Unilateral injury to hypoglossal nerve leads to all, EXCEPT:
**Core Concept**
The hypoglossal nerve (CN XII) is a motor nerve responsible for controlling the movement of the tongue. Unilateral injury to the hypoglossal nerve can lead to various clinical manifestations due to the altered function of the affected tongue.
**Why the Correct Answer is Right**
Unilateral injury to the hypoglossal nerve leads to ipsilateral weakness or paralysis of the tongue, resulting in difficulty with tongue protrusion, elevation, and retraction. This is because the hypoglossal nerve innervates the extrinsic and intrinsic muscles of the tongue, except for the palatoglossus muscle, which is innervated by the vagus nerve (CN X). The affected tongue may deviate to the side of the lesion when protruded, due to the unopposed action of the unaffected muscles.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is likely incorrect because hypoglossal nerve injury does not typically cause sensory deficits.
**Option B:** This option is likely incorrect because hypoglossal nerve injury does not typically cause dysphagia, although it may affect the coordination of swallowing.
**Option C:** This option is likely incorrect because hypoglossal nerve injury does not typically cause hoarseness or voice changes.
**Clinical Pearl / High-Yield Fact**
In a patient with unilateral hypoglossal nerve palsy, the affected tongue may be atrophic and show fasciculations due to the denervation of the intrinsic muscles. This can be a useful clinical finding to support the diagnosis.
**Correct Answer: A.**