Hey all,

I’ve decided to come here since I’m desperate. I’m currently in the neuroscience block at my school and I can’t figure out these cranial nerve lesions. I spent hours yesterday trying to find a simple explanation and pattern I can use to get through this but when I tested it out this morning it failed.

I know CN II gets complex with the decussations. I also understand CN VII motor nucleus has input bilaterally from the cortex from an UMN standpoint, which determines its deficit patterns. I also know CN VI plays a role in accommodation and conjunction and how lesioning something in either pathway can produce different deficits.

But what about the other CNs? I’m just so lost. So the big question is, what is the pattern? What happens when I lesion a CN at this specific point on this specific side of the brain (will it be ipsilateral deficits or contralateral)? I’ve read that CNs are LMN this if you lesion them the deficit will present ipsilaterally. But then that doesn’t explain others (or the questions I got wrong). Also, please keep your responses simple. No need to go super technical and allegorical. Thank you!!