Neurological examination Flashcards
How do you test the palpebral reflex?
Touch the medial or lateral canthus of the eye
Which cranial nerves are involved in the palpebral reflex?
- Trigeminal (c.n. V) = afferent supply
- Ophthalmic or maxillary branch
- Facial (c.n. VII) = efferent supply
What is the intermediate brain region involved in the palpebral reflex?
Brainstem
How do you test the corneal reflex?
Touching the corneal should elici blink and globe retraction
Which cranial nerves are involved in the corneal reflex?
- Trigeminal (c.n. V) - afferent
- Ophthalmic branch
- Abducent (c.n. VI) - efferent
- Facial (c.n. VII) - efferent
What is the intermediate brain region involved in the corneal reflex?
Brainstem
How do you test the menace response?
Move a hand/two fingers towards the eye to elicit a blink
Which animals will not display a menace response?
Very young ones
The menace response is learned, not a reflex, so young animals (e.g. foal under 14 days) will not show this.
Which cranial nerves are involved in the menace response?
- Optic (c.n. II) - afferent
- Facial (c.n. VII) - efferent
What are the intermediate brain regions involved in the menace response?
Forebrain
Cerebellum
Brainstem
What are the signs of an upper motor neurone lesion?
- Slow muscle atrophy
- High muscle tone
- Normal/increased reflexes
What are the signs of an LMN lesion?
- Rapid muscle atrophy
- Low muscle tone
- Reduced reflexes
How can you test the facial nerve?
- Observe for facial symmetry
- Test for palpebral response
- Test for menace response
- Assess lacrimal function (parasympathetic fibres of VII) using the Schirmer tear test
Nystagmus
repetitive, involuntary movement of the eye, which can be horizontal, vertical or rotatory. Nystagmus has a fast and a slow phase.
Strabismus
visual condition in which patient cannot align both eyes simultaneously; abnormal static position of the eye.
–> Can be predictably generated by lesions affecting cranial nerves III, IV and VI.
