N.B. fibers to motor neurons of CN11 are primarily ipsilateral!
vs. fibers to other motor neurons are equally distributed bilaterally
Postcentral gyrus (areas 3, 1, and 2) → most rostral portions of posterior limb of internal capsule → sensory relay nuclei of some cranial nerves and posterior column system – modulation of sensory information (selective attention / inattention to sensory information)
Neurotransmitter - glutamate (excitatory)
Cortical lesions → transient gaze palsy - eyes deviate toward lesion side (away from side of hemiplegia)
Capsular lesions – contralateral deficits:
deviation of tongue toward side of weakness
paralysis of contralateral lower half of face (central facial palsy).
weakness of contralateral palatal muscles - uvula will deviate toward ipsilateral (lesioned) side on attempted phonation.
c) internuclear fibers from ipsilateral abducens that are crossing to enter contralateral MLF, and internuclear fibers from contralateral abducens nucleus that cross to enter MLF on ipsilateral (lesioned) side
Clinically: loss of ipsilateral abduction (lateral rectus) + adduction (medial rectus, “one”) and loss of contralateral adduction (medial rectus, “half”); only remaining horizontal movement is contralateral abduction via intact abducens motor neurons.
Bibliography for ch. “Brain Stem” → follow this link >>