Long latency reflex of abductor pollicis brevis (APB) of the dominant hand among healthy adult female volunteers

Abstract

Introduction: Long Latency Reflexes (LLR) is a transcortical reflex loop obtained on submaximal stimulation of a mixed nerve. LLR is useful clinically to diagnose patients with proximal nerve lesions and in patients with S1 radiculopathy. Studies have been done to record normal values of late responses like H-reflex and F-wave in upper limb. However, there are only few studies done on LLR in upper limb muscle. Hence, the present study was undertaken to record normal value of APB LLR among females. Objective: Long Latency Reflex of Abductor pollicis Brevis (APB) of dominant hand among healthy adult female volunteers. Materials and Methods: The present observational study was done on 30 female volunteers between age group of 20-30 years. The participating females were recruited during their early follicular phase. LLR was recorded by stimulating median nerve while abducting the thumb. The LLR tracing was recorded in the digital nerve conduction machine (Recorders Medicare System, India). LLR latency and amplitude was measured, tabulated and analysed using Microsoft Excel. Result: Mean ± SD for APB LLR latency was 46.29 ± 2.58 milliseconds (ms). Mean ± SD for APB LLR amplitude was 208.21 ± 58.45 microvolt (?V). Conclusion: Thus, the normal values of LLR latency and amplitude of Abductor Pollicis Brevis of dominant hand among healthy adult female volunteers helps clinician to rule out neurological disorders. Keywords: Abductor pollicis brevis, Long latency reflex, Median nerve.