Vestibular Disease

Anne E. Chauvet, DVM, DACVIM (Neurology)

Neuroanatomy

	Brainstem and flocular
	Nodular lobes of the cerebellum
	Cerebellar peduncles
	Caudal Fossa

  Vestibular Clinical Signs  

	Head tilt – ipsilateral
	Leaning/falling/tilting – ipsilateral
	Ataxia
	Vomiting and salivation –usually more prominent in peripheral disease
	Nystagmus – labeled according to fast phase that is away from lesion
	Strabismus - ipsilateral

Peripheral disease:

	Otoscopic examination
	Endoscopy
	BAER
	Skull/bullae radiographs
	Myringotomy
	Culture and Sensitivity

Central disease

	Thoracic radiographs/metastasis check
	Complete blood work up
	Titers: toxoplasmosis, distemper, FelV, FIV, cryptococcus, FIP, tick titers, etc.
	BAER, EEG, SEP
	CT or MRI
	CSF tap

Vestibular diseases DAMNIT!

1.  Geriatric vestibular disease

	Degeneration of the receptor organ or the chain of ossicles in the middle ear
	Progressive loss of hearing

2.       Congenital peripheral vestibular disorder

	Uncommon
	German Shepherd Dog and others
	<12 weeks old
	Signs may regress in 3-4 months
	Head tilt
	No pathological nor physiological nystagmus
	Normal histopathology

3.       Congenital nystagmus

	Pendular
	Unknown etiology
	Guernsey and Holstein cows
	Ayshire bulls
	Siamese cats

4.  Neoplasia

	Older animals >4 years old
	Compressive vs invasive
	Slow onset and progressive usually
	Most common in dogs
	Meningioma is most common in dogs and cats
	Lymphoma more common in large animals
	Primary effects = compression + infiltration
	Secondary effects = edema, increase in ICP
	Signs depend on tumor location and extent

5.        GME = granulomatous meningoencephalomyelitis

	Unknown cause, suspect immune mediated
	Non suppurative perivascular inflammation
	Young to middle age dogs
	Female>Male
	Small breeds more so
	Guarded to poor prognosis because diagnosis only confirmed by histopathology
	Ocular form is uncommon
	Focal form – cerebellopontine angle
	Treatment: Steroids, Immuran, IgG, Radiation

6.       Feline viral disorders

	FIV and FelV
	Signs depend on location
	Serum and CSF titers together
	Histopathology
	Poor prognosis

7.       FIP

	Corona virus
	Immune mediated vasculitits of CNS
	Clinical signs-multisystemic
	Slow and progressive
	Caudal fossa syndrome, seizures, myelitis
	Ocular
	Hypergammaglobulinemia
	Cytoxan, steroids—fatal

8.       Canine distemper encephalitis

	Parmyxovirus
	Not always respiratory signs
	Not always neurological
	Post vaccinal
	Old dog encephalitis:dementia, ataxia, central blindness, rarely seizures
	Young dog: seizures, myoclonus, transverse myelitis
	Diagnosis by IFA, titers on serum and CSF: IgG, IgM and SNA (Cornell)
	Symptomatic treatment: steroids, HrIgG
	Permanent deficits

9.       Protozoal and Fungal Diseases

	Cats: toxo and crypto
	Dogs: blasto, aspergillosis, coccidiomycosis, toxo, neosporosis
	Equine: EPM

10.   Toxoplasmosis/Neosporosis

	Multisystemic
	Immunosupression predisposes
	Encephalitis, radiculitis, myelitis, myositis
	Titers in Colorado: IgG and IgM
	TMS-pyrimethamine-folic acid

11.   Otitis Media/Interna

	Acute or chronic
	Some breeds are predisposed
	Horner’s syndrome + CN VII
	Deafness if bilateral disease
	BAER
	Systemic antibiotics
	Saline cleanings
	Damage may be permament

12.   Abscess

	Large animals more so
	Secondary to bites
	Focal signs
	Systemic antibiotics and steroids

13.   Feline idiopathic vestibular disease

	Sudden onset
	All ages
	Late summer and fall
	Unknown etiology: cuterebra
	No treatment
	Good prognosis

14.   Metronidazole toxicity

	Unknown mechanism
	High dosages and long durations
	Never exceed 7.5 mg/kg TID
	Sudden onset of vestibular disease, seizures, disorientation
	Discontinue drug=treatment
	Time

15.   Ototoxicity

• Aminoglycosides
• Treatment= withdraw drug
• Permanent deafness
• Vestibular signs may resolve

Vestibular Emergency

	IV diazepam
	IV acepromazine at 0.002 mg/kg to 0.02 mg/kg
	Meclazine
	Padding – especially on side of lean
	Steroids?
	Differentiate from seizure