The abducens nerve has the longest subarachnoid course of all the cranial nerves.
- Increased ICP can result in downward displacement of the brainstem, causing stretching of the sixth nerve secondary to its location within Dorello's canal
- Any subarachnoid abnormality including haemorrhage, infection, and tumour, including cavernous sinus mass
- Infectious and inflammatory etiologies (eg, postviral, demyelinating, diabetes)
- Neoplasm of the pons