The Utah Early Neuropathy Scale: a sensitive clinical scale for early sensory predominant neuropathy.

Abstract

Early neuropathy is often sensory predominant and prominently involves small-diameter nerve fibers. Established neuropathy examination scales such as the Michigan Diabetic Neuropathy Scale (MDNS) and the Neuropathy Impairment Score-Lower Leg (NIS-LL) focus primarily on large-fiber sensory and motor function. Here, we validate the Utah Early Neuropathy Scale (UENS), a physical examination scale specific to early sensory predominant polyneuropathy. Compared with other scales, the UENS emphasizes severity and spatial distribution of pin (sharp) sensation loss in the foot and leg and focuses less on motor weakness. UENS, MDNS, and NIS-LL were compared in 215 diabetic or prediabetic subjects, with (129) or without neuropathy (86), and repeated in 114 neuropathy subjects after 1 year of follow-up. Neuropathy severity was also evaluated with nerve conduction studies, quantitative sensory testing, quantitative sudomotor axonal reflex testing, and intraepidermal nerve fiber density determination. The UENS had a high degree of interrater reliability (interclass correlation of 94%). UENS correlated significantly to MDNS and NIS-LL (p < 0.01), and more significantly than MDNS or NIS-LL to confirmatory tests. In this cohort, UENS had a superior profile to receiver operating characteristic analysis across a range of scores, with a sensitivity (92%) higher than MDNS (67%) or NIS-LL (81%), without sacrificing specificity. UENS more closely correlated with change in ancillary and small-fiber neuropathy measures over 1 year follow-up than did MDNS or NIS-LL. UENS is a sensitive and reproducible clinical measure of sensory and small-fiber nerve injury and may be useful in trials of early neuropathy.