American Board of Surgery Qualifying Exam (ABS QE) Practice Test

What is a common clinical sign of a hypoglossal nerve injury?

1. Tongue deviates to the opposite side

2. Hoarse voice

3. Loss of sensation in the tongue

4. Dysphagia

The correct answer is: Tongue deviates to the opposite side

A common clinical sign of a hypoglossal nerve injury is that the tongue deviates to the side of the lesion. This occurs because the hypoglossal nerve is responsible for controlling the movements of the muscles of the tongue. When there is an injury to this nerve, the affected side of the tongue becomes weak and cannot be retracted adequately, resulting in the tongue's deviation towards the side of the injury when stuck out. This phenomenon is significant in clinical practice, as it helps in diagnosing the specific location of nerve damage. Other potential signs related to tongue function, such as hoarseness, loss of sensation, or swallowing difficulties, are not primarily associated with hypoglossal nerve injury. A hoarse voice is typically related to damage of the vagus nerve, loss of sensation involves sensory pathways not linked to motor control, and dysphagia is often due to issues with multiple cranial nerves, including the vagus and glossopharyngeal nerves, rather than the hypoglossal nerve. Thus, the distinct deviation of the tongue serves as a hallmark sign of hypoglossal nerve impairment.