cn 3 4 6

Question 1

cn III lesion results

Answer 1

Eye ipsilateral to lesion deviates laterally
Medial rectus is weak and lateral rectus is unopposed, lateral strabismus
Patient cannot move the eye medially
Vertical movement impaired, weak superior and inferior recti and inferior oblique ipsilaterally
Diplopia: double vision
Ipsilateral levator palpebrae superioris weak: ptosis
Mydriasis: pupil on affected side is dilated
Pupillary dilator is unopposed as pupillary sphincter and ciliary muscle are dysfunctional
Pupil does not constrict in response to light
Lens cannot be focused for near vision