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

Copyright University of Florida 1997 Nystagmus Horizontal –Fast-Phase away from head tilt –Fast Phase toward head tilt Rotatory Vertical Positional Peripheral V.D. Central V.D.

Copyright University of Florida 1997 Vestibular Diseases Vestibular Disease Idiopathic V.D.Inner Ear DiseaseCentral V.D. 8th Nerve only 8th Nerve, 7th Nerve & Horner’s Syndrome Anything Else

Copyright University of Florida 1997 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

Copyright University of Florida 1997 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

Copyright University of Florida 1997 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

Copyright University of Florida 1997 Vestibular Diseases Vestibular Disease Idiopathic V.D.Inner Ear DiseaseCentral V.D. 8th Nerve only 8th Nerve, 7th Nerve & Horner’s Syndrome Anything Else

Copyright University of Florida 1997 Inner Ear Disease 8th Nerve Signs 7th Nerve Signs –ear & lip droop –lack of palpebral reflex –nose turn –nostril flaring Horner’s Syndrome

Copyright University of Florida 1997 Inner Ear Disease Facial nerve dysfunction –diminished ear and lip reflexes –lack of palpebral reflex with inability to blink –diminished tear production

Copyright University of Florida 1997 Horner’s Syndrome Small Animals –Ptosis –Myosis –Enophthalmos Large Animals –Facial sweating (horse) –Lack of muzzle sweating (cow)

Copyright University of Florida 1997 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

Copyright University of Florida 1997 Inner Ear Disease Remainder are –fungal infections –ear polyps –neoplasia Major rule: –“Treat for the Treatable” Therefore, most need antibiotics!

Copyright University of Florida 1997 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 radiograph Note: sharp bone edges with symmetrical appearance.

Copyright University of Florida 1997 Inner Ear Infection Radiographic 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

Copyright University of Florida 1997 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

Copyright University of Florida 1997 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.

Copyright University of Florida 1997 Ear Polyps in Cats Treatment is surgical removal. Damage can be permanent, if pressure necrosis has destroyed the inner ear structure.

Copyright University of Florida 1997 Inner Ear Disease Other Neoplasia –neurofibromas –osteosarcomas –FeLV Prognosis is Poor Other Infections –Fungal Prognosis Guarded to Poor

Copyright University of Florida 1997 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 ?

Copyright University of Florida 1997 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.

Copyright University of Florida 1997 I.E.D.- -MRI Scan MRI Scan showing osseous proliferation and soft tissue density in the osseous bulla.

Copyright University of Florida 1997 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.

Copyright University of Florida 1997 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

Copyright University of Florida 1997 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.

Copyright University of Florida 1997 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

Copyright University of Florida 1997 Central Vestibular Disease

Copyright University of Florida 1997 Vestibular Diseases Vestibular Disease Idiopathic V.D.Inner Ear DiseaseCentral V.D. 8th Nerve only 8th Nerve, 7th Nerve & Horner’s Syndrome Anything Else The referral line

Copyright University of Florida 1997 Nystagmus Horizontal –Fast-Phase away from head tilt –Fast Phase toward head tilt Rotatory Vertical Positional Peripheral V.D. Central V.D.

Copyright University of Florida 1997 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

Copyright University of Florida 1997 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

Copyright University of Florida 1997 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.

Copyright University of Florida 1997 Central Vestibular Disease Inflammatory or Infectious Diseases –canine distemper –toxoplasmosis and neosporiosis –fungal –rickettsial –GME –SRME Common Causes of Diseases in Dogs

Copyright University of Florida 1997 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

Copyright University of Florida 1997 Central Vestibular Disease MRI of Brainstem Meningioma

Copyright University of Florida 1997 Central Vestibular Disease Primary Neoplasia OligodendrogliomaChoroid Plexus Papilloma

Copyright University of Florida 1997 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.

Copyright University of Florida 1997 Central Vestibular Disease Granulomatous Meningoencephalitis GME histologically causes multifocal meningoencephalitis due to proliferation of reticulohistiocytic cells. Lesions also show multinucleated giant cells.

Copyright University of Florida 1997 Neoplasia –meningiomas Central Vestibular Disease Infectious Diseases –FIP –FeLV –toxoplasmosis –cryptococcosis Trauma Metabolic –thiamine deficiency Toxicity –organophosphates Common Causes of Diseases in Cats

Copyright University of Florida 1997 Central Vestibular Disease Common Causes of Diseases in Cats Don’t Forget Thiamine Deficiency !!! Brainstem hemorrhages secondary to thiamine deficiency.

Copyright University of Florida 1997 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

Copyright University of Florida 1997 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

Copyright University of Florida 1997 Central Vestibular Disease In Horses…… think EPM!!!!! (Equine Protozoal Myelitis) Common Causes of Diseases in Horses

Copyright University of Florida 1997 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

Copyright University of Florida 1997 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

Copyright University of Florida 1997 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

Copyright University of Florida 1997 Central Vestibular Disease MRI of Cerebellar Meningioma

Copyright University of Florida 1997 Central Vestibular Disease Corticosteroids 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 !!!