task 8 - brain damage Flashcards
vascular disorders
caused by disease or damage to blood vessels, this damage cuts off or reduces the flow of oxygen and glucose to a brain region. (this interference causes all cells in the affected region to die after 10 minutes)
cerebral vascular accident (CVA) or stroke
a sudden appearance of neurological symptoms due to interrupted blow flow
- a stroke can result from a wide range of vascular disorders but not all vascular disorders cause strokes
ischemic stroke
blood clots cutting the blood flow
hemorrhagic stroke
blood flow into the brain
symptoms of stroke
headache, nausea, sweating, sensory distortions, numbness, loss of volitional movement, slurred speech and vomiting
ischemia
refers to any group of disorders in which the symptom’s are caused by vessel blockage, preventing supply of blood to the brain
thrombosis
some of the blood in a vessel has coagulated that forms a plug or a clot that has remained in its place
embolism
a clot or other plug brought through the blood from a larger vessel and forced into a smaller one that obstructs circulation
cerebral arteriosclerosis
a narrowing of arteries caused by thickening or hardening
a migrane stroke
a transient ischemic attack which has a variety of neurological symptoms (impaired sensory function, skin numbness, difficulties in moving), depend on the affected vessels (vasospasm; constriction of blood vessels)
cerebral hemorrhage
massive bleeding in the brain, which occurs when a cerebral blood vessel ruptures and blood seeps into the surrounding neural tissue and damages it
angiomas
congenital collections of abnormal vessels that divert the normal blood flow
- supplied by 1 or more large arteries and drained by 1 or more large veins, most often located in the field of the middle cerebral artery
aneurisms
vascular widenings resulting from defects in a vessel’s elasticity
- balloonlike expansions of vessels that are weak and prone to rupture (circle of willis)
- headache present for years due to the exerting pressure on the dura matter
anticoagulant therapy
drug therapy used the remove/dissolve a clot, used in ischemic episodes within 3 hours of the episodes onset (can worsen bleeding)
neuroprotectant drugs
after strokes this can be used to limit the changes leading to cell death also uses blood-pressure reducing drugs, salty steroids to reduce cerebral edema (accumulation of fluid/around damaged tissue)
open-head injuries
the skull is penetrated or in which fragments of bone penetrate the brain substance (in most causes the injury doesn’t cause loss of consciousness)
- produce highly specific symptoms resembling those of surgical excision of a small area of the cortex
- symptoms undergo rapid and spontaneous recovery
closed-head injuries
result from a blow to the head, can subject the brain to a variety of mechanical forces
coup
a bruise at the site of the blow, caused by bone’s pushing inward even when the skull is not fractured therefore compacting the brain
counter-coup
pressure from the coup may push the brain against the opposite side of the skull, producing an additional bruise
hematoma
a growing mass of blood caused by a cerebral hemorrhage, which exerts pressure on surrounding tissues
edema
swelling, which exerts pressure on the brain tissue
tumors
is a mass of new tissue that persists and grows independently of it’s surrounding structures and has no physical use (grow from glia)
benign tumors
are not likely to come back after removal
malignant tumors
often progressive and threaten life (very invasive)
encapsulated tumor
a tumor that grows in it’s own membrane and puts pressure on other parts of the brain
- skull is fixed in size so it causes compression of the brain
meningiomas
non-gial brain tumors that grow between the meninges, they grow entirely outside the brain, are well encapsulated and are almost always benign
- disturb brain function by putting pressure on the brain producing seizures
- can erode the overlying skull bone
infiltrating tumors
are not clearly distinct from the surrounding tissue, might destroy healthy cells and occupy their place or surround existing cells and interfere with their functioning (usually malignant and any cancerous tissue that remains after surgery usually continues to grow)
gilomas
the most common malignant brain tumors that develop from glial cells
metastatic tumors
brain tumors that become established by a transfer of tumor cells by the bloodstream from some other region of the body
- metastasis: the transfer of disease from one organ/body part to another that is not directly connected
alzheimer’s disorder
→ chronic, gets worse over time
→ memory: temporal gradient → medial temporal lobe
→ language, disorientation, mood swings, loss of motivation
→ the most prevalent form of dementia is (accounts for about 65% of all dementias in people over 65)
the stages of alzheimer;s disorder
- preclinical stage; involves pathological changes in the brain and without any behavioral or cognitive symptoms
- prodromal stage; involves mild cognitive impairment. at this point combined presence of mild cognitive impairment and some biological changes can lead to a fairly reliable diagnosis
- dementia stage; starts with a progressive decline in memory, deficits in attention and personality changes, followed by marked confusion, irritability, anxiety, and deterioration of speech. swallowing and bladder control become difficult
neuritic (amyloid) plaques (aka senile plaques)
found mainly in the cerebral cortex and result from the accumulation of tau protein. their concentration in the cortex is correlated with the magnitude of cognitive deterioration
- neuritic plaques consists of a central core of protein material known as beta-amyloid, surrounded by degenerative cellular fragments of neurons
other symptoms of alzheimers
- neocortex shrinks, loosing 1/3 as the disease progresses
- the limbic system undergoes the most severe degenerative changes in alzheimer’s disease. the entorhinal cortex is the earliest affected and the most severely (major relay between neocortex and hippocampus and other related structures)
- noradrenaline, dopamine, and serotonin, as well as some glutamate receptors are reduced. greater reductions in ≥ 2 neurotransmitters
- shrinkage of large neurons. most widespread cause of cortical atrophy appears to be a loss of dendritic arborization (branching)
hyperkinetic-dystonic syndrome
a group of motor disorders that is characterized by increased motor activity
hypokinetic-rigid syndrome
a group of motor disorders that is characterized by loss of movement
parkinson’s disease
→ degenerative disease, progressive
- degeneration of neurons in substantia nigra
- dopamine deficiency
→ rigidity, muscle tremors, bradykinesia
→ characterized by positive symptoms (the addition of abnormal behavior) and negative symptoms (the loss of normal behaviors)
