Pathways & Lesions Flashcards
Function of Dorsal Columns-Medial Lemniscus
- proprioception
- vibration
- discriminatory touch
- stereognosis
function of spinothalamic tracts
pain & temperature
function of ventral spinothalamic tract
light/crude touch
function of lateral corticospinal tract
motor to distal flexor muscles
function of ventral corticospinal tract
motor to core muscles
what are the primary afferent neurons of dorsal columns-medial lemniscus?
Fasciculus cuneatus (T6^)
Fasciculus gracilis (T6_)
what are the secondary afferent neurons of dorsal columns-medial lemniscus?
medial lemniscus
primary afferent neurons of the dorsal columns-medial lemniscus pathway synapse with _____
nucleus cuneatus
nucleus gracilis
where do fibers in the dorsal columns-medial lemniscus cross?
great sensory decussation (GSD)
what are the primary afferent neurons of the spinothalamic tracts?
dorsolateral fasciculus (DLF)
what do the primary afferent neurons of spinothalamic tracts synapse with?
nucleus proprius
what are the secondary afferent neurons of the spinothalamic tract?
lateral spinothalamic tract (LSTT)
where do fibers of the spinothalamic tracts cross?
ventral white commissure (VWC)
where do secondary afferent fibers of ventral spinothalamic tracts run?
alongside lateral spinothalamic tract
where do fibers of lateral corticospinal tract cross?
pyramidal decussation (85%)
where do fibers of ventral corticospinal tract cross?
- fibers do not cross at pyramidal decussation (15%) - remain ipsilateral
- cross at ventral white commissure
what are the UMNs of corticospinal tract?
lateral corticospinal tract (LCST)
ventral corticospinal tract (VCST)
what are the LMNs of corticospinal tract?
ventral roots (synapse in ventral horn of spinal cord)
in all tracts, a lesion above the crossing of fibers will cause ____ loss of function
contralateral
in all tracts, a lesion below the crossing of fibers will cause ____ loss of function
ipsilateral
lesion of fasciculus cuneatus at T3
ipsilateral loss of proprioception/vibration/touch from T3-T6
lesion of fasciculus gracilis at T8
ipsilateral loss of proprioception/vibration/touch from T8 down
lesion of fasciculus gracilis at T2
ipsilateral loss of proprioception/vibration/touch from T6 down
lesion of medial lemniscus
contralateral loss of proprioception/vibration/touch from C1 down
lesion of nucleus cuneatus
ipsilateral loss of proprioception/vibration/touch from C1-T6
lesion of nucleus gracilis
ipsilateral loss of proprioception/vibration/touch from T6 down
lesion of dorsolateral fasciculus at T4
ipsilateral loss of pain & temperature from T4,5,6
lesion of nucleus proprius at T8
ipsilateral loss of pain & temperature at T10
lesion of ventral white commissure at T8
bilateral loss of pain & temperature at T10
lesion of lateral spinothalamic tract at T8
contralateral loss of pain & temperature from T10 down
lesion of spinocerebellar tracts
ataxia
lesion of ventral corticospinal tracts
Contralateral core weakness
lesion of lateral corticospinal tracts
ipsilateral spastic paralysis (distal flexors) from level of lesion down
lesion of ventral root
flaccid paralysis
lesion of corticospinal tracts
contralateral spastic paralysis
lesion of spinal tract (nucleus) of trigeminal
ipsilateral loss of P+T from face
lesion of chief sensory nucleus of trigeminal
ipsilateral loss of touch from face
lesion of mesencephalic nucleus of trigeminal
ipsilateral loss of proprioception from face
lesion of motor nucleus of trigeminal
paralysis of mastication muscles (jaw deviation to side of lesion)
lesion of trigeminal lemniscus below mid pons
contralateral loss of P+T from face
lesion of trigeminal lemniscus above mid pons
contralateral loss of P+T, touch, proprioception from face
lesion of CN V
- ipsilateral anesthesia of face (loss of P+T, touch, proprioception)
- inability to bite down (mastication)
- sometimes causes trigeminal neuralgia (lose all but pain)
lesion of subthalamus
hemiballismus: uncontrollable, violent torsonal movements
