QuestionSBA
QuestionChoice
This would be symptomatic of a loss of function in the superior oblique, which would be responsible for deviating the eye down and inwards.
10001770
d
The affected eye is deviated up and out
QuestionChoice
The abducens (6th) cranial nerve is responsible for the motor control of the lateral rectus, which is responsible for the abduction (outward movement) of the eye. Loss of abducens function means the eye cannot be pulled outward, so it will deviate inwards instead.
10001767
a
The affected eye deviates inwards
QuestionChoice
This would be symptomatic of an injury to the superior rectus, which allows the eye to move upwards - it is unlikely for the superior rectus to be affected in isolation. This is not consistent with a lesion in the abducens nerve.
10001769
c
The affected eye is deviated down
QuestionChoice
These are the classic symptoms you would find in a third cranial nerve palsy, affecting the oculomotor nerve. The third nerve innervates all the ocular muscles except the lateral rectus (pulling the eye out) and the superior oblique (pulling the eye down) - these are therefore the direction the eye will go when the oculomotor nerve function is lost.
10001768
b
The affected eye deviates down and out
QuestionChoice
This would be due to a lesion in the inferior rectus, which pulls the eye downwards.
10001771
e
The affected eye is deviated up
Concept
Chapter
2693
3970
Isolated cranial nerve palsies affecting the eye
Topic
141
Neurology
12900
A 79-year-old presents to the Emergency Department. Upon examination, you are worried that he may have a sixth cranial nerve palsy.

Which of the following signs and symptoms are likely to be found in a sixth nerve palsy?
a