Term
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Definition
inner ear
receptors, ganglion and peripheral axons of CN 8 |
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Term
|
Definition
vestibular nuclei in medulla
vestibular projections to cerebellum, spinal cord, and rostral brainstem |
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Term
| Central and Peripheral Vestibular Lesion Signs |
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Definition
head tilt
nystagmus
strabismus
vestibular ataxia (drunk)
tight circling |
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Term
| Peripheral Vestibular Disease Signs |
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Definition
ipsilteral head tilt
ipsilateral vestibular ataxia
horizontal or rotary nystagmus
ipsilateral circling
veering and leaning
faster nystagmus |
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Term
| Central Vestibular Disease Signs |
|
Definition
ipsilateral head tilt
ipsilateral vestibular ataxia
horizontal, rotary, vertical, or positional nystagmus
postural reaction deficit ipsilateral
possible mental defects
ipsilateral circling
nonambulatory tetraparesis
slower nystagmus |
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Term
|
Definition
head tilt away from lesion
caused by lesions in cerebellar areas affecting Purkinje cells
Purkinje cells have inhibitory effects of vestibular nuclei |
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Term
|
Definition
no know pathogenesis
decreased energy metabolism causing disturbance in axonal transport
compressive neuropathy as nerves exit through cranium
possible to see pure vestibular neuropathy
may see other cranial nerve involvement
resolution of most signs expected within 2 months but may have residual tilt |
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Term
|
Definition
thiamine plays central role in metabolism of carbohydrtes
deficiency leads to energy depletion and neuronal necrosis
caused by raw fish diet in rich thiaminses
excessive temperatures can decrease thiamin in food
sulfur dioxide as a preservative can destroy thiamin in food
decreased absorption of thiamine secondary to GI or liver disease |
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Term
| Thiamine Deficiency Signs |
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Definition
initial signs of anorexia and lethargy
bilaterally symmetric signs
vestibular
pupillary dilation
seizures ventroflexion of neck in cats |
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Term
| Idiopathic Vestibular Nerve Disease |
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Definition
very common
peracute symptoms
dogs- unilateral vestibular nerve dysfunction
cats- bilateral vestibular nerve dysfunction
typically older
ataxia, head tilt, rapid nystagmus
diagnosis of exclusion
tx with time, supportive care
NOT STEROIDS |
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Term
|
Definition
most common cause of peripheral vestibular disease in dogs and cats
extension of otitis externa
rarely hematogenous or via auditory tube
Staphylococcus intermedius, Pseudomonas
tx with systemic antibiotics |
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Term
|
Definition
typically secondary and due to spread from middle ear
may be more common in patients treated with steroids
tx with clindamycin, doxycycline, chloramphenicol to cross BBB
dx with MRI to confirm central involvement |
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Term
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Definition
may be due to drug interacting with GABA receptors in vestibular and cerebellar nuclei
see signs after 3 days starting tx
dogs=bilateral central vestibular signs
cats= cerebellar and cerebral signs
stop drug
Diazepam increases recovery |
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