Brainstem Centers that influence motor activity

Question 1

What is the pathway of the rubrospinal pathway ?

Answer 1

Red Nucleus> decussates in teh anterior tegmentum (ventral part of brainstem)> descend in the Lateral Funiculus (with the lateral CST). This will provide a functional feedback loop for cerebrellum actions. > Spinal cord

Question 2

What is the main focus of the RST ?

Answer 2

Influencing motor control of distal limbs mainly forelimbs.

Question 3

What are the large cells from the redu nucleus called

Answer 3

Magnocellular

Question 4

Where is the injury in decorticate posturing ?

Answer 4

The brainstem is transected rostral to the superior colliculus

Question 5

With decorticate posturing which control centers have input to the LMNs

Answer 5

NO cortical input
Cerebellar input to the red nucleus is intact
Rubrospinal tract is intact

Question 6

How do patients with decorticate lesions present ?

Answer 6

Patients exhibit upper limbs flexed at the elbow and lower limbs extended.

Question 7

How do patients with decerebrate lesions present ?

Answer 7

Patients exhibit upper limbs as well as lower limbs extended.

Question 8

What is midbrain syndrome

Answer 8

Unilateral lesion of the red nucleus. Also results in oculomotor ipsilateral nerve palsy since they are passing through the red nucleus to get to the eyes.

Physical sign is controlateral tremor.

Question 9

What is the Tectospinal tract TST

Answer 9

Motor pathway from the superior colliculus to motor neurons controlling neck muscles

Question 10

What is the function of the Tectospinal tract

Answer 10

To coordinate reflexive turning movements of the head and eyes.
It facilitates the upward gaze.

Question 11

Pathway of Tectospinal Tract

Answer 11

Retina/visual cortex> motor neurons controlling neck> terminates on accessory nucleus

Question 12

How often is lesion of the Tectospinal tract seen ?

Answer 12

It is virtually unseen

Question 13

Where does the Tectospinal Tract decussate ?

Answer 13

It decussates immediately on the level with the superior colliculus . It then travels in the anterior funiculus but only gets to the cervical spinal level

Question 14

What is Parinaud’s Syndrome

Answer 14

Inability to look up (loss of upward gaze) as a result of superior colliculi and posterior commissure damage.

Question 15

What are some common causes of Parinaud’s Syndrome

Answer 15

Pineal gland tumor, hydrocephalis resulting from aqueductal stenosis.

Question 16

Where does the Vestibular Nuclei get its input

Answer 16

Vestibulo nerve

Flocculus of the Cerebellum

Question 17

Describe the lateral vestibulo spinal tract

Answer 17

The cell bodies are in the vestibular nuclei.

The projections are to anterior funiculus within ipsilateral spinal cord levels

Question 18

What is the function of the Lateral Vestibulo Spinal Tract

Answer 18

Innervates extensor antigravity muscles, mainly in the trunk and lower limbs to maintain balance and posture.

Question 19

Where does the lateral vestibulo spinal originate

Answer 19

In the Pons. The Lateral Vestibular nucleus is in the pons

Question 20

Which part of the ear is information coming from

Answer 20

It is coming from the vestibule of the inner ear, of the vestibular component of the VC, projecting to the vestibular nuclei.

Question 21

Where is the vestibular nuclei

Answer 21

It is in the lateral brainstem. It is in the caudal pons and the rostral medulla.

Question 22

Patient presentation if there is a LVST lesion

Answer 22

patient will fall to the lesioned side

Question 23

Possible causes of LVST lesion

Answer 23

Vertebral artery occlusion
PICA occlusion
These are the vessels that are associated with the medulla below the basilar artery

Question 24

LVST lesion Patient symptoms

Answer 24

Loss of speech, swallowing, gag reflex, pain and temperature from the face on that side. Also vertigo and nausea. On the body: contralateral pain and temperature.