Primer 2

Question 1

In the brainstem, how are medial structures identified?

What are the four medial structures?

Answer 1

Start with M for “medial”

• Motor cranial nerve nuclei (3,4,6,12- all divide into 12)
• Motor pathway- aka corticospinal tract
• Medial Longitudinal Fasiculus (connects CN 6 & 3)
• Medial Lemniscus

Question 2

In the brainstem, how are lateral structures identified?

What are the four lateral structures?

Answer 2

Start with S for “side”

• spinothalamic tract
• sensory CN nucleus (CN5 nucleus/ tract)
• sympathetic pathway
• spinocerebellar tract

Question 3

What CN originate in the brainstem? In what specific regions?

Answer 3

1-2: above brainstem 
3-4: in the mickey mouse midbrain 
5,6,7,8: in the pons 
9,10,12: in the medulla 
11: below the brainstem (in spinal cord)

Question 4

***Hallmark of a brainstem lesion?

Answer 4

crossed findings
means IPSI CN signs + facial sensation
and CONTRA extremity signs

Question 5

***The following signs and symptoms are suggestive of what stroke syndrome? (See below) What area and artery are affected in this stroke syndrome?

• Horner’s
• Hoarseness/Dysphagia
• Ipsilateral loss of pain and temp at face/ contra at body
• vertigo, nystagmus, ataxia, nausea

Answer 5

• Wallenberg Syndrome
• Lateral Medulla (side matches the side of CN5 symptoms)
• Usually PICA
• Also called lateral meduallary syndrome or PICA syndrome

*Common in young patients, may also be caused by vertebral artery dissection: remember Fergie’s example of the woman sneezing/ causing this syndrome.

Question 6

Differential diagnosis for Intranuclear Ophtalmoplegia?

Answer 6

-MS
-medial pontine/basilar artery stroke
(MLF/ CN6 are in medial pons)

Question 7

Two possible causes of Locked In Syndrome:

Answer 7

1) bilateral basilar stroke effecting both sides of pons

2) rapid correction of hyponatremia (central pontine myelinolysis)

Question 8

***The following signs and symptoms are suggestive of what stroke syndrome? (See below) What area and artery are affected in this stroke syndrome?

• contralateral paralysis
• dysphagia, dysphonia, dysarthria
• gaze that appears “down and out”

Answer 8

Weber’s Syndrome

• medial midbrain
• PCA

*symptoms come from lesion in corticobulbar/corticospinal tracts and CN3.

Question 9

The following signs and symptoms are suggestive of what stroke syndrome? (See below) What area and artery are affected in this stroke syndrome?

• ipsilateral horners
• ipsilateral ataxia
• ipsilateral facial nerve paralysis
• ipsi loss of pain/ temp at face, contra at body

Answer 9

Lateral Inferior Pontine Syndrome

AICA

Question 10

The following signs and symptoms are suggestive of what stroke syndrome? (See below) What area and artery are affected in this stroke syndrome?

• Tongue deviation (ipsilateral)
• Contralateral paralysis + loss of fine touch

Answer 10

• medial medulla/ medial medullary syndrome

- anterior spinal artery (ASA)

Question 11

The following signs and symptoms are suggestive of what stroke syndrome? (See below) What area and artery are affected in this stroke syndrome?

• contralateral paralysis/ loss of fine touch
• gaze away from lesion
• ipsi paralysis of lateral rectus
• intranucler ophtalmoplegia

Answer 11

medial pons / medial pontine syndrome

basilar artery

Question 12

Name 7 drug classes that are teratogens: 
(Hint- we HAVE learned about all of these things in class at one point or another already)

Answer 12

ACEi
seizure drugs (valproate, phenytoin)
lithium
vitamin A
warfarin
tetracycline

Question 13

What are HOX genes?

Answer 13

Groups of genes responsible for skeletal dvlpmt

Question 14

What is required for molecular entry into a nuclear pore?

Answer 14

nuclear localization signal

Lys-Arg-Pro