BRAIN LESIONY THINGS Flashcards
Talk to me about the reticulospinal tracts. Where do they arise from? What do they do? What is the reticulospinal tract important for with regard to SCI?
They arise from the Pons and Medulla. They are responsible for arousal and recovery of the power grip.
What is the rubrospinal tract responsible for and where is it located? Where does it arise from? Where does it cross?
It is right underneath the lateral CST. It arises from the midbrain. Less defined in humans than animals, more defined in infants and becomes more predominant post CVA/SCI. Is responsible for gross motor patterns. It crosses at the midbrain.
Where does the tectospinal tract arise form and what does it do?
The superior colliculi of the midbrain. Reflexive head turning.
Where does the DCML cross?
The middle medulla.
Where does the ALS cross?
At the spinal level.
Where do the CST cross?
Lateral CST crosses in the lower medulla. The anterior CST never crosses.
What are the direct systems? Indirect?
Direct: LCST, ACST
Indirect: Rubrospinal, Reticular, Vestibular, Tectospinal
What is Wallerian Degeneration?
Typical ways that axons in the PNS can proliferate when broken down.
What is Segmental Demyelination?
Degrading of the myelin sheath. MS.
What is axonal degeneration?
Distal ends go first bc materials can’t travel - DM or alcoholic neuropathy.
What is the most common cause of SCI?
MVA
What are some primary causes of SCI? Secondary?
Primary: Cancer, Arthritis, Osteoporosis, Syringomyelia
Secondary: Vascular Supply Compromised
What happens when the Anterior Spinal Artery is blocked or cut?
@ the level you have loss of everything but the DCML, with hypotonia.
Below the level, you have loss of everything but the DCML, and you’d have UMN reflexes.
What happens if the posterior spinal artery is blocked or cut?
@ the level of loss of all DCML sensations.
Below the level, normal, except no DCML.
What are the markers of Brown-Sequard Syndrome?
Half of a segment is “out”.
DCML sensation from the ipsilateral side would be out.
ALS sensation from the contra would be out.
ACST never crosses so ipsilateral side out.
LCST has already crossed so ipsilateral side out.
All of these would be upper motor neuron issues.
During Central Cord Syndrome what type of reflexia would you see at the level?
LMN - ALS is out and usually so is the anterior horn, so no afferent/efferent pathways.
If you have cauda equina, what kind of reflexia do you have?
LMN
When your eyes are fixed, the majority of the info you are receiving comes from the _____________ visual field. If you have a lesion in your optic radiations, the vision loss will be on the _______________ side.
Contra, contra.
What are the left hemisphere dominant perceptual functions? Right?
Speech, Apraxia
Neglect, Emotional Issues
If the MCA is out, what can you expect to see?
If left MCA, aphasia/apraxia, predominantly face/arm weakness and sensation loss, visual field deficits. If the right MCA is out it’s all of this except instead of aphasia/apraxia, neglect and emotional issues.
If the ACA is out, what can you expect to see?
Contra leg weakness and sensory loss, motor planning difficulty, Front lobe abnormalities.
If the PCA is out, what can you expect to see?
Occipital lobe and midbrain, hemianopia (blindness over 1/2 the visual field), some hemiparesis (if large).
What blood supply is responsible for the cranial nerves and from where do they arise?
3 and 4, midbrain - PCA
5, 6, 7, 8, pons - pontine arteries by way of the basilar artery, SCA, AICA
9, 10, 11, 12, medulla - vertebral artery, PICA
