Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neurology (Spring 2015) > L05: Neuromuscular Syndromes (Carrera) > Flashcards

L05: Neuromuscular Syndromes (Carrera) Flashcards

1
Q

Motor Unit

A

LMN
Neuromuscular jx
Muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

muscle mass and tone are maintained by:

A

tonic inputs from the LMN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how quickly does denervation atrophy happen?

A

rapidly (5-7days)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Common LMN signs

A 
paresis, plegia
m. atrophy
poor/loss of m. tone
weakness to loss of reflexes
exercise intolerance
paretic, stiff gait
ataxia UNLIKELY
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Disease that affects nerve root of LMN

A

Polyradiculoneuritis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Disease process that affects nerve of LMN

A

polyneuropathies (axon and myelin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

disease processes that affects neuromuscular junction of LMN

A

tick paralysis
botulism
myasthenia gravis
snakebite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

dz proccesses that affects m.

A

inflammatory
infectious
neoplastic
snakes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

chars. of polyradiculoneuritis

A
  • nerve root disorder
  • demyelinating
  • may require ventilation, supportive care
  • mildly delayed nerve conduction velocity
  • albuminocytologic dissociation on CSF
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

CS of polyradiculoneuritis

A
  • acute, ascending flaccid paralysis (MOTOR only)
  • loss of reflexes and tone
  • cn deficit (cn 7)
  • weak gag reflex
  • rapid recovery
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

types of Polyneuropathy

A 
degenerative
paraneoplastic
endocrine
genetic/heritable
infectious
toxic: vincristine (a microtubule modulator)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

CS of degenerative polyneuropathy

A
  • laryngeal paresis/paralysis
  • dysphonia
  • esophageal dysfx
  • esophageal dysfx
  • paresis (esp. in PL)
  • abn. gait
  • common in labs; affects myelin and axons*
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Name 3 endocrine neuropathies

A

Paraneoplastic (ie. insulinoma)
Hypothyroidism
Diabetic neuropathy (cats)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Etiology of Tick Paralysis

A

-effects NEUROMUSCULAR JX
-presynaptic neuromuscular blockade
-Dermacentor & Amblyomma most common
-Dogs flaccid 5-9d after attachment
+/- megaesophagus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

chars. of Tetanus

A
  • effects NEUROMUSCULAR JX
  • toxin produced by Clostridium tetani absorbed at the NMJ and travels to spinal cord
  • inhibits glycine/GABA release at spinal cord –> constant m. contraction
  • cats resistant
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

CS of Tetanus

A

stiffness, lockjaw (trismus), sawhorse stance, elevated nictitans, risus sardonicus (grin) 5-10d post infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Tx of tetanus

A
  • vax only in horses
  • tetanus antitoxin
  • abx, wound debridement
  • sedatives
  • supportive care
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is tetany?

A

hyperexcitability of the membrane due to electrolyte imbalance (is not same as tetanus)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

causes of tetany

A

Na,K,Ca, or Cl- imbalance
hypocalcemia
hypoMg (cows)
strychnine

20
Q

mech. of botulism

A

botulinum toxin blocks presynaptic ACh release from the nerve terminal at the NMJ

21
Q

CS of botulism

A

-progressive, symmetric ascending paresis/paralysis
-loss of reflexes and tone
-cn 7, megaesophagus, decreased gag and jaw tone
+/- mydriasis, constipation, urinary retention

22
Q

Dx of Botulism

A
  • detect organism in ingesta, serum, vomit
  • neutralization in small rodents
  • in vitro test measuring toxin antigenicity
23
Q

Prognosis of Botulism

A

-improves in 1-3 wks after motor endplates have regenerated (2-4mo.)

24
Q

chars. of CONGENITAL Myasthenia gravis

A
  • rare
  • generalized weakness since birth
  • Jack Russels
  • INSUFFICIENT RECEPTORS
  • tx ineffective
25
Q

chars. of ACQUIRED myasthenia gravis

A

Autoantibodies against nicotinic acetylcholine receptors on the post-synaptic membrane
-receptor blocked –> m. weakness
-3 forms:
Focal (esophageal weakness)
Generalized (exercise intolerance)
Fulminant (25% of generalized patients; grave)
-usually immune mediated in younger dogs and neoplastic in older dogs

26
Q

CS of myasthenia gravis

A
  • exercise intolerance
  • postural rxns INTACT
  • reflexes present but withdrawal may be slow
  • NO cn deficits
  • megaesophagus
27
Q

Dx of myasthenia gravis

A
  • Tensilong test using ultra-short acting AChE inhibitor (think video)
  • ACh receptor Ab titer
  • Electrodiagnositcs: repetitive nerve stimulation
28
Q

Tx of myasthenia gravis

A

AChE inhibitor (increases ACh at the NMJ)
Immunosuppression (stops Ab production)
Tx underlying dz

29
Q

Causes of generalized myopathy

A 
immune-mediated
infectious (neospora caninum)
pre/para-neoplastic (lymphoma)
dermatomyositis
congenital (m. dystrophies
30
Q

Chars. of generalized Polymyositis

A
  • generalized weakness, stilted gait, dysphagia, m. atrophy
  • Do NOT lose reflexes
  • Boxers, Newfies
31
Q

Chars. of Masticatory myositis

A

-AutoAb to Type 2M variant muscle fibers, but only expressed in masticatory muscles
-Acute and chronic forms:
acute: pain on opening mouth, mild exophthalmia
chronic: masticatory m. atrophy and fibrosis, can’t open
mouth

32
Q

Dx of masticatory myositis

A

serum 2M antibody titer (Gold Standard!)

33
Q

Tx of masticatory myositis

A

immunosuppression

consider m. biopsy for prognosis

34
Q

extraocular myositis

A
  • can’t move eyes
  • bilateral ventromedial strabismus
  • tx same as masticatory myositis
35
Q

CS of Neospora caninum

A
  • polyradiculoneuritis and polymyositis
  • m. atrophy
  • contracture of PLs
36
Q

which myofibers more affected by endocrine myopathies?

A

Type 2

37
Q

Endocrine myopathy causes

A 
Hypo (dogs) or Hyperthyroidism (cats)
Glucocorticoid excess (dogs)
Electrolyte derangements
38
Q

CS of Hyperthyroidism-induced myopathy in cats

A
  • paresis
  • cervical ventroflexion
  • tremors
  • abnormal gait
39
Q

Toxoplasma gondii can also cause feline myopathy

A

:)

40
Q

CS of snake envenomation

A

mentation, paresis/plegia, rigidity, CP defitis

41
Q

Diamondbacks venom mech.

A

Myokymia - Ca interference on nerve membrane

42
Q

Mojave rattlesnake venom mech.

A

toxin inhibits Ach release at the presynaptic terminal of the NMJ leading to complete neuromuscular blockade

43
Q

Mech. of coral snake venom

A
  • postsynaptic alpha-neurotoxins
  • neuromuscular blockade
  • generalized LMN weakness –> resp. paralysis
44
Q

name 3 congenital myopathies

A

muscular dystrophy (Goldens)
myotonia congenita
hyperkalemic periodic paralysis (horses)

45
Q

Exercise Induced Collapse

A
  • labs
  • collapse, marker hyperthermia during episode but otherwise normal
  • dx of exclusion
  • cause: DNM1 mutation (gene involved in neurotransmission,etc.)
46
Q

myoclonus

A

sudden contraction-relaxation of muscles

-assoc. with distemper

Neurology (Spring 2015) (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions