Exam 2 - neuro 2 Flashcards
(163 cards)
1
Q
infectious equine neuro dzz?
A
EEE, WEE, WNV, Rabies
EHV
EPM
neuroborrelliosis
2
Q
developmental neuro dz?
A
CSM
3
Q
nutritional or metabolic neurologic dz?
A
EDM
EMND
4
Q
idiopathic neuro dz?
A
polyneuritis
5
Q
toxins that cause neuro dz?
A
tetanus
botulism
6
Q
neoplasia that causes neuro signs?
A
melanoma
7
Q
diffuse CNS dzz?
A
viral encephalitides
EHV
neuroborrelliosis
8
Q
upper motor neuron dzz?
A
CSM
EDM, NAD, EPM
9
Q
lower motor neuron dzz?
A
EMND, botulism, tetenus, equine polyneuritis syndrome
10
Q
multifocal neuro dz?
A
EMP
11
Q
infectious, diffuse CNS and spinal cord dzz:
A
viral encephalitides
equine herpes myeloencephalitis
neuroborrelliosis
EMP
12
Q
what family of virus are EEE, WEE and VEE part of?
genus?
A
arboviruses
togaviridae
13
Q
what type of genetic material do EEE, WEE and VEE have?
A
single stranded RNA viruses
14
Q
what are the reservoir hosts of EEE, WEE and VEE?
A
birds, rodents, reptiles
15
Q
t/f
the reservoir hosts do not show signs of virus
A
true
they are asymptomatic sylvatic hosts
16
Q
what is the vector for EEE, WEE and VEE?
A
mosquito
17
Q
what are the dead end hosts for EEE, WEE and VEE?
A
horse and human
18
Q
what is the geographical distribution of EEE?
A
east of the Mississippi
19
Q
what is the geographical distribution of WEE?
A
west of the Mississippi
20
Q
what is the geographical distribution of VEE?
A
Mexico and South America
sometimes SW US border states
21
Q
the US has been free of which encephalitis (E, W, V) virus since 1971?
A
VEE
22
Q
rank the virulence of EEE, WEE and VEE from greatest to least
A
EEE > VEE > WEE
mortality rates highest for EEE in horses and humans
23
Q
t/f
EEE, WEE and VEE are all reportable dzz
A
true
24
Q
what is the common name for EEE?
A
sleeping sickness
25
does EEE have enzootic or epizootic cycles?
both enzootic and epizootic cycles
26
how is EEE transmited?
during what season does this occur?
mosquito
summer months
27
t/f
EEE has a slow progression and onset
false
fast progression of 2-14 days
typically die w/in 2-3 days
28
what is the human mortality rate for EEE?
75-100%
29
what is the common clinical presentation for EEE?
what are the early symptoms?
- uncommon in foals less than 3 mos old
| - early symptoms: fever, malaise, anorexia, "colic"
30
what is the pathogenesis of EEE?
infection spreads to WBC - can be cleared with good humeral immunity if it does not spread to the spleen/liver endothelium
2nd stage of viremia: spreads to CNS
see cerebral and CNS signs in 3-5 days
31
what acute clin signs occur with EEE?
```
ataxia
head pressing
hyper excitability
somnolent, depressed, stupor - flaccid lips, tongue protrusion
recumbent, unable to rise
seizures
coma
death
```
32
what pathology is associated with EEE?
- severe inflammation, necrosis [malacia], hemorrhage, swelling
- severe lesions in cerebral cortex, thalamus and hypothalamus
- perivascular cuffing - PMNs and mononuclear cells
- brain stem: herniation of occipital lobes under tentorial process and cerebellum into foramen magnum AND mydriasis, irregular breathing arrhythmias and death
33
how to dx EEE ante mortem?
c/s
season
geography
questionable vacc hx
high or rising aby titer - Hemagglutination inhibitor test
IgM specific ELISA
RT-PCR to demonstrate viral genome
CSF: elevated protein and nucleated cell count - inc NTs
34
t/f
full recovery occurs readily after EEE
false
recovery is rare
if it does occur, animals have permanent or long term neuro deficits
35
EEE px:
vaccination - works well
| mosquito control
36
how often should EEE vacc be boostered?
4-6 mos in endemic areas
| 12 mos in non endemic areas (MO)
37
what family and genus is west nile virus in?
arbovirus
genus flavirius
38
t/f
west nile virus is considered endemic in US
true
39
what species does west nile virus affect?
humans
| horses
40
what animal is the reservoir for west nile virus?
birds [sparrows, robins, crows]
41
what is the vector for west niles virus?
mosquito
42
what is the peak outbreak for west nile virus?
spring to fall
| september to october
43
what is the mortailtiy rate for west nile virus?
28-38%
44
what % of horses develop c/s of west nile virus?
5%
45
t/f
most infections of west nile virus are likely asymptomatic
true
46
what c/s are seen with west nile virus?
fever
change in personality, behavior - hyperexictability followed by sleep like behavior, hyperesthesia
muscle fasciculations - muzzle, face chewing, rapid blinking
ataxia to inability to rise - paraparesis to tetraplegia, often asymmetrical; looks similar to laminitis initially
Cranial nerve deficits
47
what % of west nile virus patients will see full recovery?
how long will it take?
90% within 1-6 months
48
how long after initial onset of west nile virus will patients appear to recover?
w/in 3-5 days of onset
| may see recrudescense of c/s 7-10 d after apparent recovery
49
t/f
the prognosis of west nile virus is better if the horse remains standing
true
50
dx of WNV?
c/s
geographical loc
season
blood samples from early in dz:
IgM capture ELISA
RT-PCR for WN genome
CSF: elevated prot and monomuclelar pleocytosis
51
WNV tx?
supportive care - nutrition, IV fluids, sling support, paddled stall
antiinflammatory therapy: banamine, DMSO
vit E
hyperimmune plasma (maybe)
INF cl, high dose glutamate therapy
52
WNV px?
vacc and mosquito control
53
how often to vaccinate for WNV?
q6-12 mos and before mosquito season peaks
54
t/f
| rabies is not a concern for horses
false
55
t/f
rabies has distinct c/s that look different from neurological dzz
false
rabies can look like any other neurological dz - should be on ddx list for any patient with acute onset neuro symptom
56
how long after exposure can symptoms appear?
up to 6 mos
57
how fast is the progression of rabies?
rapid after first symptoms appear - patients die w/in 1 week
58
what are the 2 forms of rabies?
furious - hyper excitable, fearful, aggressive
| dumb - depressed
59
dx rabies?
post mortem - submit entire brain on ice but not frozen
FAB is MC and fastest test used - 98% sensitive - mouse innoculation - takes 5-6 days
60
c/s rabies?
prodromal signs: colic, lame, listelss, anorexia, hydrophobia
aggression, behavior changes, paralasys/paresis, fever, hyperesthesia, puritis, self mutilation, ataxia, propulsive circling, head pressing, yawning
less common: dysphagia, pytalism, vocalization, tenesmus
61
what is the pathognomonic sign for rabies? it may not always be present
negri bodies w/in neuronal and glial cells
62
what happens if an animal unvaccinated for rabies gets bitten by wildlife?
quarantined for 6 mos
63
what happens to an unvaccinated animal that bites a human?
euthanized and tested
64
what happens to a vaccinated animal if it bites a human?
quarantined for 6 mos
65
how frequently is a rabies vaccine necessary?
annually
66
what happens if a vaccinated animal gets bitten by wildlife?
booster horse immediately for rabies and all other animals on property
quarantine animals for 6 mos
67
what is the etiology for equine herpes myeloencephalitis?
EHV 1
68
t/f
the MC clinical manifestation of EHV 1 is neuro dz
false - other clin manifestations are more common than neurologic dz [upper resp virus]
69
how contagious is EHV1?
highly contagious
70
when does infection with EHV 1 occur MC in horse life?
early life
71
what is the MC strain of EHV1 seen in EHM cases?
neuropathic strain
72
what type of mutation enhances viral replication of EHV1?
mutation I DNA polymerase gene
ORF 30 of DNA polymerase gene - single nucleo tide switch - sub asparagine to aspartic acid
73
what aspect of EHM and EHV1 infection causes a greater potential for neurologic dz and larger outbreaks?
significant viremia in those infected
74
what does the wild type / non neuropathic strain of EHV1 cause?
it is not apathogenic
it causes neurologic dz but to a lesser extent - a lower degree of viremia
75
EHM pathology?
- vasculitis win CNS -> microthrombosis and ischemia
| - deficits depend on area of spinal cord affected but there is an affinity for the caudal cord
76
c/s of EMH?
- biphasic fever: over 103* for over 3 days
- maybe respiratory signs: influenza like, malaise, inappetance, lethargy
- neuro: manifest for days after fever resolves
77
what neuro signs occur with EMH?
atacia
paresis
symmetrical, pelvic limbs
dec tail tone and anal sphincter tone - constipation
bladder paralysis/dysuria - dribbling urine / incontinence, urine scalding
recumbency
intracranial signs rare
78
what is prognosis of EMH?
- good IF NOT recumbent w/in 3 days of onset of neuro signs
- complete recovery possible but many have permanent deficits
- POOR if recumbent
79
what complications occur with EMH?
pneumonia
2* infections
bladder rupture
Mm necrosis
80
dx EMH / EHV1?
which test detects shedding and which test detects viremia?
nasopharyngeal swab or lavage: RT-PCR, detects shedding
whole blood EDTA sample: RT-PCR detects viremia
81
EMH tx?
supportive care - sling, IV fluids, nutrition, bladder, catheterization
abx to px 2* infection
anti inflammatory - banamine, DMSO, steroids
anti viral therapy - acyclovir, valcyclovir
82
t/f
after EMH case, facility must be quarantined for 6 months
false
quarantine for 21-28 days
83
EMH px?
biosecurity at horse events and hospitals
vaccination
84
what is the purpose of EMH vaccine?
to maintain herd immunity and to dec shedding
85
how often should a horse get EMH vacc?
q 6 mos
| prior to entering a high risk area if not vaccinated in last 90 days
86
what is etiology of EMP? [equine protozoal myeloencephalitis]
protozoan parasite of equine CNS
sarcocystis neurona
neospora hughesi
87
t/f
depending on the area, the seroprevalence of EPM can be quite high - around 90%
despite this, the incidence of new cases is very low
true and true
88
what is the MC age of cases for EPM?
1-5 yo
| over 13 y
89
how are horses infected with S. neurona?
ingesting food/water contaminated by opossum feces and infective sporocysts
90
what species is the definitive hose of s neurona?
how is it infected with the protozoa?
opossum
eats muscle tissue of the IM hosts, which contain the latent sarcocysts
91
what are the intermediate hosts of S neurona?
how do the acquire the protozoa?
skunks racoons, cats, etc
they ingest sporozoites / sporocytes that are passed in the feces of the DH
92
how does the s neurona affect the IH?
forms latent sarcocysts in muscle tissue
93
what species is the dead end host of s neurona?
horse
94
t/f
for EPM, the protozoa gains access to most horses
false - few horses
95
how/why does the protozoa gain access into the CNS of some horses?
- individual immune susceptibility
- stress induced immune suppression
- numbers of parasites during exposure
- special strains parasite
96
what are some risk factors of EPM?
- presence of opossum near premise
- wooded area
- warmer season
- stress - exercise, transport, injury, parturition, show horses
- high stocking density
- diminished immunity
97
EPM onset acute or insidious?
either
98
t/f
EPM can cause damage to any part of the CNS
true
99
c/s of EPM?
asymmetrical abnormalities
multifocal neuroanatomical localization
UMN and LMN deficits
ataxia (UMN) with focal skeletal muscle atrophy (LMN)
manifestations: focal skeletal M atrophy - masseter, gluteal, quadriceps, triceps
```
acute onset ataxia/weakness
head tilt, facial N paralysis, dysphagia
seizures and behavorial changes
recumbency
horner's syndrome
mild lameness, not block out
radial N paralysis
```
100
if damage to grey matter occurs in EPM, what signs occur?
focal Mm atrophy
101
if damage to white matter occurs in EPM, what signs occur?
ataxia
102
describe horner's syndrome and the signs?
unilateral signs of loss of sympathetic innervation
damage to vagosympathetic trunk or Cranial cervical - trauma to c6-T2, extravascular jugular IV injections, guttural pouch dz
ptosis, miosis, enopthalmus, protrusion of 3rd eyelid, patchy sweating (face, neck)
103
EPM pathology?
multifocal, non suppurative myelencephalomeningitis
spinal cord path MC occurs than brain or brain stem path b/c protozoa migrate to spinal cord
104
EPM dx?
c/s of neuro deficits
r/o other differentials:
x ray spine to r/o wobbles
CSF analysis to r/o other dzz
demonstrate prod of aby against S neurona in the CSF
western blot or IFAT are good too
response to anti protozoal tx
105
t/f
serology offers good dz tests for EPM?
false - serology is unreliable unless you get negative
106
EPM tx?
anti protozoal drugs
anti inflammatory therapy
vit E
immune stim
107
t/f
compounded meds offer specialized treatment for EPM
false - avoid compounded drugs - adverse events and death occur
108
EPM Px?
feed off ground, fresh water, px wildlife access to pasture/stall
metaphylaxis to Px infection
ponazuril to at risk horses every 7 days
or daily low dose diclazuril
109
what is the etiology of neuroborrelliosis?
Borrelia burgdorferi
110
how is borrelia burgdorferi transmitted?
Ixodes scapularis tick - black legged deer tick
111
neuroborrelliosis dx?
difficult ante mortem
serologic testing - specific aby titers in blood and in CSF
112
c/s of neuroborrelliosis?
lethargy, anorexia, wt loss
fever, neck and back pain, ataxia, weakness
muzzle fasciculations, tremors
polysynovitis, uveitis
dysphagia, vestibular dz, facial paralysis
recumbency
beh changes, seizure
113
Tx neuroborrelliosis?
tetracycline abx
114
what do each constituent of the outer surface proteins indicate?
OSP a, c and f
```
a = inc in vaccinated animals
c = early infection (3 wks after infection)
f = chronic infection (5-8 wks after infection)
```
115
UMN dzz?
cervical vertebral stenotic myelopathy (CSM)
equine degenerative myopathy (EDM) and neuroaxonal dystrophy (NAD)
EMP
116
what is the common name for cervical vertebral stenotic myelopathy?
wobbles syndrome
117
what is nature of CSM?
developmental
orthopedic dz
vertebral canal fails to develop adequate diameter
cord is damaged as result of vertebral impingement and movement
118
common presentation of CSM?
any age and breed but common in
young male thoroghbreds btwn 4 m and 4 y
progressive symmetrical ataxia in pelvic limbs - sometimes evident in all 4 limbs - hindlimbs more abnormal than forelimbs
circling, raising head, walking over obstacles or inclines worsen signs
119
CSM dx?
survey cervical radio graphy
saggittal diameter ratio
less than 50% suggests compression
myelography - neutral, flexed and extended views
50% attenuation of dorsal dye column
120
CSM management?
conservative if less than 1 yo - pacedration
rest, anti inflammatories, vit E/se supplemenetation
sx: modified cloward technique "basket surgery", arthrodesis of adjacent vertebrae, expensive
euthanasia - sx is expensive and horse will not return to full athletecism after
121
what is the nature of degenerative myeloencephalopathy and neuroaxonal dystrophy?
dzz of axonal degeneration in the CNS
122
c/s of EDM/NAD?
age of development
symmetrical ataxia, abnormal base wide stance, proprioceptive deficits in all 4 limbs
12 mos - 2 years
123
where are lesion in NAD?
in brain stem only, less severe form
124
where are EDM lesions?
white matter of spinal cord, brain stem
125
EDM and NAD neuro exam findings?
- gain analysis consistent w UMN deficits - symmetrical ataxia - pelvic limbs and advance to forelimbs
- dysmetria, pacing gate
- diminished reflexes (LMN) in long standing cases
- thoracolaryngeal slap test reflex
- local cervical and cervoci facial refleces
- cutaneous trunci reflexes
126
risk factors of EDM/NAD?
- dry lot, insecticides, exposure to wood preservatives, lack of dietary vit E possibly
127
dx EDM/NAD?
low plasma vit E, low CSF vit E
128
EDM/NAD tx?
vit E
129
what is localization of equine motor neuron dz (EMND)?
LMN
130
is EMND hereditary? what is classic presentation?
young adults - avg 9 yo
NOT Inherited
131
cause of EMND?
insufficient dietary vit E - imbalance btwn oxidants and anti-oxidants
132
what region of CNS affected in EMND?
alpha motor neurons in ventral horn of the spinal cord and brainstem
anti gravity Mm
133
what human dz is EMND commparable to?
ALS - lou gehrig dz
134
EMND c/s?
weakness, muscle fasciculations
M atrophy, quadriceps, triceps, gluteals
narrow based stance - tail and head posture
black pigmentation of teeth
constantly shifting weight, difficulty / ataxia when restrained
fundic lesions - retinal pigment accumulation
- hooves tucked under and muscle atrophy in limb girdle muscle groups
135
pathology in eye of EMND?
retinal - lipopigment accumulation in pigment epithelium - brown pigment deposition in fundus
136
EMND dx?
elevated serum AST activity
low serum vit E
EMG - neurogenic atrophy
muscle biopsy - neurogenic atrophy - sacrocaudalis dorsalis medialis Mm - type 1 fibers are good samples for EMND dx
137
EMND tx?
vit E natural a tocopherol (RRR isomer)
138
polyneuritis equi pathogensis?
progressive immune degradation of peripheral nerves of the horse
"cauda equine neuritis"
any peripheral nn affected
p2 myelin protein aby
139
what type of inflammation of nerve roots during polyneuritis equi?
granulomatous inflammation
140
what dz is polyneuritis equi comparable to in the dog?
coonhound paralysis in the dog
141
what is primary presentation in the acute form of polyneuritis equi?
hyperesthesia of perineal or head region
142
what is primary presentation of chronic form of polyneuritis equi?
paralysis of tail, anal sphincter, bladder and rectum
dysuria, urine scald, penile paralysis
impaction colic
pelvic limb involvement - less common
other nerves: CrN 5, 7, 8
143
what is common name of tetanus?
'lock jaw'
144
what is etiology of tetanus?
toxins produced by clostridium tetani - soil organism - cause rigid muscle paralysis
often inoculated during castration, puncture wounds, tail docking
145
what does tetanolysin toxin cause?
tissue damage
146
what does tetanospasmin cause?
neurotoxin
147
how susceptible are horses to tetanus toxins?
very susceptible
148
tetanus dx?
c/s
149
what effects do tetanus neurotoxins have on neurotransmitter?
inhibition of release of inhibitory NTs - resulting in tetanic muscle contraction
150
tetanus c/s:
```
saw horse stance ***
elevation of tail head
grimmace / sardonic grin - retracted lips, erect ears
protrusion of 3rd eyelid
colic
dysphagia
generalized stiffness, immobilization
recumbency
respiratory failure
death
```
151
tetanus tx?
tetanus immunoprophylaxis - antiserum and boost tetanus toxoid
tx wounds appropriately
penicillin
ace, robaxin
intrathecal tetanus anti serum
supportive care - dec external stimuli - fluids, nutrition
recovery can take weeks
152
botulism etiology?
| common name?
clostridium botulinum neurotoxin
forage poisoning
153
what syndrome in foals occurs with tetanus?
shaker foal syndrome
| 1-3 mos of age
154
how might a horse acquire botulism?
wound botulism
| ingestion of pre formed toxin [dead animals]
155
what is onset of botulism?
acute onset weakness
slow to eat grain - dysphagia
can present as outbreak
156
botulism c/s?
```
weak muscle fasciculations
camped under stance
Cr N deficits - mydriasis, sluggish, PLRs, ptosis, dysphagie
constipation and urine retention
ileus
recumbency
respiratory distress
death
```
157
where does botulism toxin bind on NT?
to terminal of alpha motor neuron at neuromuscular jxn
inhibition of vesicle tethering and release of NT Ach -> flaccid muscle paralysis
158
dx botulism?
c/s
mouse bio assay
PCR
159
botulism Tx?
antiserum - will not target toxin once in nerve terminals
supportive care
160
botulism prognosis?
fair or milder cases - poor for rapidly progressive cases
161
botulism px?
toxoid vacc
162
t/f
neurologic neoplasia is common in horses
false
| rare
163
what types of neoplasia are seen in neurologic horese?
which are "NOT true neoplasms"?
- cholesterinic granulomas in ventricles [not true neoplasm]
- pituitary adenoma [not true neoplasm]
- melanoma [in grey horses]
- lymphosarcoma [schwann cell tumors]
