Post on 08-Jul-2015
Copyright University of Florida 1997
New tilt on an old problem.
Copyright University of Florida 1997
Cardinal Signs of V.D.
• Head Tilt• Nystagmus
– Horizontal– Rotatory– Vertical– Positional
• Circling (tight)
• Imbalance & Incoordination
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Nystagmus
• Horizontal– Fast-Phase away from head tilt
– Fast Phase toward head tilt
• Rotatory
• Vertical
• Positional
• Peripheral V.D.
• Central V.D.
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Vestibular Diseases
Vestibular Disease
Idiopathic V.D. Inner Ear Disease Central V.D.
8th Nerve only
8th Nerve,
7th Nerve &
Horner’s SyndromeAnything Else
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Idiopathic V.D.
• Acute Onset of Vestibular Signs– Head tilt
– Horizontal or Rotatory nystagmus with fast-phase away from head tilt
– Nothing else
• Can Be Very Severe
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Idiopathic V.D.Minimum Data Base
• Physical Examination
• Neurologic Examination– Only 8th nerve signs
• Odoscopic Examination
• Other tests as indicated– Heartworm Check– Fecal
– Chest and Abdominal Radiographs
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Idiopathic V.D.
• Re-check in one week– Ought to be better
• Re-check in one month– Should still be
improving
• Re-check again if any signs persist– Head tilt may be
permanent
• Thought to be secondary to an immune act on the 8th nerve– Remember each
cranial nerve is antigenically distinct
• Can re-occur
Summary of Case Management
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Vestibular Diseases
Vestibular Disease
Idiopathic V.D. Inner Ear Disease Central V.D.
8th Nerve only
8th Nerve,
7th Nerve &
Horner’s SyndromeAnything Else
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Inner Ear Disease
• 8th Nerve Signs• 7th Nerve Signs
– ear & lip droop– lack of palpebral
reflex– nose turn– nostril flaring
• Horner’s Syndrome
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Inner Ear Disease
• Facial nerve dysfunction– diminished ear and
lip reflexes
– lack of palpebral reflex with inability to blink
– diminished tear production
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Horner’s Syndrome
• Small Animals– Ptosis– Myosis
– Enophthalmos
• Large Animals– Facial sweating
(horse)– Lack of muzzle
sweating (cow)
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Inner Ear Disease
• Most cases are secondary to bacterial infection (otitis media & interna)– extension from otitis
externa
– pharyngitis with extension up the eustachian tube
– hematogenous spread
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Inner Ear Disease
• Remainder are– fungal infections– ear polyps
– neoplasia
• Major rule:– “Treat for the Treatable”
• Therefore, most need antibiotics!
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Diagnosis of Inner Ear Disease
• PE, NE, OE– Schirmer’s tear test
• CBC
• UA• Skull Radiographs• Other (if indicated)
– Chest & Abdominal Radiographs
– Ear Culture– Cardiac Exam
Minimum Data Base
Normal bulla radiographNote: sharp bone edges with symmetrical
appearance.
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Inner Ear InfectionRadiographic Findings
Right-lateral and DV radiograph of dog with unilateral otitis interna showing
sclerosis of the tympanic bulla on the right side with loss of detail in the region
of the osseous petrous-temporal bone.
RR
L
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Inner Ear Infection
• Treat with bacterio-cidal drugs which penetrate bone and blood-tissue barriers– Combination therapy
• cephalosporins
• sulfa drugs
– Enrofloxacin
• Must treat 6-8 weeks
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Ear Polyps in Cats
• Benign growth in the external ear canal which causes signs by extension.
• Can also be pharyngeal mass which grows into middle ear via the eusthasian tube.
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Ear Polyps in Cats
• Treatment is surgical removal.
• Damage can be permanent, if pressure necrosis has destroyed the inner ear structure.
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Inner Ear Disease
• Other Neoplasia– neurofibromas– osteosarcomas
– FeLV
• Prognosis is Poor
• Other Infections– Fungal
• Prognosis Guarded to Poor
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Inner Ear Disease
• Consider Advanced Imaging Techniques– Bone Scan
– MRI Scan
• Consider Surgical Drainage of Bulla
• If owner can not afford additional tests or referral, may try changing antibiotics.
• Main reason for failure is not treating long enough.
What if Antibiotics Fail ?
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I.E.D. (Special Dx- -Imaging)
• Bone Scan– demonstrates
enhanced uptake of radioisotope in region of infection.
• MRI Scan– shows fluid levels or
soft tissue proliferation.
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I.E.D.- -MRI Scan
MRI Scan showing osseous proliferation and soft tissue density
in the osseous bulla.
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B.A.E.R. test
Provides indication of the ability of the auditory portion of the 8th nerve to function and relay that information through the brainstem toward the cerebral cortex.
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Bilateral I.E. Disease
• No Head Tilt• No Nystagmus
– spontaneous or– physiologic
• Wide head excursions due to inability to fix eyes on vertical with movement.
Open mouth radiograph with
chronic changes in both bullas
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Bilateral I.E. Disease
• MRI image shows bilateral disease in middle and inner ear.
• May respond to aggressive antibiotic therapy.
• Some patients will also be deaf.
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Inner Ear Disease
• Treat with antibiotics and recheck in 2 weeks– if better, continue– if worse, reassess
• Recheck in 1 month– if normal, stop
antibiotics
– if still residual problems, continue 2 more weeks
• Recheck at 6 months– re-examine any
abnormalities (such as abnormal bulla radio-graphs)
• If problems worsens or persists without change for 4 weeks, consider referral.
Summary of Case Management
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Central Vestibular Disease
Copyright University of Florida 1997
Vestibular Diseases
Vestibular Disease
Idiopathic V.D. Inner Ear Disease Central V.D.
8th Nerve only
8th Nerve,
7th Nerve &
Horner’s SyndromeAnything Else
The referral line
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Nystagmus
• Horizontal– Fast-Phase away from head tilt
– Fast Phase toward head tilt
• Rotatory
• Vertical
• Positional
• Peripheral V.D.
• Central V.D.
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Diagnosis of C.V.D.
• PE, NE, OE, FE– NE shows weakness,
postural response changes, and/or reflex changes
• CBC, Chemistry, UA• Skull Radiographs• CSF tap
– CSF titers
• BAER test• Advanced Imaging
– CT Scan– MRI Scan– Bone or Brain Scan
• Surgical Biopsy
Minimum Data Base
The Referral Line
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Central Vestibular Disease
• Postural Changes– CP Deficit– Dysmetria
• Reflex Changes– hyperactive reflexes– crossed-extensor
reflexes– Babinski’s sign
Conscious proprioceptive deficit
may be on the same or opposite side
of the lesion.
Long Tract Signs
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Central Vestibular Disease
• CSF Analysis– may be normal or
show increased pressure, protein and/or cells.
• CSF Titers– species specific tests– many must be paired
with serum titers.
CSF Tap and Analysis
CSF cytology form a dog exhibiting
a mixed reaction with neutrophils,
lymphocytes and macrophages.
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Central Vestibular Disease
• Inflammatory or Infectious Diseases– canine distemper
– toxoplasmosis and neosporiosis
– fungal– rickettsial– GME– SRME
Common Causes of Diseases in Dogs
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Central Vestibular Disease
• Trauma or Vascular– remember dogs don’t
get atherosclerosis !
• Neoplasia– meningiomas– choroid plexus
papillomas– oligodendrogliomas
– astrocytomas– metastatic neoplasia
Common Causes of Diseases in Dogs
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Central Vestibular DiseaseMRI of Brainstem Meningioma
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Central Vestibular DiseasePrimary Neoplasia
Oligodendroglioma Choroid Plexus Papilloma
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Central Vestibular Disease
• Can be:– peracute– acute & progressive
– chronic
• In brainstem, tends to be a multifocal inflammatory disorder
• Responds temporarily to steroids.
Granulomatous Meningoencephalitis
Patient with GME presenting with
vertical nystagmus, long tract signs,
and circling with incoordination.
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Central Vestibular DiseaseGranulomatous Meningoencephalitis
GME histologically causes multifocal meningoencephalitis due to proliferation
of reticulohistiocytic cells. Lesions also show multinucleated giant cells.
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• Neoplasia– meningiomas
Central Vestibular Disease
• Infectious Diseases– FIP– FeLV
– toxoplasmosis– cryptococcosis
• Trauma• Metabolic
– thiamine deficiency
• Toxicity– organophosphates
Common Causes of Diseases in Cats
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Central Vestibular DiseaseCommon Causes of Diseases in Cats
Don’t Forget Thiamine Deficiency !!!
Brainstem hemorrhages secondary to thiamine deficiency.
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Central Vestibular Disease
• Most Common Cause is Infection of Brainstem by Listeria monocytogenes– 50-75% respond to anti-
biotic therapy
• May result from invasion of infection into blood sinuses, resulting in Basillar Empyema
Common Causes of Diseases in Ruminants
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Central Vestibular Disease
• Listeriosis is common in adult cattle and goats.
• Culture is difficult, requires cold-enhancement.
• Treat with penicillins and sulfas for 2-4 weeks.
Multifocal areas of hemorrhage due to
Listeriosis-induced meningoencephalitis.
Common Causes of Diseases in Ruminants
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Central Vestibular Disease
In Horses……
think
EPM!!!!!
(Equine Protozoal Myelitis)
Common Causes of Diseases in Horses
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Central Vestibular Disease
• Signs include head tilt– paradoxical (head tilt is
away from the lesion)
• If horizontal nystagmus exists, the fast-phase is toward the head tilt
• Also signs of dysmetria and whole body tremors (including head)
Cerebellar Disorders
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Central Vestibular Disease
The output of the cerebellum is through the activation of the Purkenjie cells. This output is inhibitory. When the cerebel-lum is damaged, the result is disinhibition of brainstem nuclei. Asymmetrical damage cause increased in motor tone on the side of the lesion, leading to the head tilting away from the damage.
Paradoxical Head Tilt in Cerebellar Disorders
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Central Vestibular Disease
• Chronic distemper in dogs
• FIP in cats
• Thiamine deficiency in cats, horses, and ruminants
• OP intoxication in dogs and cats
• Lead poisoning in all animals
• Meningiomas in dogs and cats
Causes of Cerebellar Disorders
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Central Vestibular DiseaseMRI of Cerebellar Meningioma
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Central Vestibular Disease
• Corticosteroids– prednisolone @ 1
mg/kg/day in 3 divided doses for 3-7 days
– reduce prednisolone dose to 1/3 mg/kg twice a day
– find minimum daily dose and go to alternate-day therapy (over weeks)
• Misoprostol– 3-4 µg/kg twice a day– may stop when at
alternate-day steroids
• Doxycycline– 5-10 mg/kg once a day
for 2 weeks
• Sulfadimethoxine– 15 mg/kg twice a day
When Referral is Not an Option.TREAT FOR THE TREATABLE !!!