Corticobulbar

Question 1

corticobulbar input to cranial nerves

Answer 1

gives bilateral input to the entire motor component

Question 2

exceptions to the corticobulbar system giving bilateral input to the entire motor component of the cranial nerves

Answer 2

cortical control of facial motor nucleus (muscles of facial expression)
cortical control of hypoglossal nucleus
cortical control of extraocular eye muscles

Question 3

corticobulbar LMN

• location
• axon travels to…

Answer 3

location
-ventral horn of spinal cord
OR
-cranial nerve motor nucleus
axon leaves spinal cord or brainstem to innervate motor unite of skeletal muscle

Question 4

S/S of corticobulbar LMN lesions

Answer 4

flaccid paralysis (atonia or hypotonia)
areflexia or hyporeflexia
atrophy of muscle (muscle wasting)
fasciculations and fibrillations

Question 5

corticobulbar UMN

• location
• synapse with…

Answer 5

location
-cell bodies located at suprasegmental levels of CNS
-anons end in the ventral horn or cranial nerve motor nucleus
synapse on interneurons or alpha or gamma motor neurons

Question 6

S/S of corticobulbar UMN lesion

Answer 6

initial flaccid paralysis, followed by

• abnormal cutaneous reflexes (Babinski skgn)
• abnormal reflexes: clonus, clasp knife
• spasticity (velocity dependent hypertonia
• abnormal timing of muscle activation (slower onset, prolonged contraction)
• paresis or plegia (weakness)

Question 7

paralysis definition

Answer 7

total loss of motor function

Question 8

-plegia definition

Answer 8

loss of activation of voluntary motor activity

• sometimes incorrectly referred to as paralysis
  i. e. hemiplegia is a loss of accurate activation of muscle activity over half of the body

Question 9

-paresis definition

Answer 9

weakness

small strokes can result in a paresis or weakness, as opposed to the -plegia of a major stroke

Question 10

corticobulbar pathologies

Answer 10

Brown-sequard syndrome
syringomyelia
poliomyelitis
amyotrophic lateral sclerosis (ALS)
multiple sclerosis

Question 11

Brown-Sequard Syndrome

-what is the lesion

Answer 11

hemisection of the spinal cord

Question 12

Syringomyelia

• lesion caused by…
• lesion encroaches upon…
• what does it effect?

Answer 12

cause by cavitation of the central canal, the remnant of the lumen of the neural tube
lesion encroaches upon anterior white commissure
-further ventral and lateral enlargement of the cavity will then encroach upon the ventral horm
affects LMNs of axial then appendicular musculature

Question 13

Poliomyelitis

• attacks…
• S/S
• what is Post-Polio syndrome?

Answer 13

attacks LMNs in the ventral horn of the spinal cord or cranial nerve nuclei
S/S
-flu-like symptoms followed by weakness (flaccid) of muscules and fasciculations
Post-Polio syndrome
-clinical concern due to overuse of intact motor units

Question 14

ALS

• origin
• what does it do?
• rate of onset

Answer 14

unknown origin
destroys LMNs in the ventral horn and brain stem nuclei
-also destroys white matter pathways
slow in onset

Question 15

multiple sclerosis

• what is thought to be the cause?
• develops in…
• disease of…

Answer 15

autoimmune attack on myelin
develops in spinal cord, brainstem, and optic nerve
disease of UMNs and central myelinated pathways, as well as sensory pathways