Lecture 12: Motor Tracts COPY Flashcards

1
Q

Where are the cell bodies of the UMNs located?

A

Cerebral cortex or brainstem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

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

A

LMNs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Fibers traveling through the medial corticospinal tract innervate what muscles?

A

Postural muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Fibers traveling through the lateral corticospinal tract innervate what muscles?

A

Limb muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Voluntary motor action is associated with what tract?

A

Corticospinal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Fractionation of movement is associated with what tract?

A

Lateral corticospinal tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

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

A

Ventral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

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

A

Posterior limb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

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

A

Ipsilateral postural muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

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

A

5, 7, 9, 10, 11, 12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

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

A

Genu

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the relationship between the corticobulbar and corticospinal tracts?

A

Corticobulbar travels medially to corticospinal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

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

A

Ipsilateral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

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

A

Medial project to axial muscles

Lateral project to limbs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What tracts do the medial LMNs receive input from?

A

Tectospinal

Medial vestibulospinal

Medial reticulospinal

Medial corticospinal

Lateral vestibulospinal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What tracts do lateral LMNs receive input from?

A

Rubrospinal

Lateral reticulospinal

Lateral corticospinal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

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

A

Lateral Vestibulospinal tract

Ipsilateral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Where do the medial vestibulospinal fibers terminate?

A

T2 to T3

(innervate neck and shoulder muscles)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

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

A

Medial reticulospinal (pontine)

Ipsilateral

20
Q

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

A

Facilitates flexor motor neurons

Inhibits extensor motor neurons

21
Q

What does the rubrospinal tract innervate?

A

Upper limb flexors

22
Q

What tract is involved with visual reflexes to auditory stimuli?

A

Tectospinal

23
Q

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

A

Lower motor neurons

24
Q

What tract is lost in UMN syndrome?

A

Corticospinal tract (direct)

Loss of regulation from indirect pathway

25
Q

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

A

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

Underactive: distal extremity strength

26
Q

What side and level would LMN lesion signs manifest?

A

Ipsilateral at the level of the lesion

27
Q

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

A

Contralateral - Above lower medulla (where corticospinal tract crosses)

Ipsilateral - Spinal cord

28
Q

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

A

Below level of lesion

29
Q

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

A

Above the level of the red nucleus (UMN)

30
Q

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

A

Below red nucleus, above reticulospinal and vestibulospinal

31
Q

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?

A

Spinal shock

Corticospinal tract (appears as a UMN lesion)

32
Q

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

A

Brown Sequard’s Syndrome

UMN of the CST, Dorsal column, spinothalamic tract

33
Q

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

A

Ventral horns

34
Q

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

A

Lateral corticospinal tract

35
Q

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?

A

Anterior cord syndrome

36
Q

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?

A

Central cord syndrome

37
Q

What structures are lost in lateral medullary syndrome?

A

Spinothalamic tract (ALS)

Spinal trigeminal nucleus/tract

Nucleus ambiguus

vestibular nuclei

Inferior cerebellar peduncle

38
Q

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

A

Anterior spinal A.

39
Q

What structures are lost in medial medullary/Dejerine syndrome?

A

Pyramids

Medial lemniscus

CN 12 nucleus

40
Q

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

A

Corticobulbar tract

Lower facial motor nucleus

41
Q

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

A

Pons

Corticospinal tract

Corticobulbar tract

CN 3

42
Q

What neurons are affected in amyotrophic lateral sclerosis?

A

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

43
Q

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

A

Polyneuropathy

44
Q

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?

A

Lateral Medullary/Wallenberg’s syndrome

PICA

45
Q

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?

A

Medial medullary/Dejerine syndrome

46
Q

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?

A

Weber