Range of motion of the neck is normal. No crepitation or areas of tenderness of the neck or spine are present. Spurling maneuver does not elicit any hand or upper extremity pain or parasthesias. There is no tenderness with palpation of the elbow or wrist. The muscle stretch reflexes of the finger flexors are intact and symmetric.
Muscle tone is normal except in the atrophic muscles of the involved hand.
The asymmetry of this lesion reduces the likelihood that the etiology is a diffuse process, such as a peripheral polyneuropathy. The history and clinical presentation are not consistent with a central nervous system lesion. The absence of abnormal muscle tone and upper motor neuron signs, such as a Hoffman reflex, makes a central nervous system lesion very unlikely. A more likely diagnosis is ulnar mononeuropathy. No skin trauma, e.g., callus, or other lesions are noted on the hands.