Fourth Nerve Palsy
What is a fourth nerve palsy?
The fourth cranial nerve innervates the superior oblique muscle, so weakness of the nerve is also known as superior oblique palsy.Weakness of the superior oblique muscle causes a combination of vertical, horizontal and torsional misalignment of the eyes. This condition is usually unilateral (one eye) but can be bilateral (both eyes).
Does superior oblique palsy cause double vision (diplopia)?
Superior oblique palsy may cause double vision because of misalignment of the eyes (the brain perceives an image from two different directions). The double visionmay be vertical (one image on top of the other), diagonal (vertically and horizontally separated) and less often torsional (rotated or twisted). The torsional phenomenon occurs more frequently with acquired cases superior oblique palsy.
Is the head tilted with superior oblique palsy?
Head tilt and/or turn is common with superior oblique palsy. The abnormal head position allows better alignment of the eyes, sometimesaiding in relief of diplopia. A child with a head tilt should be evaluated by an ophthalmologist for superior oblique palsy and other possible eye problems.
What causes superior oblique palsy?
Superior oblique palsy is most commonly congenital (present at birth) or may be associated with craniosynostosis. A common cause of superior oblique palsy is head trauma, including relatively minor trauma. A concussion or whiplash injury from a motor vehicle accident may be sufficient to cause the problem. Rare causes of superior oblique palsyare stroke, tumor and aneurysm.
How is superior oblique palsy treated?
During that period, diplopia can be managed with prism glasses. Prisms merge two images into one but do not strengthen the eye muscles. If prism is not effective, patching or covering one eye can alleviate the double vision. If the palsy does not recover over this 6 months period and if prisms are not able to adequately control the diplopia, surgery may be indicated.