Flashcards in Lesions & Tracts - Bales Deck (15):
Leaves sensory and extrapyramidal input intact; sxs: spastic paralysis, no atrophy
Sxs: hypotonia/atonia, hyporeflexia/areflexia, flaccid paralysis
Progressive death of motor neurons; initial sx are either LMN or UMN, but ultimately mixed
Where in the corticospinal tract (CST) are the giant Betz cells located?
Which fibers and from which nucleus cross immediately in ventral segmental decussation of mesencephalon?
Rubrospinal fibers from red nucleus
Which fibers and from which nucleus cross immediately in dorsal segmental decussation of mess encephalon?
Tectospinal fibers from superior collicus
Which tract is in the ventral funiculus and is excitatory to extensors and inhibitory to flexors?
Pontine reticulospinal tract
Which tract is in the lateral funiculus and is inhibitory to extensors and excitatory to flexors?
Medullary reticulospinal tract
Contralateral eye turned up and in
Trochlear (CN IV) nerve lesion
Sxs: bilateral ptosis, bilateral elevation loss, ipsilateral eye turned out, ipsilateral loss of convergence
Unilateral Oculomotor (CN III) LMN lesion
What is the corticonuclear tract (CNT) pathway?
Lower lateral gyrus → genu of PLIC → medial end of middle 3/5 of crus cerebri
Sxs: drooping lid, abduction of unopposed lateral rectus, cannot elevate because of inferior oblique and superior rectus palsy
LMN ipsilateral lesion
Sxs: elevation weakness
LMN contralateral lesion
Sxs: dilated pupil, focusing weakness