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116 Cards in this Set

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Immune mediated polymyositis
-T-cell mediated (not humoral)
May be associated with SLE, other immune disorders, thymoma
Stiff, hunched, painful gait; exercise intolerance (can look very similar to MG)
+/- fever
Extreme pain on limb, paraspinal muscle palpation
DDx: other acute MU disease (rarely, a disseminated neospora (dog) or toxoplasma (cat) myositis/ radiculoneuritis infection can mimic)
Dx: CK, EMG, Muscle biopsy
Acute, focal or asymmetrical motor unit disorders
-infectious myositis/polyradiculoneuritis from neospora or txoplamosis
-traumatic neuropathy from brachial plexus avulsion
-masticatory muscle myositis from immune system of infection
Protozoal polyradiculoneuritis
-neospora in dogs or toxo in cats
-may see concurrent myositis in both
-Dx by serum titer (neospora) or CSF titer (toxo or neospora)
Neospora
-dog difinitive host and shed oocytes
-also dead end intermediate host if tissue infected with tachyzoites
-CNS can harbor bradyzoites
-can be transplacental transmission
-cattle are common intermediate host
-young pups: pneumonia, myocarditis, hepatitis, encephalaomyelitis, death
-pups 3wks to 6months: pelivic limb myositis/radiculitis followed by ascending paralysis
-non-suppurative polyradiculoneuritis and myelitis seen
-treat early otherwise too late
-rare in adult dogs
Neospora in adult dogs
-multifocal CNS signs common
-pelive limbs (LMN or UMN)
-fecal, urinary incontinence
-Ptosis, jaw paralysis, dysphagia, tonge paresis, facial paresis, horners
-cerebellar signs like seizures from necrotizing, non-supparative cerebellitis
-pyomyositis, dermatitis, necrotizing pancreastitis
Traumatic neuropathies
-usually one limb
-wallerian degeneration
brachial plexus injury most common
-EMG changes 8-10 days post injury
Brachial plexus avulsion
roots avulsed in one limb
-acute paralysis (C7, C8, T1, T2)
-anesthetic (no deep pain) below elbow
-loss of panniculus reflex and horners syndrome
Px poor but can wait if not mutilating
can include musculocutaneous nerve roots
Immune Masticatory Muscle Myositis (MMM)
-Autoimmune attack of type 2M muscle fibers (unique to masseter m.)
-mononuclear cell infultrate, necrosis
-acutely: muscle swelling, pain, fever
-Chronic: sever TM atrophy, fibrosis, trismus (lockjaw)
-Dx: type II M antibody titer, EMG,
-Rx: immunosippressive therapy; watch out for "pred head"
Diabetic Neuropathy
-associated with poorly regulated diabetes
-more common in cats than dogs
-motor nerve degeneration, esp. sciatic
-chronic course, sever atrophy
-plantagrade stance and decreased reflexes
-will progress to all four legs
-nerves to tail and urethra are spared
-exercise intolerance
-don't regain full function with diabetes control
Hypothyroid neuropathy
-slow axonal transport defect?
-many possible neuropathic sigsn
-paresis, loss of patellar reflex, decreased flexor reflex usually in pelvic limbs
-not usually plantigrade or palmagrade
-CN VII, VIII, X, IX
-can be reversed, great prognosis
Cushing's myopathy
-spontaneous or iatrogenic
-stiff gait, esp pelvic limbs
-protein catabolism, increase muscel membrane excitability
-muscle atrophy (type II) +/- hypertrophy
-EMG: Pseudomyotonia
Idiopathic Neuropathy of Aged Dogs
-common in large breed dogs, esp, Labs over 10yrs old
-slow, progressive rear to fore neuropathy
-femoral and distal sciatic affected most
-may see recurrent laryngeal nerve inv.
-muscle atrophy and paresis can be severe
-Dx: EMG, NCV, m/n biopsy
Paraneoplasic neuropathy
-molecular mimicry of tumor cells ag's
-demyelination moslty: some axonal degeneration
-usually mild to moderate signs
-insulinoma: need to sort out weakness due to hypoglycemia versus neuropathy
Inherited polyneuropathies
-breed specific (usually large breeds)
-affected at young age
-exercise intolerance, reflex loss, muscle atrophy, laryngeal paralysis
Muscular Dystrophy
-Dystrophin defect (poor excit/contraction coupling)
-common in goldens
-GRMD: X-linked, signs early in life
-stiff gait, dysphagia, trismus, muscle atrophy, joint instability
-pretty rare
Dx: CK, EMG, muscle biopsy (neg for dystrophin)
Peripheral nerve sheath tumor (PNST)
-grow distal to proximal up to the cord
-compresses the fibers along the way and causes lamenss and is slowly progressive
-follwed by paresis/atrophy
-DX: EMG, NCV, determines if cord invasion has occured or if its just disuse atrophy
congenital myotonia
-stiff and hypertrophied muscles
-facial contraction
-sawhorse type gait
-bunnyhop while walking
-warm out of stiffness with exercise so workout is good
-due to muscle membrane defect where muscle is hyper-excitable
Equine Degenerative Myeloencephalopathy
-symmetrical, noncompressive spinal cord lesion of young horses
- affects white and grey matter
-lesions most pronounced in spinocerebellar tracts
-demyelination associated with low Vit E levels
- progressive ataxia
Cervical vertebral malformation
- spine cord compression from stenosis (narrowing of vertebral canal) or dynamic (subluxation of vertebra during flexion or extension of neck)
- diffuse, bilaterally symmetrical vacuolation of ventral and lateral white columns
-ataxia in front and hind limbs
Equine protozoal myeloencephalitis
- from sarcocystis neurona or neospora hughesi
-assymetric proprioceptive deficits, multifocal lesion, muscel atrophy
- Dx with serology, CSF and antibody determination
Equine Herpes Virus 1
-respiratory disease which can affect CNS when it infects vscular endothelia
- causes vasculitis and thromboishemic necrosis of nervous tissue
Latency
-suspended animation of a virus (like herpes)
- lymph nodes or trigeminal ganglion
-horse can still infect others
- symptoms: urinary incontinence, fever, depressed, nasal discharge, ataxia
Equine Motor Neuron Disease
- acute onset of muscular trembling and weight loss
- find sever denervation atrophy and fibrosis when sacrocaudalis dorsalis muscle is biopsyed
-affects animals w/o access to green pasture
-low Vit E?
-Type 1 myofibers are affected
-lesions in ventral horn cells of spinal gray matter and nuclei of CN 5, 7, 12, and nucleus ambiguus (all get noninflammatory degeneration)
-pigment retinopathy
Carpine Arthritis Encephalitis
-retroviral disease that causes chronic arthritis or leukoencephalomyelitis
- signs: acute ataxia, weakness, paralysis, hyper or hypotonis, symmertical or not
- focal brown color of white matter in brain and spinal cord
- multifocal, mononuclear, perivascular, inflammatory leukoencephalomyelitis
Cerebrospinal Nematodiasis
-acute and progressive
-hind limb ataxia and weakness
- may be asymmetric
- CSF fluid has eosinophils
- general inflammation, mild, focal areas of malacia and necrosis with perivascular cuffing with lymphicyts and some eosinophils
Obturator nerve paralysis
- from ventral roots of L5-6
- courses medial to iliac shaft and hip, exits through obturator foramen
-stops motor impulses to adductor, pectineus, and gracilis
- does not cause paralysis by itself
Sciatic nerve paralysis
- from L6, S1-2, passes of ischiatic notch
- innervates hip extensors, flexors of stifle, and most of distal limb
- damage at sacroilliac region
- post injection neuropathy can occur in neonate and calves
- signs: dropped, extended stifle, flexed hock, knuckled foot, recumbent if bilateral
- calving paralysis: ambulatory patiens = favorable prognosis, recumbent = guarded
Sweeny in horses
-damage to suprascapular n. causes paralysis and neurogenic atrophy of infraspinatous and supraspinatus m
Radial nerve paralysis
- innervates triceps brachii and digital extensors
- damage = can't flex shoulder or extend limb
Laryngeal Hemiplegia
- progressive loss of large myelinated fibers in recurrent laryngeal nerve causesatrophy of cricoarytenoideus
- arytenoid cartilage becomes flaccid and hangs into airway
- causes roaring
Polyneuritis Equi
- retaining feces in rectum, dec tail and anal tone, dec sensation to peri-anal region
-progressive to inability to contract baldder and incoordination and loss of muscle mass
- unknown etiology but might be immune mediated
- thickening of epineural nerve roots of cauda equina
Botulism
- ingest toxin or spores (Shaker foals) or wound conamination
- mustrule out everything else
- toxin binds irreversibly to presynaptic nerve terminal, blocking release of Ach which causes flaccid paralysis
Nutritional Myodegeneration
-White muscle disease can be peracute or subacute
-myodegenerative disease of cardiac and skeletal muscle due to Vit E and/or Selenium deficiency
- seen in claves, lambs, kids, and foals
-white streaks in muscle due to coagulative necrosis of fibrosis
Recurrent exertional rhabdomyolysis
- seen in nervous, young female race horses
- expressedd when horses are subjected to training
- signs: stiff gait, pain, muscles of back and rump are hard and painful
- elevated CK, AST, and LDH
Clostridial Myonecrosis
2 forms
- rapid progressive depression = death
- post injection = hot swollen muscle with gas production and death
- spores enter wound
Cerebellar Signs
-ataxia, truncal sway, titubation (back and forward truncal sway)
-hypermetria
- loss of menace
-possible nystagmus (vertical downbeat)
- possible opisthotonus (upward ridgid extension of neck)
- Head intention tremor if diffuse disease
-head tilt if unilateral
Cerebellar disease
Neoplasia: CPP, meningioma, glioma, osteochondroma of skull
Inflammatory (Toxo, FIP, Cryptococcus)
Toxic: Flagyl, mycotoxins
Idiopathic: “Tremor syndrome”
Head trauma
Congenital/degenerative: Cyst, hypoplasia, abiotrophy, Lysosomal storage disease
Cerebellar Differential Diagnosis
generalized: degenerative, metabolic, toxic
lateralized/asymmetric: neoplastic, inflammatory, infectious, vascular, traumatic
Cerebellar hypoplasia
- truncal sway, tetra-ataxia, intention tremor
-not progressive
-from panleukopenia virus in utero
Cerebellar Abiotrophy
- inherited in dogs and cats
- normall cerebellum development then Purkinje cell degeneration
- signs after 8 wks old, slow progression
Lysosomal storage disease
- grey matter dysfunction
- white matte dysfunction in Niemann-Pick disease type A and Globoid cell leukodystrophy
- signs at 6-8 wks
- signs begin as cerebellar then multifocal
Neoplasia of cerebellum
- meningioma
-choroid plexus tumor
- gliomas
- medulloblastoma in young dogs
- multilobular osteochondroma (grow top down, can be surgically removed b/c slow growers
-osteosarcoma
Vascular disease of the Brain
-cerebellum, brainstem, and cerebrum
-peracute, signs lateralize
- ishemic infarction more common than hemorrhage
-caused by hypertension, hypercoagulable states, hyperviscosity, hyperthyroidism, vasculitis, tumor emboli, coagulopathy
Idiopathic tremor syndrome of dogs
Little White Dog Shakers
- acute onset in young adult small breed dogs
- generalized, head and body tremors, ocular tremors
- normal mentation and no recumbency
- hyperthermia secondary to muscle tremors
-treat with diazepam, corticosteroids
Cerebral Signs
- seizures
- behavior change if temporal or frontal affected
- contralateral visual deficit (PLR OK)
- contralateral CP deficit
- ipsilateral circling
- contralateral facial sensory deficit (nasal)
-good strength and coordination
Neoplasia
- progression is more gradual than GME or infectious disease
- CSF has inc protein with normal cell count
Meningioma
#1 brain tumor in dogs and cats
-invasive in dogs
- well demarcated in cats
Astrocytomas and oligodendrogliomas
- most common type in Brachycephalic breeds
- very invasive, poorly demarcated, intraxial
Other Forebrain Tumors
- choroid plexu papilloma (CPP) in ventricles and causes hydrocephalus
- Ependymoma (like CPP)
- Metastic tumors (HAS is very common)
-pituitary/hypothalamic tumors
Granulomatous Meningoencephalomyelitis (GME)
- immune mediated
- toy breeds 1-5 yr old
- signs progress rapidly
- anorexia, lethargy then CNS signs
-brainstem/ vestibular first then forebrain, then spinal cord, finally multifocal
Necrotizing encephalitis
pug dog encephalitis (also in Maltese and Yorkies)
-inflammatory forebrain encephalitis and immune mediated
-affects grey and white matter
-young dogs under 18 months
-acute and chronic forms
-seizures and forebrain sigsn predominate
Feline ishemic encephalopathy
- unilateral cerebrocortical infartion from vasospasm of middle cerebral artery
- idiopathic but sometimes from cuterebra
- young to middle aged cats
-peracute onset of cerebral signs (circling, behavior change, unilateral visual deficits, CP deficits, seizures)
Cerebrovascular disease in old dogs and cats
- more common in cats
- hypertension or hypercoag
- many idiopathic cases
- acute has edema
old, previous infarction: may see atrophy and midline shift
Craniocerebral Trauma
- multifocal brain signs
vascular compression/damage alters blood flos which causes endothelial injury, which causes vasogenic edema, which causes decreased tissue perfusion which causes cytotoxic edema which causes more vascular compression

can inc intracranial pressure and cause herniation which can cause bradycardia, hypertension, neurogenic pulmonary edema and death
transtentorial herniation
- decerebrate rigidity
- early miosis followed by fixed dialated pupils
- loss of Doll's eye
- respiratory dysrhythmias
foramen magnum hernation
- decerebellate rigidity
- ataxic respiration followed by complete apnea
treating brain trauma
- re-establish intravascular volume with hypertonic saline and hydroxyethyl stars followed by LRS
- elevate head and avoid jugular vein compression
- correct hypoventilation
- if <2 hr, methylprednisolone sodium succinate
- if elevated ICP, mannitol
-diazepam for short term seizure control and phenobarb, bromid for long term
Metabolic Encephalopathis
-secondary to toxins, hypoxia, deficient energy substrates, or electrolyte imbalance
- DIFFUSE cerebral signs
- if you correct extracranial problem, fix CNS problem
Hypoglycemia
- weakness, collpase, seizures in juvenile and old dogs
- old dogs get tremors, excitability, tachycardia, mydriasis
- pups show stupor, miosis, bradycardia, and hypothermia
- can be from insulinoma in old dogs with <50 mg/dl
Hepatic Encephalopathy
- portocaval shunt or acquired liver disease stops clearing endogenous toxins
- inc brain GABAergic tone
- aromatic amino acids causes formation of false neurotrasnmitters
- hypoglycemia
- dementia, head pressing, ataxia, seizures, intermittent blindness
- cats also have ptyalism and gagging
ascites, icterus and weight loss if acquired
Canine Cognitive Dysfunction Syndrome
- gradual cognitive decline after 12yrs old
- behavior problems ( dec spatial orientation, social interaction, loss of house training, altered sleep cycles
- prolonged course
status elipticus
- non-interrupted seizure lasting 20-30 min
seizure stages
aura: behavior change
Ictus: 30 sec to 2 min
Post-ictus: minutes to days of transient ataxia, weakness, dementia, disorientation, blindness, pacing, paralysis
kindling effect
- multiple epileptic foci develop over time if excitatiry activity is persistent and unchecked
Idiopathic epilepsy
primary epilepsy: genetic component
-generalized
-old inactive lesion but is a seizure focus
Seizure causes
Metabolic: portosystemic shunt, hypoglycemia, electrolyte imbalance, uremia
Toxic: lead, organophosphates, metronidazole, methylaxanthines, bromethalin, strychnine
Pseudo seizures
-tremor syndromes
-acute vestibular episodes
-drug induced
-myoclonus
-cataplexy, narcolepsy, syncope
Polioencephalomalacia
-depression, opisthotonus (star gazing), blindness, circling, strabismus/nystagmus, extensor rigidity, convulsions, recumbancy
- thiamine deficiency in ruminants
- cerebrocortical necrosis, laminar necrosis of grey matter
- treat with thiamin and good prognosis before animal is blind
Listeriosis
- vestibular signs
- CSF has elevated protein and inc cell count (>100) with inc neutrophils and monocytes and lymphocytes predominate
- microabscesses of neutrophils in medulla, perivascular cuffing with mononuclear cells and neutrophils
Scrapies (Spongiform encephalopathy)
- puritis,weight loss, ataxia
- slowly progressive, fatal, neurodegeneratve diseases
Bovine Spongiform encephalopathy
- excitement, aprehension, aggression, head tossing, weight loss, ataxia
- neuronal vacuolation and PrPsc accumulation
cerebellar abiotrophy
- arab foals
- degeneration and loss of Purkinji cells
Viral encephalitis
- depressed, fever
-CP deficits from cerebral problem
- horse is dead end host with low viremia accept for Venezuelan EE
UMN injury
- inc extensor tone in lateral recumbency
-normal reflexes maybe patellar hyperreflexia
-C1-C5: UMN tetraparesis/tetraplegia
-T3-L3: UMN paraparesis/paraplegia
-ataxia from UP lesion (C1-T2) causes ataxia worse in pelivc limb
LMN cord injury
-dec muscle tone
-reduced or absent reflexes
-muscle atrophy
C6 -T2 or L4-S2
spinothalamic tract
-lose deep pain if destroyed

- pain associated with extramedullary lesion
Intervertebral disk disease (IVDD)
Hansen type I: nucleus pulposis ruptures through annulus fibrosis into spinal canal, called disc extrusion, acute or subacute, progressive and common in chondrodystrophic breeds
Type II: slow protrusion of defenerated disc with slow progression, Propreceptive loss/paresis, and common in non-chondrodystrophic breeds, can become type I
Type III: from sever trauma causes nondegenerative nucleus puplosus into canal and is concussive
Chondroid metaplasia
nucleus pulposus degeneration with inc collagen and dec water and calcification
- usually type I in chondrodystrophic breeds
- usually between year 3 and 6
- most T11-L2, rest C2-C3
fibroid metaplasia
- Degeneration of nucleus pulposus (does not calcify) with secondary hypertrophy and hyperplasia of the dorsal annulus fibrosis
- Annular fibers partially rupture but do not allow nucleus to extrude
- See slow protrusion of disk into the canal (type II disk)
- any breed at T-L juntion or C5-C7
Ascending and descending Myelomalacia
- usually with UMN plegia, rarely from Type I IVD at T-L junction
- progressive 1-7 days
- descending signs: LMN to pelvic limbs/bladder
-ascending signs: panniculus loss, respiratory problems, thoracic limb involvment
Diskospondylitis
-infection of IVD space in young large breeds
-C6-C7, mid thoracic spine, L7-S1
- often multifocal
- fever, anorexia, weight loss, hyperesthesia, stilited gait, hunched posture, CP deficits/apresis/plegia
Degenerative Myelopathy
- slow degeneration of thoracolumbar white matter
- >5yr old large breed dogs like German shepherds, boxers, collies, Corgi
-insidious onset and progressive
T3-L3 signs
Spinal Neoplasia
-large breeds/older
-Extradural: vertebral body tumors and lymphosarcoma in cats,Compressive/longer course/ painful/often asymmetrical
-Intradural/extramedullary:Peripheral nerve sheath tumor, meningioma, neuroepithelioma, Compressive/longer course/ painful/often asymmetrical
- intramedullary:gliomas, Expansile/shorter course/non-painful/often symmetrical
Type I IVDD signs vs Type II IVDD
Type I
-acute/subacute
- thoracolumbar junction and C1-C5 most common
- pain
- CP, then UP, then UMN, then pain signs
-C6-T2 or L4-S3 may produce root signs
Type II
- slow onset/progression
- asymmetrical or symmetrical
-procprioceptive loss/paresis
-pain not as severe
Fibrocartilagenous emboli
- occludes spinal cord arterioles, arteris, venules, or veins
- ishcemic necrosis of cord parenchyma (white and gray matter)
-focal or multifocal
Fibrocartilagenous infarct
- large breed dogs 2-10 yrs, aslo mini schnauzer
-peracute with episodes of crying out when exercising followed by static progression
-anywhere in cord
-no spinal hyperpathia
-diagnosis of exclusion
- better prognosis if UMN and lateralized paresis than LMN or bilateral plegia
Cervial Vertebral Spondylomyelopathy
Wobbler syndrome
-malformation of vertebral bodies and/or secondary articular facet degeneration, annulus and ligamentous hypertrophy and type II disk protrusion
-aquired form in dobies and rotties with late onset located at C6-C7 or C5-C6, Type II IVDD, ligamentum flavum hypertrophy, articular facet degenerative joint disease
-congenital form in great danes, bony canal stenosis with malformed pedicles and articular facets, with synovial cysts, redudndant ligamentum flavum and fibrous tissue between dorsal arches
-signs: usually chronic onset and progression, symmetrical pelvic limb ataxia/paresis, choppy/stiff thoracic limb gait, dec elbow flexion (LMN to musculocutaneous/UMN to radial and ulnar), rare neck pain
Lumbosacral stenosis
-acquired in large breeds like german shepherds
-ventral and lateral spondylosis with nerve root compression
-Type II IVDD at L7-S1 with subluxation and ligamentum flavum hypertrophy
- signs: pain, difficulty rising, maybe root signs, flaccid tail, dec anal tone, urinary incontinence, caudal paresis, and exaggerated patellar reflex
Caudal Occipital Malformation syndrome (COMS)
Chiari-like syndrome in dogs
- toy breeds and Cavaliers
-age varies and congenital
- occipital/Foramen magnum malformation which causes secondary caudal fossa crowding, partial cerebellar herniation, +/- secondary hydrocephalus, and syringohydromelia
-dorsal funiculi and horns are most susceptible
Meningitis/Meningomyelitis
-inflammation of meninges +/- cord parenchyma
- multifocal to diffuse with cervical area severly affected
-idiopathic, viral, fungal, rickettsial, protozoal, parasitic, bacterial
-hematogenous in origin
-Meningitis: neck pain and rigidity, stiff, stilted gait, hunched posture, fever
- Myelitis: Cp deficits, ataxia, paresis
Feline Infectious Peritonitis
-corona virus which mutates from enteric coronavirus in cats under 3
- esp. multicat households
- immune complex vaculitis
-pyogranulomatous inflammatory response
Immune-mediated Meningitis/Meningomyelitis
- sterile, suppurative meningitis
- young, large breed dogs
- rare neuro deficitis
- Neurtrophilic pleocytosis in CSF
Granulomatous Meningoencephalomyelitis (GME)
-young toy breeds
- Granulomatous inflammation in CSF with lymphocytes, plasma cells and macrophages
Atlantoaxial Subluxation
- absent or hypoplastic dens
- ligaments fail to form properly
- instability predisposes to injury from even minor trauma
- signs: acute onset in young toy breeds, sever neck pain (C1-C2), mild or sever tetra-ataxia/tetraparesis or plegia (UMN), caudal brain stem involvment
Cranial Nerve origins
CN II: retina to supratentorial compartment
CN III and IV: Midbrain
CN V: Pons
CN VI - XII: Medulla
Idiopathic Trigeminal Neuritis
-dropped jaw syndrome
- acute onset, nonprogressive in adult dogs, resolves in 2-4 wks
- can't close mouth, hard time eating and drinking
- affects motor of V +/- horner's
Idiopathic facial paralysis
Bell's Palsy
- acute onset in adult dogs esp Cockers
- facial droop (CN VII), loss of palpebral and lip tone, usually unilateral
- guarded to fair prognosis
Idiopathic Horner's
- acute onset and non-progressive in dogs and cats
- post-ganglionic lesion but not well-defined
- phenylephrine test confirms 3rd order lesion by rapid dilation, slow dilation if 1st or 2nd order
- good prognosis
Idiopathic Optic Neuritis
- autoimmune inflammation of optic nerves
- acute onset of blindness, mydriasis if bilateral and absent PLR
-
Trigeminal Nerve Sheath Tumor
- unilateral in aged dogs
- slowly progressive atrophy of TM muscles followed by facial sensory loss
Cavernous Sinus Syndrome
- paired venous sinus on floor of cranial vault; assoviated with CNs III, IV, VI, opthalmic branch of V and sympathetic nerve to eye
- tumors, granulomas can invade
- causes an immovable eye with no PLR, retractor oculi or palpebral
- vision remains and absence of exophthalmos
Congenital Sensorineural deafness
- cochlear hair cells/spiral ganglion degenerate after birth, usually bilateral
- deafness is complete and permanent
Laryngeal paralysis
- caused by degeneration of recurrent laryngeal nerve bilaterally
- older, medium to large breed dogs, esp labs
- often associated with polyneuropathy
- gradual onset, exercise intolerance, inspiratory dyspnea, voice change, gagging
Vestibular signs
- head tilt, rolling, falling, circling, torticollis,
- limb muscle tone asymmetry
- nystagmus
Peripheral: resting, horizontal or rotary fast phase away from lesion
Central: positional or resting, may change direction, horizontal or rotary with fast ohase usually away from lesion, or vertical
- positional ventral strabismus
-if bilateral (peripheral): wide side-to-side head excursion swith truncal ataxia, no nystagmus, poor or abent doll's eye
Paradoxical vestibular disease
-central
-head tilt and nystagmus (fast towards lesion when it should be AWAY) on one side but everything else on the other (correct) side
-
Idiopathic Vestibular disease
- old dogs over 12 yrs
- peracute sever dysequilibrium
- head tilt, falling, rotary or horizontal nystagmus, no central signs
- improves after 1-4 days
Otitis Interna
secondary to otitis media/externa in dogs or polyp or ear mites in cats
- Signs: ataxia, nystagmus
- facial paralysis in 50% of dogs
- Horner's syndrome and facial paralysis common in cats
- acute or chronic and if acute doesn't improve without treatment
Inner/Middle Ear Neoplasia
- SCC, ceruminous gland adenocarcinoma, OSA, or neurofibroma
- slow progression
- VII and VIII signs
Hypothyroidism
- any breed, usually mid to old dogs
- signs may be acute and have peripheral and central features
- Dx with thyroid panel and slow to improve with supplements
Granulomatous Meningoencephalomyelitis (GME)
- immune mediated in toy breed 1-5 yrs old
- signs progress rapidly
- anorexia, lethargy followed by CNS signs first in brainstem, then forebrain, then spinal cord, then multifocal
- treat with immunosuppressives
FIP
- virulent mutant of enteric coronavirus
-macrophage is vehicle
-immune complexes/complement fixation, vasculitis, and sever pyogranulomatous reaction
- likes to get into 4th ventricle and cause pyogranulomatous inflammation and eat away at vestibular nuclei
- brainstem then forebrain then cord then cavernous sinus
- fever, anorexia, ocular signs in young cats in multi-cat househols
Cryptococcus
- inhalation via soil and causes granulomatous lesions
- rapid onset
- common cause of central vestibular signs (like vertical nystagmus) in large breed dogs, young and outdoorsy
- focal or multifocal
- antigen titer is very useful
- cats can get respiraotry and ocular while dogs get it in the brain
Canine Distemper
- dogs between 12 wks and 1 yr get immune reactionwith secondary CNS injury and common vestibulocerebellar signs
- likes periventricular white matter around 4th ventricle (home of vestibular nuclei)
vestibular neoplasia
- pontomedullary tumors cause central vestibular signs with gradual progression in comparison to GME or infection
-CSF has inc protein with normal cell count
Metronidazole toxicity
- given to combat diarrhea
- central vestibular signs and muscle weakeness, muscle tremors and nystagmus without head tilt
-good Px if stop flagyl and give Diazepam
Thiamine deficiency
- hemorrhage and necrosis of vestibular, oculomotor and other brainstem nuclei that have high aerobic metabolism
- signs: ataxia, nystagmus, torticollis, neck ventroflexion, myrdiasis (pupil dilation) no PLR