The article titled “The diagnostic accuracy of Neuropad® for assessing large and small fiber diabetic neuropathy” (Ponirakis et al., 2014) discusses the use of Neuropad® as a diagnostic tool for diabetic peripheral neuropathy. The study compared the diagnostic performance of Neuropad® against established measures of large and small fibre damage in patients with diabetes.
In this cross-sectional study of 127 individuals with diabetes—comprising 89 without and 38 with confirmed diabetic peripheral neuropathy—Ponirakis et al. evaluated the performance of the Neuropad indicator plaster alongside established measures of both large-fibre and small-fibre neuropathy (including Neuropathy Disability Score, vibration perception threshold, motor nerve conduction velocity, corneal nerve-fibre length, and warm perception threshold). The Neuropad’s purpose is to detect sudomotor (sweat gland) dysfunction via a colour change in response to moisture—an indirect measure of cholinergic small-fibre integrity.
Key findings revealed that Neuropad demonstrated high sensitivity but moderate specificity when compared to large‑fibre assessments (e.g. 70% sensitivity and 50% specificity versus NDS; 83% and 53% versus VPT; 81% and 54% versus nerve conduction studies). However, its diagnostic accuracy improved significantly when benchmarked against small‑fibre damage—exhibiting 83% sensitivity and 80% specificity relative to corneal nerve-fibre length, and an area under the ROC curve of 85%.
These results underscore Neuropad’s aptitude as a practical and accessible tool for identifying small‑fibre neuropathy, performing comparably to corneal microscopy—a recognized gold standard—while offering a much simpler and lower‑cost alternative. Its simplicity and non-invasiveness make it especially suitable for high-throughput clinical settings and potentially for home-based monitoring.
In essence, Ponirakis et al. demonstrate that while Neuropad may be less discriminating for large-fibre neuropathy, which is not its aim, it shines in detecting early small-fibre and autonomic dysfunction—areas critical for intervention before sensory loss becomes irreversible. As such, Neuropad constitutes a compelling addition to diabetic neuropathy screening protocols, offering both scientific validity and everyday clinical utility.