Nerve
Abducens nerve (CN VI)
Motor nerve that turns the eye outward
High-yield
A nerve lesion weakens abduction of one eye. Damage to the abducens nucleus can prevent both eyes from looking toward that side. Raised intracranial pressure can stretch CN VI, so palsy does not always locate the underlying lesion.
Overview
CN VI carries motor signals from the lower pons to lateral rectus. Its long intracranial route passes up the clivus, through Dorello’s canal and beside the internal carotid artery within the cavernous sinus before entering the orbit.
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Reference facts
- Origin
- Abducens nucleus in the dorsal lower pons, beneath the facial colliculus; fibers emerge near the midline at the pontomedullary junction
- Skull exit
- Superior orbital fissure, within the common tendinous ring
- Course
- Ascends beside the clivus, passes beneath the petrosphenoidal ligament in Dorello’s canal, then travels beside the cavernous internal carotid artery to the orbit
- Motor
- Lateral rectus, producing abduction of the eye
- Sensory
- Classified as somatic motor; no cutaneous sensory territory
Mnemonic
LR6, SO4: lateral rectus uses CN VI and superior oblique uses CN IV; CN III supplies the other extraocular muscles.
Clinical correlation
An affected eye may turn inward, with horizontal double vision worse when looking toward the weak lateral rectus. Some people compensate by turning their head that way. Cavernous-sinus disease can affect CN VI alongside other nearby structures.
Frequently asked questions
Where does the abducens nerve (CN VI) arise?
Abducens nucleus in the dorsal lower pons, beneath the facial colliculus; fibers emerge near the midline at the pontomedullary junction.
What muscles does the abducens nerve (CN VI) supply?
Lateral rectus, producing abduction of the eye.
What is the sensory distribution of the abducens nerve (CN VI)?
Classified as somatic motor; no cutaneous sensory territory.
Where does the abducens nerve (CN VI) leave the skull?
Superior orbital fissure, within the common tendinous ring.