Transcript No Slide Title

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
• Peripheral V.D.
• Rotatory
• Vertical
• Central V.D.
• Positional
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Vestibular Diseases
Vestibular Disease
8th Nerve only
Idiopathic V.D.
8th Nerve,
7th Nerve &
Horner’s Syndrome
Inner Ear Disease
Anything Else
Central V.D.
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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.
Summary of Case Management
• Re-check in one week
– Ought to be better
• Re-check in one
month
– Should still be
improving
• Thought to be
secondary to an
immune act on the
8th nerve
– Remember each
cranial nerve is
antigenically distinct
• Re-check again if any
•
Can
re-occur
signs persist
– Head tilt may be
permanent
Copyright University of Florida 1997
Vestibular Diseases
Vestibular Disease
8th Nerve only
Idiopathic V.D.
8th Nerve,
7th Nerve &
Horner’s Syndrome
Inner Ear Disease
Anything Else
Central V.D.
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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
Minimum Data Base
• PE, NE, OE
– Schirmer’s tear test
•
•
•
•
CBC
UA
Skull Radiographs
Other (if indicated)
– Chest & Abdominal
Radiographs
– Ear Culture
– Cardiac Exam
Normal bulla radiograph
Note: sharp bone edges with symmetrical
appearance.
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Inner Ear Infection
Radiographic Findings
L
R
R
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.
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Inner Ear Infection
• Treat with bacteriocidal 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
• Other Infections
– Fungal
• Prognosis Guarded
to Poor
• Prognosis is Poor
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Inner Ear Disease
What if Antibiotics Fail ?
• 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.
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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
Summary of Case Management
• 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 radiographs)
• If problems worsens or
persists without
change for 4 weeks,
consider referral.
Copyright University of Florida 1997
Central Vestibular Disease
Copyright University of Florida 1997
Vestibular Diseases
Vestibular Disease
8th Nerve only
Idiopathic V.D.
8th Nerve,
7th Nerve &
Horner’s Syndrome
Inner Ear Disease
Anything Else
Central V.D.
The referral line
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Nystagmus
• Horizontal
– Fast-Phase away from head tilt
– Fast Phase toward head tilt
• Peripheral V.D.
• Rotatory
• Vertical
• Central V.D.
• Positional
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Diagnosis of C.V.D.
Minimum Data Base
• PE, NE, OE, FE
– NE shows weakness,
postural response
changes, and/or reflex
changes
• CBC, Chemistry, UA
• Skull Radiographs
• CSF tap
• BAER test
• Advanced Imaging
– CT Scan
– MRI Scan
– Bone or Brain Scan
• Surgical Biopsy
– CSF titers
The Referral Line
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Central Vestibular Disease
Long Tract Signs
• 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.
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Central Vestibular Disease
CSF Tap and Analysis
• 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 cytology form a dog exhibiting
a mixed reaction with neutrophils,
lymphocytes and macrophages.
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Central Vestibular Disease
Common Causes of Diseases in Dogs
• Inflammatory or
Infectious Diseases
– canine distemper
– toxoplasmosis and
neosporiosis
– fungal
– rickettsial
– GME
– SRME
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Central Vestibular Disease
Common Causes of Diseases in Dogs
• Trauma or Vascular
– remember dogs don’t
get atherosclerosis !
• Neoplasia
– meningiomas
– choroid plexus
papillomas
– oligodendrogliomas
– astrocytomas
– metastatic neoplasia
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Central Vestibular Disease
MRI of Brainstem Meningioma
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Central Vestibular Disease
Primary Neoplasia
Oligodendroglioma
Choroid Plexus Papilloma
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Central Vestibular Disease
Granulomatous Meningoencephalitis
• Can be:
– peracute
– acute & progressive
– chronic
• In brainstem, tends to
be a multifocal
inflammatory disorder
• Responds temporarily
to steroids.
Patient with GME presenting with
vertical nystagmus, long tract signs,
and circling with incoordination.
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Central Vestibular Disease
Granulomatous Meningoencephalitis
GME histologically causes multifocal meningoencephalitis due to proliferation
of reticulohistiocytic cells. Lesions also show multinucleated giant cells.
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Central Vestibular Disease
Common Causes of Diseases in Cats
• Infectious Diseases
–
–
–
–
FIP
FeLV
toxoplasmosis
cryptococcosis
• Neoplasia
– meningiomas
• Trauma
• Metabolic
– thiamine deficiency
• Toxicity
– organophosphates
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Central Vestibular Disease
Common Causes of Diseases in Cats
Brainstem hemorrhages secondary to thiamine deficiency.
Don’t Forget Thiamine Deficiency !!!
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Central Vestibular Disease
Common Causes of Diseases in Ruminants
• Most Common Cause is
Infection of Brainstem by
Listeria monocytogenes
– 50-75% respond to antibiotic therapy
• May result from invasion
of infection into blood
sinuses, resulting in
Basillar Empyema
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Central Vestibular Disease
Common Causes of Diseases in Ruminants
• Listeriosis is common
in adult cattle and
goats.
• Culture is difficult,
requires coldenhancement.
• Treat with penicillins
and sulfas for 2-4
weeks.
Multifocal areas of hemorrhage due to
Listeriosis-induced meningoencephalitis.
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Central Vestibular Disease
Common Causes of Diseases in Horses
In Horses……
think
EPM!!!!!
(Equine Protozoal
Myelitis)
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Central Vestibular Disease
Cerebellar Disorders
• 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)
Copyright University of Florida 1997
Central Vestibular Disease
Paradoxical Head Tilt in Cerebellar Disorders
The output of the cerebellum is through
the activation of the Purkenjie cells. This
output is inhibitory. When the cerebellum 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.
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Central Vestibular Disease
Causes of Cerebellar Disorders
• 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
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Central Vestibular Disease
MRI of Cerebellar Meningioma
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Central Vestibular Disease
When Referral is Not an Option.
TREAT FOR THE TREATABLE !!!
• 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
Copyright University of Florida 1997