CNI-XII, cerebellum and extrapyramidal pathway -

Question 1

Ptosis:

Answer 1

Ptosis is present if the eyelid droops over the pupil when the eyes are fully open. Since the levator palpebrae muscle contains both skeletal and smooth muscle, ptosis signifies either a III nerve palsy or a sympathetic lesion and is more prominent with the former

Question 2

A lesion of the III nerve produces:

Answer 2

• external paresis
  
  • impairment of eye movement
  • impairment of lid movement
• internal paresis
  
  • disturbance of pupillary response
• Internal paresis + External paresis = Total paresis

Question 3

The superior oblique muscle normally:

Answer 3

• depresses
• intorts
• abducts the eye

Question 4

Trochlear nerve lesion:

Answer 4

When the trochlear is weak -> superior oblique is weak.
You can’t look down and out.
Diplopia.