Neuro Flashcards
(181 cards)
1
Q
What are the CS of meningitis in cattle/ sheep?
A
No menace, dull, depressed then progressing to hyperaesthetic and opisthotonic
2
Q
Describe the causes OM in cattle
A
- Ascending infection down the eustachian tube following pneumonia
- Haematogenous via navel/ joint ill
3
Q
What is CCN, whats the CS and how do you treat it?
A
-Cerebrocortical necrosis- cause dby Vit B1 deficiency. CS: dull, blind, no menace, star gazing. Tx= IV Thiamine hydrochloride
4
Q
What are the different diseases of sheep and cattle that can cause a head tilt?
A
Sheep= Listeria, Scrapie, CCN, GID, Vestibular disease Cattle= Listeria, BSE, Cerebellar hypoplasia, Bacterial meningitis, brain abscess, OM/ vestibular dx,
5
Q
Briefly describe listeriosis
A
- Caused by poor quality silage with L.monocytogenes. If pH over 5.5. it can grow
- Head tilt, paralysis of infected side, circling, excess salivation
- Tx= penicillins e.g. amppicillin
6
Q
Briefly describe MCF (CS, diagnosis, tx)
A
(Caused by OHV2)
CS- Marked pyrexia (41), mucopurulent nasal discharge, buccal mucosa necrosis, tachycardia
Diagnosis- PCR viral Ag, Hx of contact with lambing sheep, PM findings (GIT, UT and resp tract lesions. Enlarged haemorrhagic LNs)
No Treatment
7
Q
Briefly describe TEME
A
- Thromboembolic meningoencephalitis
- Caused by Histophilus (severe bactereamia)
- CS: ataxia, proprioceptive deficits, pyrexia
- Diagnosis: CS and CSF culture
- Tx: ABs (oxytetracycline or penicillin) and NSAIDs.
8
Q
Briefly describe lead poisoning
A
- CS; ataxia, tonic clonic convulsions, head pressing, bruxism, muscle twitches
- Tx: IV chelating agent e.g. Ca-EDTA. Oral agents e.g. Magnesium sulphate and supportive drugs -xylazine for sedation
- If diagnosed must report to APHA
9
Q
Briefly describe OP poisoning
A
- Blocks cholinesterases so ACh persists
- CS: Excess salivation, nasal discharge, muscel twitches, dyspnoea, CNS depression
- Tx: Atropine sulphate slowly IV.
10
Q
How can ionophore posioning occur?
A
Cocciostat supplementation- monensin is both a growth promoter and coccidiostat
11
Q
What disease can be casued by horsetail?
A
CCN (cerebrocortical necrosis)
12
Q
What infectious diseases in sheep can cause neuro signs?
A
Border dx (viral)
Meningitis (bacterial)
GID (parasitic)
13
Q
Where in the CNS will you find listeriosis lesions?
A
Pontomedullary
14
Q
Which metabolic diseases cause neuro signs in sheep?
A
Hypocalcaemia, preg toxaemia, hypomagnasaemia
15
Q
What are the d/ds of Maedi Visna?
A
Listeriosis
Abherrant larval migration
Spinal mass/ abscess
Scrapie
16
Q
What type of flock is affected by Maedi Visna?
A
Upland/ hill
17
Q
Briefly describe swayback in sheep
A
Copper deficiency
Diagnosis: histopath brain/ SC looking for cavitation of white matter (in congenital cases) In delayed cases looking for demyelination in SC.
-Chelated copper inj
18
Q
Briefly describe GID
A
-Coenuris cerebralis (larval Taenia multiceps)
Acute- 10 days after turn out onto heavy dog poo pasture
Chronic- 2-6mnths after larval hatching/migration
ZOONOTIC
Tx- usually euthanasia
19
Q
What causes oxalate poisoning in sheep?
A
Beet crop leaves
20
Q
Briefly describe idiopathic vestibular dx
A
- Unlikely to be idiopathic if its peripheral vestibular dx
- Diagnose by advanced images, should look normal in idiopathic cases.
- D/d otitis externa/ media
- AKA doggy stroke
21
Q
What helps you locate a vestibular lesion- central or peripheral?
A
Central= if it has head tilt, ataxia, nystagmus, proprioception, paresis, facial paralysis, horners, cranial nerve deficites
Peipheral- will not have paresis and the only cranial nerve deficits it may have are horners or facial paralysis.
22
Q
On CT how do you distinguish between a fibrocartilagenous embolism or just concussion of SC?
A
-Both cause hyperintensity however on the transverse image concussion would affect all of SC whereas fibro only affects a region.
23
Q
Briefly describe fibrocartilagenous smbolisms
A
Sudden onset Non painful Non progressive Prognosis is dependant on location Tx= cage rest
24
Q
Briefly decsribe ischaemic myelopathy
A
- AKA saddle thrombus
- Common in cats v rare in dogs
- D/d for FCE
- Acute onset, painful
- Painful, pulseless HLs with paresis
- Thromboembolic dx of descending aorta
- Secondary to heart disease
- Dx: clinical exam, ultrasound, cardiac exam
25
Briefly describe ischaemic encephalopathy
- Secondary - post anaethetic in cats OR primary disease that occurs spontaneously in cats
- Present with unconsciousness
- Hypoxic episodes cause transient blindness
26
What is a common cause for spontaneous haemorrhage anywhere in nervous system?
Angiostrongylus
27
In a pre purchase vetting exam what are you looking for regarding eyes?
- Evidence of congenital or hereditory ocular dx
- Diseases that may lead to decreased vision
- Any evidence of uveitis
- Tumours (SCC)
28
What are the common causes of hepatic encepalopathy?
Plant poisoning or eating fertiliser
| CS= aggression, ataxia, seizures, blindness) (Diag= blood ammonia concentration) (d/d= staggers or nervous ketosis
29
Briefly explain hypomagnesaemia
- Usually from being on rich pasture with too much fert. Competing K, Na
- Causes hypocalcaemia due to inhibition of PTH
- CS: tremors, incr HR, blindness, aggression, nystagmus
- D/d: Pb toxicity, Rabies, Nervous ketosis, BSE
- Diagnosis: bloods (1.7-3norm)
- Tx: 400ml Ca Mg bottle IV and s/c mg salts
30
What are the clinical signs and d/ds of hypoglycaemia in farm animals?
AKA nervous ketosis
-Muscle weakness
-Tremor
-Head pressing
-Compulsive licking
-Ataxia
-Blindness
Cattle- rabies, hypoMg, BSE, Pb tox
Sheep- listeriosis, cerebral abscess, rabies
31
What are the 3 routes of entry to infection to the nervous system
1) Bacteraemia- penetration through BBB
2) Bacterial embolism in brain
3) direct extension of otitis interna / sinusitis
32
How can bacteria damage the nervous system?
- Replicate in cells
- Produce toxins
- Cross BBB
- Induce immune response
33
How do you diagnose a CNS infection?
- CSF tap- coloured indicates high protein, low glucose suggests meningitis, SG increases due to high proteins
- In viral meningitis the lymphocyte count increases BUT not in bacterial
34
What common daily procedure can cause discospondylitis?
Dentals- the bacteria on the teeth enter blood stream causing bacteraemia
35
Describe why bacteria tends to lodge near the SC
- Narrow loop of blood vessel near the vertebrae= blood slows and turbulence increases= microbes build up in efferent loop resulting in an inflammatory response and formation of a microthrombus
- Not many phagocytes in the loop which helps bacteria.
36
What is the pathophysiology of discospondylitis?
Causes bone destruction due to MMPs and leads to ischaemia
37
What agents commonly cause discospondylitis?
Staphylococcus
Pasteurella multicode
Actinomyces
Fungal = aspergillus which is usually walled off caused granulomatous tissue
38
What disease is unusual in that its a nervous system infection that leads to encephalitis?
Listeria
39
How do you diagnose listeria?
Histology= perivascular cuffing/ microabscesses
CSF
Blood smears- gram + rods
(Tx= penicillins e.g. ampicillin)
40
Which toxins affect the CNS?
Clostridium
- Botulinum (ingested)
- Tetanus
Botulism causes flaccid paralysis whereas tetanus causes spastic paralysis
41
How do you treat C. botulinum and C.tetani?
```
Botulinum= guanidine hydrochloride (enhance NT release)
Tetanus= large dose penicullin IM
```
42
Describe the guidelines for ataxia grading
```
0-normal
1-hard to see
2-hard but seen at walk
3- easily seen at walk
4- very ataxic
5-recumbent
```
43
Briefly describe EDM (clinical signs, d/d, diagnosis, tx)
Selenium/ Vit E deficiency?
CS = tetraparesis but HL worse, <2yo
Diagnosis= x-rays should look normal (cf CVM), Diagnosis on PM (neuroaxonal degen brainstem and SC). No tx.
44
Briefly describe CVM
Cervical vertebral malformation (wobblers). HL worse than FL, bilat ataxia. Toe drag= flexor weakness, weak tail pull = extensor weakness
2 types: juvenile <2 but O might not spot till 2+ and in work. Or adult osteoarthritis (can also be caused by trauma)
Xray of C5/C6 look at articular facet joints.
Look at saggital diameter and ratios= if ratio >50% its wobblers.
Myelography IF doing surgery.
Tx= steroids intra atricular. NSAIDs, exercise/ nutrient restriction, surgical stabilisation.
45
Briefly describe equine herpes infections
EHV 1/4. 1= abortion/ weak foals/ resp. 4= resp dx.
Both cause myeloencephalopathy.
EH1= outbreaks. Ataxia, recumbency, (dog sit) due to HL ataxia, decr tail tone.
Transmitted by inhalation. can have latency period
Diagnose= serology?
Tx- IV dexmethasone, BID, acyclovir (anti inflam), dimethylsulphoxide (free rad scavenger)
46
What causes rye grass staggers?
Mycotoxin
47
What equine neuro disease is caused by opposums?
Equine protozoal myeloencephalitis
48
Describe an example of viral encephalitidies in the horse
West Nile- reservoir= birds. NFD. Affects caudal SC= ataxia, weakness, hyperaesthesia
Diag= Ag in CSF or blood
Tx= nursing and anti-inflams
49
Briefly explain PAS
Perinatal asphyxia syndrome- normal for first 12-24 hours. Unobserved delivery/ red beg. No suck, recumbent, head press, dysphagia. Tx= diazepam and support.
50
Which horse breeds are prone to collapse narcolepsy?
Minis, shetlands, apaloosas, Suffolks
51
How do you treat head trauma in a horse?
Osmotic diuretics e.g. dimethylsulphoxide or mannitol to reduce ICP
52
Whats different between collapse narcolepsy and idiopathic hypersomnia?
In hypersomnia they don't get REM.
53
Describe polyneuritis equi
Immune mediated affects cauda equina (demyelination), results in incontinence.
54
Briefly describe equine motor neuron dx
-Spontaneous, assoc vit E/ selenium deficiency(like EDM), NOT ATAXIC, low head carriage, weight loss, polyphagic,elephant on a barrel, excessive sweating
Diagnosis= Black teeth, incr creatinine kinase, retinal exam looking for mosaic pattern on fundus (lipofuscin deposits)
55
What is idiopathic headshaking?
Disease seen in horses, repeated vertical movements. Caused by CNS stimulation. Tx= cyproheptidine.
56
Briefly explain equine grass sickness
Though to be linked to pasture toxin (botulinum) so often more than one case from a paddock
-Mainly GI nervous system signs e.g. ileus
Vagal tone loss= tachycardia
Glossopharyngeal nerve= dysphagia
Nasogastic reflux
Rhinitis sicca
Seasonal bias: april- july
Tx= nursing, analgesia. Hand feeding, small feeds but often. Prokinetics. Diazepam to stim appetite.
57
What are the d/d for equine grass sickness?
Botulism, Pb toxicity, rabies, guttural pouch disease
58
Describe equine uveitis
- Major cause of blindness
- Secondary to trauma or infection e.g. EHV 1/4
- OCULAR PAIN, Blepharospams, excess lacrimation, +-Fibrin, miosis, corneal oedema
- Sequelae caused
- Tx= systemic nsaids e.g. fluxinin/ Atropine/ ABs (BS)
59
Explain how atropine helps in the treatment of uveitis
- Reverses miasis helping improve drainage hence helps pain
| - Decreases risk of syncheciae and iris rests forming.
60
What must you warn owners of when treating a horse with uveitis?
- Often can reoccur
| - Reduces sale value of the horse, can fail vettings due to sequelae
61
Give examples of sequelae from uveitis
- Iris rests
- Synchechiae
- Glaucoma
- Cataracts
- Blindness
62
Give examples of anterior chamber conditions of horses
- Hypopyon- often concurrent uveitis due to pus irritating eye. Happens in neonates secondary to sepsis. Tx= cure underlying bacteraemia
- Fibrin- common in polo ponies due to blunt trauma. Straw coloured strands. Tx= TPA inj
63
Describe chorioretinitis
- Look for pale optic discs
- EHV-1 causes bullet hole lesions in retina
- Diffuse lesions caused by blood loss, infarction, head trauma
64
Describe EMND retinopathy
Vit E deficiency- oxidative damage to NTF giving lace like appearance. Ceroid lipofuscin accumulation.
65
What are the two types of eye stain used in horses?
Fluorescein or rose bengal
66
What eye diseases are common in foals?
Ulcers
Uveitis (hypopyon from sepsis)
Congeital e.g. micropthalmus, PPMs
67
How do you manage an eyelid injury in a horse?
A2 agonist sedation
Don't debride
Suture through 2 layers BUT don't go through to cornea
Suture standing
68
Describe different eyelid neoplasias in horses
- SCC-3rd EL, often reoccur, cisplatin chemo
- Melanoma
- Sarcoids
- Habronemiasis-granulomatous lesion, medial canthus, ivemectin/ NSAIDs
69
In the horse what agent are melting ulcers assoc with?
Pseudomonas
(proteinases melt corneal surface, have grey appearance around edges)
Tx-chloramphenicol? and Plasma drops
70
What do you treat fungal eye ulcers with?
Miconazole
71
Describe the surgical tx of ulcers in horses
- Use LA
- Debride with sterile cotton wool
- Can do keretectomy to promote adherance of epithelium
72
What causes viral kertosis in horses?
Assoc with EHV 2.
| Diagnose with fluorescein dye
73
What does hyphaema suggest?
In 12+ dogs= neoplasia
| in 12+ cats= systemic hypertension
74
Which ocular reflex tests have CN 2 afferent and CN 7 efferent?
Dazzle reflex, menace
75
Describe the innervation for PLR
Afferent nerve CN 2, efferent nerve CN 3
76
Describe STT
- Aqueous tear production, BOTH basal and reflex production.
- Leave in for 1 minute
- Dogs: 15-25 normal, <10= +dry eye, 10-15 suggests dry eye, >25= ocular irritation
- Cats: very variable. 5-10 very common, just check same in both eyes.
77
How do you use a direct opthalmascope?
0 for retina
8-12 for lens
20 for cornea
78
Briefly list the methods of opthalmoscopy
Direct- another question covers this
Distant direct: scope on 0, opacities show black
Close direct: usually done after indirect, good for retina.
79
Describe tonometry
Normal values:
Dogs 15-25mmHg
Cats 15-25mmHg
Horses 17-28mmHg
Rabbit 15-20mmHg
Applanation- more accurate, tests pressure, need LA, very pricey
Rebound- tests deceleration, easier than applanation, no LA
80
What is the Jones test?
Patency of tear duct: fluorescein dye dribble out when put in eyes. Within 3-5 minutes.
81
What is the seidel test?
Check for corneal integrity- does the aqueous humour flush the fluorescein away?
82
How do you take swabs for ocular diseases?
- LA, expose 3rd EL, roll swab across EL or at edge of ulcer
- Bacteria- in charcoal
- PCR in sterile tube- FHV-1 or Chlamidya felis
83
How do you perform nasolacrimal flushes?
- Horses, dog, rabbits may be done with just LA but cats must be GA
- Cannulate upper punctum, check fluid coming from lower punctum then occlude lower and check coming from ipsilateral nostril.
84
What is dacrocystitis?
Infected or inflammed tear ducts
| Common in rabbits
85
What is gonioscopy?
Checking the drainage angle to see if eye predisposed to glaucoma (iridocorneal angle)
86
Why are slit lamps so useful?
Good for helping judge depth of ulcers.
87
Describe acute conjunctivitis
-CS: hyperaemia, chemosis, pruritis, mild irritation, discharge
-Dogs: seconadry bacterial infections, CHV-1, underlying non infectious e.g. entropian. Tx= isathal or chloramphicol
Chronic also get epithelial hyperplasia, follicular hyperplasia ad hyperpigmentation
-Cats: non infectious causes not common. Commonly FHV-1 or C.felis. Tx for herpes- amoxyclav, tx for c.felis- 3wk SID doxytetracyclilne
88
Describe conjunctivitis in cats- C.felis and FHV-1
FHV-1: if young/ kittens. Bilateral, gt upper resp signs, +- corneal ulcer. If adults: unilateral with hx of resp dx.
Diagnosis= swab conjunctiva for PCR
Tx= amoxyclav tablets and fusidic acid (isathal) topical
C.felis: becomes bilateral in few days, no/ v mild resp signs, no corneal signs, marked chemosis/ hyperaemia
Diagnosis: PCR swab
Tx: doxytetracyline 3wks SID (amoxyclav in pregn// kittens)
89
Describe KCS
Keratoconjunctivitis sicca
- Immune meadiated destruction of lacrimal tissue
-Common cause of conjunctivitis in dogs
-Tenaceous discharge and recurring conjunctivitis
-WHWT, pugs, Shih tzu, bull dogs
-Commonly young dogs/ bilateral
-Presents as recurring conjunctivitis that resolves when giving topical ointment that lubricates eye
-Diagnosis= STT
-Tx= tear replacement (lanolin ointments)
tear stimulants- cyclosporine (optimmune)
BS ABs for secondary infections.
90
Why do superficial ulcers tend to hurt more than deeper?
Because the nerves end in the epithelium/ stroma so can be exposed.
91
What are the layers of the cornea?
Epithelium, stroma, descements membrane, endothelium
92
Describe the process of corneal healing
- Epithelium heals rapidly
- Stroma only heals once covered by epithelium
- Descemets doesn't heal well
- Endothelium has very poor healing ability
93
What are the common causes of corneal ulcers?
- KCS
- Trauma (FB, abrasiaon etc)
- Bacterial infection
- Eyelids problems (ectropian/ entropian etc)
94
What does ulcers secondary to KCS often look like?
Punched out holes
95
What are the CS of ulcers?
```
Hyperaemia
Discahrge
Corneal oedema
Blepharospasm (pain triangle)
Incr lacrimation (pain triangle)
Photophobia (pain triangle)
```
96
How do you diagnose corneal ulcers?
- Fluorescein dye (only stains stroma)
- STT
- Corneal biopsy
- C&S swabs
97
Describe superficial corneal ulcers
```
Acute onset
Epithelial loss ONLY
Sharp/ distinct borders
Tx: ID/ Tx underlying cause
Prevent secondary infection (Chloramphenicol or fusidic acid)
Systemic NSAIDs
Atropine drops
R/c 3-5 days (1-2 if brachycephalics)
```
98
Describe indolent ulcers/ SCEDD
-Non healing, spontaneous often >7yo
-Common in boxers
- Epithelium grows across BUT doesn't adhere to stroma
-Indistinct border which often underruns with dye
-Tx: Debride, keretotomy (improve adhesion)
Fusididc acid/ chlormaphenicol, NSAIDs, chloramphenicol
99
Describe stromal ulcers
- Chronic or acute
- Fluorescein dye stains walls and floor
- CAN ALL BECOME COMPLEX - e.g. descemetocoele, melting, deep stromal
- Common anterior uveitis
100
Describe a descemetocoele
-Acute or chronic
-Complete stromal loss (down to DM)
-Walls or ulcer/ crater usually obvious
-Floor will not stain but looks clear or black- MUST flush away excess dye
MEDICAL EMERGENCY
101
Describe a melting ulcer (aka keratomalacia)
-Acute and painful
-Lots of gloopy discharge
-Marked corneal oedema and anterior uveitis
-Enzymes (proteinases/ collagenases) break down stroma
-2 causes: cornea itself or bacteria e.g. pseudomonas
STEROIDS MAKE IT WORSE
Tx= fluoroquinolones (ciprolaxin) treat uveitis and give NSAIDs.
Plasma drops good.
EDTA inhibits MMPs
102
You have a cat presented with conjuntivitis and mared respiratory disease... whats are your top 2 d/ds?
Calicivirus or FHV-1
103
What is lipogranulomatous conjunctivitis?
Swelling of meibomeum glands
Presents with pain assoc sunlight
Happens in cats
104
What is haws syndrome?
3rd eyelid protrusion
105
What corneal conditions are seen in cats?
Herpes keratitis (FHV1), proliferative/ eosinophilic keratitis, corneal sequestrum (necrosis)
106
What is herpes keratitis?
Shows dendritic ulcers which are pathognomic with herpes. Diagnose with a PCR swab
Tx= antivirals e.g. trifluorothymidine or famcyclovir
107
Which feline eye condition looks like cottage cheese
Eosinophilic keratitis
-diffuse corneal oedema, vascularisation, plaques - look like cottage cheese
Tx=steroids or cyclosporine.
108
Describe the tumours that affect the eyes of cats
Primary- diffuse iris melanoma (DIM) ciliary body adenomcarcinoma
Secondary- FeLV, lymphoma
109
What are the causes of cataracts in cats?
Post trauma sarcoma or E.cuniculi
110
What are the main causes of uveitis in the cat?
FeLV, FIP, Toxoplasmosis
111
What causes aa band shaped lesion dorsal to teh optic disc in cats?
Taurine deficiency
112
What condition in sheep causes cystic structures on conjunctiva and damages the hide?
Besnoitiosis (NFD)
113
What farm animal diseases can be associated with eyes?
Blue tongue, Besnoitiosis, BHV-1 (IBR), IBK, Malignant catharral, silage eye, SCC
114
Describe silage eye (bovine iritis)
- L.monocytogenes
-Very inflammed eyes
-Neovascularisation
-Ulceration
-Tx: Subconjunctival inj of AB and steroids
(in pictures the 3rd eyelid looks all mushy and weird)
-d/d IBK
115
Describe IBK (new Forest dx)
- Assoc Morexella bovis fly
- Often self limiting
- Central area of keratitis (white dot) and cornea oedema (blue tint)
- Tx: topical Cloxacillin ointment and oxytetracyline IM
116
Describe IBR
- Caused by BHV1
- Affects upper resp tract and eyes
- Bilat conjunctivitis and hyperaemia
- Bilateral serous discharge (manky white gloop)
- Also called red nose. Raw ulceration of ELs can cause blindness and dx can cause abortion
117
What nervous diseases of young farm stock are associate with eyes?
Listeriosis (paralyse EL), CCN, Meningitis, Pb toxicity (blindness), Tetanus
118
Describe SCC in cattle
- Can affect EL or eyeball
- Herefords more common?
- Tx= surgery, may be encucleation
119
What does hypovitaminosis A do to the eyes?
Affects retinal function causing night blindness
| Picture of fluffy optic disc and odd blood vessels
120
What neuro diseases affect pigs?
- Meningitis: Streptococcus suis 1, 2 and 4
- Water deprivation/ salt poisoning
- Oedema dx
- Aujeszky's (NFD)
- Teschen virus (NFD)
121
Explain meningitis in pigs
- Streptococcal suis
- Zoonotic
- Causes arthritis and serositis
- Strep suis 1: in sows tonsils, affects piglets 10-14days. Diag CS/PM. Tx 3-5days penicillin
- Strep suis 2/4: via abrasions, growing pigs after stresses, sudden death, pyrexia, acute arthritis, Tx 33-5 days penicillin
122
Briefly describe water deprivation in pigs
- Commonly cuaed by lack of access to water, they then drink loads causing cerebral oedema increasing ICP.
- CS= Recumbency, convulsions, ataxia, dog siting.
- Diagnose on CS or PM
- Tx= Slow rehydration, ensure access to water at all times to prevent.
123
Describe oedema disease in pigs
Occurs 7-10 days post weaning.
CS- ataxia, recumbency, CHANGE IN SQUEAK in laryngeal odeama
-Caused by vasoactive toxaemia causing gelatinous oedema
-Intestinal infection
-Tx: neomycin prophylcatically. Zinc oxide in feeds to control E.coli toxins!
124
Describe Aujesky's disease
- Herpes virus. Causes outbreaks in young pigs.
- Young= ataxia, recumbency, paddling (d/d meningitis)
- Older= goose steppping, run nose on floor
- Diagnose= Serology/ histology
125
What type of virus causes Teschen virus?
Enterovirus (serology diagnosis)
126
What is primary and secondary epilepsy?
```
Primary= idiopathic, no dx at brain level
Secondary= structural epilepsy, disease at brain level e.g. brain tumour
```
127
What are the different stages of seizure?
Prodome (change in behaviour)
Preictus(anxiety, excitability, seconds to minutes)
Ictus (convulsions, unconsciouness)
Postictus (tired, aggression, incr appetite, min to days)
128
What is the definition of status epilepticus?
Lasts more than 5 minutes or have 2+ seizures with incomplete recovery of consciousness between fro 30 minutes
Life threatening
129
What is the definition of cluster seizures?
2 or more in 24 hours with normal recovery between
130
When do you start AEDs?
- Generalised seizures or more than 2 in 6 months
- Severe postictus periods
- ID of lesion
- SE
131
Describe phenobarbitones
- Increase GABA inhibition by acting on glutamate Rc, inhibit voltage gated Ca channels
- Metabolised by liver
- 1/2 life in dogs decreases if given long time
- Ataxia, hepatotoxicity in dogs
- Give IV in dogs in SE, then orally when can swallow
- Start dose by weight then adjust on serum concentration
- HL dogs 30-90hrs
- HL cats 3-83hrs
132
Describe bromide
-Give with phenobarb in refractory epilepsy
-Usually potassium bromide BUT with addisons or sensitive stomachs give sodium bromide
-GABA gated Cl channels
-No liver metabolism
- Sedation, PUPD, Diarrhoea, Pancreatitis
NOT TO CATS= FATAL ASTHMA
-HL dogs 24.9 days
-HL cats 12 days
133
Describe imepitoin
- Low affinity partial agaonist of BZD recognition sites
- Potentiates GABA inhibition activity on neuron
- NOT to dogs in SE/ cluster seizures
- Good for cats
- Given in idiopathic cases
134
Describe BZDs
- Bind to regulatory site of GABA -a Rc NOT GABA binding site
- Incr affinity of GABA to Rc
- Causes acute hepatitis in cats
- Used in SE dogs and cats
135
What is UVD?
Uveitis dermatological syndrome
| Auto immune, results in severe uveitis due to melanocytes in the eye being attacked.
136
What systemic disease in cats affects the eyes?
Herpes- dendritic ulcers
137
What endocrine diseases affect the eyes?
HAC- corneal calcification
| HypoT4- corneal lipidosis (bilateral shiny crystals in cornea)
138
Briefly describe why eyes are good sites for metasteses and name 2 common neoplasias of the eye
- Due to good bloody supply
- Lymphoma
- Epitheliotropic lymphoma
- Melanoma?
- SCC
139
Describe Rabies
- Lyssavirus
- Pathogenesis: replicates in brain(saliva- wound-travels up nerves to SC/ brain) completes when enters salivary gland.
- 2 forms: furious (dogs/ cats) and dumb
- Diagnosis: Histopaathology/ CNS tissue PM
140
How do you diagnose WNV and what sort of virus is it?
- ELISA Abs
| - Flavivirus
141
What NFD causes sudden death of in contact cats?
- Aujeszky's virus
| - CS in pigs: paddling, circling, convulsions
142
Which pestiviruses cause neuro symptoms?
- Border dx (infected early gestation causes PI)
- BVD (mainly calves infected in utero 120+ days)
- Diagnose: ELISA viral Ag, PCR
143
What are the CS of border dx?
Cerebellar hypoplasia, poor suck, demyelination of CNS causing shakes, abortion
144
What causes wobbly kittens?
- Feline parvovirus
- Faecal-oral
- Low WBC, cerebellar hypoplasia
145
What virus which causes neuro signs is diagnosed with a haemoglutination assay?
Louping ill
146
Which of the disease vaccinated against in core canine vaccines can cause neurological signs?
Distemper (paramyxovirus)- once neuro signs appear normally euthanase
-dx also causes enamel hypoplasia and old dog encephalitis (dementia, blindness, circling)
Diagnosed with nasal swab or PCR
147
Briefly describe FIP
- A coronavirus
- Often cats <2yo and pure breeds
- If it begins replicating in onocytes the coronavirus develops into FIP. Stress is a big part?
- 2 types= wet/ dry
- Dry neuro sign= uveitis
- Albumin: globulin ratio (alb stays same:glob incr)
148
What are the 3 methods of spinal decompression surgery?
- Dorsal (good for bilateral NOT C1/C2 regions)
- Hemilaminectomy ( TL region, hard in cervical due to vertebral artery)
- Ventral (in cervical)
- Must have clear X-rays before beginning
- Can remove 1 AF joint without causing instability (2 or more of the 3 articulation points are compromised= unstable)
149
When does a spinal fracture become unstable?
If its stable then conservative therapy better
Counts as stable so long as only 1/3 compartments compromised. (Dorsal laminae, dorsal VB, ventral VB)
-Conservative therapy: strict cage rest for min 6 weeks, consider bladder management, nursing, analgesia, PHYSIO)
150
Describe internal/ external fixation of spinal fractures
- Internal= orthopaedic plates or pins and hydroxyapetite
| - External= spinal casting- good for cervical areas
151
What must you remember when getting anaesthesia for a neuro case?
MUST keep SC and brain perfused! Pathology of SC trauma continues for 48 hours = ischaemia risk! SO give fluids!
152
What ocular emergency should you leave lone for 20 minutes to allow it to plug itself?
Perforated corneal ulcer
153
What value IOP indicates an ocular emergency?
>40mmHG, gives a blue appearance to eye and means you must act fast to save the eye.
- Giving lotanoprost (PG analogue)
- Give NSAIDs
- Refer to opthalmologist
- Remember purebreeds= priimary glaucoma, terriers= lens subluxation so this will need fixing: Look at lens with US
154
What is tarsshopy?
Surgical procedure where you sew EL together to correct prolapsed eyeball
- Suture horizontal mattress through EL NOT full thickness aiming for meibomeum glands
- Remember traction of optic nerve can cause permanent blindness
- Globe prolapse can cause corneal ulceration and dessication
- Medial rectal muscle often first to tear, results in lateral strabismus but will rectify
155
How do you manage a retrobulbarabscess?
- CS= pain when opening mouth, exopthalmus, pyrexia?acute onset
- If exopthlmus is pronounced you have to drain the abscess via the mouth cavity. Use US for guidance and poke artery forceps into abscess, make a big hole so it can continue to drain.
- Pack throat so it doesn't drain down there
- Give ABs
- DONT flush
156
How do you manage a globe prolapse?
- Want to take pressure off optic nerve ASAP and keep globe moist with wet saline swab
- Prep with povidine- iodine
- Pull EL forwards using stay suture OR do lateral canthotomy
- Give systemic NSAIDs and ABs
- Remove tarrsorrhaphy stitches 10-14days
157
What can cause sudden vision loss?
- Acute glaucoma
- Acute uveitis
- Intraocular ahemorrahge
- Retinal detachment
158
What are dozolamide, brinzolamide and what do they treat?
Carbonic anhydrase inhibitors used to treat glaucoma by reducing AH production
e.g. Azopt
159
What drugs can you use to treat KCS?
- Lanolin ointements
| - Cyclosporine
160
How do you treat cerebellar herniation?
With mannitol (osmotic diuretic)
161
Very briefly, how do you manage spinal trauma?
- SHOCK
- Give fluids
- X-rays, MRI?
- Think about bladder management
- Stabilise/ refer
162
How do you manage status epilepticus?
-Give Diazepam IV (action 20 mins) Can be repeated
-Give PB (2nd line drug, lasts 12 hours but take 20 mins to work so often give propofol whilst waiting for it too work)
Whilst doing this try to work out what's happening- electrolytes, temperature, glycaemia??
163
Describe how to manage cranial trauma and what you must consider
- Think of the triangle (tissue, blood, CSF) if one increases the other two decrease to compensate. All affect ICP.
- So if brain swells, CSF is pushed out and ventricles are squashed causing decreased perfusion and ischeamia
- Must maintain perfusion, give oxygen and maintain bloodflow and pressure
164
What are the causes of head tilt in rabbits?
- E.cuniculi
- ToxoplasmaListeria
- Middle ear infection
- Meningitis
165
Describe E.cuniculi infections in rabbits
- Protozoan infection
- Affects brain and kidneys
- CS= head tilt, renal dx, paresis, emaciation
- Diagnosis= Xrays, renal biopsy, serology
166
Describe the action of lead as a neuro toxin
- Binds Sulfahydryl group
| - Ataxia, bruxism, PU/PD, head pressing
167
Describe the action of strychnine as a neuron toxin
- Blocks glycine
- Excitatory
- DO NOT INDUCE EMESIS- risk of aspiration too high
168
Describe the action of metaldehydes as a neuro toxin
- Excitatory
- Descr GABA, decr norepinephrine, decr serotinin
- Induces pro convulsive state
169
Describe the action of methylxanthines as a neuro toxin
- Excitatory
- Incr CAMP, incr Ca
- Competitive inhibition of adenosine Rc= CNS stimulation
170
Describe the action of permethrin as a neuro toxin
- Excitatory
| - Na channel open/ close more slowly causing poor depolarisation
171
Describe the action of OPs as a neuro toxin
- Excitatory
| - Block AChE so get build up of ACh
172
Describe the action of ivermectin as a neuro toxin
-GABA gated Cl channels agonist= excitement then flaccid paralysis/ coma
173
Which neuro toxin causes clinical signs similar to ear disease?
-Metronidazole- causes axonal degeneration of vestibular tract (also purkunje cell loss)
174
What drug do to give when dealing with a lipophilic toxin in the blood stream?
Intralipid
175
What are the types of MUA, how do you diagnose and whats the treatment?
GME, NME, NLE
Diagnosis= CSF: incr cellularity, incr TP (pink in colour?)
MRI: oedema white, necrotising black
Tx- corticosteroids long course then gradually reduce over 6 months to a maintenance dose.
Can also use cyctosine arabinosie, cyclosporine or azathioprine
176
What is the action of cytosine arabinoside?
Affects DNA polymerase so affects mitosis
177
Whats is the action of cyclosporine?
Supresses T cells
178
Briefly describe SRMA
-Young dogs 6-18months
- CS: PROFOUND CERVICAL HYPERESTHESIA, pyrexia, depression
-Diagnosis: CSF- neutrophilic pleocytosis
MRI: longus colli myositis (swelling)
Measure IgA in serum and CSF?
Tx= Corticosteroids
Prognosis better than MUA
179
Briefly describe cauda equina necrosis
- Female hroses mainly
- Leads to tail paralysis and sphincter incontinence
- Caused by auto immune dx or post infection (herpes, adenovirus)
- Poor prognosis
180
What inflammatory CNS disease affects greyhound/ sight hounds?
- Pachimeningitis
- Thickened dura mater
- CS= Dropped jaw and CN deficits
- Diagnosis: MRI
- Corticosteroid tx
- Prognosis variable
181
Which pain tract is responsible for superficial/ touch pain and which is responsible for deep/ visceral pain?
Superficial/ touch= spinocervicothalamic
| Deep/ visceral= spinoreticular
