Corticomotor

Question 1

What is the Origin of the corticospinal tract?

Answer 1

60% frontal lobe areas 4,6,8

40 % somatosnsory complex

Question 2

Where does the corticospinal tract terminate?

Answer 2

Sensory in dorsal horn

Motor onto monosynaptic connections/ interneurons.

Question 3

What is the general function of the cortico spinal tract?

Answer 3

Control of distal muscles as well as proximal flexors.

Question 4

Where does the corticonuclear tract originate?

Answer 4

Originates in the primary motor cortex (4,6,8)

Sensory and motor to face.

Question 5

Where does the rubrospinal tract originate?

Answer 5

Red nucleus

Question 6

How would a lesion to the lateral corticospinal tract present?

Answer 6

No spasticity
Weakness of arm with slight hyperreflexia
Babinskis sign would be present

Question 7

What broadmans area is correlated to the motor cortex?

Answer 7

Broadmans area 4

Question 8

What are the functions of the motor cortex?

Answer 8

Controls muscles for movement.

Question 9

What effect would a lesion to the motor cortex show?

Answer 9

Weakness (Paresis) NOT PARALYSIS
Spactisity can occur if other areas also damaged.
Persistant hypotonia
Can cause permanent deficit in hand control.

Question 10

Which broadmans areas are associated with the premotor cortex?

Answer 10

Areas 6,8

Question 11

What is the function of the premotor cortex?

Answer 11

Visual guided movement
Reaching/grasping
Mirror neurons here!

Question 12

Lesions of premotor cortex?

Answer 12

Apraxia = Inability to initiate certain tasks.

Question 13

What function does the supplementary motor area have?

Answer 13

Planning/preparing for motor acts

Coordinating posture and vol. movements.

Question 14

What is seen in a lesion to the supplementary motor area?

Answer 14

Inability for complex 2 handed tasks.

Damage to puntamen in parkinsons can cause difficulty with initiating.

Question 15

Which broadmans areas are associated with the posterior parietal cortex?

Answer 15

Broadmans areas 5,7

Question 16

What is the function of the posterior parietal cortex?

Answer 16

Sends information from the sensory and motor cortices to the cerebellum via pontine nuclei.

Question 17

What occurs in posterior parietal cortex lesions?

Answer 17

Contralateral neglect syndrome (non dominant hemi-lesion)

Aprraxia (dominant hemi)

Question 18

What broadmans areas are related to the frontal eye fields?

Answer 18

Broadmans area 8

Question 19

Lesion to Frontal eye field

Answer 19

Pt cannot voluntarily direct eyes away from stimulus.

Question 20

An infarction to the anterior cerebral artery bilaterally would present in which way?

Answer 20

Paraplegia affecting lower extremities sparing the face and hands.
Incontinence
Abulic and motor aphasia.

Frontal lobe changes: Personality change and contralateral grip reflex.

Question 21

How will Brown Sequard syndrome resent?

Answer 21

Hemisection of the spinal cord:

1) Loss of ipsilateral motor control.
2) Loss of ipsilateral vibration, and proprioception.
3) Contralateral loss of pain and temp sensation 1-2 segments below lesion. (Spinothalamic)
4) Loss of all ipsilateral sensation with flaccid paralysis. at the level of the lesion.

Question 22

What is crossed paralysis?

Answer 22

Seen in some brainstem lesions. Lesion occurs before the motor neurons have crossed affecting the contralateral side.

Question 23

Which fibers would be affected in a lesion to the genu of the internal capsule?

Answer 23

Corticonuclear fibers.

Question 24

Which fibers would be affected in a lesion to the posterior limb of the internal capsule?

Answer 24

Corticospinal fibers

Question 25

What signs would be seen in an infarct to the lenticulostriate arteries?

Answer 25

Pure UMN motor signs contralateral to the lesion.