Physical Exam

Cranial Nerve XII

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Video coming September 2026

How to Perform

Inspect the tongue at rest on the floor of the mouth for atrophy or fasciculations, then ask the patient to protrude it and observe for deviation of the tongue to one side. Test tongue strength by having the patient push the tongue against the inside of each cheek against your finger.

How to Interpret

This test’s findings are all below your current evidence filter.

References

Galeazzi L, Holzman J, Mondoloni M, Rochefort J. Lingual fasciculation: a point of call for the diagnosis of amyotrophic lateral sclerosis. Clin Case Rep. 2023;11(6):e7560. doi:10.1002/ccr3.7560. PMID: 37334341. PMCID: PMC10276246 (open access).
Umapathi T, Venketasubramanian N, Leck KJ, Tan CB, Lee WL, Tjia H. Tongue deviation in acute ischaemic stroke: a study of supranuclear twelfth cranial nerve palsy in 300 stroke patients. Cerebrovasc Dis. 2000;10(6):462-465. doi:10.1159/000016108. PMID 11070377.
Bickley LS, Szilagyi PG, Hoffman RM, Soriano RP. Bates' Guide to Physical Examination and History Taking. 13th ed. Philadelphia, PA: Wolters Kluwer; 2021.
Swartz MH. Textbook of Physical Diagnosis: History and Examination. 9th ed. Philadelphia, PA: Elsevier; 2025.

Research last updated September 10, 2026.