Causes of Brain Dysfunction Flashcards
brain is __ % of body weight but receives __ % of cardiac output
2, 15
if blood supply is disturbed for seconds =
neurological symptoms
if blood supply is disturbed for minutes =
irreversible damage
what is a stroke?
neurological symptoms/signs resulting from diseases involving blood vesssels
what is infarct?
dead/dying tissue
what is penumbra?
dysfunctional area surrounding infarct, tissue may recover/die
strokes are the ___ leading cause of death in canada. __ % of people ___+ have had a stroke
3, 10, 65
what are the 4 consequences of stroke (varies)?
- memory (amnesia)
- language (aphasia)
- motor function (paralysis)
- consciousness
what are the 6 risk factors?
- high blood pressure
- high cholesterol
- diabetes
- smoking
- cardiovascular conditions
- psychosocial stress (lack of food, inadequate public health ed)
strokes are either ____ or ____
Ischemic, hemorrhagic
what is ischemic stroke ?
blockage of blood vessel
what is hemorrhagic stroke?
bleeding from vessel
what are the 3 types of ischemic stroke?
- thrombosis
- embolism
^(both can be arteerial or venous) - arteriosclerosis
what is a thrombosis (ischemic stroke)?
blockage due to blood clot or other substance
what is an embolism (ischemic stroke)
results from a moving thrombus
what is arteriosclerosis (ischemic stroke)?
thickening/hardening/narrowing arteries due to fatty plaque build up
what damage does ischemic stroke make (3)?
- takes a while to develop (hours to days)
- some brain areas more vulnerable (hippocampus)
- multiple mechanisms of damage
what are the 4 mechanisms of damage of an ischemic stroke?
- excitotoxicity (excessive glutamate release)
- cell death signaling
- neuroinflammation (break down BBB)
- oxidative stress
what is a transient ischemic attack (TIA)?
interruption of blood flow causing neurological symptoms, no lasting brain damage
- highly predictive of future stroke
what is an aneurysm?
weakened vessel wall (from birth or develop from high blood pressure/accumulated damage)
2 aneurysm treatments?
- clipping (use titanium metal clip to completely shut off blood flow to the aneurysm)
- coiling (platinum coils fill up aneurysm causing blood to clot inside & seal off from further blood flow
3 stroke treatments?
- tissue plasminogen activator (tPA) -injection, break up blood clots
- therapeutic hypothermia - cooling to slow down/prevent secondary damage
- many other potential drug targets (ie. astrocytes)
what is a tumor?
mass of cells growing independently of the rest of the body
what is an ENCAPSULATED tumor?
grow within their own membrane
what is an INFILTRATING tumor?
not self-contained, difficult to remove/destroy
what is an BENIGN tumor?
surgically removeable w/ little risk of further growth in body
what is an MALIGNANT tumor?
tending to grow & spread, sometimes due to metastasis
what is meningiomas?
tumors that grow between the meninges
- encapsulated
- benign tumours (usually)
- relatively positive prognosis
what is glioblastomas?
usually located in cerebral cortex
- infiltrating
- malignant
- less positive prognosis
what is metastatic tumours?
infiltrating, grow from tumour fragments in other parts of body (commonly breast/lung)
when bacteria grow in the brain they often lead to…
- inflammation (encephalitis)
- formation of cerebral abscesses (pocket of pus)
what is meningitis & what is treatment?
when bacteria infect the meninges, producing inflammation
treatment: antibiotics
what is syphilis & general paresis & what is its treatment?
bacteria that spreads as STI, cause general paresis
general paresis: mental disorder characterized by delusions & personality changes
treatment: antibiotics
what are the 2 types of viral infections?
- nervous system-specific (ie. rabies)
- indiscriminate (ie. herpes simplex)
all cause encephalitis (inflammation)
what is neurocysticercosis & what is treatment?
tapeworm in the brain
treatment: antihelminthic treatments + treat possible resulting epilepsy
what are neurotoxins?
chemicals destructive to nerve tissue
what is mercury as a neurotoxin?
accumulate in brain & produce a toxic psychosis
are vaccines safe? do they cause autism?
yes, no
what is lead as a neurotoxin?
accumulate in body over time, exposure lead to toxic psychosis, low level affect children learning & development
what is traumatic brain injury (TBI)?
brain injury caused by an outside force
what are some common TBI symptoms?
exhaustion, headache, dizziness, vomiting, light/noise sensitivity
what are open-head injuries?
perforating/penetrating TBI
- typically very severe
- high risk of infection & complications
what are closed-head injuries?
caused by hitting head, often include coup (brain hit front of skull) & contrecoup (brain hit back of skull) injuries
what is contusion (closed-head injuries)?
“bruise” on brain from slamming the skull
what is an epidural hematoma?
pooling blood between skin & skull
what is an subdural hematoma?
pooling blood between skull & brain
what is an intracranial hematoma?
pooling blood in the brain
what is diffuse axonal injury?
injury to axons following a TBI, can be distal to site of injury (disconnection of neural network)
what is a concussion?
roughly equivalent to mTBI (no contusion or structural damage but disturbance of function
how long does it take for a single mTBI to recover?
within 12 weeks
what happens when you have multiple TBI?
chronic traumatic encephalopy (CTE)
what is chronic traumatic encephalopathy (CTE)?
dementia, memory problems, inappropriate/explosive behaviour
what do tau proteins normally do?
stabilize microtubules (part of healthy cell shape)
what is tauopathy?
in CTE, when misfolded tau proteins accumulate
ALSO seeds their misfolding to other tau proteins (act as prions)
what is different about alzheimer’s disease’s tau pathology?
distributed differently & accompanied by other abnormalities absent in CTE
how is CTE diagnosed?
post-mortem based on accumulation of abnormal tau proteins (accumulate first in sulci & small vessels)
