5. Symptoms of upper and lower motorneuron lesions Flashcards
Define upper motor neuron lesion
Damage anywhere along the corticospinal (pyramidal) tract
What does upper motor neuron lesion lead to?
Spastic paralysis of the associated muscles (hyperreflexia)
Most important symptom of upper motor neuron lesion
Positive pyramidal signs
- babinski
- hyperreflexia
- weakness
- spasticity
Where does the ventral corticospinal tract decussate?
It doesn’t
Where does lateral corticospinal tract decussate?
Medulla, pyramidal decussation
What does the ventral corticospinal tract innervate?
Trunk and upper leg muscles (posture and locomotor)
What does lateral corticospinal tract innervate?
Distal limb muscles (fine manipulation)
What % of fibers go through lateral corticospinal tract? (the rest going thourgh ventral)
80%
Define lower motorneuron lesion
Damage anywhere from anterior horn cells of spinal cord to the muscle innervation (nerve roots, plexuses or peripheral nerves)
What does lesion of lower motorneuron lead to?
flaccid paralysis of associated muscles
What is the function of fibers going through anterior horn?
Motor function
Most important symptom of lower motor neuron lesions:
Visible fasciculations
8 different symp./clinical signs to list when comparing UMNL and LMNL (list them only)
Paresis, muscle volume, muscle tone, muscle power, deep tendon reflexes, pyramidal signs, fasciculations, muscles involved
UMNL vs LMNL: paresis
UMNL: spastic (flexors of upper limbs, extensor of lower)
LMNL: flaccid
UMNL vs LMNL: muscle volume
UMNL: initially no atrophy, later diffuse
LMNL: hypotrophy/atrophy, due to no innervation
