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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 • Peripheral V.D. • Rotatory • Vertical • Central V.D. • Positional 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. 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. 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. 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 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. Copyright University of Florida 1997 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. Copyright University of Florida 1997 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 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 • Other Infections – Fungal • Prognosis Guarded to Poor • Prognosis is Poor Copyright University of Florida 1997 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. 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 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 Copyright University of Florida 1997 Nystagmus • Horizontal – Fast-Phase away from head tilt – Fast Phase toward head tilt • Peripheral V.D. • Rotatory • Vertical • Central V.D. • Positional Copyright University of Florida 1997 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 Copyright University of Florida 1997 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. Copyright University of Florida 1997 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. Copyright University of Florida 1997 Central Vestibular Disease Common Causes of Diseases in Dogs • Inflammatory or Infectious Diseases – canine distemper – toxoplasmosis and neosporiosis – fungal – rickettsial – GME – SRME Copyright University of Florida 1997 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 Copyright University of Florida 1997 Central Vestibular Disease MRI of Brainstem Meningioma Copyright University of Florida 1997 Central Vestibular Disease Primary Neoplasia Oligodendroglioma Choroid Plexus Papilloma Copyright University of Florida 1997 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. 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 Central Vestibular Disease Common Causes of Diseases in Cats • Infectious Diseases – – – – FIP FeLV toxoplasmosis cryptococcosis • Neoplasia – meningiomas • Trauma • Metabolic – thiamine deficiency • Toxicity – organophosphates Copyright University of Florida 1997 Central Vestibular Disease Common Causes of Diseases in Cats Brainstem hemorrhages secondary to thiamine deficiency. Don’t Forget Thiamine Deficiency !!! Copyright University of Florida 1997 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 Copyright University of Florida 1997 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. Copyright University of Florida 1997 Central Vestibular Disease Common Causes of Diseases in Horses In Horses…… think EPM!!!!! (Equine Protozoal Myelitis) Copyright University of Florida 1997 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. Copyright University of Florida 1997 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 Copyright University of Florida 1997 Central Vestibular Disease MRI of Cerebellar Meningioma Copyright University of Florida 1997 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