10th Cranial Nerve – Vagus Nerve Lesions

Definition:

Tenth (X) cranial nerve palsies are pathological processes which negatively affect the nerve’s function.

Causes:

An isolated palsy of the Vagus nerve is extremely rare. Causes include:

  • trauma
  • brainstem lesions
  • tumours in the cerebellopontine angle
  • Gullain-Barr syndrome
  • space occupying lesions
  • dissecting aortic aneyurism

Examination:

Vagus nerve lesions commonly result in palatal and pharyngeal paralysis; laryngeal paralysis; and abnormalities of oesophageal motility, gastric acid secretion, gallbladder emptying, and heart rate; as well as other autonomic dysfunctions.

Upon examination, the practitioner should listen to the patient talk looking for any hoarseness, whispering, nasal speech, which may be signs that the vagus nerve is affected. The patient should be questioned regarding any complaint of aspiration and/or regurgitation of liquids.

Have the patient open the mouth and inspect the palatal arch on each side for asymmetry. Use a tongue blade to depress the base of the tongue gently if necessary. Observe the palatal arches as they contract and the soft palate as it swings up and back in order to close off the nasopharynx from the oropharynx. Normal palatal arches will constrict and elevate, and the uvula will remain in the midline as it is elevated. With paralysis there is no elevation or constriction of the affected side. Gently touch first one and then the other palatal arch with a tongue blade, waiting each time for gagging. Laryngoscopy is necessary to evaluate the vocal cord