Ulnar neuritis refers to irritation of the ulnar nerve, which passes along the posteromedial aspecit of the elbow. The ulnar nerve supplies motor function to most of the muscles in the hand as well as sensation to the 4th and 5th digits of the hand. The ulnar nerve can also commonly be trapped or irritated at the wrist by Guyon’s canal.
Most commonly, neuritis is due to some irritation, compression or stretching of the ulnar nerve within the relatively restricted confines of the cubital tunnel through which it travels. The nerve is vulnerable within this space for a number of reasons:
The space itself is relatively confined, with little room to accommodate any soft tissue swelling
The surrounding soft tissue envelope provides little protection and is thus at risk from trauma such as a direct blow during contact sports (like football or rugby)
In some cases (up to 17 percent) of the population, the nerve can actual be “unstable,” i.e., the nerve can actually move back and forth across the medial side of the elbow (the medial epicondyle), leading to repetitive stresses within the nerve. In an athlete performing repetitive overhead activity (baseball pitcher, tennis player, weight lifter), this can lead to neuritis as well.
Laxity of the elbow’s medial (inside) ligament can also result in increased forces on the ulnar nerve, causing symptoms.
Sensation of numbness, tingling or radiating discomfort down the ulnar side (inside aspect) of the forearm or into the little and ring fingers
Occasional pain, discomfort or aching within the area of the cubital tunnel itself
Sense of hand weakness or clumsiness
Loss of normal sense of finger dexterity, grip strength and control
Compromised athletic performance (decreased throwing or serving velocity or accuracy, decreased weight-lifting ability)
The ulnar nerve can be “hydrodissected” under ultrasound. In this procedure, saline is injected around the nerve to free up the nerve from any restrictive adhesions. Occasionally, cortisone will be added to decrease any inflammation around the nerve.