Checkpoint: Basic NCS Physiology & Annomalous Innervations-Session recording

Video Transcription

Video Summary

Dr. Daniel Simmons, a neurologist and clinical neurophysiologist from Boise, delivers a detailed presentation on nerve conduction physiology and anomalies. He aims to shift thinking from algorithmic to conceptual, enhancing understanding of conditions like axonal injuries, demyelination, and conduction blocks. The first segment focuses on nerve anatomy and physiology, highlighting the functions of axons and myelin. In nerve conduction studies, a stimulator sends currents through nerves, and the responses are observed to assess their health.<br /><br />Dr. Morgan Jordan joins to explain normal nerve function versus different types of nerve injuries, including axonal injury characterized by reduced amplitude in response due to axon loss, and demyelination, where loss of myelin results in slowed signal conduction. Dr. Jordan also addresses conduction block, where signal transmission fails due to demyelination, appearing like reduced axons functionally.<br /><br />Conduction velocity, onset latency, and response amplitude are crucial in distinguishing between these conditions. The presentation illustrates that axonal loss may cause mild slowing, sometimes misidentified as demyelination. Accurate diagnosis relies on examining conduction latencies and responses to determine nerve injury type.<br /><br />Dr. Simmons discusses common anomalous innervations, particularly Martin-Gruber anastomosis and accessory peroneal nerve, that affect nerve conduction studies but are often clinically irrelevant. Through case studies, he underscores how to differentiate these anomalies from nerve pathologies like conduction block, emphasizing careful assessment of symptoms and study results. Identifying these variations ensures precise diagnoses and effective treatment plans for patients with potential nerve injuries.

Keywords

nerve conduction

axonal injuries

demyelination

conduction blocks

nerve anatomy

nerve physiology

axons

myelin

conduction velocity

onset latency

response amplitude

Martin-Gruber anastomosis

accessory peroneal nerve