Certified Neuroscience Registered Nurse (CNRN) Practice Exam

What is the Phalen's sign used to diagnose?

1. Ulnar nerve injury

2. Tendon injuries in the wrist

3. Carpal tunnel syndrome

4. Brachial plexus injury

The correct answer is: Carpal tunnel syndrome

Phalen's sign is a clinical test utilized to help diagnose carpal tunnel syndrome, which is characterized by the compression of the median nerve as it travels through the carpal tunnel in the wrist. When a patient flexes their wrist for an extended period, typically by pressing the backs of their hands together with fingers pointing downwards, it can provoke symptoms such as tingling, numbness, or pain in the distribution of the median nerve, particularly in the thumb, index, and middle fingers. The presence of these symptoms upon performing the test supports the diagnosis of carpal tunnel syndrome. This condition is commonly seen in individuals who engage in repetitive wrist motions or those with certain health conditions like diabetes or rheumatoid arthritis, making it relevant in clinical practice. Although other options like ulnar nerve injury, tendon injuries in the wrist, and brachial plexus injury may involve different assessments and clinical signs, they do not relate specifically to Phalen's sign, which is a distinctive and valuable diagnostic tool for carpal tunnel syndrome.