Cerebellar and vestibular disease - problem solving - neurology videos Flashcards
How easy is it to differentiate ataxia and weakness in horses?
very difficult: weakness in horses short shuffle steps, knuckling over and toe dragging but can be seen with ataxia too. For ataxia look for hypermetria.
How common are cerebellar diseases in horses?
rare
Which regions do you test for facial sensation?
- palpebral
- in ear
- nasal planum
- upper lip
How do dogs and cats differ in the lesions that cause them to hop? Versus hrse?
In cats, you need quite large lesions to cause hopping defects unlike dogs where these defects are more obvious with smaller lesions. Hopping in horse – testing strength, in small animals you are looking more for proprioceptive dysfunction.
Which species is usually tested for extensor postural thrust most commonly?
cats - d/t size
How do you detect a headache in dogs/ cats?
you press head down and press on area where you would take CSF. If headache, this makes pain worse.
What might cause a feline CSF tap to have increased protein, increased TNCC and neutrophilic pleocytosis?
• VIRAL o Coronavirus (FIP) • PROTOZOAL o Toxoplasma • BACTERIAL • FUNGAL o Cryptococcus o Phaeohyphomycosis o Hyalohyphomycosis
How do you test for Toxoplasma gondii?
- ELISA
- serology
- PCR
How can you test for FIP coronavirus?
test for abnormal spike protein – new more specific test (for mutated virus which causes FIP versus the normal coronavirus which doesn’t cause FIP)
CS - FIP
- other neuro signs common (seizure, cerebellar signs)
- systemic and ocular involvement
Pathogenesis - FIP
•
Dx - FIP
- FCoV Ab titre > 128-
- Albumin: Globulin (A:G) ration raised to globulin to over 40g/L. Ratio of >0.8 rule out FIP, if between 0.4-0.84 consider other parameter
- Acid glycoprotein level (AGP): this is an APP, usually >1500 in FIP
- Haematology
- MRI or CT imaging
- CSF (+PCR)
Haematology findings - FIP
Classically lymphopaenia, a non-regenerative anaemia with a haematocrit of 30% or less and often a neutrophilia with a shift to the left.
MRI or CT imaging of FIP
meningeal and ependymal enhancement
CSF - FIP
neutrophilic pleocytosis
Tx - FIP
SUPPORTIVE ONLY:
- steroids
- IFN
- prognosis: tx only offers a short prolongation of life
If a horse likes having all 4 feet on the ground, does this suggest it is most likely ataxic or weak?
weak
If a horse doesn’t look in the direction of being turned, what does it suggest?
the horse doesn’t like turning
Are you more likely to get a nystagmus with an acute or chronic onset of brainstem problem?
acute - more likely to have nystagmus
How common is it to have a vascular lesion causing an acute onset neuro disease in horses?
Rare
Where does facial nn exit skull?
stylomastoid foramen
Which CN controls soft palate?
CN 9
Tx - equine head trauma causing haematoma in GP
- steroids contraindicated
- drugs to limit oedema formation (hypertonic saline much more economical in horses than mannitol)
- NSAIDs
- euthanasia (realistic)
Which skull bones are most commonly fractured in head trauma in horses? 2
Basisphenoid and basioccipital bone
Prognosis - equine CNS trauma
- Most horses that are recumbent for more than 24-48 hours don’t get up.
- Deal with things 24 hours at a time
Other names for precubital ulcers
pressure ulcers/ pressure sores
Different types of meningoencephalitis in dogs
- GME - granulomatous meningoencephalomyelitis
- NME - necrotising meningoencephalomyelitis
- NLE = necrotising leukoencephalomyelitis
- Unknown aetiology (MUA)
Dx - meningoencephalitis
- CSF
- CT or MRI
- R/o infectious diseases
Signalment - GME
any breed (especially toy and terriers), mean 5 yo, female predisposition in many studies
3 main forms - GME
o Multifocal or disseminated CNS signs
o Focal CNS signs
o Ocular form: optic nerve, can progress into disseminated or focal forms or can be seen with disseminated form
3 main forms - GME
o Multifocal or disseminated CNS signs
o Focal CNS signs
o Ocular form: optic nerve, can progress into disseminated or focal forms or can be seen with disseminated form
Tx - GEM
• Various tx options
o initial symptomatic tx
corticosteroids (prednisolone) until remission of signs/ stabilisation (wks) then slowly decrease dose
radiation therapy (selected patient)
ocular form - retrobulbar corticosteroids + oral steroid therapy
o Monitoring
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Signalment - NME
• Signalment: 6months - 7 years, mean age 19 months (range 8-34), fawn coloured females
Clinical course - NME
o few days to months before presentation o FOREBRAIN (cerebrum +/- thalamus) o MST = 23 days (range 3-85 months)
Signalment - NLE
1-10 years (mean age 4.5 years), no sex predilection
• Yorkshire terriers and other breeds
Clinical course - NLE
o highly variable, usually chronic progressive
o FOREBRAIN and BRAINSTEM
o altered mentation, seizures, central blindness, central vestibular signs
Forms - Canine Distemper Encephalitis (CDE)
o ACUTE: commonest, associated with URT/ GIT signs, ‘myoclonus - rhythmical contractions
o CHRONIC: chronic slowly progressive signs
o Old dog encephalitis
What are the different forms of rabies?
• FURIOUS FORM: o more common in cats o aggression, cerebral signs • DUMB/ PARALYTIC FORM: o mainly brainstem signs o dropped jaw o swallowing difficulties
Dx - toxoplasmosis/ neosporosis - 4
o IgG/ IgM serology
o MRI or CT
o CSF - mixed cell pleocytosis
o PCR on CSF
Tx - toxoplasmosis/ neosporosis
o TMPS
o Clindamycin
o for 8-12 weeks
Clinical presentation - Angiostrongylus coagulopathy
- mainly young dogs
- coughing
- dyspnoea (interstitial pneumonia)
- SC swelling or haemorrhage
- Coagulopathies, thrombocytopaenia
- Sudden death (acute heart failure)
- neurological and ocular signs
Ddx - head tilt in horses
- Trauma - e.g. baisphenoid bone fracture
- Idiopathic
- Temporohyoid osteoarthropathy
- Otitis interna/ media (rare)
Temporohyoid osteoarthropathy - aetiology
- Chronic otitis media/ interna: infection spreads to tympanohyoid joint and stylohyoid bone. The inflammatory process fuses the tympanohyoid joint.
- Degenerative changes over time then mechanical forces of mm contraction during swallowing or mastication induce a pathologic fracture that extends into the pertrous temporal bone
Tx - temporohyoid osteopathy
- Cefquinome/ TMPS
- NSAIDs
- Ceratohyoid bone removal
Prognosis - temporohyoid osteoarthropathy
- of 33 horses, 67% survival
- 95% athletic use
- 60% residual facial deficits
- 55% residual vestibular deificts
- maximal recovery may take a year or more
- risk of repeated episodes
Why is thiamine important?
Thiamine (vit B1) is important for oxidative metabolism of carbohydrates
4 reasons for thiamine deficiency (small animals)
o reduced uptake: d/t anorexia r vomiting, deficiency in food d/t overheating, thiaminase activity of fish or cereals, sulphur dioxide
o Decreased absorption (diarrhoea)
o Altered utilisation (hepatopathy)
o Increased consumption (fever, infection, increased diuresis)
CS - thiamine deficiency (SA)
o anorexia and lethargy
o vestibular signs
o pupilllary dilation with reduced or absent PLR
o seizures
o cats often also show head ventroflexion
Dx - thiamine deficiency (SA) - 3
o MRI bilateral symmetrical lesion in brainstem nuclei
o Transketolase activity in erythrocytes
o increase in certain urinary organic acids
Tx - thiamine deficiency - SA
o Thiamine supplement IM or SC q24 hours until oral supplementation possible
