Corticobulbar Tract Flashcards
Motor and sensory innervation of head and neck including special senses.
Purely motor, purely sensory, mixed
CN nuclei located within the brainstem
Cranial Nerve
Corticonuclear fibers originate in…
precentral gyrus
Corticonuclear fibers pass with corticospinal tract fibers through:
corona radiata, internal capsule (area 4 at genu( and cerebral peduncle
Cortionuclear fibers project:
BILATERAL!!!
Corticonuclear fibers end in:
brainstem motor nuclei of CNS V, VII (contralateral) CN XII (contralatera) and nucleus ambiguus (CNs IX and X) and acessory nucleus
Cotriconuclear fibers end in the contralateral:
brainstem motor nuclei of CNS V and VII
and CN XII
Corticonuclear fibers end in the ispilateral:
nucleas ambiguis (CN IX and X) and the accessory nucleus
CN V (motor nucleus of V) is for : and is contralateral or bilateral termination of brainstem motor nuclei
muscles of mastication
bilateral
CN VII (facial nucleus) is for: and is contralateral or bilateral termiantion of brainstem motor nuclei
muslces of facial expression
Contralateral
CN X (nucleus ambiguus) is for: and is contralateral or bilateral termiantion of brainstem motor nuclei
muslces of soft palate, pharynx and larynx
bilateral
CN XI (Accessory nucleus) is for: and is contralateral or bilateral termiantion of brainstem motor nuclei
sternocleomastoid and trapezius
bilateral
CN XII (hypoglossal nucleus) is for: and has bilateral or contralateral termination of brainstem
intrinsic and extrinsic muscles of tongue
contralateral
Corticobulbar tract has one UMN that projects to LMN in the:
cranial nerver motor nuclei of brainstem
Fuctionof the corticobulbar tract
controls muscles of head, face and neck
corticobulbar tract route:
cerebral cortex–> corona radiata –> internal capsule –> and through posterior limb of internal capsule and end on the CN motor nuclei
Where do corticobulbar tract end?
CN motor nuclei
As the corticobulbar fibers project through posterior limb of internal capsule, they are further or closer than the CST?
CLOSER to genu
Precentral gyrus projects with corticospinal tract to CN motor nuclei in brainstem and are the ____ for the brainstem CN nuclei
UMN
Nuclei that recieve direct corticobulbar fibers include:
trigeminal, facial, hyoglossal nuclei
bilateral lesion of corticobulbar tract is:
Pseudobulbar palsy
What are the symptoms of a Pseudobulbar pasly?
dysphagia, dyarthria, paresis of tongue, loss of emotion control
(bilateral lesion of corticobulbar tract)
Causes of Pseudobulbar palsy
brainstem infarct, ALS, MS
Lesion int the internal capsule with affect both:
corticobulbar and corticospinal tract
will have contralateral hemiplegia with
CNVII or CN XII deficiets
Patient has drooling on the right side of face but normal forehead wrinkle… the lesion is:
left corticobulbar tract before facial nucleus
possible stroke in patients right cortex
Patient has drooling on right side of face and eye droop and no wrinkling of forehead… the lesion is:
Right peripheral nerve: belz palsy
paralysis of contralateral lower quadrant of face
coticobulbar tract lesion
-see food pockets on the other side (opp from lesion), droop and have trouble talking/smiling but the whole forehead is fine because of dual innervation to trigeminal nerve
Where is the UMN from the left hypoglossal nucleus controlling the tongue come from?
right cortex in the corticobulbar/corticonuclear tract, its a contralateral innervation!
Where is the the lesion from the right hypoglossal nucleus controlling the tongue come from?
From the left corticonuclear tract or from right CN XII after it leaves the right hypoglossal nerve
Corticonuclear tract lesion will cause the tongue to
deviate away from lesioned side
Peripheral lesion of CN XII causes tongue to:
deviate towards lesioned side
bilatearal lesion of UMN that make up corticonuclear tract
Pseudobulbar palsy
weakness of musles involved in chewing, swallowing, speaking and LOSS of emotional control
Pseudobublar palsy
Possible causes of Pseudobulbar palsy
brainstem infarcts, ALS, MS
These two tracks get cortical control of motor activity
corticospinal tract/pyramidal system and corticobulbar tract
