Brainstem Infarcts

Question 1

Name the artery, affected structures, and associated deficits for the following syndrome:

Lateral medullary plate syndrome aka Wallenburg syndrome

Answer 1

Artery: Vertebral or PICA

Affected structures:

1. Inferior cerebellar peduncle –> ipsilateral gait and limb ataxia (damage to reticulospinal tract, an ipsilateral pathway), nystagmus (damage to vestibular nuclei inputs and outputs)
2. Solitary tract and nucleus –> loss of taste sensation
3. Nucleus ambiguus –> loss of motor for IX, X (dysphagia, hoarseness)
4. Spinal trigeminal tract –> no pain and temp. sensation from the ipsilateral face
5. Spinothalamic tract –> no pain and temp. sensation from the contralateral body
6. Damage to hypothalamospinal (sympathetic control) fibers –> Horner’s syndrome

Question 2

Name the artery, affected structures, and associated deficits for the following syndrome:

Medial medullary plate syndrome

Answer 2

Artery: anterior spinal artery

Affected structures:

1. Medial lemniscus –> contralateral loss of discriminative touch, vibration, and conscious proprioception
2. Pyramidal tract –> contralateral hemiparesis
3. Hypoglossal nerve and nucleus –> ipsilateral tongue deviation on protrusion

Question 3

Name the artery, affected structures, and associated deficits for the following syndrome:

Weber’s syndrome

Answer 3

Artery: paramedian branches of the PCA

Affected structures:

1. Cerebral peduncle –> contralateral body and facial paralysis (corticospinal and corticobulbar tracts)
2. CN III –> CN III palsy (blown pupil, down-and-out, ptosis)

Question 4

Name the artery, affected structures, and associated deficits for the following syndrome:

Locked-in syndrome

Answer 4

Artery: Basilar a.

Affected structures:

Descending corticobulbar and corticospinal tracts –> total paralysis of limbs and face (except CN III, can still blink)