Brainstem Vascular Syndromes

Question 1

What is the blood supply to the brainstem?

Answer 1

PARAMEDIAN
-pons 
Basilar artery
-medulla
Vertebral arteries
Basilar artery

CIRCUMFERENTIAL
-midbrain
Posterior cerebral artery
Superior cerebellar artery
-pons
Superior cerebellar artery
Anterior inferior cerebellar artery
-medulla
Posterior inferior cerebellar artery

Question 2

What are the rules of 4?

Answer 2

In the rule of 4 there are 4 rules.

1. 4 Midline structures starting with (M)
2. 4 structures in the Side starting with (S)
3. 4 CN in medulla, 4 in pons and 4 above pons
4. 4 motor nuclei in the midline are factorials of 12 (except 1 and 2). CN 5,7,9,11 are lateral.

The 4 M

1. Motor pathway- contralateral hemiparesis
2. Medial Lemniscus- contralateral loss of vibration and proprioception
3. MLF- ipsilateral INO
4. Motor nuclei- ipsilateral eye and tongue paresis

The 4 S

1. Spinocerebellar- ipsilateral ataxia
2. Spinothalamic- contralateral pain and temperature loss of limbs
3. Sensory nucleus of 5- ipsilateral face pain and temperature loss
4. Sympathetic- ipsilateral Horner’s

Question 3

What are the features of medial medullary syndrome?

Answer 3

Contralateral hemiparesis of limbs
Contralateral loss of vib & proprio

Ipsilateral tongue paresis->MEDULLA
ipsilateral lateral gaze palsy->PONS
ipsilateral III nerve palsy->MIDBRAIN

Question 4

What are the features of lateral medullary syndrome?

Answer 4

Ipsilateral limb cerebellar ataxia

Contralateral loss of pain & temp in limbs
Ipsilateral loss of pain & temp in face
Ipsilateral Horner’s syndrome