Jugular foramen

Exit foramen · CN IX CN X CN XI

A large irregular opening between the petrous temporal and occipital bones in the posterior cranial fossa. IX leaves through the anteromedial part with the inferior petrosal sinus; X, XI and the internal jugular vein (the continuation of the sigmoid sinus) pass through the larger posterolateral part with the posterior meningeal artery. The hypoglossal canal lies just anteromedial, so large lesions add XII.

Traced from the start

  1. Medulla oblongata
  2. Glossopharyngeal nerve (CN IX)Vagus nerve (CN X)Accessory nerve (CN XI)
  3. Jugular foramen

Detail

Transmits
Glossopharyngeal (IX), vagus (X), accessory (XI), internal jugular vein from the sigmoid sinus, inferior petrosal sinus, posterior meningeal artery
Neighbours
Hypoglossal canal (XII) anteromedially, carotid canal anteriorly, foramen magnum posteromedially
Below the foramen
IX, X and XI run between the internal carotid artery and the internal jugular vein with XII before dispersing

When it goes wrong

Jugular foramen syndrome (Vernet syndrome) from a glomus jugulare paraganglioma, schwannoma, meningioma, nasopharyngeal carcinoma, skull base metastasis, osteomyelitis or fracture

Ipsilateral loss of the gag reflex and posterior-tongue taste (IX), palatal weakness with the uvula deviating away, hoarseness and dysphagia (X), and weak head-turning and shoulder shrug with wasting of sternocleidomastoid and trapezius (XI)

The same lesion extending to the hypoglossal canal (Collet–Sicard syndrome)

Vernet's triad plus tongue deviation towards the lesion with wasting and fasciculation

Glomus jugulare tumour eroding into the middle ear

Pulsatile tinnitus and a reddish-blue mass behind the eardrum before the lower cranial nerve palsies appear

Practise this structure

4 questions in the bank tagged Cranial Nerves.