Can Ultrasound of the Tibial Nerve Detect Diabetic Peripheral Neuropathy?

Abstract

OBJECTIVEPeripheral nerve imaging by portable ultrasound (US) may serve as a noninvasive and lower-cost alternative to nerve conduction studies (NCS) for diagnosis and staging of diabetic sensorimotor polyneuropathy (DSP). We aimed to examine the association between the size of the posterior tibial nerve (PTN) and the presence and severity of DSP.RESEARCH DESIGN AND METHODSWe performed a cross-sectional study of 98 consecutive diabetic patients classified by NCS as subjects with DSP or control subjects. Severity was determined using the Toronto Clinical Neuropathy Score. A masked expert sonographer measured the cross-sectional area (CSA) of the PTN at 1, 3, and 5 cm proximal to the medial malleolus.RESULTSFifty-five patients had DSP. The mean CSA of the PTN in DSP compared with control subjects at distances of 1 (23.03 vs. 17.72 mm2; P = 0.004), 3 (22.59 vs. 17.69 mm2; P < 0.0001), and 5 cm (22.05 vs. 17.25 mm2; P = 0.0005) proximal to the medial malleolus was significantly larger. Although the area under the curve (AUC) for CSA measurements at all three anatomical levels was similar, the CSA measured at 3 cm above the medial malleolus had an optimal threshold value for identification of DSP (19.01 mm2) with a sensitivity of 0.69 and a specificity of 0.77 by AUC analysis.CONCLUSIONSThis large study of diabetic patients confirms that the CSA of the PTN is larger in patients with DSP than in control subjects, and US is a promising point-of-care screening tool for DSP.

Ultrasound Findings After Surgical Decompression of the Tarsal Tunnel in Patients With Painful Diabetic Polyneuropathy: A Prospective Randomized Study

“…Variations in methods in the current literature give a variation in results and make the studies difficult to compare (11,12,(16)(17)(18)(19)(20)(21). For example, Lee and Dauphinée (11) found an increased CSA using ultrasound in patients with DPN (24 mm 2 ) compared with healthy control subjects (12 mm 2 ).…”

“…Four studies evaluated healthy individuals and describe CSAs between 7.9 and 13.7 mm 2 . All the CSAs were measured at different locations in the ankle (16)(17)(18)20 (12,21).…”

“…The use of a 12-MHz transducer cranial of the tarsal tunnel might be helpful since the nerve is located deeper at that location than in the tarsal tunnel. Riazi et al (18) measured the CSA of the tibial nerve at three locations, respectively 1, 2, and 3 cm proximal to the medial malleolus, and found at 3 cm a sensitivity of 0.69 and a specificity 0.77 for determining DPN. Based on these findings, we suggest future studies to measure at this location.…”

Reconsidering Nerve Decompression: An Overlooked Opportunity to Limit Diabetic Foot Ulcer Recurrence and Amputation

“…• For the hypothesized nerve enlargement in DSPN by strong objective level I evidence; 47,48 • Asymmetry and variability of global foot sensibility, Oxford EBM level II-1; 45,52 • High perineural tissue pressures within inflexible anatomic tunnel structures, and relief of pressure by ND, Level II-1;…”

Comment on Tesfaye et al. Mechanisms and Management of Diabetic Painful Distal Symmetrical Polyneuropathy. Diabetes Care 2013;36:2456–2465

“…Riazi et al (2) and others (3) have pointed out that ultrasonographic nerve enlargement is present in these neuropathy cases and might actually be used as a bedside diagnostic tool. Meta-analyses (4,5) have reviewed the favorable response of DSPN patients to nerve decompression (ND) by surgical external neurolysis at the several fibro-osseous tunnel nerve trunk entrapment sites in the lower extremity.…”