Limitation of Extraocular Movement
August 18th, 2017
Overview
How to Perform
- Ask the patient to follow your finger with their eyes, without moving their head. Move the testing finger in a modified H pattern - up and down to the left, right and centrally.
Causes of Limited Ocular Movement
- Upper motor neuron lesion - trauma, tumour, ischaemia, haemorrhage, demyelination
- Lower motor neuron lesion - oculomotor (III), trochlear (IV) or abducens (VI) nerve palsy
- Neuromuscular disorder - myaesthenia gravis
- Myopathy - e.g. muscular dystrophies
Interpretation
- Oculomotor nerve (III) lesion - eye deviated downward and outward, with ptosis and loss of pupillary reflexes
- Trochlear nerve (IV) lesion - eye turned upward, with vertical diplopia and inability to look down and in
- Abducens nerve (VI) lesion - eye turned inward (strabismus), with horizontal diplopia and inability to look laterally
Muscles Involved in Eye Movement
Muscles
Occulomotor Nerve (III)
- SRSuperior rectus - intorsion and elevation
- IRInferior Rectus - abduction and depression
- MRMedial rectus - adduction
- IOInferior oblique - extorsion, abduction and elevation
Trochlear Nerve (IV)
- SOSuperior oblique - intorsion, abduction and depression
Abducens Nerve (VI)
- LRLateral rectus - abduction
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------