Spaces of the neck

Question 1

Carotid space lesion differentials

Answer 1

1. Schwannoma (high T2 usually)
2. Meningioma
3. Paraganglioma

Look for where nerves arise and whether there is displacement.

Vagus nerve more posterolateral to carotid artery. Sympathetic plexus more medially.

Question 2

Cranial nerves within carotid sheath

What are they?

What position do they lie?

Answer 2

If tumour of 9th or 12th nerves, they will push ICA posteriorly.

If tumour arises from 10th or 11th nerves then will push ICA anteriorly

If mass is below hyoid - it can only be a Vagal schwannoma (as the rest exit in suprahyoid neck).

Question 3

How to identify levator veli palatini?

Answer 3

Anterior to ICA at level of nasopharynx.

Posterior and inferior to torus tubaris.

Question 4

What is significance of tensor veli palatini?

Answer 4

Serves as a barrier to tumour spread in the nasopharynx.

If tumour remains medial to muscle then ovale and lateral structures are protected.

Also look at foramen lacerum directly inferior to cavernous ICA