Expansion
Oh Oh Oh To Take A Vacation
Mnemonic
“O TOM CAT”, with the nerves in the lateral wall from top to bottom and the last two free within the sinus:
- O - Oculomotor, III
- T - Trochlear, IV
- O - Ophthalmic, V1
- M - Maxillary, V2
- C - internal Carotid artery
- AT - Abducens, VI
The abducens nerve runs free within the sinus alongside the carotid, rather than in the wall, which is why it is the first nerve affected in cavernous sinus pathology and why a raised intracranial pressure causes a false localising sixth nerve palsy.
The sinus receives the facial vein through the ophthalmic veins, and because these are valveless it is the route by which infection in the danger triangle of the face reaches the skull.
Expansion
- Lateral wall - CN III, CN IV, CN V1, CN V2
- Through the sinus - CN VI and the internal carotid artery