What causes CN VI palsy?
WHAT CAUSES CRANIAL NERVE VI PALSY? The most common causes of sixth cranial nerve palsy are stroke, trauma, viral illness, brain tumor, inflammation, infection, migraine headache and elevated pressure inside the brain. The condition can be present at birth; however, the most common cause in children is trauma.
What is the motor function of the abducens nerve?
Function. The abducens nerve is a purely somatic motor nerve, It has no sensory function. It innervates the lateral rectus muscle, an extraocular muscles of the eye, which is responsible for the abduction of the eyes on the same (ipsilateral) side.
What is an Abducens nerve?
Cranial nerve six (CN VI), also known as the abducens nerve, is one of the nerves responsible for the extraocular motor functions of the eye, along with the oculomotor nerve (CN III) and the trochlear nerve (CN IV).
What is the function of the hypoglossal nerve?
The hypoglossal nerve enables tongue movement. It controls the hyoglossus, intrinsic, genioglossus and styloglossus muscles. These muscles help you speak, swallow and move substances around in your mouth.
What is the main function of CN VII?
The two 7th Cranial Nerves (CN VII) are located on either side of the brainstem, at the top of the medulla. They are mixed cranial nerves with BOTH sensory and motor function. CN VII controls the face and is mainly FACE MOVEMENT with some face sensation.
Is the abducens nerve sensory or motor nerve?
This nerve has only a motor function and is lacking a sensory function. The abducens is considered an extraocular nerve, which literally means “outside of the eye.”
How does damage to the abducens nerve cause double 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. The affected eye is pulled to look towards the midline. In order to see without double vision, patients will rotate their heads so that both eyes are toward the temple.
What causes nerve palsy in the abducens nerve?
Abducens nerve palsy can be caused by any structural pathology which leads to downwards pressure on the brainstem (e.g. space-occupying lesion). This can stretch the nerve from its origin at the junction of the pons and medulla.
Where does the abducens nerve attach to the sclera?
The abducens nerve provides innervation to the lateral rectus muscle – one of the extraocular muscles. The lateral rectus originates from the lateral part of the common tendinous ring, and attaches to the anterolateral aspect of the sclera.