What effect is seen in the tongue when there is a hypoglossal nerve paralysis?

In cases of hypoglossal nerve paralysis, the affected tongue muscle on the side of the lesion becomes weak and unable to contract properly. As a result, when the patient attempts to stick out their tongue, it will deviate towards the affected side. This occurs because the muscles on the unaffected side still retain their strength and can push the tongue towards the weaker side, leading to lateral deviation.

The hypoglossal nerve (cranial nerve XII) primarily innervates the muscles of the tongue, and damage to this nerve disrupts the motor control needed for normal tongue movement. Therefore, when asked about the effect on the tongue with hypoglossal nerve involvement, the characteristic finding would be that the tongue points towards the affected side, reflecting the imbalance of muscle strength between the two sides.