Checkpoint: Basic NCS Physiology & Annomalous Innervations-Dr. Simmons Presentation

Dr. Simmons Presentation - Anomalous

Pdf Summary

The document, authored by Dr. Daniel B. Simmons from Saint Alphonsus Health System, focuses on common anomalous neurological innervations and presents a series of clinical cases. The primary focus of the presentation is the Martin-Gruber Anastomosis (MGA), an anatomical variant where motor fibers from the median nerve cross to join the ulnar nerve, present in 15-30% of the population. MGA is usually asymptomatic but can affect the interpretation of nerve conduction studies, seen when there is an amplitude drop in the impulse from wrist to below elbow during diagnosis.<br /><br />Several patient cases are detailed: primarily focusing on 60-year-old women with hand weakness or bilateral paresthesias. Diagnoses mentioned include Chronic Inflammatory Demyelinating Polyneuropathy (CIDP), ulnar neuropathy, normal studies, Martin-Gruber Anastomosis, and UNE (Ulnar Neuropathy at the Elbow). Other cases involve accessory fibular nerves and rare anomalies like the Riche-Cannieu anastomosis—a connection between the median and ulnar nerves in the palm. The latter is estimated to occur in up to 70% of cases but "all-ulnar hand" is very rare.<br /><br />The document also discusses the Accessory Fibular Nerve with cases involving conditions like foot drop. The document concludes with anatomy references for nerve pathways and a diagnosis of accessory fibular nerve, explaining the innervation involving common and superficial fibular nerves and its impact on muscle innervation.<br /><br />Educational references include textbooks and articles regarding anatomical nerve variations and their implications for diagnosis using electromyography. Clinicians are encouraged to use the AANEM app for feedback and claiming educational credits associated with session attendance.

Keywords

Martin-Gruber Anastomosis

neurological innervations

nerve conduction studies

ncs

Chronic Inflammatory Demyelinating Polyneuropathy

cidp

ulnar neuropathy

Riche-Cannieu anastomosis

accessory fibular nerve

electromyography

EMG

nerve pathways

AANEM app

cidp

Chronic Inflammatory Demyelinating Polyneuropathy

EMG

electromyography

nerve conduction studies

nerve conduction study

ncs