The Quantitative Relationship Between Physical Examinations and the Nerve Conduction of the Carpal Tunnel Syndrome in Patients With and Without a Diabetic Polyneuropathy

OBJECTIVE To understand the quantitative correlation between the clinical severity and physical examinations along with the electrodiagnostic findings by subjects with carpal tunnel syndrome (CTS) and also the influence of diabetic polyneuropathy (DPN) on physical examinations by subjects with CTS. METHODS Among 200 patients suffering from hand tingling sensations, 68 patients were diagnosed with CTS on at least one hand by nerve conduction tests. Therefore, the Phalen test (PT), hand elevation test (HET), Tinel sign (TS) results were recorded on both hands. The physical examination grades were compared with the electrophysiological CTS grades in 126 hands of 68 patients. Also the comorbidity effect of DPN to CTS was evaluated. For the evaluation of the severity correlations between CTS, PT, HET, and TS, the Spearman analysis was used. An attempt was started to create a formula which could depict the electrophysiological severity of CTS. RESULTS Out of the 68 tested subjects, 31 were diagnosed with both DPN and CTS, and 37 with CTS only. Both PT and HET correlated well with the severity of CTS where the correlation of PT was higher than that of HET. The formula were the motor distal latency (MDL)=(72.4-PT)/5.3 and MDL=(76-HET)/7.2. Both PT and HET showed in the presence of DPN a relatively higher relation with CTS without significance. CONCLUSION PT and HET would be useful screening tools for the diagnosis and treatment of CTS as the grade of PT and HET present the severity of CTS well. During this study, a formula was created expecting the severity of nerve conduction study with PT and HET through the time domain value of physical examinations.