Upper Motor Neuron Lesions

Hemiplegia

paralysis on one side of the body

Cortex or internal capsule

An upper motor neuron lesion may occur as a result of damage to where?

Stroke

Common cause of upper motor neuron lesion

Spinal cord lesion

What affects CNS pathways?

Atrophy, fibrilations, fasciculations

What are NOT signs of an upper motor neuron lesion?

Flaccid paralysis and spinal shock (similar to a lower motor neuron lesion)

What are the initial signs of an upper motor neuron lesion?

Increased tone; rigid, exaggerated response Hyper innervation of reflex loops Hyperflexia (knee jerk)- spastic paralysis (spasticity) Clasp-knife phenomenon

What are the later signs of an upper motor neuron lesion?

Arm/leg usually affected together on the contralateral side

What is affected if an upper motor neuron lesion occurs before axons cross over?

Weakness or paralysis

What is common to both an upper motor neuron and lower motor neuron lesion?

Trunk (due to bilateral projections at cord)

What is usually not affected by an upper motor neuron lesion?

Babinski's sign

present in an infant and people with upper motor neuron lesions absent in healthy adults big to extends, toes fan Reflex indicates corticospinal tract is not intact