Lower Motor Neuron Lesions

Question 1

What is a lower motor neuron lesion?

Answer 1

disrupts the nerve pathways from the spinal cord to the muscles, resulting in weakness, reduced reflexes, and potentially muscle atrophy and fasciculations

Question 2

Weakness

Answer 2

Muscles become weak or paralyzed due to the inability to receive signals

Question 3

Hyporeflexia/Areflexia

Answer 3

Reduced or absent reflexes because the efferent (motor) limb of the reflex arc is interrupted

Question 4

Flaccid Paralysis

Answer 4

Muscles become floppy and lack tone due to the loss of excitatory drive from the neuron

Question 5

Muscle Atrophy

Answer 5

The affected muscles can shrink due to disuse and denervation

Question 6

Fasciculations

Answer 6

Involuntary twitching of muscle fibers, potentially seen as a sign of lower motor neuron damage

Question 7

Spinal Muscular Atrophy (example)

Answer 7

A group of genetic diseases where motor neurons in the spinal cord degenerate

Question 8

Bell’s Palsy (example)

Answer 8

Facial paralysis due to damage to the facial nerve

Question 9

Motor Neurone Disease

Answer 9

Also known as Amyotrophic Lateral Sclerosis (ALS), a progressive neurodegenerative disorder affecting motor neurons

Question 10

Muscular dystrophy

Answer 10

A group of genetic disorders causing muscle weakness and atrophy

Question 11

Hyoptonia/ hypertonia

Answer 11

-Decreased muscle tone (lower)
-increased muscle tone (upper)

Question 12

Location of lower motor neuron lesions

Answer 12

located in the spinal cord or peripheral nerves, result in flaccid paralysis, hyporeflexia, and muscle atrophy