Superior oblique palsy (aipg2011)

Q.Damage to Superior oblique nerve causes diplopia:
A. Horizontal and downward
B. Vertical and downward
C. Horizontal and upward
D. Vertical and upward

ANSWER:

Ans : B
Injury to the trochlear nerve cause weakness of downward eye movement with consequent vertical diplopia (double vision). The affected eye drifts upward relative to the normal eye, due to the unopposed actions of the remaining extraocular muscles.
As would be expected, the diplopia gets worse when the affected eye looks toward the nose – the contribution of the superior oblique muscle to downward gaze is greater in this position. Common activities requiring this type of convergent gaze are reading the newspaper and walking down stairs. Diplopia associated with these activities may be the initial symptom of a fourth nerve palsy.