T7.4 Corticospinal and Corticobulbar Fibers Flashcards
The medial premotor cortex is mainly associated with which task?
A. Watching a football being thrown back and forth B. Playing piano C. Yoga D. Running E. Chewing
FA
B. Playing piano, the supplementary motor cortex, also called the medial premotor cortex is heavily involved in the planning of complex movements.
the decorticate posture is described as the person lying, with upper limbs flexed and lower limbs extended and resulting from a lesion above the midbrain. Describe why this position comes about.
FA
in Decorticate Posture, the arms are flexed due to the Rubrospinal tract’s strong presence on the flexors. The rubrospinal tract directly innervates the Alpha and gamma motor neurons of the upper limb only! As you move towards the lower limb, the pontine Reticulopsinal, lateral Vestibulospinal, and medial Vestibulospinal tract dominate the motor neurons, resulting in extension of the lower limbs.
A man comes into the clinic with infarction compressing the right internal capsule. Which symptom is likely to present?
A. Tongue deviation to the left B. Tongue deviation to the right C. Gaze toward the left D. Gaze towards the right E. paralysis of all facial muscles F. Paralysis of ipsilateral lower half facial muscles G. Paralysis contralateral lower half facial muscles. H. A, C . F I. B ,C , E J. A, D, G K. B ,D, G L. A. D ,F
RFA
Ans. J- tongue will goes away from lesion
gaze towards lesion
contralateral of lesion facial paralysis lower half of
this is for the corticobulbar fibers
A man comes in with a right side lesion at the level of the medulla. Which is most likely.
A. Lost of Taste anterior 2/3
B. Deviation of tongue to the left
C. Deviation of tongue to the right
D. Loss of sensation of smell
RFA
Ans C. lesion is at the level of the medulla so the hypoglossal nerve not the Corticobulbar tract is most likely damaged. If the hypoglossal nerve is damage the tongue will protrude ipsilateral with the lesion/
A 52 year old women is in a car crash her head went through the windshield. She come in showing upper and lower limbs extended in her posture. What fibers are damage?
A. Coritcospinal B. Corticobular C. Rubrospinal D. Reticulospinal E. ALL the above F. A & B G. A & C H. A & D I. A, B & C J. B, C & D
RFA
Ans. I - the patient is presenting Decerebrate posturing which is damage to the Corticospinal Corticobulbar & Rubrospinal tracts
In Decorticate posture the patient would have upper limbs flexed and lower limbs extended. The Corticospinal and Corticobulbar pathways would be damaged.
A dude named Josh Gad is general piece of shit and see a homeless guy on the street so he kicks him in the head and the homeless guy falls back into his cardboard mansion. When the homeless guy is brought into the ER by a outstandingly kind man named Black Mark you begin examining him. Your cracking jokes left and right and the homeless man is loving it. You notice when he laughs the patients left mouth doesn’t move but his upper forehead is animated. Which of the following is damaged? (mm)
A) Right Corticobulbar Fiber B) Left Lower Facial Nerve C) Left Upper Motor Neuron D) Left Corticobulbar Fiber E) Right Lateral Gaze
Answer is A
B would cause full loss of right side face
C and D are same and would lose lower right face
E would be a correct symptom is there was dmg to the R internal capsule or R frontal eye field.
You receive a call from your Spanish buddy about a friend who needs medical help but is an illegal immigrant so he is scared to go to the hospital. You go to his house and he tells you that he fell of a ladder a work 4 weeks ago and hasn’t gotten of the couch because he was in so much pain. He is finally now trying to walk but his legs are constantly contracted and he can’t relax them so finally called for help. He also whispers to you that he keeps peeing himself even tho he doesn’t feel like he has to pee. During physical exam you notice clonus and bilateral extensor plantar response. What is this patients diagnosis? (mm)
The trauma would indicate a spinal cord lesion but both legs are not working properly so this would indicate probably ASAS or Paraplegia. There is spasticity after 4 weeks (legs contracted) and loss of urine sensation. The loss of bladder sensation would indicate paraplegia more than ASAS because sensation is retained in ASAS. The Clonus and bilateral Babinski reflex findings confirm this is an UMN lesion.
Answer - Paraplegia
