Trans 053 NMJ Disorders Flashcards
Most common NMJ Disease?
MG
When we say NMJ, we are talking of receptors and neurotransmitters, specifically ______
Ach
This substance block Ach release?
Botulinum Toxin
A drug that blocks Ach receptors? (poison darts)
Curare
What blocks acetylcholinesterase?
Organophosphates
3 mechanisms that causes NMJ problems?
- Decrease Ach release
- Decrease Ach effects on muscle cells
- Decreased acetylcholineesterase activity results in acetylcholine having a stronger effect on mm cell.
NMJ problems can be post or presynaptic, T or F?
T
Pattern of weakness in NMJ? proximal or distal?
Both
is extraocular and facial mm involved in weakness in NMJ?
Yes
NMJ is [variable/constant] within the day?
Variable:
Nagkakaroon kasi ng fatigue, so pag active na active, you need more and more of the Ach, so the patient will have weakness. So patients with NMJ disorders, esp. with myasthenia gravis, pag gising sa umaga, malakas pero by midday, mahina na sila.
Are sensory and tendon reflexes affected in NMJ disorders?
No
Fluctuating weakness is predominantly in proximal/distal muscles and associated with fatigability.
proximal
Ocular and bulbar muscles are frequently [more severely/not much affected]?
more severely
Generalized fatigue without true weakness is not atypical. T or F?
F. TYPICAL
Symptoms of sensory loss, paresthesia, or neuropathic pain are absent. T or F?
T
Autonomic symptoms of dry mouth, blurry vision, impotence, constipation, and difficulty with urination may be noted in
LEMS and botulism
Weakness with predilection for proximal limb, ocular, and bulbar muscles is not typical. T or F?
F. Typical
Extraocular and bulbar weakness are early and prominent in MG and botulism but less prominent in LEMS. If ocular weakness is an initial symptom, LEMS is unlikely. T or F?
T. If ocular weakness is an initial symptom, LEMS is unlikely.
Pupillary responses are usually reduced in
Botulism
Pupils are not affected in MG. T or F?
T
Reflexes are characteristically present/absent in presynaptic NMJDs but preserved/absent in postsynaptic NMJDs.
absent
preserved
Facilitation of reflexes with brief exercise is pathognomonic of
LEMS
NMJ DISORDERS can be subdivided into 3: what are those?
Toxin induced
Immune Mediated
Genetic
For toxin induced NMJ disorder what are the examplse?
Botulism
snake venoms
organophosphates