Trochlear nerve palsy

Causes and risk

The most common causes of trochlear nerve palsy divide by age:

• Congenital, in a child.
• Acquired: trauma in young adults, and ischaemic in the old.

How it presents

The trochlear nerve palsy gives diplopia, and the eye deviates upward and inward. There is weakness of downward gaze, which is felt while going down stairs or while reading. The head tilts away from the lesion to minimize the diplopia.