Chapter 10: Brain Pathology

Question 1

what is a tumor?

Answer 1

a mass of cells that grow independently of the body

Question 2

encapsulated tumours

Answer 2

• contained within a membrane
• can be surgically removed

Question 3

infiltrating tumour

Answer 3

• doesn’t have a boundary and can spread to nearby cells
• prognosis is more serious

Question 4

what is a meningioma?

Answer 4

an encapsulated tumour that grows within the layers of the meninges and pushes down on the brain, exerting pressure

Question 5

how are meningiomas identified?

Answer 5

through neuroimaging (CT scan)

Question 6

what are the risk factors associated with meningiomas?

Answer 6

• age (typically later in life, ~60 yrs)
• slightly more common in women due to progesterone
• underproduction of the protein merlin

Question 7

what is a glioblastoma?

Answer 7

an infiltrating tumour (unregulated growth of glial cells)

Question 8

which types of glial cells can make up a glioblastoma?

Answer 8

• astrocytes (more common)
• oligodendrocytes

Question 9

what is the age of onset for a glioblastoma?

Answer 9

can occur in 30s and 40s but most common in 60s

Question 10

what are the symptoms associated with glioblastomas?

Answer 10

• headache
• hemiparesis (numbness on one side of the body)
• seizures

Question 11

how are glioblastomas identified?

Answer 11

through an MRI

Question 12

low grade vs high grade glioblastomas

Answer 12

low grade: not readily spreading to the surrounding tissue. can stay this way for years
high grade: starts infiltrating and becomes more dangerous

Question 13

what are the treatment options for a glioblastoma?

Answer 13

• stereotactic neurosurgery and radiation
• chemotherapy
• gene therapy

Question 14

what is a metastic tumour?

Answer 14

a tumour that starts in one place and travels to the brain through the bloodstream

Question 15

what is an acoustic neuroma?

Answer 15

an encapsulated tumour that presses against the auditory nerve

Question 16

what are the symptoms associated with an acoustic neuroma?

Answer 16

• affects hearing in one ear (ringing or hearing loss)
• balance problems

Question 17

what is an ischemic stroke?

Answer 17

a blockage of blood to a certain area of the brain, starving that area of oxygen (anoxia)

Question 18

what is a hemorrhagic stroke?

Answer 18

a ruptured blood vessel that causes bleeding in the brain

Question 19

what type of neuroimaging is used to diagnose a hemorrhagic stroke?

Answer 19

CT scan

Question 20

what type of neuroimaging is used to diagnose an ischemic stroke?

Answer 20

MRI

Question 21

what is an angiogram used to diagnose?

Answer 21

used to determine if there is a blockage of blood originating in the heart

Question 22

what is thrombosis?

Answer 22

a blockage that occurs at a certain part of the brain (ischemic stroke)

Question 23

what is an embolism?

Answer 23

a blockage that occurs near the heart and moves to the brain (ischemic stroke)

Question 24

what is an aneurysm?

Answer 24

a rupturing of blood vessels that has no warning and is associated with a hemorrhagic stroke

Question 25

what are the effects of stroke?

Answer 25

- excitotoxity - necrosis - infarct - penumbra

Question 26

excitotoxity

Answer 26

an extreme release of glutamate in nearby cells

Question 27

necrosis

Answer 27

contents of the cell leak out and create responses in nearby cells

Question 28

infarct

Answer 28

where cell death is occurring

Question 29

penumbra

Answer 29

cells that are responding to cell death and may be damaged

Question 30

what are the symptoms that can be associated with a stroke?

Answer 30

- contralateral effects (hemiparesis, visual deficits, loss of awareness) - aphasia - spatial neglect

Question 31

what causes spatial neglect?

Answer 31

damage to the parietal lobe

Question 32

what are the long-term treatment options for a stroke?

Answer 32

- diet change - blood pressure medication - blood thinners

Question 33

what is a contusion?

Answer 33

the brain hitting the skull, resulting in a hematoma

Question 34

what is a countercoup?

Answer 34

a secondary type of injury that occurs when the brain hits the opposite end of the skull from where the impact was

Question 35

what is thought to cause chronic traumatic encephalopathy?

Answer 35

chronic concussions

Question 36

what is levodopa?

Answer 36

medication used to alleviate unwanted Parkinson's symptoms such as resting tremor

Question 37

what is carbidopa?

Answer 37

medication taken in conjunction with levodopa and helps lessen tolerance and unwanted side effects, and allows more concentrated doses of L-dopa to enter the brain

Question 38

what is epilepsy?

Answer 38

- electrical disturbances in the brain - can be localized (usually to the temporal lobe) or generalized (spread between both hemispheres)

Question 39

how is epilepsy diagnosed?

Answer 39

through brain imaging (EEG)

Question 40

what are focal seizures?

Answer 40

a category of seizure that is localized to a specific region of the brain (originates mostly in the temporal lobe)

Question 41

what are focal seizures characterized by?

Answer 41

- aura (can sense the seizure coming on) - automatisms (rhythmic, repetitive movements) - postural changes (become very rigid) - changes in awareness ( zone out/loss of consciousness)

Question 42

what are generalized seizures?

Answer 42

seizures that spread from an origin point (typically the temporal lobe) to areas throughout the brain

Question 43

what are generalized seizures characterized by?

Answer 43

loss of consciousness and stereotyped motor activity

Question 44

what are the stages of a generalized seizure?

Answer 44

- tonic stage (very rigid) - clonic stage (shaking) - postictal depression (confusion)

Question 45

what are the characteristics of an absence seizure?

Answer 45

- develops in childhood - loss of consciousness for a few seconds - typically goes unnoticed - kids can grow out of it

Question 46

what are the treatment options for epilepsy?

Answer 46

- anticonvulsant medications - surgery

Question 47

how do anticonvulsant medications work?

Answer 47

- promotes the effects of the neurotransmitter GABA - calms the brain

Question 48

what are the types of surgery used to treat seizures?

Answer 48

- focal resection (remove part of the brain) - corpus callosum resection (sever the corpus callosum)

Question 49

what is encephalitis?

Answer 49

inflammation in the brain

Question 50

meningitis

Answer 50

a bacterial infection in cerebrospinal fluid that can be treated with antibiotics if caught early enough

Question 51

how is meningitis diagnosed?

Answer 51

through a spinal tap

Question 52

syphilis

Answer 52

viral infection that causes general paresis and can lie dormant for years

Question 53

rabies

Answer 53

a viral infection that attacks the brain and leads to inflammation. causes cognitive decline, behavioural changes, coma, and muscle paralysis

Question 54

beta-amyloid plaques

Answer 54

plaques that build up in the brain and suffocate neurons

Question 55

neurofibrillary tangles

Answer 55

string-like filaments associated with plaque buildup and death

Question 56

which region of the brain is targeted first in Alzheimer's disease?

Answer 56

hippocampus is attacked first, causing memory loss

Question 57

acetylcholine antagonists

Answer 57

a treatment option for Alzheimer's, helps to hold symptoms at bay

Question 58

Multiple Sclerosis

Answer 58

an autoimmune disease where the immune system attacks and degrades myelin in the CNS

Question 59

what are the symptoms of MS?

Answer 59

- ataxia (person loses fine motor control and becomes clumsy) - numbness in limbs - pain