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Flashcards in Brainstem Lesions Deck (21):

Lesion of spinal lemniscus in brainstem would result in?
What tract is involved?

Pain/temp hemianesthesia contralaterally in body
Spinothalamic tract- Lateral brainstem


Lesion of medial lemniscus in brainstem would result in?
What tract is involved?

Proprioception/2-pt tactile contralateral hemianesthesia in body. Posterior column/medial lemniscal system- Medial brainstem


Lesion of trigeminal lemniscus would result in?

Loss of pain/temp from opposite side of face


Lesion of medial longitudinal fasciculus?

Ipsilateral intranuclear opthalmaplegia


Lesions of lateral lemniscus result in?

B/L hearing loss, most prominent in contralateral ear


What 4 cranial nerves exit the brainstem near the corticospinal tract and can cause alternating hemiplegia?

CN 5,6,3,12


What is alternating hemiplegia?

Loss of a cranial nerve plus corticospinal tract-> ipsilateral crainial nerve deficit, contralateral motor paralysis/paresis.


What would a lesion of uncrossed corticobulbar fibers cause?

Affect contralateral crainial nerves below the lesion


Unilateral lesions of corticobulbar tract above the level of the decussation cause what?

Supranuclear facial palsy (contralateral paralysis of lower half of face) from uncrossed fibers (also CN4, 12, 10)


What would a lesion of the descending tract of V cause?

Ipsilateral pain/temp analgesia in face


What cranial nerves are at the level of the pontomedullary sulcus?



What characteristic features does the medulla have on an MRI?

4th ventricle, ION, Pyramids (CST)


What usually causes thalamic syndrome and what is a classic sign?

Thrombosis of posterior choroidal or thalamogenticulate branches of PCA branches. May have contralateral hemihypalgesia ("crawling ant" sensation)


What causes Parinaud's syndrome and what are the sx?

Lesion of the superior colliculus, may be d/t pineal tumor or Great vein of galen varix. Causes paralysis of upward gaze. May also destroy posterior commissure and lose consensual light reflex.


What is alternating hemianalgesia?

Ipsilateral loss of pain/temp from face (descending tract of 5) and contralateral loss of pain/temp from body. (spinal lemniscus)


A lesion of the Nucleus Ambiguous would result in what?

Dysphagia, dysarthria, hoarseness
Deviation of uvula away from affected side


What does the trigeminal lemniscus convey?

Pain/temp/crude tactile sensations from opposite side of face


A dorsal extension of alternating hemiplegia results in compromise of what?

Medial lemniscus- contralateral propriocepion/2 pt tactile loss


External strabismus, complete ptosis, and dilated pupil indicate what cranial nerve lesion? Where is it in the brainstem?

CN3 palsy on ipsilateral side, in the midbrain (mesencephalon)


What are charactaristics of Lateral medullary syndrome?

Alternating hemianalgesia, destruction of nucleus ambiguous, vestibular nuclei, solitary nucleus, CN9 and CN10, destruction of spinal lemniscus and descending tract of 5..


What syndrome involves CN3, the CST, and the CBT? Sx?

Weber's syndrome (A3H).
Oculomotor palsy, contralateral spastic hemiplegia, contralateral palsy of CN4, 5, 12, 10