Eye movements, nns and palsys

Question 1

Describe which eye mm do which movements

Answer 1

Rectus mm (do what their name says)

• Lateral rectus - abduction
• Medial rectus - adduction
• Superior rectus - elevation and abduction
• Inferior rectus - depression and abduction

Oblique mm (do the Opposite of what their name says

• Superior oblique - depression and adduction
• Inferior oblique - elevation and adduction

Levator palpebrae superioris - elevates eyelid

Question 2

Innervation of extra occular mm

Answer 2

REMEMBER: LR6SO4

Lateral rectus CN VI (abducents)

Superior oblique CN IV (trochlear)

Everything else CN III (Oculomotor), including levator palpebrae superioris

Facial nerve closes eye

Question 3

Symptoms of CN III palsy

Answer 3

• May have Efferent pupil defect (dilated pupil + unreactive to light and accomodation)
• Ptosis
• Eye looks down + out
• Diplopia

Question 4

CN IV palsy sx

Answer 4

• Head tilt away from lesion
• Hypertrophia (eye looking up)
• Diplopia

Question 5

CNVI palsy sx

Answer 5

• Esotrophia (eye looks inwards) especially when looking in distance
• Diplopia

Question 6

Facial nn palsy optic sx

Answer 6

Facial nerve palsy causes incomplete lid closure

Question 7

Innervation of intraoccular mm

Answer 7

Constritcion of pupil: pupillary spincter (circular mm) CN III

Dialation of pupil: dialator pupili (radial mm) sympathetic innervation ergo dilation is part of fight or flight reaction