Vestibular Disease Flashcards
Central vestibular disease (brainstem or cerebellum)
- Head tilt?
- Paresis?
- CP deficits?
- Consciousness?
- CN deficits?
- Stabismus?
- Horner’s?
- Nystagmus?
- Head tilt: yes
- Paresis: possible
- CP deficits: possible, ipsilateral
- Consciousness: +/- obtunded, stuporous, coma
- CN deficits: +/- CN 5-12
- Stabismus: possible
- Horner’s: rare
- Nystagmus: fast phase in any direction
Peripheral vestibular disease (ear: canal, bulla or CN8)
- Head tilt?
- Paresis?
- CP deficits?
- Consciousness?
- CN deficits?
- Stabismus?
- Horner’s?
- Nystagmus?
- Head tilt: yes, toward lesion
- Paresis: no
- CP deficits: no
- Consciousness: alert +/- disoriented
- CN deficits: CN 7 or 8
- Stabismus: possible
- Horner’s: possible
- Nystagmus: fast phase AWAY from lesion, head position does not alter direction
What EOM does CN 3 innervate?
Dorsal, medial and ventral rectus mm.
What EOM does CN 4 innervate?
Dorsal oblique m.
What EOM does CN 6 innervate?
Lateral rectus m, retractor bulbi m.
Vestibular inputs are bilateral and tonic; therefore you lose tonic input on the side of the lesion. The body is pushed ____ from the abnormality. The normal side ____ and the affected side ____.
AWAY
Normal = extends
Affected = lack of extension
What is Horner’s Syndrome? What are the hallmark clinical signs associated with Horner’s? Lesion localization?
Sympathetic nerve paralysis/denervation - PS takes over
- ptosis
- mitosis
- protrusion of 3rd eyelid
- enophthalmos
- sweating in horses
Localization: head/cervical trauma, mediastinal disease, C6-T2, orbit/middle ear
Visual + normal PLR
Normal
Visual + no PLR
CN 3 efferent problem
Blind + normal PLR
Cataract or cortical disease
Blind + no PLR
Retina, optic nerve affected
If the lesion is before the chiasm
Affected eye: no vision + no direct + consensual
If the lesion is in CN 3 pathway (non-crossing)
Affected eye: vision + no direct + no consensual
If the lesion is in the optic chiasm
No vision + no PLR in either eye
