What is a key sign of cubital tunnel syndrome?

Cubital tunnel syndrome is primarily associated with compression of the ulnar nerve as it passes through the cubital tunnel at the elbow. A hallmark sign of this condition is paresthesia, which refers to sensations of tingling, numbness, or burning in the fingers. Specifically, individuals often report symptoms affecting the 4th (ring) and 5th (little) fingers because these digits are innervated by the ulnar nerve. This symptom is a direct result of nerve compression, leading to altered nerve signaling and discomfort in the areas served by the ulnar nerve.

The other options do not directly relate to the key features of cubital tunnel syndrome. Pain in the lateral elbow is more indicative of conditions such as lateral epicondylitis (tennis elbow). Decreased range of motion in the shoulder may arise from various shoulder pathologies but does not specifically correlate with the symptoms of cubital tunnel syndrome. Swelling around the biceps could suggest issues with the biceps tendon or surrounding structures, but it is not a defining characteristic of cubital tunnel syndrome either. Thus, the presence of paresthesia in the 4th and 5th fingers remains a critical indicator for diagnosis.