Fourth nerve palsy Flashcards
What is the name of the fourth cranial nerve?
Trochlear nerve
What does the trochlear nerve control?
Superior oblique muscle
What is the function of the superior oblique?
Depresses eye, moves inward
What are the symptoms of fourth nerve palsy?
Vertical diplopia
Head tilt to compensate for the palsy
Eye appears to deviate upwards and is rotated outwards
When is the vertical diplopia usually noticed?
When reading a book or going downstairs
What is vertical diplopia?
Double vision worse in the vertical plane
Why might a patient develop a head tilt?
To compensate for the palsy
How might the eye appear in someone with fourth nerve palsy when they are looking straight?
The eye deviates upwards and is rotated outwards
What are the most common causes of fourth nerve palsy?
Ocular trauma
Diabetes mellitus
