CNS pathology Flashcards
Neurons are
nondividing, postmitotic, permanent cells.
What is the Neurons response to injury?
The axon and/or cell body may become swollen upon injury. Rapid death results in phagocytosis. Axons may be regenerated.
Start undergoing exitotoxicity
What is the Oligodendroglia response to injury?
these myelinating cells do not regenerate
What is the Microglia response to injury?
Transform into phagocytic cells once activated by chemotactic factors.
What is the Astrocytes response to injury?
undergo hypertrophy and hyperplasia with just about any brain injury; this reaction is called “gliosis.”
What are the Ependymal cells responses to injury?
these cells line the ventricles and do not regenerate.
What is the main difference with damage to the brain?
there is no scarring by fibrosis. Rather, a hole is left. Astrocytes surrounding the damaged area hypertrophy and proliferate.
What is Global ischemia?
not enough oxygen gets to the brain tissue
What is Cerebral Infarction?
stroke – this is when a blood vessel bursts or leaks (hemorrhagic) or when it is blocked by a blood clot, atherosclerotic plaque or embolism
What is Intracerebral hemorrhage
bleeding in the brain, such as from a malformed vessel that is weak (aneurysm) or due to trauma
Ischemic stroke streatment
1) Lab work/CT scan
2) tPA of Alteplase
How is t-PA administered?
0.9mg/kg max of 90mg
10% Bolus over 1 minute and the remainder is infused over 1 hour
What disqualifies someone from tpa
BP >185/110 post injection or clinical worsening
If someone has an acute stroke and has uncontrolled BP (High) what should be given
Labtolol or
Enalapril
What are the 2 treatments for hemorrhagic stroke
- Blood pressure control and supportive care to reduce intracranial pressure
- Reduce further risk, e.g. reverse anti-clotting if relevant
What are causes of Intracerebral Hemorrhages
- Common complication of head trauma
- Rupture of intracerebral vessels
- Gunshot wounds
- Nontraumatic forms
(e.g., stroke) - Common in hematologic
What are some infections of the CNS?
Encephalitis
Myelitis
Cerebral abscess
Meningitis
Neurosyphilis
AIDS-related CNS lesions
What is encephalitis?
An inflammation of the brain and spinal cord usually caused by viral infection.
Types of Encephalitis?
infectious encephalitis
post-infectious
autoimmune
chronic
What is the difference between infectious encephalitis and
post-infectious
infectious encephalitis – the inflammation occurs as a direct result of an infection, which is often viral
post-infectious – the inflammation caused by the immune system reacts to a previous infection or vaccine; this can occur many days, weeks or sometimes months after the initial infection
What are complications that may arise due to Encephalitis?
Complications of the most severe cases: respiratory arrest, coma and death.
What is impaired during ischemia?
Autoregulation of cerebral blood flow
Why is the treatment of tpa less then 4.5 hours?
beyond that excitotoxicity creates extensive neuronal death
An epidural hematoma:
occurs when blood accumulates between the skull and the dura mater, the thick membrane covering the brain
Can cause brain pressure
Which viruses can cause Encephalitis?
measles
herpes virus
West Nile virus
mumps
The mechanism of action for alteplase is
activation of plasminogen to plasmin to dissolve fibrin clots
A cerebral aneurysm can
cause a focal deficit upon hemorrhage
What is excitotoxicity?
The release of glutamate and aspartate causes an increase calcium and sodium in the neurons, this causes cell death
What is the dosage of t-pa?
0.9mg/kg max 90mg
