Neurologic organization

Question 1

LMN

Answer 1

Weakness/paralysis
Decreased/absent muscle tone
Decreased/absent reflex strength
Rapid muscle wasting

Question 2

LMN caused by

Answer 2

poliomyelitis, 
MN disease, 
spinal cord injury, 
peripheral nerve dysfunction, 
muscle myotonias, 
myasthenia gravis, 
muscular dystrophies

Question 3

UMN

Answer 3

Weakness/paralysis
Increased muscle tone
Increased reflex strength + babinski sign
Muscle mass maintained

Question 4

UMN caused by

Answer 4

Stroke (contralateral symptoms), cord section

Question 5

muscle

Answer 5

No sensory symptoms
Usually bilateral 
Usually proximal weakness
Usually have muscle pain
Can have muscle atrophy

Question 6

NMJ

Answer 6

No sensory symptoms
Usually bilateral
Fatiguability (weakness that varies w/ use of muscles)
Symptoms affect limbs and face

Question 7

Peripheral Nerve

Answer 7

Usually affects BOTH sensory and motor
Does NOT usually affect both arm and leg on same side
Does NOT usually affect a full extremity

Question 8

Mononeuropathy/__multiplex

Answer 8

Unilateral
Fits one nerve distribution
If multiple individual nerves --> mononeunropathy multiplex
asymmetric
Specific nerves

Question 9

polyneuropathy

Answer 9

Bilateral
Distal > Proximal
Stocking/glove
Usually sensory, less commonly both, rarely pure motor

Question 10

C5 myotome

Answer 10

deltoid: abduction of shoulder

Question 11

C5/6 myotome

Answer 11

flexion of arm, biceps

Question 12

C7 myotome

Answer 12

triceps reflex, elbow extension

Question 13

L4 myotome

Answer 13

leg extension at knee, patellar tendon reflex

Question 14

L5 myotome

Answer 14

dorsiflexion at angle

Question 15

S1 myotome

Answer 15

plantar flexion at ankle

Achilles tendon reflex

Question 16

LMN disease

Answer 16

No sensory symptoms
Systemic process (like polyneuropathy)
LMN signs

Question 17

Spinal cord disease/lesion

Answer 17

Sensory level
Commonly split pain/temp and vibration/proprioception
No facial involvement

Question 18

Brainstem lesion

Answer 18

Cranial nerve abnormality
Face involvement on one side, body involvement on the other
Usually affects a cranial nerve (with a few exceptions)

Question 19

Internal capsule lesion

Answer 19

Equal face/arm/leg weakness

Less prominent or no sensory loss

Question 20

Thalamus lesion

Answer 20

Often face/arm/leg numbness

Minimal to no motor loss

Question 21

Cortex/Corona radiata lesion

Answer 21

Often affects higher functions:

language, attention, memory ,vision, visuospatial, behavior