Reliability of the neurological scores for assessment of sensorimotor neuropathy in type 2 diabetics

Objective: To check the reliability of the commonly used neurological scoring systems taking the nerve conduction studies as the reference. Methods: Diagnosed diabetics (n=60) were selected by purposive sampling. Detection and grading of neuropathy were done according to Diabetic Neuropathy Symptom Score (DNS), modified Neuropathy Symptom Score (NSS), Diabetic Neuropathy Examination (DNE) and modified Neuropathy Disability Score (NDS). For the nerve conduction studies, amplitudes, velocities and latencies of minimum two (Sural, Peroneal) and maximum six i.e. three sensory (Sural, Ulnar, Median) and three motor (Peroneal, Ulnar, Tibial) nerves were checked. If the patient had 2 or more than two abnormal findings in any of the nerve he was labeled to have peripheral sensorimotor neuropathy. Later the sensitivity, specificity and diagnostic efficacy of each neurological score was checked taking nerve conduction studies as the gold standard. Results: Taking the NCS as gold standard DNS, DNE, NSS and NDS had 64.1%, 17.95%, 82.05%, 92.31% sensitivity and 80.95%, 100%, 66.67%, 47.62% specificity, respectively. Diagnostic efficacy of DNS was 70%, DNE was 47%, NSS was 77% and NDS was 77%. Conclusions: Combining different scores gives better sensitivity and specificity. NDS is the most reliable neurological test for detecting and grading DPN.