Summary Pharmacology: Disorders of Motor and Brain Function

Disorders of Motor and Brain Function
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neuromuscular junction (NMJ) >
- peripheral polyneruopathy
• synapse between motor neuron and skeletal muscle • disorder of multiple peripheral nerves
fiber - cause muscle weakness, with or w/out atrophy
• transmission of impulses mediated by achetylcholine and sensory changes
from axon terminals • demyelination or axonal degeneration of multiple
- ACh binds to receptors in end plate region of peripheral nerves
muscle fiber leads to muscle contraction - leads to symmetric sensory, motor, mixed
movement planning sensorimotor deficits
• primary motor cortex - execution of movements • longer axons involved first, symtpms begin in
• premotor cortex - planning of movements distal extremities
• supplemental - rehearsing sequence of movements • caused by immune-mediated mechanisms,
> myasthenia gravis (autoimmune) exposure to toxins, metabolic conditions
• disorder of transmission at NMJ - affects >
- guillain-barre syndrome
communcation between motoneuron and innervated • acute, immune-mediated polyneuropathy
myocyte
• occur at any age, peak in young adulthood, 3x more • motor function, sensory functioning
common in female • etiology and pathogenesis
• etiology and pathogensis - infiltration of mononuclear cells in peripheral
- caused by sensitized helpter T cels, antibody neurons, demyelination of neurons
directed attack on Ach receptors in MNJ, impaired signal • clinical manifestations
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transmission - progressive, ascending muscle weakness of limbs
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clinical manifestations - paresthesia, numbness, cranial nerve impairments
• generalized weakness, fatigue - ANS response: postural hypotension, arrythmias,
• ptosis, diplopia facial flush, diasphoresis, urinary retention
• dysphagia - pain
• proximal limb weakness - starts goes distal • treatment
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• myasthenic crisis - airway and breathing - supportive measures based on paralysis (airway
involvement, increase in times of stress involvement)
Y treatment
- IVIG
• reversible cholinesterase inhibitors - neostigmine
- cerebellum
• immunosuppresive therapies
• IVIG - in crisis • coordination of motor movements (run, swim, jog)
• supportive measures during crisis - ABCDE • disorder cause - congentical, vascular accident,
>
- reversible cholinesterase inhibitors - neostigmine tumor
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- basal ganglia (BG)
• therapeutic uses • deep, interrelated subcortical nuclei - control of
- reversal of depolarizing MN blocking agents movements
• complications • recieve indirect input from cerebellum and sensory
- excessive muscarinic stimulation: systems and direct input from motor cortex
- increased GI motility/secretions, diaphoresis, - function in organization of inherited and highly
increased salivation, bradycardia, urinary urgency learned movements
- cholinergic crisis - bronchospasm and cardiac arrest - cognitive and perceptive functions
• contraindications
g

• disorder characteristics - involuntary movements,
- pregnancy/lactaation, obstruction of Gi and renal, alterations in muscle tone, body posture
seizure disorder, hyperhthroidism, PUD, asthma, disturbances
bradycardia, hypotension
• interactions
atropine, NM blockers
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