E3266. Don’t Lose Your Nerve! Lesion Localization in Patients with Ulnar Nerve Symptoms
  1. Steven Daniels; New York University
  2. Karen Noh; Robert Wood Johnson Medical School
  3. Christina Drafta; New York University
  4. Jadie De Tolla; New York University
Lesions at several different anatomic sites can produce ulnar nerve symptoms, namely altered sensation of the ring and small fingers and weakness of the ulnar nerve innervated intrinsic hand muscles. A thorough history and physical examination paired with electrodiagnostic testing can help localize the lesion site though accurate localization but can be difficult even for experienced clinicians. Imaging plays a key role in verifying sites of nerve lesions and characterizing nerve abnormalities. As imaging is best performed targeted to a specific anatomic location, it is important for radiologists to understand the potential lesion sites in patients with ulnar nerve symptoms and how these sites can be best imaged.

Educational Goals / Teaching Points
This exhibit describes the anatomy of the ulnar nerve, reviews clinical and electrodiagnostic findings pertinent to lesion localization in patients with ulnar nerve symptoms, discusses pitfalls in clinical and electrodiagnostic lesion localization, and demonstrates examples of nerve lesions in patients with ulnar nerve symptoms. After viewing this presentation, the reader should be able to describe the common lesion sites in patients with ulnar nerve symptoms and discuss the advantages and disadvantages of different imaging modalities in evaluating these lesions.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Specific lesion sites in patients with ulnar nerve symptoms include the cervical nerve roots, lower trunk and medial cord of the brachial plexus, and ulnar nerve in the upper arm, cubital tunnel, forearm, and Guyon’s canal. Cases of ulnar nerve lesions in these anatomic locations will be shown and our imaging approach to evaluating these sites will be discussed.

Imaging plays an important role in the work-up of patients with ulnar nerve symptoms. It is important for radiologists to have a sound understanding of the clinical and electrodiagnostic evaluation of these patients to actively guide referring clinicians in ordering appropriate imaging and reaching the correct diagnosis.