Upper Vs Lower Neuronal Lesion

Question 1

Signs of Motor Neuron Lesions =

Answer 1

Paresis/Paralysis
Muscle atrophy
Involuntary mms contractions
Abnormal tone
Abnormal reflexes
Muscle hyper-stiffness
Disturbances of movement efficiency and speed
Impaired postural control

Question 2

Central Nervous Signs/Sx =

Answer 2

Brain and Spinal Cord

Increased Tone
> Spasticity
> Rigidity
Clonus/Babinski

Increased Deep Tendon Reflexes

Atrophy over a prolonged period of time

Question 3

Peripheral Nervous Signs/SX =

Answer 3

Outgoing/Input “Wires”
Decreased Tone/Flaccidity
No or diminished DTRs
Quick atrophy

Question 4

Muscle tone =

Answer 4

Peripheral + Central Components

Normal Muscle Tone =Palpable stiffness (stretch resistance) in resting muscles

Question 5

Low Muscle Tone =

Answer 5

hypotonia or flaccidity
LMN lesions
Acute UMN lesions (usually temporary)
Developmental disorders

Question 6

High Muscle Tone =

Answer 6

Chronic UMN lesions
Some basal ganglia disorders
May be spastic or rigid

Question 7

Abnormal Muscle Tone =

Answer 7

Brain is the mediator
Spinal Cord is the router
Peripheral nerves are just wires sending signals

No dampening of signals – increased tone, spasticity, rigidity, and a cycling of stretch reflexes

Question 8

-Paresis =

Answer 8

A decrease in the amount of movement or strength

Hemi- One side of the body (R vs L)

Para- Caudal half (below arms)

Tetra*- All limbs

Question 9

-Plegia (paralysis) =

Answer 9

A complete loss of the ability to move

Hemi-
Para-
Tetra*-
Formerly Quad-

Question 10

What is Atrophy?

Answer 10

loss of muscle bulk

Denervated muscles demonstrate the most severe atrophy; even small, partial innervation will maintain some muscle fibers’ health

LMN damage results in rapid atrophy due to changes in the pattern of protein production

UMN damage = Muscles still receive stimulation from intact LMNs and atrophy is slower

Question 11

Neurogenic atrophy:

Answer 11

due to nervous system damage

Question 12

Disuse atrophy:

Answer 12

due to disuse

Question 13

Types of Involuntary Muscle Contractions =

Answer 13

Abnormal movements due to basal ganglia dysfunction

muscle spasms
cramps
myoclonus
fasciculations
fibrillations

Question 14

Muscle spasms =

Answer 14

Sudden, involuntary contractions of muscles

Question 15

Cramps =

Answer 15

Particularly severe and painful muscle spasms

Question 16

Myoclonus =

Answer 16

Brief, involuntary contractions of a muscle or group of muscles

May occur in a healthy nervous system or be signs of pathology (dependent on context)

Question 17

Fasciculations =

Answer 17

Quick twitches of single motor unit muscle fibers that are visible on the surface of the skin

Question 18

Fibrillations =

Answer 18

Brief contractions of single muscle fibers not visible on the surface of the skin

May occur with UMN or LMN disorders

Question 19

Spinal/Cerebral Shock =

Answer 19

Occurs when UMN lesion disrupts descending motor command and results in a temporary inactivity of the LMNs
> Cannot elicit stretch reflexes, muscles are hypotonic

After recovery, interneurons and LMNs become active again but activity is no longer modulated by UMNs

Often in the months after UMN lesion muscle tone and stiffness increases within causing excessive resistance to muscle stretch

Question 20

the differences between sensory losses at C7 and C8 =

Answer 20

Injury at ~C7 on (R)

Anterolateral spinothalamic tract
> Discriminative pain and temperature
> Fibers cross at spinal cord entrance

Impacting C7 fibers crossing anteriorly and those below after the decussation
> C7 (R) & below C8 (L)

Question 21

Flushing =

Answer 21

Vasodilation

Question 22

Miosis =

Answer 22

Dilator pupillae muscle paralysis (Muller’s) with pupil constriction

Question 23

Ptosis =

Answer 23

Eyelid falling or drooping

Question 24

Enophthalmosis =

Answer 24

Recession of eyeball in orbit

Question 25

Presentation is like Horner’s Syndrome =

Answer 25

Would have anhidrosis

Question 26

Autonomic Nervous System outputs =

Answer 26

Thoracolumbar – Sympathetic
Craniosacral - Parasympathetic

Question 27

Innervation of visceral muscles and glands =

Answer 27

Cardiac muscles, lungs, secretory glands

GI tract - large portions of its innervation is localized

Question 28

Parasympathetic Nervous System =

Answer 28

Homeostasis (Rest and repose #chillin’)

Question 29

Sympathetic Nervous System =

Answer 29

Arousal (Fight or flight)

Cell bodies of the preganglionic neurons are located in the thoracic intermediolateral gray horn.

So, while the sympathetic paravertebral ganglia are physically intact, their neurons are impacted by the site of lesion because the artery involved also supplies the SNS ganglia.