lesions of the brainstem Flashcards
what do we get in a UMN lesion of the occulomotor nerve
minimal effect due to bilateral innervation
what do we get in a LMN lesion of the occulomotor nerve
fixed, dilated pupil with a ptosis
what do we get in a UMN lesion of the trochlear nerve
minimal effect with bilateral innervation
what do we get in a LMN lesion of the trochlear nerve
superior oblique weakness, so cant move the eye down when adducted very well
what do we get in a UMN lesion of the trigeminal nerve
slight contralateral jaw weakness, minor due to bilateral innervation
what do we get in a LMN lesion of the trigeminal nerve
jaw deviates to wards the lesion, ipsilateral weakness of the muscles
what do we get in a UMN lesion of the abducens nerve
minimal due to bilateral input
what do we get in a LMN lesion of the abducens nerve
eye cant move laterally
what do we get in a UMN lesion of the facial nerve
contralateral weakness of lower face muscles due to the contralateral innervation of lower face, but bilateral of upper face
what do we get in a LMN lesion of the facial nerve
total ipsilateral facial paralysis
what do we get with UMN lesion of the glossopharyngeal and vagus nerves
minial due to bilateral innervations. sometimes uvula deviates away from lesion side
what do we get with LMN lesion of the glossopharyngeal and vagus nerves
the uvula goes away from affected side, hoarseness of voice and dysphagia, ipsilateral palate weakness
what do we get with UMN lesion of the cranial root accessory nerve
contralateral sternocleidomastoid weakness and ipsilateral traps weakness
what do we get with LMN lesion of the cranial root accessory nerve
Ipsilateral weakness of SCM and trapezius → trouble shrugging shoulder and turning head away from lesion.
what do we get with UMN lesion of hypoglossal nerve
more minimal due to bilateral innervation but since innervation is stronger bilaterally. there will be some deviation of tongue to contralateral side of injury
what do we get with LMN lesion of hypoglossal nerve
tongue atrophy on side of lesion and deviation toward lesion
what will be affected when we have superior colliculus midbrain stroke
medial longitudinal fasciculus, occulomotor nerve and EW nucleus, some extent of corticospinal tract
corticobulbar tract
umn lesions of 5,7,9,10,12
what will be affected when we have inferior colliculus midbrain stroke
some extent of the corticospinal tracts, medial lemniscal pathway
spinothalamic pathway
VTTT gone
what is affected by a mid pons stroke
corticospinal tracts.
weakness of the 7,9,10,12 UMN related
trigeminal nerve and nuclei could be affected
medial lemniscus
medial longitudinal fasciculus
VTTT partly affected
why will VTTT only party be affected in pons lesions
cause some of the pain and temp fibres have crossed over at that level and are thus affected. resulting in some pain and temp loss on the other side of the face. not light touch and vibration as thats high
what will be affected in a caudal pons lesion
abducens nerve, faclial nerve if lateral enough,
corticospinal tract
corticobulbar so 11 and 10 and 12 affected
medial longitudinal fasciculus
medial lemniscus
maybe spinothalamic if lateral enough
VTTT below affected
what is seen in medial medullary syndrome
LMN lesion of the 12
corticospinal tract damage
medial lemniscus damage
VTTT not really affc=ected as not many fibres have crossed over at this point
what is seen in lateral medullary syndrome
spinothalamic is lost
dorsal motor x and nucleus ambiguus are lost - hoarse voice and dysphagia
Spinal trigeminal tract and the nucleus of the tract are affected so there will be some
IPSILATERAL loss of pain and temp to head - fibres cross above this level
Inferior cerebellar peduncle carrying the dorsal spino-cerebellar tract also - impaired coordination
