Third cranial nerve disorder (disorder of eye movement)

Description The third cranial n...

Description

The third cranial nerve, also called the oculomotor nerve, is one of three cranial nerves that control the movement of the eye. This nerve also controls constriction of the pupil and eyelid movement. A complete third nerve palsy causes the eye to be stuck downward and outward, a droopy eyelid and dilated pupil. The actual symptoms experienced depend on where the damage to the nerve occurs as it travels from the brain to the eye and the extent of damage. In some cases, only the eye muscle weakness is experienced. Conditions causing this disorder include congenital oculomotor palsy, diabetes, atherosclerosis, cerebral artery aneurysms, brain tumors, meningitis, traumatic injuries, multiple sclerosis, thiamine deficiency (Wernicke encephalopathy) and cavernous sinus thrombosis.

Symptoms

Double vision, cross eyed or wandering eye, droopy eyelid (ptosis), the pupil may be abnormally dilated or normal appearing.

Tests

Common tests used for diagnosis and treatment

Workup:
A history and physical exam will be performed to make the diagnosis. Brain imaging with a CT scan or MRI, is usually ordered to help determine the cause .

Tests:
Complete blood count (CBC), Comprehensive metabolic panel (CMP), CT Scan, Magnetic resonance imaging (MRI)

Other Specific Tests: Thiamine can be administered to rule out thiamine deficiency.

Specialists:
Neurosurgery, Neurology, Pediatric Neurology, Pediatric Neurosurgery

Treatment

Treatment depends on the cause. Emergency treatment is required if a life-threatening disorder is the cause. If caused by thiamine deficiency, it may respond to thiamine.