A Practical Two-Step Quantitative Clinical and Electrophysiological Assessment for the Diagnosis and Staging of Diabetic Neuropathy

OBJECTIVE Early diagnosis of distal symmetric sensorimotor polyneuropathy, a common complication of diabetes, may decrease patient morbidity by allowing for potential therapeutic interventions. We have designed an outpatient program to facilitate diagnosis of diabetic neuropathy.

RESEARCH DESIGN AND METHODS Patients are initially administered a brief questionnaire and screening examination, designated the Michigan Neuropathy Screening Instrument (MNSI). Diabetic neuropathy is confirmed in patients with a positive assessment by a quantitative neurological examination coupled with nerve conduction studies, designated the Michigan Diabetic Neuropathy Score (MDNS). In this study, 56 outpatients with confirmed type I or II diabetes were administered the standardized quantitative components required to diagnose and stage diabetic neuropathy according to the San Antonio Consensus Statement (1) and the Mayo Clinic protocol (2). These same patients were then assessed with the MNSI and the MDNS.

RESULTS Of 29 patients with a clinical MNSI score > 2, 28 had neuropathy. Twenty-eight patients with an MDNS of ≥ 7 had neuropathy, while 21 non-neuropathic patients had a score ≤ 6. Of 35 patients with diabetic neuropathy, 34 had ≥ 2 abnormal nerve conductions. Twenty-one normal patients and one patient with neuropathy had ≤ 1 abnormal nerve conduction.

CONCLUSIONS The results indicate that the MNSI is a good screening tool for diabetic neuropathy and that the MDNS coupled with nerve conductions provides a simple means to confirm this diagnosis.