Term
| reduced pain sensation R finger |
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Definition
spinothalamic tract crossed within 2 segments in cord
cross in CERVICAL spinal cord
no lesion below the cervical cord can affect sensation of the hand |
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Term
| weakness left ankle dorsiflexion |
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Definition
| corticospinal pathway crosses in lower medulla |
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Term
| weakness of left eye closure |
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Definition
| corticobulbar pathway (facial strength) crosses in high pons |
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Term
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Definition
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Term
| pain & temp pathway for face |
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Definition
trigeminal nerve -->
Pons -->
descend (same side) via ipsilateral trigeminothalalmic pathway
cross in upper cervical spinal cord -->
ascend to thalamus |
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Term
| reduced pain sensation little toe |
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Definition
| cross within 2 segments of entry (lower cord) |
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Term
| reduced vibration sense, L big toe |
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Definition
ascend ipsilateral
cross in medulla |
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Term
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Definition
ascend ipsilateral side
cross in lower medulla |
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Term
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Definition
corticospinal tract
DESCEND, most cross in lower medulla (pyramid)
continue descending contralaterally |
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Term
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Definition
CN V enters pons
cross in pons
ascend contralaterally to thalamus |
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Term
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Definition
CN V enters pons
descends same side
cross in cervical spinal cord
ascend contralateral side to thalamus |
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Term
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Definition
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Term
R pupil bigger than L pupil
asymmetry more pronounced in light |
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Definition
PARASYMPATHETIC lesion of side of larger pupil
pathway NEVER crosses midline
dorsal midbrain --> CN III |
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Term
L pupil larger than R pupil
most pronounced in DARK |
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Definition
SYMPATHETIC lesion - asymmetry (aniscoria) that is more pronounced in dark
NEVER CROSSES midline
descending pathway:
hypothalamus --> down to C8/T1 --> exit to sympathetic chain |
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Term
| parasympathetic innervation of pupil |
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Definition
originates in midbrain
lesion --> ipsilateral pupil larger, especially in bright light |
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Term
| auditory information pathway |
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Definition
carried from the ear via CN VIII to the pons
once the pathway enters the brainstem it merges with the contralateral auditory pathway |
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Term
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Definition
indicates a lesion in the peripheral segment
no crossing
only a unilateral PONS LESION can produce unilateral hearing loss |
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Term
| unilateral pontine lesion |
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Definition
ipsilateral hearing loss
ipsilateral monocular abduction impairment
reduced pain and temp contralateral side
weakness on contralateral side |
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Term
| impaired abduction of L eye only |
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Definition
ipsilateral lesion in the lateral rectus muscle, the NMJ, or CN VI at any point between the pons and the orbit
no crossing
CN VI in pons --> exit driectly, same side |
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Term
| monocular impairment of abduction of ipsilateral eye |
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Definition
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Term
| facial strength - including eye closure |
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Definition
descending pathway from cortex --> eye
crosses in high pons
no lesion below the level of the pons can produce facial weakness |
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Term
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Definition
ascending pathway
cross in upper spinal cord
(start CN V to pons, end contralateral thalamus/cortex) |
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Term
|
Definition
cross in upper cervical cord
(enter pons)
(end in thalamus/cortex) |
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