Validation of the Toronto Clinical Scoring System for diabetic polyneuropathy. Diabetes Care 2002

OBJECTIVE — The aim of the current study was to determine the validity of the Toronto Clinical Scoring System (CSS) in reflecting the presence and severity of diabetic peripheral sensorimotor polyneuropathy (DSP) as determined by myelinated fiber density (FD) on sural nerve biopsy. RESEARCH DESIGN AND METHODS — Eighty-nine patients with both type 1 and type 2 diabetes, ascertained from a large therapeutic randomized controlled trial, were included in this cross-sectional, observational cohort study. Morphological severity of DSP was expressed as the FD in the sural nerve biopsy. The Toronto CSS was applied to all patients to determine a clinical neuropathy score. General linear regression models were used to assess the relationship between the morphological severity of DSP and the Toronto CSS. RESULTS — The Toronto CSS showed a significant negative correlation with sural nerve FD (R2 0.256, P 0.0001). The Toronto CSS was lower in those with better glycemic control (HbA1c 8%). Sural nerve FD and the Toronto CSS showed strong correlations with electro-physiology, by both summed amplitude and summed conduction velocity values. CONCLUSIONS — The Toronto CSS is a valid instrument to reflect the presence and se