Fig. 2. Definition and severity assessment of diabetic peripheral neuropathy (DPN) proposed by the Toronto Diabetic Neuropathy Expert Group. Numbers in each column refer to the definitions of the minimal criteria for DPN, and the number in parentheses is the stage of severity: 1 ("possible"), 2 ("probable"), or 3 ("confirmed") for clinical practice and 3 or 4 ("subclinical") for research studies [6]. Severity is staged based on the symptoms, signs, and nerve conduction (NC) abnormalities: stage 0, no NC abnormality; 1a, subclinical but without symptoms or signs; 1b, subclinical with signs but no symptoms; 2a, subclinical with symptoms regardless of signs; and 2b (not shown here), subclinical with unequivocal weakness of ankle dorsiflexion [5].