Parapharyngeal abscess can involve both the pre- and post-styloid compartments. Involvement of the post-styloid (retrostyloid) compartment is particularly dangerous because it contains:

• A The parotid gland and the facial nerve
• B The internal carotid artery, internal jugular vein, cranial nerves IX-XII, and sympathetic chain ✓
• C The pterygoid venous plexus and the maxillary artery
• D The tensor veli palatini and levator veli palatini muscles

Explanation

The parapharyngeal space is divided by the styloid process and its muscles into: pre-styloid compartment (anterior) containing the deep lobe of parotid, CN V3, internal maxillary artery, ascending pharyngeal artery, and fat; and post-styloid (retrostyloid) compartment (posterior) containing the internal carotid artery, internal jugular vein, CNs IX (glossopharyngeal), X (vagus), XI (accessory), XII (hypoglossal), and the cervical sympathetic chain. Post-styloid compartment involvement risks carotid artery erosion/rupture, jugular vein thrombosis, and multiple cranial nerve palsies — far more dangerous than pre-styloid involvement.

Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.