Abducens nerve

abducent nerveabducensVIcranial nerve VIabducens nerve injuryAbducens nervesabducentsixthsixth cranial nerveAbducens (VI)
The abducens nerve (or abducent nerve) is the sixth cranial nerve (CNVI), in humans, that controls the movement of the lateral rectus muscle, responsible for outward gaze.wikipedia
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Cranial nerves

cranial nervecranialCN
The abducens nerve (or abducent nerve) is the sixth cranial nerve (CNVI), in humans, that controls the movement of the lateral rectus muscle, responsible for outward gaze.
They are: the olfactory nerve (I), the optic nerve (II), oculomotor nerve (III), trochlear nerve (IV), trigeminal nerve (V), abducens nerve (VI), facial nerve (VII), vestibulocochlear nerve (VIII), glossopharyngeal nerve (IX), vagus nerve (X), accessory nerve (XI), and hypoglossal nerve (XII).

Facial nerve

facialcranial nerve VIIVII
The abducens nerve leaves the brainstem at the junction of the pons and the medulla, medial to the facial nerve.
It arises from the brainstem from an area posterior to the cranial nerve VI (abducens nerve) and anterior to cranial nerve VIII (vestibulocochlear nerve).

Dorello's canal

It runs upward between the pons and the clivus, and then pierces the dura mater to run between the dura and the skull through Dorello's canal.
Dorello's Canal is the bow-shaped bony enclosure surrounding the abducens nerve and the inferior petrosal sinus as the two structures merge with the cavernous sinus.

Lateral rectus muscle

lateral rectuslateralRectus lateralis
The abducens nerve (or abducent nerve) is the sixth cranial nerve (CNVI), in humans, that controls the movement of the lateral rectus muscle, responsible for outward gaze. It then enters the orbit through the superior orbital fissure and innervates the lateral rectus muscle of the eye.
It is the only muscle supplied by the abducens nerve, cranial nerve VI.

Abducens nucleus

nucleus of the abducent nerve
The abducens nucleus is located in the pons, on the floor of the fourth ventricle, at the level of the facial colliculus.
The abducens nucleus is the originating nucleus from which the abducens nerve (VI) emerges—a cranial nerve nucleus.

Brainstem

brain stembrain-stemback of the skull
The abducens nerve leaves the brainstem at the junction of the pons and the medulla, medial to the facial nerve.
From this junction, CN VI (abducens nerve), CN VII (facial nerve) and CN VIII (vestibulocochlear nerve) emerge.

Superior orbital fissure

Fissura orbitalis superiorSphenoidal fissureRochon-Duvigneaud's syndrome
It then enters the orbit through the superior orbital fissure and innervates the lateral rectus muscle of the eye.

Diplopia

double visionMonocular diplopiadouble-vision
Damage to the peripheral part of the abducens nerve will cause double vision (diplopia), due to the unopposed muscle tone of the medial rectus muscle.
Problems with these muscles may be due to mechanical problems, disorders of the neuromuscular junction, disorders of the cranial nerves (III, IV, and VI) that innervate the muscles, and occasionally disorders involving the supranuclear oculomotor pathways or ingestion of toxins.

Clivus (anatomy)

clivus
It runs upward between the pons and the clivus, and then pierces the dura mater to run between the dura and the skull through Dorello's canal.
The abducens nerve (cranial nerve VI) tracks along the clivus during its course.

Cavernous sinus

cavernous sinusescavernouscavernous sinus syndrome
At the tip of the petrous part of the temporal bone it makes a sharp turn forward to enter the cavernous sinus.

Sixth nerve palsy

Sixth (abducent) nerve palsyabducens palsiesabducens palsy
Damage to the abducens nucleus does not produce an isolated sixth nerve palsy, but rather a horizontal gaze palsy that affects both eyes simultaneously.
Sixth nerve palsy, or abducens nerve palsy, is a disorder associated with dysfunction of cranial nerve VI (the abducens nerve), which is responsible for causing contraction of the lateral rectus muscle to abduct (i.e., turn out) the eye.

Idiopathic intracranial hypertension

pseudotumor cerebribenign intracranial hypertensionIIH
Indirect damage to the sixth nerve can be caused by any process (brain tumor, hydrocephalus, pseudotumor cerebri, hemorrhage, edema) that exerts downward pressure on the brainstem, causing the nerve to stretch along the clivus.
Most commonly, the abducens nerve (sixth nerve) is involved.

Internal carotid artery

internal carotid arteriesinternal carotidinternal
In the cavernous sinus it runs alongside the internal carotid artery.
This portion of the artery is surrounded by filaments of the sympathetic trunk and on its lateral side is the abducent nerve, or cranial nerve VI.

Medial longitudinal fasciculus

medial
The control of conjugate gaze is mediated in the brainstem by the medial longitudinal fasciculus (MLF), a nerve tract that connects the three extraocular motor nuclei (abducens, trochlear and oculomotor) into a single functional unit.
The MLF is the main central connection for the oculomotor nerve, trochlear nerve, and abducens nerve.

Hydrocephalus

hydrocephalyhydrocephalicobstructive hydrocephalus
Indirect damage to the sixth nerve can be caused by any process (brain tumor, hydrocephalus, pseudotumor cerebri, hemorrhage, edema) that exerts downward pressure on the brainstem, causing the nerve to stretch along the clivus.
Focal neurological deficits may also occur, such as abducens nerve palsy and vertical gaze palsy (Parinaud syndrome due to compression of the quadrigeminal plate, where the neural centers coordinating the conjugated vertical eye movement are located).

Diabetic neuropathy

neuropathydiabetic neuropathiesdiabetic peripheral neuropathy
Perhaps the most common overall cause of sixth nerve impairment is diabetic neuropathy.
The sixth nerve, the abducens nerve, which innervates the lateral rectus muscle of the eye (moves the eye laterally), is also commonly affected but fourth nerve, the trochlear nerve, (innervates the superior oblique muscle, which moves the eye downward) involvement is unusual.

Conjugate gaze palsy

gaze palsyconjugate gazeConjugated eye deviation
Damage to the abducens nucleus does not produce an isolated sixth nerve palsy, but rather a horizontal gaze palsy that affects both eyes simultaneously.
This is where the cranial nerve VI leaves on its way to the Lateral rectus muscle, which controls eye movement horizontally away from the midline of the body.

Tolosa–Hunt syndrome

Tolosa-Hunt syndromeTolosa Hunt Syndrome
Rare causes of isolated sixth nerve damage include Wernicke-Korsakoff syndrome and Tolosa-Hunt syndrome.

Somatic (biology)

somaticsomasomatic cells
It is a somatic efferent nerve.

Efferent nerve fiber

efferentefferent nerveefferent fibers
It is a somatic efferent nerve.

Pons

pontinePons Varoliiannular protuberance
The abducens nerve leaves the brainstem at the junction of the pons and the medulla, medial to the facial nerve.

Medulla oblongata

medullabulbarmedullary
The abducens nerve leaves the brainstem at the junction of the pons and the medulla, medial to the facial nerve.

Meninges

subarachnoid spacemeningealleptomeninges
The nerve enters the subarachnoid space when it emerges from the brainstem.

Dura mater

duraduralcovering of the spinal cord
It runs upward between the pons and the clivus, and then pierces the dura mater to run between the dura and the skull through Dorello's canal.

Petrous part of the temporal bone

petrous bonepetrous portionpetrous portion of the temporal bone
At the tip of the petrous part of the temporal bone it makes a sharp turn forward to enter the cavernous sinus.