Upper Vs Lower Motor Neuron Lesions

Question 1

What is an upper motor neuron lesion?

Answer 1

an injury or abnormality that affects the neural pathway above the spinal cord’s anterior horn cell or cranial nerve motor nuclei.

Question 2

What is a lower motor neuron lesion?

Answer 2

damage or dysfunction of the nerve cells that directly control muscle movement

Question 3

Location of upper motor neuron lesion

Answer 3

originate in the cerebral cortex or brainstem and project down to synapse with LMNs. Brain and spinal cord (central nervous system)

Question 4

Location of lower motor neuron lesion

Answer 4

originate in the spinal cord or brainstem and project directly to muscles (spinal cord- peripheral)

Question 5

Paralysis in upper

Answer 5

Spastic (increased tone/ hypertonia)

Question 6

Paralysis in lower

Answer 6

Flaccid (decreased tone/ hypotonia)

Question 7

Reflexes in upper vs lower

Answer 7

-Hyperereflexia (upper)
-Hyporeflexia (lower)

Question 8

Babinski sigh in upper vs lower

Answer 8

-Positive (toes point upward/ upper)
-negative (toes point downwards or no response/ lower)

Question 9

Atrophy in upper vs lower

Answer 9

-May occur with prolonged immobilization (upper)
-characteristic (lower)

Question 10

Fasciculations In upper vs lower

Answer 10

-May occur (upper)
-present (lower)