Upper or Lower Motor Neuron Lesion?

Sign: Weakness

Both UMN & LMN lesions have this sign

Atrophy

Lower Motor Neuron Lesion

Decreased Muscle Tone

Lower Motor Neuron Lesion

Clonus

Upper Motor Neuron Lesion

Decreased Reflexes

Lower Motor Neuron Lesion

Fasciculations (contractions of a small # of motor units causing worm-like contractions)

Lower Motor Neuron Lesion

Negative Babinski Sign

Lower Motor Neuron Lesion

No Clonus

Lower Motor Neuron Lesion

Describe the findings of a Lower Motor Neuron Lesion

Muscle Weakness, Atrophy, and Fasciculations Decreased Reflexes & Muscle Tone Negative Babinski Sign, No Clonus

Describe the findings of an Upper Motor Neuron Lesion

Muscle weakness, Clonus, Positive Babinski Sign Increased Reflexes & Muscle Tone No Fasciculations or Atrophy

Increased Muscle Tone

Upper Motor Neuron Lesion

Increased Reflexes

Upper Motor Neuron Lesion

Positive Babinski Sign

Upper Motor Neuron Lesion

spastic motor responses that feature increased muscle tone, hyperactive muscle stretch reflexes, and clonus

Upper Motor Neuron Lesion