Variant 1: Anosmia or other abnormalities of the sense of smell (olfactory nerve, CN I). Initial imaging.
Variant 2: Unilateral isolated weakness of the mastication muscles, paralysis of the mastication muscles, sensory abnormalities of the face and head, facial numbness, or trigeminal neuralgia (trigeminal nerve, CN V). Initial imaging.
Variant 3: Unilateral isolated weakness of the facial expression, paralysis of the facial expression, hemifacial spasm, or Bell palsy (facial nerve, CN VII). Initial imaging.
Variant 4: Multiple different middle cranial nerve palsies (CN V-VII). Initial imaging.
Variant 5: Oropharyngeal neurogenic dysphagia or oropharyngeal pain (glossopharyngeal nerve, CN IX). Initial imaging.
Variant 6: Unilateral isolated palatal or vocal cord paralysis or both (vagal nerve, CN X). Initial imaging.
Variant 7: Unilateral isolated weakness or paralysis of the sternocleidomastoid and trapezius muscles (accessory nerve, CN XI). Initial imaging.
Variant 8: Unilateral isolated weakness or paralysis of the tongue (hypoglossal nerve, CN XII). Initial imaging.
Variant 9: Multiple different lower cranial nerve palsies or combined lower cranial nerve syndromes (CN IX-XII). Initial imaging.
Variant 10: Head and neck cancer. Suspected or known perineural spread of tumor. Initial imaging.
Appendix Key

A more complete discussion of the items presented below can be found by accessing the supporting documents at the designated hyperlinks.

Appropriateness Category:The panel’s recommendation for a procedure based on the assessment of the risks and benefits of performing the procedure for the specified clinical scenario.

SOE: Strength of Evidence. The assessment of the amount and quality of evidence found in the peer reviewed medical literature for an appropriateness recommendation.

  • References: The citation number and PMID for the reference(s) associated with the recommendation.
  • Study Quality: The assessment of the quality of an individual reference based on the number of study quality elements described in the reference.

RRL: Relative Radiation Level. A population based assessment of the amount of radiation a typical patient may be exposed to during the specified procedure.

Rating: The final rating (1-9 scale) for the procedure as determined by the panel during rating rounds.

Median: The median rating (1-9 scale) for the procedure as determined by the panel during rating rounds.

Final tabulations: A histogram showing the number of panel members who rated the procedure as noted in the column heading (ie, 1, 2, 3, etc.).

Additional supporting documents about the AC methodology and processes can be found at