Shows the linear regression model for IENFD as a function of the sural sensory nerve action potential amplitude. (R² = 0.22, p<0.001).

<p>Shows the linear regression model for IENFD as a function of the sural sensory nerve action potential amplitude. (R² = 0.22, p<0.001).</p

Shows the ROC curves for large fiber function tests of sural nerve amplitude and conduction velocity and vibration perception thresholds at index finger and first toe.

<p>The curve for sural nerve amplitude lies closest to the upper y-axis and has the largest AUC at 0.75.</p

Comparison of the Area Under the Receiver Operating Characteristic Curve and Optimal Thresholds for Sural Nerve Amplitude and the Other Nerve Fiber Function Tests.

*<p>Two-tailed p values were calculated using a z-score obtained from testing the hypothesis that the areas under two different ROC curves are the same, according to the method of Pencina et al.</p>†<p>P value not applicable for sural nerve amplitude as it used as the reference to which the other tests are compared.</p>**<p>Optimal values were obtained by calculating the shortest distance between each variable’s ROC curve and the upper left hand corner of the ROC graph, according to the distance formula for two points in the plane, .</p

Characteristics of the 72 Patients with Clinical Polyneuropathy and Normal Large Fiber Tests According to Presence and Nature of Small Fiber Neuropathy.

*<p>P values for dichotomous variables were calculated with the χ2 test and t-test was used for continuous variables.</p><p>For VPT, the normal values are highly age-dependent, but values ≤5 are normal in the finger and ≤15 Volts are normal in the toe. For VPT, data are available in 42 patients with normal IENFD and on 24 patients with SFSN.</p><p>Cut-offs for quantitative sensory thresholds are age-dependent although, generally a normal CDT would be ≥25°C. The normal values for heat pain are ≤50°C.</p

Shows the ROC curves for small fiber function tests of cooling detection thresholds and heat perception thresholds in upper and lower extremities and the laser Doppler flow studies in the foot.

<p>Shows the ROC curves for small fiber function tests of cooling detection thresholds and heat perception thresholds in upper and lower extremities and the laser Doppler flow studies in the foot.</p

Scatterplots (A,B) and Bland-Altman plots (C,D) for comparison of the point-of-care nerve conduction method versus standard NCS for SNAP or SNCV.

<p>Panels A and B: Scatterplot of SNAP (A) and SNCV (B) showing the line of unity (diagonal solid line) between the two methods. Panels C and D: The Bland-Altman plots demonstrating the mean difference (depicted by the solid line) between SNAP (C) or SNCV (D) obtained by the two methods. Points above or below zero on the y-axis represent over- and underestimation by the point-of-care device, respectively. The dotted lines represent the upper and lower limits of the 85% confidence interval. Unrecordable SNCV results for both nerve conduction methods were assigned a value of 30.4 m/s, representing the lowest value in the dataset. Such data handling was applied to 9 values for standard NCS and 3 values for the point-of-care device.</p

Sample nerve conduction recordings from standard NCS (A) and the point-of-care device (B) from a 60-year-old female with type 2 diabetes and an image of the point-of-care procedure (C).

<p>Panel A: Sample standard NCS recording. Sural nerve amplitude potential was 6.8 µV and conduction velocity was 48.3 m/s. Panel B: Sample recording from the point-of-care device. Sural nerve amplitude potential was 8 µV and conduction velocity was 56 m/s. Panel C: The device was placed on the lateral aspect of the leg and the sural nerve was stimulated and recorded by the electrical probes and biosensor, respectively.</p

Intra- and interrater reliability of the sural nerve amplitude potential and conduction velocity using the point-of-care device for 44 subjects with type 1 and type 2 diabetes.

<p>IQR = Interquartile range; ICC = Interclass correlation coefficients class(2,1); SNAP = sural nerve amplitude potential; SNCV = sural nerve conduction velocity.</p

Baseline Characteristics of the 251 Prevalent DSP Cases and the 107 Prevalent Controls According to the 4-Year Incidence of DSP.

<p>Data are means ± standard deviations or <i>n</i> (%). For comparisons between two groups, p values reported are χ² test statistics for categorical variables and T-tests for continuous variables. For comparisons between three groups, p values reported are χ² test statistics for categorical variables and ANOVA for continuous variables. Normal values for individual NCS are as follows. Sural amp≥7.2 µV for age ≤65 and ≥5.5 µV for age >65, sural CV≥40 m/s, peroneal amp≥5 µV for age ≤65 and ≥3 for age >65, peroneal CV≥40 m/s, peroneal F wave ≤59 ms for height ≥182.9 cm and ≤58 ms for height ≤182.9 cm, tibial amp≥10 µV, tibial CV≥40 m/s, tibial F wave ≤55 ms.</p>*<p>p-value for ANOVA between Prevalent Cases, Incident DSP Cases and Incident DSP Controls.</p>†<p>By subject self-report.</p>‡<p>HbA1C, glycated hemoglobin A1C.</p>§<p>Summative parameters are composed of the following: sum amplitude = sural+tibial, sum conduction velocity = sural+peroneal +tibial, sum F-wave latency = peroneal+tibial.</p>¶<p>Summed amplitude potentials are expressed in arbitrary units since sural amplitude potential is measured in microvolts and tibial amplitude potential is measured in millivolts.</p>∥<p>Statistical tests for the NCS parameters applied a Bonferroni correction for multiple comparisons for significance such that p-values <0.0045 (0.05/11) were considered significant. All p-values except for two indicated by this symbol, met significance criteria.</p><p> <b>TCNS, Toronto Clinical Neuropathy Score. Amp, amplitude potential. CV, conduction velocity. F-wave, F-wave latency.</b></p

Concurrent validity ROC curves for sural, peroneal, tibial and summative parameters.

<p>See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0058783#pone-0058783-t002" target="_blank">Table 2</a> for estimates of AROC for each parameter. Peroneal conduction velocity and sural amplitude potential had the highest AROC (AROC 0.90 and 0.83, respectively). Dashed lines represent amplitude potentials. Solid lines represent conduction velocities. Dotted lines represent F-wave latencies.</p