectional area and mean thickness of nerve fascicle of the tibial nerve is larger in diabetic patients with or without peripheral neuropathy than in healthy subjects and it showed correlation with severity and high resolution USG can be used as a screening tool in these patients.

Keywords: cross sectional area, maximum thickness of nerve fascicle, tibial nerve, sonography, diabetic neuropathy.

1. Callaghan BC, Cheng HT, Stables CL, Smith AL, Feldman EL: Diabe­tic neuropathy: Clinical manifestations and current treatments. Lancet Neurol 2012; 11: 521–534.
2. Llewelyn JG: The diabetic neuropathies: types, diagnosis and manage­ment. J Neurol Neurosurg Psychiatry 2003; 74: ii15–ii19.
3. Catwright MS, Passmore LV, Yoon JS, Brown ME, Caress JB, Walker FO: Cross-sectional area reference values for nerve ultrasonography. Muscle Nerve 2008; 37: 566–571.
4. Watanabe T, Ito H, Sekine A, Katano Y, Nishimura T, Kato Y et al.: Sonographic evaluation of the peripheral nerve in diabetic patients: the relationship between nerve conduction studies, echo intensity, and cross-sectional area. J Ultrasound Med 2010; 29: 697–708.
5. Riazi S, Bril V, Perkins BA, Abbas S, Chan VW, Ngo M et al.: Can ul­trasound of the tibial nerve detect diabetic peripheral neuropathy? A cross-sectional study. Diabetes Care 2012; 35: 2575–2579.
6. Bril V, Perkins BA: Validation of the Toronto Clinical Scoring System for diabetic polyneuropathy. Diabetes Care 2002; 25: 2048–2052.
7. Böhm J: High resolution sonography of peripheral nerves: normal va­lues in healthy worth individuals and the role of sonography in rare disorders of peripheral nerves (doctoral dissertation).
8. Silvestri E, Martinoli C, Derchi LE, Bertolotto M, Chiaramondia M, Rosenberg I: Echotexture of peripheral nerves: correlation between US and histologic findings and criteria to differentiate tendons. Radiology 1995; 197: 291–296.
9. Lawande AD, Warrier SS, Joshi MS: Role of ultrasound in evaluation of peripheral nerves. Indian J Radiol Imaging 2014; 24: 254–258.
10. Perkins BA, Bril V: Diabetic neuropathy: a review emphasizing diagno­stic methods. Clin Neurophysiol 2003; 114: 1167–1175.
11. Arezzo JC: The use of electrophysiology for the assessment of diabetic neuropathy. Neurosci Res Commun 1997; 21: 13–23.
12. Fantino O, Coillard JY, Borne J, Bordet B: Ultrasound of the tarsal tunnel: Normal and pathological imaging features. J Radiol 2011; 92: 1072–1080.
13. Bae JS, Kim BJ: Subclinical diabetic neuropathy with normal conven­tional electrophysiological study. J Neurol 2007; 254: 53–59.
14. Kowalska B, Sudoł-Szopińska I: Normal and sonography anatomy of selected peripheral nerves. Part III: Peripheral nerves of the lower limb. J Ultrason 2012; 12: 148–163.
15. Kim WK, Kwon SH, Lee SH, Sunwoo I: Asymptomatic electrophysio­logic carpal tunnel syndrome in diabetics: Entrapment or polyneuro­pathy. Yonsei Med J 2000; 41: 123–127.
16. Dyck PJ, Kratz KM, Karnes JL, Litchy WJ, Klein R, Pach JM et al.: The prevalence by staged severity of various types of diabetic neuropathy, retinopathy, and nephropathy in a population-based cohort: the Roche­ster Diabetic Neuropathic Study. Neurology 1993; 43: 817–824.
17. Ishibashi F, Taniguchi M, Kojima R, Kawasaki A, Kosaka A, Uetake H: Morphological changes of the peripheral nerves evaluated by high-re­solution ultrasonography are associated with the severity of diabetic neuropathy, but not corneal nerve fiber pathology in patients with type 2 diabetes. J Diabetes Investig 2015; 6: 334–342.
18. Nathan DM, Kuenen J, Borg R, Zheng H, Schoenfeld D, Heine RJ et al.: Translating the A1C assay into estimated average glucose values. Dia­betes Care 2008; 31: 1473–1478.
19. Kang S, Kim SH, Yang SN, Yoon JS: Sonographic features of periphe­ral nerves at multiple sites in patients with diabetic polyneuropathy. J Diabetes Complications 2016; 30: 518–523.
20. Cartwright MS, Passmore LV, Yoon JS, Brown ME, Caress JB, Walker FO. Cross-sectional area reference value for nerve ultrasonography. Muscle Nerve 2008; 37:566–571.
21. Dyck PJ, Kratz KM, Karnes JL, et al. The prevalence by staged severity of various types of diabetic neuropathy, retinopathy, and nephropathy in a population-based cohort: the Rechester diabetic neuropathic study. Neurology 1993; 43:817–824.
22. Severinsen K, Andersen H. Evaluation of atrophy of foot muscles in diabetic neuropathy: a comparative study of nerve conduction studies and ultrasonography. Clin Neurophysiol 2007; 118:2172–2175.
23. Suzuki E, Yasuda K, Yasuda K, et al. 1H-NMR analysis of nerve edema in the streptozotocin-induced diabetic rat. J Lab Clin Med 1994; 124:627–637.
24. M Graif, A.Seton, J.Nerubai, H. Horoszowski, Y, Itzchak. Sciatic nerve: Sonographic evaluation and anatomic considerations.
25. Duncan I, Sullivan P, Lomas F. Sonography in the diagnosis of carpal tunnel  AJR Am J Roentgenol. 1999;173:681–684
26. Kunwarpal S, Kamlesh G, Sukhdeep k : HRUSG of tibial nerve in Diabetic neuropathy, 2017; 17:246-252.
27. Heckmatt JZ, Dubowitz V, Leeman S. Detection of pathological change in dystrophic muscle with B-scan ultrasound imaging. Lancet. 1980;1:1389–1390

Dr T. Aravind

Junior Resident, Department of Radiodiagnosis, SCB Medical College