Brainstem

CNs in each brainstem section, go!

CN I-IV in midbrain or above, CN V-VIII in pons, CN IX-XII in medulla or below

CNs in medial vs lateral brainstem sections!

Midbrain (M): 3, 4

Midbrain (L): NA

Pons (M): 6

Pons (L): 5, 7, 8

Medulla (M): 12

Medulla (L): 9, 10, 11

What are the four structures part of the medial rule? (Middle= M)

Motor CNs, MLF, ML, Motor pathway

What are the four structures part of the lateral rule? (Side= S)

Spinocerebellar pathways, spinal nucleus/tract of CN V, sympathetic pathway, spinothalamic pathway

Midbrain, Pons, Medulla vascular supplies!

Midbrain: only PCA

Pons: Basilar in the middle, AICA on the sides

Medulla: ASA in the middle, PICA on the sides

Describe medial medullary syndrome!

ASA stroke, primarily affects CN XII (ips tongue deviation) and motor and sensory pathways (contralateral weakness and t/v/p sense)

What section of the spinal cord is not supplied by ASA?

Dorsal columns, DCML may be spared

Describe lateral medullary syndrome!

PICA stroke, affects CN IX and X

• Pain/temp sense ips in face and cont in body, limb dysmetria, dysphagia/dysarthria/dysphonia/palate paralysis, Horner’s syndrome, cont uvula deviation, vertigo/nausea/nystagmus

Describe lateral pontine syndrome!

AICA stroke, CN V+VII+ VIII

• Pain/temp sense ips in face and cont in body, ips facial weakness, ips hearing loss, limb ataxia, Horner’s syndrome, vertigo/nausea/nystagmus

What is locked in syndrome at where does stroke occur?

• What is still able to move?

Locked in syndrome is no movement or words spoken but conscious, usually mid-upper pontine stroke

• Vertical eye movements, blinking