FUNCTION -- Movements of the Tongue

TEST -- Protrusion and other Movements
The patient should be instructed to stick the tongue straight out. The tongue held in this position allows the clinician to visually inspect for lateral deviation abnormal muscular mass, and aberrant movements (e.g., fasciculations). Subsequently, an assessment should be made of lateral and vertical movements of the tongue. Click here to see the movements of the tongue close up.

INTERPRETATION
Lateral deviation of the tongue may indicate dysfunction of either cranial nerve XII or higher centers. A pronounced loss of muscular mass with or without fasciculations (often ipsilateral to the side of deviation upon protrusion) tends to suggest dysfunction of lower motor neurons. The failure of the tongue to emerge fully from the mouth suggests bilateral involvement.