Neurology Flashcards
(89 cards)
1
Q
list spinal reflexes used in horses NE
A
- thoracolaryneal adductor response
- spinal segmental: cervicofacial, panniculus
- tail/anal
2
Q
gait factors assessed
A
- proprioceptive deficits
- ataxia
- paresis
- dysmetria
3
Q
brain regions
A
- forebrain
- brainstem/CNs
- cerebellum
4
Q
spinal cord regions
A
- C1-C6
- C6-T2
- T3-L3
- L3-S5
5
Q
peripheral neuro regions
A
- brachial plexus (FLS)
- HLs
- NMJs
- (primary muscle issue)
6
Q
RAS is active in what brain regions
A
- brainstem
- cerebrum
7
Q
hypermetria, intention tremors, strength –> region?
A
cerebellar disease
8
Q
seizures, blindness, dementia, mild ataxia/weakness –> region?
A
cerebral disease/forebrain
9
Q
gait deficits, altered consciousness –> region?
A
brainstem
10
Q
tail/bladder paralysis, perineal hypalgesia –> region?
A
sacral
11
Q
front limb ataxia worse than hind –> region?
A
C6-T2
12
Q
what spinal segment lesions may result in horner’s?
A
C1 - C5
C6-T2
13
Q
3 types of ataxia
A
- proprioceptive (spinal)
- vestibular
- cerebellar
14
Q
2 types of paresis
A
LMN vs UMN
15
Q
tests of proprioception
A
- Posture
- Truncal sway
- Circling: circumduction, interference, pivoting
16
Q
tail pull at rest tests
A
extensor strength - LMNs
17
Q
tail pull while walking tests
A
extension and flexion
UMNs and LMNs
18
Q
muscle fasciculations are assoc. w/
A
LMN weakness
19
Q
Grade 1 ataxia
A
mild/inconsistent ataxia at walk, worse when manipulated
20
Q
Grade 2 ataxia
A
obvious ataxia at walk, worse when manipulated
21
Q
Grade 3 ataxia
A
prominent ataxia, fall over if manipulated
22
Q
Grade 4 ataxia
A
severe + might fall
23
Q
Grade 5 ataxia
A
recumbent + can’t get up
24
Q
px hendra
A
euthanasia
25
Hendra incubation and shedding
shed 2 days before CS
| 5-16 days incubation
26
Dx Hendra
- rectal, nasal, oral swabs --> EDTA blood
| - -> ELISA, virus isolation PCR
27
medications assoc. w/ seizures if intracarotid
- xylazine, flunixin
- bute
- procaine pen (IV at all)
28
dx of bacterial meningitis and px
CSF tap --> poor px
29
fungal cause of meningitis in WA
cryptococcus
30
ddx for neurogenic blindness
- forebrain dz
- PPID (optic chiasm compression from macroadenoma formation)
- trauma
- neonatal encephalopathy
- toxins
- intra-carotid injections
31
ddx. diffuse/multifocal disease
- arboviral encephalomyelitides
32
name 2 alphaviruses assoc. w/ encephalomeningitis
- ross river virus
| - eastern/western/venezuelan equine encephalitides
33
names 2 flaviruses assoc. w/ encephalomeningitis
- west nile virus/kunjin variant
| - murray valley encephalitis/japanese encephalitis
34
cs of ross river virus
- polyarthralgia + effusions
- distal limb oedema
- systemic illness
- not usu ataxia
35
cs of west nile fever/kunjin virus
- muscle tremors (esp. muzzle)
- variable fevers
- variable RAS signs - obtundation/hyper-altert
- ataxia/weakness
- recumbency
36
px west nile
50% have residual signs
mortality ~ 30%
recovery in 3-4wks
37
rank the encephalitides viruses in order of highest to lowest mortality
1. EEE
2. VEE
3. WEE
4. WNV (Kunjin)
5. JE
38
CSF tap findings of viral encephalitides
neutrophilic --> lymphocytic
39
tx of viral encephalitides
- anti-inflam: flunixin, dex
- anti-ox
- cooling
- IVFT/lytes/glucose
- anti-oedema tx
40
incubation/pathophys of ABLV
- long, variable incubation period (2wks->6months) --> delayed progression/viral replication in muscle cells at wound
- ascends via peripheral or cranial nerves to brain
- reduced production of normal functional proteins --> fatal in 3-10days
41
ABLV CS
- cerebral signs: mania/aggression, seizures, obtundation
- RAS: altered consciousness
- CN: dysphagia
- Spinal: ataxia, weakness, paralysis, cauda equina
42
dx of ABLV
PM test --> euthanase
| - refrigerated brain --> direct FA test, negri bodies in purkinje cells
43
management of ALBV
- vaccination in endemic areas
- human vax
- euthanasia of suspect
44
pathogen of EPM
Sarcocystis neurona
45
CS of EPM
- often vague/subtle multifocal disease
| - asymm. ataxia/atrophy
46
dx of EPM
CSF/serology antibodies
47
Tx of EPM (and px)
Ponazuril/Diclazuril - at least 28days
| - 60% horses response to tx +/- relapses
48
pathogens of verminous myeloencephalitis
usu aberrant migration of;
- halicephalobus
- strongylus
- parelaphostronglylus
49
cerebellar dx in arabian foals ddx
cerebellar abiotrophy
50
cs of shivers
- cerebellar disease
- hindlimb elevation: diff. trimming hind feet, backing, turning
- high fat, low sugar diet? +/- PSSM
- draught horses
51
annual and perennial ryegrass toxicity cs
- vestibulocerebellar signs w/ diffuse spinal or peripheral nerve involvement
- severely affected horses may stumble or fall --> tetanic muscle spasms
- signs often improve w/ recumbency
- excitement or blind-folding exacerbates the signs
- removal from affect fx (recovery 1-3wks)
52
px of annual vs. perennial ryegrass toxs
annual --> suddenly dies - may never fully recover
| perennial --> usu good recovery
53
toxin in annual ryegrass tox
tunicaminyluracil ABs
54
toxin in perennial ryegrass tox
lolitrem B
55
ddx. trigeminal neuropathy
guttural pouch disease, ear mites, other hyoid disorders, EPM
56
trigeminal neuropathy presentation and cs
- 8-10yrs, Geldings > mares
- flicking/tossing nose, rubbing nose, snorting
- often mistaken 'bee-sting'
57
medical management of trigeminal neuropathy
- cyproheptadine - serotonin antagonist/antihistamine
- carbamazepine - anti-convulsant
- nose-nets
58
cs of vestibular syndrome
- head tilt (poll towards lesion)
- nystagmus
- ataxia with strength (if peripheral)
- lean/circle towards lesions, truncal sway
- other signs if central - weakness, somnolence, CNs
59
ddx peripheral vestibular syndrome
- temporal osteopathy
- trauma - fx of stylohyoid
- middle/inner ear disease
- idiopathic
60
ddx central vestibular syndrome
- trauma
- EPM
- abscess/neoplasia/mass
- migrating parasites
- tremorgenic toxins
- diffuse encephalitis
61
signs inc or decrease w/ peripheral vestibular syndrome when blindfolded?
worse!! thus signs increase
62
ddx facial nerve paralysis
- trauma, GA (headcollar)
- multifocal
- GP disease (Strangles!)
63
Cervical vertebral stenotic myelopathy causes
cord compression - stenosis of vertebral canal --> Wobblers
64
typical presentation for Wobblers
TBs + WBs
Males > Females * large rapid growth
4 months - 4yrs (and older)
65
2 major CVSM subtypes
1. Dynamic: young horse, C3-5, stenosis is dependent on position
2. Static: older horse, C6-7, stenosis not position dependent
66
typical CS of type 1 CVSM
- weanling to ~24months
- symmetric
- pelvic limbs > thoracic limbs
- neck pain is rare
- C3-5
67
typical CS/presentation of type 2 CVSM
- older horses 18mo to 4yrs
- occ. asymmetry
- pelvic limbs > thoracic limbs
- neck pain more likely - OA of facet joints
- C5-T1
68
list 4 subjective rad measurements when assessing for CVSM
- alignment
- vertebrae shape and size
- intervertebral foramen
- facet joints
69
list 2 objective rad measurements when assessing for CVSM
- intervertebral sagittal ratios: abnormal <0.485
| - intravertebral sagittal ratios: abnormal if vertebral canal is less than half the size of the vertebral body
70
limitations of myelography to diagnose CVSM
- requires GA in an ataxic horse
| - no as sensitive/specific as first thought
71
treatment of CVSM in foals
- restrict calories
72
tx of cervical facet disease (OA)
- pain w/out neuro signs --> usu older horses
| - tx w/ corticosteroids
73
why might a horse present with spinal neuro signs days after a known trauma?
they can actually 'splint' a fracture w/ their own muscle strength but after a few days they fatigue and fx may displace and cause neuro signs
74
ddx urinary incontinence
- EHV
- trauma eg. foaling
- multifocal/systemic neuro
- chronic sudan grass tox
- urogenital causes
75
pathophysiology of EHV-1
vasculitis (capiliary endothelia) --> thrombosis --> ischaemia --> myeloencephalitis
+/- resp/repro disease
76
cs of EHV-1
- initial biphasic fever: URT infection --> viraemia
- rapid progression (peaks at 24-48hrs) then plateuaus
- spinal cord signs usu. ascending - symmetric paresis and ataxia *HLs, bladder atony (overdistension)
+/- CN/brainstem signs
*usu larger horses, >5yo
77
dx of EHV-1
- nasal swab and whole blood (buffy coat) --> PCR and virus isolation
- serology (paired titres)
- CSF: xanthochromia, increased protein, normal cell count (albuminocytologic dissociation)
78
management of EHV-1
1. Notifiable disease
2. NSAIDs
3. Antivirals: valcyclovir
4. Anti-coags: heparin
5. Supportive: limb support, bladder catheter
79
MOA of tetanus
blocks GABA release - an inhibitory neurotransmitter --> tetany
80
pathophys of clostridium tetani
<1-3wks incubation period
- peripheral/cranial neuropathy: somatic and autonomic nerves affected, symmetrical
- hyperaesthesia and hypertonicitiy: spastic paralysis
81
CS of tetanus
- head then limbs
- muscle rigidity 'saw-horse' stance
- muscle spasms: nictitans prolapse (extraoc. muscles), trismus, dysphagia
- sympathetic overdrive
- recumbency
- resp. failure and death
82
tetanus management
1. reduce stim: dark, quiet, ear plugs
2. Sedation: ACP, phenobarbital
3. Muscle relaxation: Methocarbamol, Diazepam, Midazolam CRI, Dantrolene, MgSO4
4. Source control: Debride and flush wound, metronidazole > Pen.G, antitoxin
83
indicators of good px w/ tetanus
- response to ACP
- stabilises w/in 48hs
- able to eat and stand unassisted
- --> recovery 6-8wks
84
tetanus vax protocol
2 primary vaccines 4-6wks apart --> boosters thereafter
85
MOA of botulism
prevents ACh release from NMJ --> flaccid paralysis
86
tx for botulism
- resp support
- nutritional support
- ABs for secondaries
87
damage to the suprascap nerve causes
sweeney
88
stringhalt is caused by what plant?
Hypochaeris radicata (yellow daisy one)
89
cs of stringhalt + recovery
- laryngeal hemiplegia
- recumbency
- bilateral or polyneuropathy
