Abstracts

Introduction: Median nerve is formed in axilla by contributions from medial and lateral cords of brachial plexus.It descends in the arm, forearm and passes through carpal tunnel in close conjunction with flexor tendons of forearm.Median nerve cross sectional area (CSA) and flattening ratio (FR) can be assessed by ultrasonography (US).Flattening ratio is the ratio of transverse axis to the anteroposterior axis and serves as a potential diagnostic criterion for carpal tunnel syndrome (CTS). Aims and Objectives:To assess median nerve by US and tabulate mean values for CSA and FR in asymptomatic population which would serve to limit the cutoff values that differentiate normal nerves from neuropathic nerves. Material and Methods:The Study was conducted in Department Of Anatomy, KGMU, Lucknow, and included 50 randomly selected undergraduate students (30 males, 20 females).Height, weight, and wrist circumference were noted.Ultrasonography was performed using high frequency linear probe, and observations were made at two pre-determined sites.Observations were recorded, tabulated and analyzed.Results: Median nerve was easily observable at both sites.It was round in shape in forearm, and flattened as it reached the carpal tunnel.On the right side nerves were rounder in forearm in males (FRFoRt-1.68)as compared to females (FRFoRt-1.77).At both sites, flattening was more on right side (FRFoRt-1.71;FRCtRt-3.08)than on left side (FRFoLt-1.66;FRCtLt-2.78)among all 50 study subjects.Increased flattening was observed in females (FRCtRt-3.30)as compared to males (FRCtRt-2.94).In left forearm median nerve was slightly more rounder in females (FRFoLt-1.66)as compared to males (FRFoLt-1.69),whereas FR was similar in both(males FRCtLt-2.83;females FRCtLt-2.83). Conclusion:Study will help in generating database for facilitating comparisons between symptomatic (CTS) and asymptomatic individuals.Altered FR has both diagnostic as well as prognostic values in carpal tunnel syndrome DR.O.