Brain Tumors
What is a primary brain tumor?
A tumor that originates in the brain.
What is the most common cause of TBI?
Falls.
What is the only FDA-approved medication for acute SCI?
Methylprednisolone.
What percentage of people with HIV develop HAND?
More than half
What part of the neuron does MS target?
The myelin sheath.
What is the most common malignant brain tumor?
Glioblastoma.
What progressive disorder is associated with repeated head trauma?
CTE (chronic traumatic encephalopathy).
Why must methylprednisolone be given within 8 hours?
It reduces inflammation early and prevents secondary damage.
Can HAND be reversed? Explain your answer.
Antiretroviral treatment (ARVs) may prevent or reverse it in many people.
Which climates have higher MS risk?
MS is five times more prevalent in temperate climates (e.g., northern US, Europe) than tropics.
*Lower vitamin D may contribute to dysregulated immune attacks, increasing MS risk.
What neurotransmitter do gliomas release at toxic levels?
Glutamate.
Why can even mild concussions lead to long-term changes?
They cause microbleeds, inflammation, and volume loss that may persist.
Name two leading causes of SCI.
Vehicle accidents, falls, violence, or sports injuries.
T/F HAND only damages white matter tracts.
F. It damages both grey (neuronal bodies, dendrites, unmyelinated axons) and white matter (myelinated axons)
Name one MS disease course (category) and explain it.
Relapsing-remitting: characterized by flare-ups of new or worsening symptoms followed by complete or partial remission of symptoms
primary-progressive: defined by progressive worsening of symptoms after disease onset
secondary-progressive: relapsing-remitting disease has transitioned into a progressive form of disease that worsens over time
the classification refers to presence (“active”) or absence (“not active”) of new areas of inflammation, seen on MRI scans
What is stereotactic radiosurgery?
Precisely targeted high-dose radiation that shrinks the tumor while sparing healthy tissue.
How is increased skull pressure treated?
Removing fluid, using medication, or performing a craniotomy.
Name one experimental repair strategy.
Stem cells, axon regrowth stimulation, circuit retraining, or neurochemical barrier removal.
Can HAND occur even with antiretroviral therapy? Why or why not.
Yes, viral proteins continue damaging neurons or inflammation persists.
What is tPA and why is timing critical?
A clot-dissolving drug; must be given within ~3 hours to restore blood flow before brain damage becomes permanent.
Explain why blocking blood vessel formation (anti-angiogenesis) is especially critical in treating glioblastomas.
Glioblastomas grow rapidly and rely on dense, abnormal vascular networks. Blocking angiogenesis starves the tumor of nutrients and oxygen, slowing growth and enhancing treatment sensitivity.
Explain how inflammation after a mild TBI can continue to damage the brain long after the initial injury.
Neurons release pro-inflammatory molecules, activating microglia that remain overactive, causing ongoing neurotoxicity, impaired blood flow, and long-term neural degeneration.
Explain why stimulating axon regrowth in the spinal cord is difficult compared to regrowth in the peripheral nervous system.
CNS axons face inhibitory molecules, scar tissue, lack of growth signals, and myelin-associated inhibitors not found in the PNS, preventing regrowth across the injury site.
Describe one key structural brain change seen in HAND and explain how it leads to cognitive symptoms.
Cortical and subcortical shrinkage reduces connectivity and neural communication, impairing memory, coordination, and decision-making. (loss of nerve cells, white matter abnormalities, and damage to cellular structures involved in cell-to-cell communication. Inflammation and vessel disease can also be present.)
Explain how stem cell transplants may aid stroke recovery even when done several days after the stroke.
Stem cells may secrete growth factors, support neuroplasticity, reduce inflammation, and promote new circuit formation, enhancing recovery beyond the acute phase.