Ulnar nerve entrapment

Ulnar nerve entrapment is a condition where the ulnar nerve becomes physically trapped or pinched, resulting in pain, numbness, or weakness, primarily affecting the little finger and ring finger of the hand. Entrapment may occur at any point from the spine at cervical vertebra C7 to the wrist; the most common point of entrapment is in the elbow (Cubital tunnel syndrome). Prevention is mostly through correct posture and avoiding repetitive or constant strain (e.g. "cell phone elbow"). Treatment is usually conservative, including medication, activity modification, and exercise, but may sometimes include surgery. Prognosis is generally good, with mild to moderate symptoms often resolving spontaneously. In general, ulnar neuropathy will result in symptoms in a specific anatomic distribution, affecting the little finger, the ulnar half of the ring finger, and the intrinsic muscles of the hand. The specific symptoms experienced in the characteristic distribution depend on the specific location of ulnar nerve impingement. Symptoms of ulnar neuropathy may be motor, sensory, or both depending on the location of injury. Motor symptoms consistent of muscle weakness; sensory symptoms or paresthesias consist of numbness or tingling in the areas innervated by the ulnar nerve. Proximal impingement is associated with mixed symptoms, as the proximal nerve consists of mixed sensory and motor innervation. Distal impingement is associated with variable symptoms, as the ulnar nerve separates near the hand into distinct motor and sensory branches. In cubital tunnel syndrome (a proximal impingement), sensory and motor symptoms tend to occur in a certain sequence. Initially, there may be numbness of the small and ulnar fourth finger which may be transient. If the impingement is not corrected, the numbness may become constant and progress to hand weakness. A characteristic resting hand position of "ulnar claw," where the small and ring fingers curl up, occurs late in the disease and is a sign of severe neuropathy.