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Flashcards in Neurology 4 Deck (37):
1

What is seen with vestibular disease?

  • Peripheral or central
    • Head tilt
    • Circling and falling
    • Nystagmus
  • Most issues arise due to ear infections reaching middle ear
  • Brain itself is fine--info coming in is messed up
  • Signs will appear on the same side as the lesion

2

How do you differentiate between peripheral and central lesions?

  • Peripheral
    • No CP def/pares
    • No depression
    • Fac/Horner's? (runs through ear)
    • Nystagmus--horiz./rotational
      • Not variable with head movement
      • Eyes move together
  • Central
    • Tetra or hemiparesis
    • Depression (RAS)
    • Other cranial nerves
    • Nystagmus--vert too
      • Varies w/ head movement
      • Eyes move independently (dif. directions)

3

What are the 4 causes of peripheral brain conditions?

  1. Otitis media interna
  2. Feline idiopathic vestibular disease
  3. Canine geriatric vestibular disease
  4. Miscellaneous (congenital)

4

Otitis media-interna

  • Otoscopy/rads/CT
    • Red lining, tympanic membrane destroyed = infection entered inner ear
  • Antibiotics--systemic/topical
  • Infection in vestibular system = treat systemically as well
  • Clinical signs: scratching, shaking head

5

Feline idiopathic vestibular disease

Canine geriatric vestibular disease

Miscellaneous peripheral vestibular disease (congenital)

  • Feline
    • Lack of physio nystagmus
    • Tend to sway side to side
    • Fall over to one side
    • Recommend antihistamines--can increase blood supply in certain areas
  • Canine
    • Dogs seem completely normal on neuro/physical exam
    • Usually improve faster than cats
    • Cosmetic problems can remain
  • Congenital
    • Delayed development
      • GSD, beagle, dobes, siam., burm.
    • Signs by 3 m. and resolve over 3m.

6

Central peripheral diseases

  • Neoplasia (older animals)
  • Infectious
    • Viral (distemper)
    • Bacterial
    • Crypto, toxo/neosporum
  • Toxicity--aminoglycosides, metronidazole (dose important)
  • Hypothyroidism--can cause any peripheral neuropathy
  • GME
  • Thiamine deficiency (cats fed all-fish diets)
  • Trauma
  • Strokes

7

Paradoxical vestibular syndrome

  • Signs on OPPOSITE side of the lesion
  • Lack of inhibition on the vestibular nucleus on the side of the lesion in the cerebellum --> increased extensor muscle tone on that side of the body --> head tilt, circling, falling to opposite side (mimicking a vestibular lesion on the opposite side)
  • Animal has proprioceptive deficits on the side of the cerebellar lesion but vestibular signs on the opposite side 
  • Lesion in the cerebellum is on the opposite side to that indicated by the head tilt, falling, and slow phase of nystagmus; it is on the same side as indicated by the proprioceptive deficits

8

What does the cerebellum control? What are the common cerebellar signs (8)?

  • Cerebellum: fine-tune muscle activity/maintains equilibrium

Signs

  • Wide based stance
  • Truncal ataxia (sways)
  • Dystmetria--improper measuring (over-stepping)
  • Intention tremor--head bob (eating/drinking)
  • CP and reflexes ok
  • Signs with SC tract damage
  • Decerebellate rigidity--hind legs flex up tightly
  • Shiff-Sherrington syndrome (front legs extended out, back legs floppy)

9

What is associated with cerebellar hypoplasia in cats vs. dogs? What are the signs?

  • Cats--in utero: panleuk (parvo)
  • Dogs
    • Congenital hypo/aplasia
    • Parvo
  • Signs--6 weeks
    • Trunkal ataxia, dysmetria, tremor
    • Non-progressive + may compensate
    • Definitive diag: CT/MRI/necropsy

10

Give examples of the following:

Cerebellar abiotrophies

Cerebellar infections

Neoplasia

 

  • Abiotrophies
    • Early neuronal death--disrupted metabolism
    • Almost every dog breed but rare in cats
    • Signs progressive (old animals)
    • Diagnose at necropsy
  • Infections
    • Distemper/FIP + other neuro/syst signs
      • Cerebral, seizures, facial nerve paralysis, vestibular nerve signs
  • Neoplasia
    • Primary--medullablastomas, gliomas
    • Secondary--wide variety

11

Shaker dog disease--tell me all the things, including differential diagnoses

  • Maltese-- < 15kg
  • Tremors head + limbs
  • Worse with exercise/excitement
  • Not when asleep
  • Prednisone--2mg/kg
    • Respond very well, taper off
  • DD's
    • Fear
    • Hypomyelination 
      • Born w/o myelin--> whole body trembling
    • Tremorgens (toxins prod. by mold)
    • Toxins
    • Orthostatic tremor (large breed dogs)
    • Head bobbing
    • Old dog hind limb tremors

12

Scotty cramp

 

  • Serotonin deficiency (brain) +/- PG abnormality 
  • Animal folds up in ball
  • Stiffen with exercise
  • Tryptophan/serotonin-increasing drugs effective
  • Prozac--selective serotonin reuptake inhibitor 

13

Episodic falling

  • CKC's--hypertonicity with exercise
  • Clonazepam and time

14

Hydrocephalus (general)

  • Dilated ventricles of brain
  • Dec. CSF flow--cong, neoplasia, subarach. hem., meningitis
  • Inc. secretion (tumor choroid plexus) 
  • Inc. pressure --> atrophy of surrounding cells --> dec. function

15

Signs of hydrocephaly?

  • Most congenital--toys + brachycephalics
  • Signs at weeks/months--progressive
    • Mental attitude--depressed/excited
    • Learning, seizures, blind, deaf
    • Tetraparesis--clumsy, uncoordinated
    • Strabismus--lateral divergent
  • Skull domed, fontanel's open often
  • Acquired--signs of cause--FIP, toxo

16

How do you diagnose hydrocephalus? What is the treatment?

  • CT/MRI imaging
  • Ultrasound if fontanelles open
  • CSF--herniation
    • Do NOT collect CSF--> brainstem herniation from decreased pressure
  • Treatment
    • Shunts: CSF ---> abdominal/jug
      • Tube runs from ventricles to abdomen
      • When brain gets to full, empties into tube --> abdomen --> reabsorbed
    • Dex--temp, dec. signs
    • Pred, diuretics, promethesol (temporary)
    • Surgery ASAP--control pressure and dec. possible damage to ventricles

17

Brain neoplasia

  • Primary--gliomas (20%) and meningiomas (45%--cats)
  • Secondary--range of mets
    • HAs, lymph (cats), carcino
  • Older dogs (> 7yr) and cats (8-10)
  • Signs depend on site/rate
    • Cortex = behavior, seizures, circling (af), vision/nasal (con)
    • Stem = depression, paresis, cranial nerve abnormalities; slow, no seizures
  • Diagnosis--imaging, CSF (biopsy)

18

Treatment of brain neoplasias? Prognosis?

  • Benign superficial (meningiomas)--surgery
    • Remove skull, scoop tumor out
  • Dexamethazone/mannitol to reduce edema
    • Take away inflammation
    • Temporarily dec. tumor
  • Radiation?
  • Prognosis--metastasize; nothing you can really do
    • Meningiomas 4m-1-3y
    • Gliomas (secondaries) 4-12m

19

Brain herniation

  • Space-occupying lesion
  • Decrease CSF outflow --> increasing intracranial pressure
  • Falx cerebri or tentorium cerebelli
  • Most severe when cerebellum pushed out of foramen magnum
    • Rapidly fatal (compress brainstem)

20

What are the signs of a brain herniation?

  • Underlying cause--CSF tap/volatile anesth.
  • Increased ICP:
    • Depression
    • Poor PLRs
    • Breathing abnormalities (cyclic)
    • Cranial nerve deficits
  • Herniation--acute, rapidly prog. tetraparesis (motor tract compression)
  • Coma
  • Respiratory arrest
  • Always look at ICP before anesthetizing animal w/ brain problems--can give steroids, block CSF prod.-->reduce swelling/pressure, THEN perform CSF tap after

21

Diagnosis and treatment of brain herniation?

  • Diagnosis
    • Clinical suspicion 
    • MRI
    • Necropsy diagnosis
  • Treatment
    • Remove underlying cause
    • Dex may reduce edema + herniation
    • Manitol

22

Cranial trauma

  • Increased in cats
  • Dysfunction with:
    • Concussion
      • No morphological lesion 
      • Transient unconsciousness
      • Confusion/ataxia for a few days
    • Contusion = focal hemorrhage + edema
      • More confused and ataxic
      • CP deficits
      • Unconscious longer
    • More severe hemorrhage
      • Meningeal (extracerebral) = cortex
        • Develop slowly, can remove
      • Brain vessels (intracerebral) = stem

23

What are the signs of cranial trauma?

Depends on site

  • Cortex
    • Decreased consciousness
    • Normal cranial nerves (menace + nostril stimulation)
    • Seizures
    • Contralateral hemiparesis
  • Brain stem
    • Decreased consciousness
    • Abnormal cranial nerves
    • Irregular respiration
    • Bradycardia
    • Abnormal PLRs--mydriasis
    • UMN signs--extensor rigidity 

24

What occurs when an animal is decerebrate?

  • Unconscious
  • Forelimbs extended
  • Hindlimbs extended

25

What is the difference between primary and secondary damage with cranial trauma?

  • Primary
    • Primary damage to parenchyma and vessels from the trauma
    • No control over this
  • Secondary
    • Abnormal metabolic processes
    • Leads to decreased perfusion, increased ICP
    • Can be treated--make sure no complications arise

26

How do you diagnose cranial trauma?

  • History + physical + neuro exam
    • Cranial nerves
    • Pupils
    • Respiration
  • Stabilize, then take skull rads
  • CRI/MRI--intra vs. extracerebral

27

How do you treat cranial trauma?

  • Shock/life-threatening injuries = ABC (airways, breathing, cardiovascular)
    • Hetastarch/hypertonic--BP/ICP
  • Increased PaCO2 + decreased PO2 --vasodilation - increased ICP
  • Body < 30o -- venous + CSF outflow
  • Soluble corticosteroids?
  • Deteriorating/severe--mannitol
    • MUST wait til animal is stabilized 
  • Seizures--diazepam (best/safest), phenobarb, propofol (put animal to sleep--> brain works less)
  • Hematomas/wounds/deep fractures--surgery--prop + isoflurane

28

What are the different prognoses of cranial trauma?

  • Response to medical therapy in 4-6hrs--promising prognosis
  • Coma > 2d = grave prognosis
  • Irregular respiration + unresponsive bilateral mydriasis = poor prognosis
  • Euth--intractable seizures/resp failure
  • Coma score--monitoring and prognosis
    • Motor activity
    • Brain stem reflexes
    • Consciousness

29

Narcolepsy--all the things

  • Sudden attacks of sleep +/- cataplexy
  • Excitement
  • Can awaken
  • Classical sleep EEG
    • Autonomic imbalances
    • Orexin (sleep neurotransmitter), hypocretins
  • Amphetamines (Ritalin)--decrease excitement receptors 
  • Antidepress--imipramine

30

What are some conditions with multiple neurological signs?

  • Rabies
  • Distemper
  • Parvo
  • Neospora
  • Herpes
  • Toxo
  • FIV encephalitis

30% neurotrophic, behavior +/- focal

31

Feline ischemic encephalopathy

  • Acute ischemic necrosis--Cuterebra migration
    • Accidental migration to brain
  • Non-progressive signs of behavior changes, seizures, unilateral blindness, circling, hemiparesis, head tilt
  • Usually recover, seizures may persist
  • Steroids not a good idea--can get anaphylactic rxn when larvae die

32

Granulomatous meningoencephalomyelitis

  • Inflammatory--cell-mediated
  • Middle aged, small breeds
  • Focal form--chronic
    • Resembles tumor--only 1 part of brain, slow-growing
  • Disseminated form--acute
    • Dangerous--can die w/in hours after appearing normal
  • Diagnosis--CSF, MRI (25% normal), histopathology
  • No treatment--1w-2m; 1 year seizures usually
  • Prednisone--1w-3m (doesn't respond to pred)
  • Cytosine arabinoside (anti-metabolism), ciclosporin, procarbazine (anti-neoplastic agent)--1yr

33

What are the signs in the following?

FIP

FeLV

Feline polioencephalomyelitis

Bacterial meningioencephalitis

  • FIP
    • Dry form--CNS + eye signs
  • FeLV
    • Degenerative myelopathy
  • Feline polioencephalomyelitis ("Staggering disease")
    • Staggers, circles, nystagmus, paresis, psychoseizures, BORNA
  • Bacterial meingioencephalitis
    • Rare--S. intermedius--hematogenous, direct spread
    • Fever, neck pain + rigidity, seizures
    • Diagnosis--CSF--pleocytosis, protein
    • Poor prognosis
    • Antibiotics--chloro? 6 weeks

34

Steroid-responsive meningitis-arteritis

  • Cervical area--meningeal arteritis, hemorrhage, and inflammation
  • Young dogs < 2yrs--Beagles, boxers, Bernese, etc.
  • Acute onset, fever, neck pain--recurs/chronic
  • Peripheral neutrophilia + CSF pleocytosis + IgA
    • IgA levels raised in steroid-responsive meningitis (relatively level in bacterial meningitis)
  • Immunosuppressive prednisone 
    • Should only be stopped 6 months after all findings are normal 

35

Dysautonomia

  • Degeneration of sym + para ganglia
    • C. botulinum
      • Extremely potent
      • Antibodies against organism suggests animal has it growing inside them 
  • Autonomic signs
    • Parasympathetic dysfunction
    • 3rd eyelid prolapse
  • 30% survive
  • Anorexia, wt. loss, obtundation

36

What are the signs of dysautonomia in dogs?

  • Dysuria
  • Distended bladder
  • Mydriasis
  • Absent PLR
  • Dry mm
  • Weight loss
  • Dec. tears
  • Dec. anal reflex
  • Dec. appetite
  • Vomit/regurg
  • 70% mortality

37

What are the 3 types of deafness?

  1. Conductive--from continuous infections
  2. Central--rare
  3. Sensorineural--cochlear congenital 
    • Congenital
      • Pigment
      • Dalmations
      • Cats white coat + blue eyes
    • Acquired 
      • Noise, toxic--antibiotics
      • Antibiotics, ceruminolytics, antiseptics (chlorhex 0.2%)
    • Presbycusis
    • Diagnosis--BAEP, euth/neuter--hearing aids?