Physical examination maneuver

Physical Exam

Cranial Nerve XII

🎬
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 move it from side to side. Strength can be tested by having the patient push the tongue against the inside of each cheek against your finger.

How to Interpret

Showing 1 of 2 findings

Acute Ischaemic Stroke

Tongue deviation toward the weak side — on protrusion the tongue points toward the hemiparetic side, a supranuclear twelfth-nerve sign of acute hemispheric stroke (the genioglossus has mainly crossed cortical innervation, so the lesion is on the opposite side)
Rule in
Helpful
Rule out
—
Evidence:Limited

References

  • 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.

Related Bedside Tests

🎬Video coming Sept 2026
Mouth and Tongue Inspection
Rule in:SHMeasles, IEAcute Leukemia, IEAdrenal Insufficiency +9 more
Rule out:SHHypovolemia, MHMeasles, IEAcute Leukemia +10 more
🎬Video coming Sept 2026
Cranial Nerve IX and X
Rule in:IEBulbar Palsy (CN IX and CN X Lesion)
Rule out:IEBulbar Palsy (CN IX and CN X Lesion)
🎬Video coming Sept 2026
Pupillary Light Reaction
Rule in:IEAnticholinergic Toxicity, IECholinergic Toxicity, IECranial Nerve III Palsy +7 more
Rule out:IEAnticholinergic Toxicity, IECholinergic Toxicity, IECranial Nerve III Palsy +7 more
🎬Video coming Sept 2026
Alternate Cover Test (Test of Skew)
aka Cross-cover test
Rule in:IEPeripheral Vestibular Dysfunction, IEPosterior Circulation Stroke
Rule out:IEPeripheral Vestibular Dysfunction, IEPosterior Circulation Stroke
🎬Video coming Sept 2026
Babinski Reflex
aka Plantar reflex
Rule in:VHUpper Motor Neuron Lesion, IEMotor Neuron Disease (ALS), IEMultiple Sclerosis +2 more
Rule out:SHUpper Motor Neuron Lesion, IEMotor Neuron Disease (ALS), IEMultiple Sclerosis +2 more
🎬Video coming Sept 2026
Dix-Hallpike Maneuver
Rule in:IECentral Vestibular Lesion, IEPosterior Canal BPPV
Rule out:IECentral Vestibular Lesion, IEPosterior Canal BPPV