5.2.3 Brainstem Lesions

Question 1

What are the differences between pseudobulbar and bulbar palsy?

Answer 1

Pseudobulbar palsy (UMN) - bilateral damage, lesion above the medulla

Bulbar palsy (LMN) - unilateral damage, lesion in medulla

Bulbar = medulla. Patient will present with difficulty swallowing and speech (trouble elevating palate, decreased pharyngeal sensation, tongue movement)

Question 2

What is binocular double vison?

Answer 2

Double vision that only occurs when both are open, typically due to a defect in eye movement

Question 3

Identify these nuclei and their respective CNs

Answer 3

Question 4

Answer 4

Question 5

What areas of the face are affected in a central seventh nerve palsy?

Answer 5

Lower face

The upper face is not affected because there is bilateral innervation by the cerebral cortex (UMN). Central = cerebral cortex and its projections to the facial nuclei

Question 6

What are the symptoms and signs of lateral medullary syndrome?

Answer 6

Ipsi Palatal weakness -> CN X Ambigous

Ipsi Palatal numbness -> CN IX Solitary

Ipsi Face numbness -> CN V nucleus and tract

Contra Body numbness -> Spinothalamic tract

Ipsi Right Horner’s -> Sympathetic fibers

Vertigo (left beating nystagmus) -> Vestibular nucleus

Ipsi Ataxia -> Inferior cerebellar peduncle

Question 7

Occlusion of what artery or its branches can result in lateral medullary syndrome?

Answer 7

PICA (Posterior inferior cerebellar artery)

Question 8

What structures are involved with horizontal eye movements?

Answer 8

• Frontal Eye Fields (FEF)
• Paramedian Pontine Reticular Formation (PPRF)
• Abducens Nucleus
• CN VI
• MLF
• Oculomotor Nucleus and Nerve

Question 9

If there is assemtry in the presentation of patient presenting with difficulty swallowing and sensation, is it more likely a bulbar or pseudobulbar lesion?

Answer 9

Bulbar lesion

Question 10

What are the deficits in alternating hemiplegia (due to a brainstem lesion)?

Answer 10

Ipsilateral CN

Contralateral Long Tracts (weakness and numbness)

Question 11

What areas of the face are affected in a peripheral seventh nerve palsy?

Answer 11

Upper and lower face

Peripheral = Lesion must be at the facial motor nucleus (pons) or distally before tracts divide between upper and lower faces

Question 12

What is the hallmark of brainstem lesion deficits?

Answer 12

Alternating hemiplegia

Question 13

Where do supranuclear, nuclear, and internuclear lesions occur?

Answer 13

Supranuclear is equivalent of a UMN lesion

Nuclear is equivalent of a LMN lesion

B/t the two nuclei = internuclear lesion = damage to the MLF