NBEO Ocular Anatomy Posterior Segment (Post Seg) and Cranial Nerves Practice Test

Raising intracranial pressure stretches the abducens nerve as it traverses a long intracranial path from the brainstem to the orbit. It is particularly vulnerable because it is tethered at fixed points along its route, notably at the petrous apex where it passes through Dorello's canal, making it prone to traction when ICP rises. Since this nerve controls the lateral rectus, its damage leads to an inability to move the eye outward (abduction) and horizontal diplopia, especially on gaze toward the affected side. While other nerves can be impacted by different processes, the pattern most typical of increased ICP is a VI nerve palsy due to its susceptible course.