In CN IV palsy the deviation is worse on opposite gaze (WOOG).
In the CN IV palsy a deviation is better on opposite tilt (BOOT).
Unilateral CN IV palsy is characterised by less than 10 degrees.
Bilateral lesions are often thought to be unilateral until squint surgery is performed, following which the contralateral CN IV palsy is often revealed.
routine neuroimaging for isolated CN IV palsy is not required.