Motor Tracts

Question 1

Where are the cell bodies of the UMNs located?

Answer 1

Cerebral cortex or brainstem

Question 2

What type of motor neurons are the cranial and peripheral nerves?

Answer 2

LMNs

Question 3

Fibers traveling through the medial corticospinal tract innervate what muscles?

Answer 3

Postural muscles

Question 4

Fibers traveling through the lateral corticospinal tract innervate what muscles?

Answer 4

Limb muscles

Question 5

Voluntary motor action is associated with what tract?

Answer 5

Corticospinal

Question 6

Fractionation of movement is associated with what tract?

Answer 6

Lateral corticospinal tract

Question 7

What horn do the UMNs and LMNs of the corticospinal tract synapse?

Answer 7

Ventral

Question 8

What part of the internal capsule do the cell bodies of the corticospinal tract travel through?

Answer 8

Posterior limb

Question 9

Lesion in the median corticospinal tract would affect what structures? On what side?

Answer 9

Ipsilateral postural muscles

Question 10

What are the cranial nerves are influenced by the corticobulbar tract?

Answer 10

5, 7, 9, 10, 11, 12

Question 11

What part of the internal capsule does the corticobulbar tract travel through?

Answer 11

Genu

Question 12

What is the relationship between the corticobulbar and corticospinal tracts?

Answer 12

Corticobulbar travels medially to corticospinal

Question 13

If CN IX is being influenced by the corticobulbar tract, what side is being affected?

Answer 13

Ipsilateral

Question 14

What muscles do the medial LMNs in the ventral horn innervate? Lateral?

Answer 14

Medial project to axial muscles

Lateral project to limbs

Question 15

What tracts do the medial LMNs receive input from?

Answer 15

Tectospinal

Medial vestibulospinal

Medial reticulospinal

Medial corticospinal

Lateral vestibulospinal

Question 16

What tracts do lateral LMNs receive input from?

Answer 16

Rubrospinal

Lateral reticulospinal

Lateral corticospinal

Question 17

Which vestibulospinal tract goes to all spinal levels? What side does it innervate?

Answer 17

Lateral Vestibulospinal tract

Ipsilateral

Question 18

Where do the medial vestibulospinal fibers terminate?

Answer 18

T2 to T3

(innervate neck and shoulder muscles)

Question 19

Which reticulospinal tract innervates postural muscles and limb extensors? What side?

Answer 19

Medial reticulospinal (pontine)

Ipsilateral

Question 20

What neurons do the lateral (medullary) reticulospinal tract facilitate and inhibit?

Answer 20

Facilitates flexor motor neurons

Inhibits extensor motor neurons

Question 21

What does the rubrospinal tract innervate?

Answer 21

Upper limb flexors

Question 22

What tract is involved with visual reflexes to auditory stimuli?

Answer 22

Tectospinal

Question 23

Patient presenting with flaccid paralysis, muscle atrophy, hyporeflexia, and hypotonia or fasciculations probably has a lesion where?

Answer 23

Lower motor neurons

Question 24

What tract is lost in UMN syndrome?

Answer 24

Corticospinal tract (direct)

Loss of regulation from indirect pathway

Question 25

In an UMN lesion, what is overactive and what is underactive?

Answer 25

Overactive: Muscles - hypertonic, spastic (collapse of resistance at end of ROM), hyperreflexia Underactive: distal extremity strength

Question 26

What side and level would LMN lesion signs manifest?

Answer 26

Ipsilateral at the level of the lesion

Question 27

Where would a UMN lesion have contralateral and ipsilateral clinical signs?

Answer 27

Contralateral - Above lower medulla (where corticospinal tract crosses) Ipsilateral - Spinal cord

Question 28

If UMN is lesioned, where do the clinical signs manifest?

Answer 28

Below level of lesion

Question 29

If a patient has decorticate posturing, where is the lesion?

Answer 29

Above the level of the red nucleus (UMN)

Question 30

In decerebrate posturing, what nuclei is the lesion located between?

Answer 30

Below red nucleus, above reticulospinal and vestibulospinal

Question 31

After suffering an injury to the spinal cord, a patient initially shows +1/4 DTRs. After a period of a couple weeks, pt shows +4/4 DTRs. What disorder does he have? What has been lesioned?

Answer 31

Spinal shock Corticospinal tract (appears as a UMN lesion)

Question 32

Patient presents with hemiparaplegia on the ipsilateral side and hemianesthesia on the contralateral side. What syndrome is this and what has been lesioned?

Answer 32

Brown Sequard's Syndrome UMN of the CST, Dorsal column, spinothalamic tract

Question 33

In a syringomyelia, what is affected if that pt has LMN signs?

Answer 33

Ventral horns

Question 34

In a syringomyelia, what is affected if that pt has UMN signs?

Answer 34

Lateral corticospinal tract

Question 35

Patient with ipsilateral flaccid paralysis and hyperreflexia, contralateral loss of pain and temperature sensation. However, vibratory sense is intact. You suspect that the anterior spinal artery has been hit. What syndrome is this?

Answer 35

Anterior cord syndrome

Question 36

Patient presents after MVC where he was rear-ended. Pt states he doesn't have a headrest and his head "flew back". The patient complains of loss of motion in the arms and hands. What syndrome might he ahve?

Answer 36

Central cord syndrome

Question 37

What structures are lost in lateral medullary syndrome?

Answer 37

Spinothalamic tract (ALS) Spinal trigeminal nucleus/tract Nucleus ambiguus vestibular nuclei Inferior cerebellar peduncle

Question 38

Dejerine syndrome can be brought on by occlusion of what artery?

Answer 38

Anterior spinal A.

Question 39

What structures are lost in medial medullary/Dejerine syndrome?

Answer 39

Pyramids Medial lemniscus CN 12 nucleus

Question 40

What tract is lesioned in central 7 palsy? What nucleus?

Answer 40

Corticobulbar tract Lower facial motor nucleus

Question 41

Where is the lesion in Weber Syndrome? What structures are affected?

Answer 41

Pons Corticospinal tract Corticobulbar tract CN 3

Question 42

What neurons are affected in amyotrophic lateral sclerosis?

Answer 42

Somatic motor neurons (both UMNs and brainstem/SC LMNs)

Question 43

Progressive loss of sensory and motor function in the hands and feet towards the body may be a sign of what disorder?

Answer 43

Polyneuropathy

Question 44

Patient presents with ataxia, vertigo, loss of pain/temp to the R face but loss of pain/temp to the L arm. What syndrome is this patient suspicious for? What artery may be occluded?

Answer 44

Lateral Medullary/Wallenberg's syndrome PICA

Question 45

Pt presents with R sided loss of proprioception, vibratory loss, as well as R arm flaccid paralysis. Also presents with L tongue deviation. What is this patient suspicious for?

Answer 45

Medial medullary/Dejerine syndrome

Question 46

Pt presents with R lower face droop, flaccid paralysis of the R arm, as well as R tongue deviation and L uvula deviation. Upon eye examination their R eye is dilated. What syndrome might this patient have?

Answer 46

Weber