Neuromuscular System Flashcards
NM01-04 (89 cards)
1
Q
start of NM01
name the 5 steps of the neurological exam of horses
A
- head
- neck & trunk
- Perineum
- gait & posture
- autonomous zones
2
Q
name 2 diseases that could cause ‘dirty tongue’ in horses
A
- botulism (weak tongue)
- choke
3
Q
list the 7 structures involved in the pupillary light reflex (PLR) in order
A
- optic nerve
- optic chiasm
- optic tract
- pretectal nucleus
- oculomotor nucleus
- oculomotor nerve
- ciliary ganglion
4
Q
what will the pupil of an eye affected with an optic nerve lesion do in response to indirect light stimulation
A
constrict
5
Q
what will the pupil of an eye affected with an optic nerve lesion do in response to direct light stimulation
A
dilate
6
Q
should you remove an eye that can elicit an indirect PLR in the other eye?
A
no! it is still functional
7
Q
name the 10 structures involved in the menace response in order
A
- optic nerve
- optic chiasm
- optic tract
- lateral geniculate nucleus
- optic radiation
- occipital cortex
- motor cortex
- internal capsule
- facial nucleus
- facial nerve
8
Q
name the 2 cranial nerves involved in the palpebral reflex
A
- afferent CN 5
efferent CN 7
9
Q
name the 3 cranial nerves that innervate extraocular muscles
A
- CN 3
- CN 4
- CN 6
10
Q
what spinal cord segments are included in cervical intumescence
A
C7-T2
11
Q
list the 3 part pathway of the cuntaneous trunci reflex
A
- dorsal route into spinal cord
- cervical intumescence (C7-T2)
- lateral thoracic nerve
12
Q
name the part of the horse
consists of:
sacrococcygeal spinal cord segments, spinal nerve rootlets and roots, sacral plexus and peripheral nerves to the bladder, rectum, anus, tail and perineum
A
cauda equina
13
Q
name 2 sites where CSF can be collected from the subarachnois space at
A
- atlanto-occipital site
- lumbosacral site
14
Q
which location should be used forCSF location if brain lesion is suspected
A
atlanto-occipital site
15
Q
which location should be used forCSF location if spinal lesion is suspected
A
lumbosacral site
16
Q
what will be the clinical signs of a spinal cord lesion in C1-C5
A
increased tone and ataxia of all limbs
17
Q
what will be the clinical signs of a spinal cord lesion in C6-T2
A
increased tone and ataxia of pelvic limbs ;
paresis of thoracic limbs
18
Q
what will be the clinical signs of a spinal cord lesion in T3-L3
A
normal thoracic limbs ;
incr tone and ataxia of pelvic limbs
19
Q
what will be the clinical signs of a spinal cord lesion in L4-S3
A
normal thoracic limbs;
paresis of pelvic limbs
20
Q
what will be the clinical signs of a spinal cord lesion in Cd1-5
A
perineal paresis and hypalgesia
21
Q
start of NM02
what kind of deficit causes ataxia
A
proprioceptive deficit
22
Q
name the type of ataxia
due to loss of conscious and subconscious proprioceptive pathways;
compression lesions always UMN paresis also
A
spinal cord ataxia
23
Q
name the type of ataxia
loss of balance, ipsilateral antigravity muscle paresis (nystagmus, circling)
A
vestibular ataxia
24
Q
name the type of ataxia
loss of subconscious proprioception only (hypermetria)
A
cerebellar ataxia
25
name 5 causes of spinal cord ataxia "wobblers"
1. cervical vertebral malformation
2. trauma
3. EHV-1 myeloencephalopathy
4. EPM
5. West Nile virus encephalomyelitis
26
# name the grade of spinal cord ataxia
just evident
grade 1
27
# name the grade of spinal cord ataxia
owners can spot
grade 2
28
# name the grade of spinal cord ataxia
severe
grade 3
29
# name the grade of spinal cord ataxia
about to fall over
grade 4
30
this is a structural narrowing of the spinal canal due to a variety of vertebral malformations and potentially trauma that leads to spinal cord compression;
horses exhibit clinical signs of general proprioceptive deficits and UMN spasticity and paresis
cervical vertebral malformation
31
why is pelvic limb ataxia invariably worse in cervical vertebral malformation (CVM)?
peripheral location of spinocerebellar tracts
32
name 6 clinical signs of cervical vertebral malformation (CVM)
1. knuckling, stumbling and toe dragging (paresis)
2. lack of coordination in foot placement
3. delayed corrective response when limbs in abnormal location
4. tight circling reveals both circumduction and pivoting on inside limb
5. dysmetria
6. worse pelvic limb ataxia
33
# name the type of cervical vertebral malformation (CVM)
large, younger horses;
various manifestations of developmental orthopaedic disease;
vertebral canal stenosis/wedging/angular fixation;
often C3-C4
type 1 cervical vertebral malformation (CVM)
34
name 4 characteristics/morphologies of type 1 cervical vertebral malformation (CVM)
1. angulation
2. OCD lesions of articular process joints (not 'facets')
3. epiphysitis
4. caudal extension of dorsal arches
35
what size must the vertebral canal be in relation to the width of the vertebra
more than 50% of the width of the vertebra
36
# name the type of cervical vertebral malformation (CVM)
large, older horses;
arthritis of caudal cervical vertebrae;
compression of spinal cord by bone and soft tissues
type 2 cervical vertebral malformation (CVM)
37
how to treat cervical vertebral malformation (CVM) via surgery?
fusion of vertebral bodies
38
this is a disease caused by equine alphaherpes 1 virus (EHV-1);
spread from horse to horse through contact with nasal discharge, aerosol droplets or fomites;
incubation period ranges from 2-10d;
worldwide outbreaks of abortion and resp disease;
reservoir is latently infected horses (trigeminal ganglia)
equine herpes myeloencephalopathy (EHM)
39
name 5 clinical signs of equine herpes myeloencephalopathy (EHM)
1. acute onset symmetrical ataxia and paresis
2. signs progress rapidly ~2d, then stabilise
3. pelvic limb ataxia > thoracic limbs
4. CSF often xanthochromic
5. cauda equina signs
.
40
what is the diagnostic test of choice for equine herpes myeloencephalopathy (EHM)
quantitative PCR of nasal swabs and anticoagulated blood
41
how to treat equine herpes myeloencephalopathy (EHM)?
early dexamethasone and antiviral agents (Valacyclovir)
42
name 4 places vestibular nuclei project to
1. extraocular nuclei
2. spinal cord
3. cerebellum
4. cerebrum
43
what muscles does the vestibular system facilitate?
ipsilteral antigravity muscles
44
what muscles does the vestibular system inhibit?
contralateral antigravity muscles
45
what cells in the cerebellum inhibit UMNs?
Purkinje cells
46
what clinical sign will cerebellar pathology result in?
hypermetria
(incoordination with big movements)
| (no paresis)
47
# start of NM03
name 3 inflammatory/infectious causes of forebrain disease
1. viral diseases
2. meningitis in foals
3. polyneuritis equi
48
name 2 metabolic forebrain diseases
1. hepatic encephalopathy
2. neonatal hypoxia/ischaemia
49
name 2 toxic causes forebrain diseases
1. leukoencephalomalacia
2. intracarotid injections
50
# name the bacterial CNS infection
failure of passive transfer;
gram neg organisms;
forebrain signs/head held lowered in rigid extension;
depressed mental status;
recumbency, weakness, abnormal PLRs, decr suckling reflex, seizures
foal septicaemia-meningitis
51
this is the most common cause of diffuse brain disease of horses in UK;
pyrrolizidine alkaloids (ragwort)
hepatic encephalopathy
52
what are the clinical signs of hepatic encephalopathy due to?
imbalance of GABA and glutamate
53
name 8 clinical signs of hepatic encephalopathy
1. icterus
2. weight loss
3. diarrhoea
4. abdominal pain
5. head pressing
6. yawning
7. leaving food in mouth
8. seizures
54
name 4 clinical signs of neonatal encephalopathy - usually delayed few hours to 2 days
1. reduced awareness of environment
2. failure to find udder and suck
3. funny 'barking' noises
4. lack of affinity for mare
55
name 2 important causes to r/o when diagnosing neonatal encephalopathy
1. failure of passive transfer
2. sepsis
56
this nerve contains somatic fibres that innervate the muscles of facial expression & parasympathetic fibres that stimulate tear production;
courses through middle ear, dorsal aspect of guttural pouch, ventral ramus of mandible and ventral to the facial crest
facial nerve
57
name 3 clinical signs of guttural pouch mycosis
1. CN VII/VIII
2. horners syndrome
3. dysphagia
58
name 4 clinical signs of temporohyoid osteoarthropathy (when the petrous temporal bone fuses with the temporohyoid joint)
1. CN VIII
2. CN VII
3. head shaking
4. dysphagia
59
what is the surgical treatment of temporohyoid osteoarthropathy
removal of one of the bones of the hyoid apparatus
(ceratohyoidectomy)
60
this is chronic granulomatous inflammation of the extradural nerve roots of many peripheral nerves;
can present first with cranial nerve signs (VII/VIII);
progressive disease and early euthanasia should be considered
polyneuritis equina
61
name 2 exercise-related myopathies
1. spradic exertional rhabdomyolysis
2. chronic exertional rhabdomyolysis
62
name 9 key clinical signs associated with weakness
1. narrow base stance
2. low head carriage
3. weight loss
4. incr periods of recumbency
5. dyaphagia
6. weight shifting
7. muscle tremors
8. reluctance to move
9. toe dragging
| (NO ATAXIA)
63
name 6 generalised neuromuscular diseases causing weakness/myasthenia
1. myopathies
2. botulism
3. EMND
4. electrolyte disorders (HPP & hypocalcaemia)
5. EGS
6. myaesthenia gravis
64
name 5 generalised neuromuscular diseases causing stiffness/spasticity/hypertonia
1. myopathies
2. electrolyte disorders (HPP & hypocalcaemia)
3. tetanus
4. shivering
5. stiff horse syndrome
65
# name the disease causing classic myaesthenia
found ubiquitously in soil;
grows and produces toxin in anaerobic environments (decaying veg and animal carcasses);
silage provides suitable growth medium;
horses most susceptible to B and C toxins;
toxins block acetylcholine release and cleaves proteins required for vesivle release
Clostridium botulinum
(Botulism)
66
name 3 locations where botulism toxin blocks acetylcholine release at
1. neuromuscular junctions
2. peripheral cholinergic nerve terminals in autonomic ganglia
3. post-ganglionic parasympathetic nerve endings
67
name 3 modes of intoxication with botulism
1. ingestion of preformed toxin (forage poisoning)
2. growth of organism in GIT (toxicoinfectious botulism)
3. contamination of wounds (wound botulism)
68
name 3 clinical signs of Botulism in the early stages
1. depression
2. inappetence
3. exercise intolerance
69
name 3 cranial nerve signs seen in a horse with Botulism
1. sluggish PLR
2. dysphagia (V, VII, IX, X), salivation
3. reduced tongue tone
70
name 5 clinical signs associated with gait and posture in a horse with botulism
1. weak
2. fasciculation
3. sloppy, short gait
4. low head carriage
5. symmetrical and predictable
| (NO ATAXIA)
71
# name the disease characterised by stiffness
found in soil and GIT;
requires anaerobic conditions;
consider sites of contamination - puncture wounds!
produces potent endotoxins
Clostridium tetani
(Tetanus)
72
name 2 potent exotoxins produced by C. tetani
1. tetanolysin
2. tetanospasmin
73
# name the C. tetani exotoxin
promotes necrosis and spread of infection
tetanolysin
74
# name the C. tetani exotoxin
inhibits exocytosis of GABA and glycine
tetanospasmin
75
name 6 clinical signs of tetanus
1. change in gait (stilted action)
2. difficulty eating
3. spastic muscle contractions
4. head and neck extension
5. elevated tail head
6. anxious expression
76
name 3 features of an anxious expression in horses
1. flared nostrils
2. retracted eyelids
3. erect ears
77
name 5 therapeutics for a horse with tetanus
1. ACP
2. sodium benzyl penicillin
3. procaine penicillin
4. antitoxin
5. hydrogen peroxide (1%)
78
how to prevent tetanus?
VACCINATION
79
# name the exercise related neuromuscular disorder
classic 'tying up'/set fast;
generally one-off incidents;
associated with training/feeding mismanagement;
easily managed and treated;
unclear metabolic dysfunction within muscle leading to muscle hypoxia;
hindlimbs especially affected
sporadic exertional rhabdomyolysis
80
name 5 clinical signs of sporadic exertional rhabdomyolysis
1. painful muscles
2. sweating
3. elevated rectal temp
4. red/brown urine!
5. stiff stilted gait
81
name 2 laboratory findings in a horse with sporadic exertional rhabdomyolysis (ER)
1. elevation in muscle-derived enzymes (CK, AST)
2. myoglobinuria
82
name 4 differential diagnoses for sporadic exertional rhabdomyolysis (ER)
1. laminitis
2. colic
3. injuries to pelvic region
4. aorto-iliac thrombosis
83
name 4 parts of treatment for sporadic exertional rhabdomyolysis (ER)
1. rest
2. analgesia (NSAIDs)
3. sedatives (acepromazine)
4. fluids (in severe cases)
84
name 4 key give aways for acute severe myopathy (atypical myopathy)
1. time of year (autumn)
2. signs of myopathy
3. brown urine
4. high CK/AST
85
# name the exercise related neuromuscular disorder
mainly thoroughbreds, fillies, and those with nervous temperaments;
pathophysiology unknown - altered intracellular calcium balance may be involved;
recurrent exertional rhabdomyolysis (RER)
86
name 3 glycogen storage disorders
1. Glycogen Branching Enzyme Disease (GBED)
2. Polysaccharide Storage Myopathy (PSSM)
3. Equine Polysaccharide Storage Myopathy (EPSM)
87
# name the glycogen storage disorder
quarter horse and related breeds (morgan, appaloosa, paints);
recurrent episodes of 'tying up';
CK and AST raised disproportional to amount of work and remains elevated for considerable time
Polysaccharide Storage Myopathy (PSSM)
88
this is a specific mutation in the glycogen synthase gene (single base pair substitution);
autosomal dominant (N/N vs P/N vs P/P)
Polysaccharide Storage Myopathy (PSSM) type 1
| (all other types of PSSM denoted type 2)
89
this is a transient event caused by cerebral hypoperfusion
syncope
