Conditions

Question 1

[basis of] Midbrain (Weber’s) syndrome

Answer 1

• midbrain lesion
• ipsilateral Cranial III signs:
  one eye ptosis, lateral deviation, dilation (Right in this example)
• contralateral weakness of upper and lower limbs and face (Left)
• PCA blood supply

Question 2

Blood Vessels of Brainstem

Answer 2

Question 3

Medial Medullary (Dejerine’s) Syndrome

Answer 3

• medulla lesion
• weakness of (L-contralateral) arm and leg
• impaired fine touch and and vibratory sense of (L-contralateral) arm and leg
• atrophy of (R - ipsilateral) tongue
• ASA blood supply (anterior spinal artery)

Question 4

Lateral Medullary (Wallenberg’s) Syndrome

Answer 4

• medulla
• decreased pain and temperature sensation over the (L-contralateral) arm and leg and (R-ipsilateral) side of face
• (R-ipsilateral) palate does not elevate
• dizziness
• PICA blood supply

Question 5

Horner’s Syndrome

Answer 5

• ptosis (slight drooping of eyelids)
• miosis (small pupil)
• anhidrosis (reduced sweating)
• lesion of descending sympathetics (central or peripheral nervous system)
• with lateral medullary syndrome

Pathway:
Fibers from the hypothalamus that are involved in sympathetic control → through brainstem (located medial to spinothalamic tract) → T1 & T2 levels of spinal cord (where axons form synapses with preganglionic neurons in spinal cord) → paravertebral sympathetic chain (where fibers ascend) → superior cervical ganglion (where axons form synapses with postganglionic neurons) → axons accompany carotid plexus and innervate pupillary dilator muscle, superior tarsal muscle, and sympathetics to skin and sweat glands of face and neck.

Horner’s syndrome can result from damage in many locations, as suggested by the pathway, e.g.:

1) Lateral brainstem
2) Spinal cord (Cervical to T1-T2 levels)
3) Sympathetic chain
4) Carotid plexus
5) Cavernous sinus
6) Orbit