Fundamentals Of Human Neuropsychology. Kolb.- Neuroimaging

Front 1

What are Basic (experimental) neuroimaging methods?

Back 1

Basic (experimental)
* Characterizing brain structure

* Mapping the dynamics of cognitive functions

Front 2

What are Diagnostic(clinical) neuroimaging methods?

Back 2

Diagnostic (clinical)
* Pathophysiology
* Anatomical localization

Front 3

What neuroimaging techniques are the structural ones?

Back 3

Structural techniques – show you what the brain look like
* CT,
* sMRI,
* DTI,
*cerebral angiography

Front 4

What is Skull x-ray for?

Back 4

* Can see the skull in the image, cannot see the brain
* Would be useful for skull fractures (can be serious → bleeding)

Front 5

what is Pneumoencephalogram?

Back 5

inject in a little bit of air that increases the visibility of the brain by some degree, had side effects and was painful

Front 6

What is CT scan?

Back 6

Computerized Axial Tomography (CT)
* 3D Xray
* Signs of injury or impairment can be easily identified (powerful method)
* Important because it is safe for everyone
* Criticisms: exposure to radiation

Front 7

How does CT Scan work?

Back 7

* Capitalizing on the fact that different types of tissues have different densities (bone, brain, fluid → absorb radiation @ different rates)

Front 8

How does sMRI work?

Back 8

Structural Magnetic Resonance Imaging (sMRI)
* Looks @ magnetic properties of ions, differences in resonance (based on density)
* A proportion of hydrogen ions align along the magnetic field →a radio wave is introduced and knocks those ions out of alignment → give off a signal (resonance) → come back into alignment → reconstruct signals into a brain image
* Resonance signal size differ based on the type of tissue (more dense = smaller signal → bone)

Front 9

What's important about sMRI?

Back 9

* Extremely clear image of the brain (can see gyri, sulci, grey and white matter, meninges) → takes 80s
* Shows you clear signs or injury or impairment

Front 10

What's the cons of sMRI?

Back 10

* Cannot be used in everyone → cannot have iron-based metal in their body (if you have a pacemaker you cannot have one)
** If they cannot they get a CT scan

Front 11

What is Diffusion tensor imaging (DTI)?

Back 11

* Designed to look @ axons in your brain using the movement in water
* Shakes you up and gets the water in your brain moving (water moves along axons more freely then in any other direction → can infer where these are in the brain)
* Has better capacity to show you the connections of the brain
* New technique, important for neurological injury

Front 12

What is Cerebral angiography and what is it good for?

Back 12

Cerebral angiography
* Looking at the blood flow in the brain
* Good for identifying of a stroke

Front 13

What are functional techniques of scanning the brain(4)?

Back 13

Functional techniques – show you what the brain is doing, blood flow, etc
* EEG, PET, fMRI, TMS

Front 14

Electroencephalography (EEG)

Back 14

* Looking at electrical signals in the brain
* Electrodes in cap pick up electrical signals in the brain
* Allows us to study sleep and understand where seizures are coming from

Front 15

How does EEG help scanning a seizure?

Back 15

o As you enter sleep brain waves slow down
o When someone has a seizure, one area of the brain starts to fire out of control
o Can localize the source of seizures

Front 16

How does Positron Emission Tomography (PET) scan work?•
o Looking at neurochemistry, blood flow
o Exposing people to radiation

Back 16

• Cyclotron: creates radioactive isotopes
o Specifically designed to interact w/ something in the brain you are interested in
o Inject radioactive substance into someones blood stream, gives act radioactive activity and collides w/ what you are interested in → give off gamma ray from collisions

Front 17

PET scanner = ____ ray detector

Back 17

gamma

Front 18

PET scanner Can look at things that were never before image-able(4):

Back 18

* Blood flow in Alzheimer’s disease (dramatically reduced and disrupted in temporal lobes)
* Can look at Mild cognitive impairment (stepping stone on the way to more severe dementia → early diagnosis and prevention for the onset of dementia
* Parkinson’s disease: can see dopamine levels in basal ganglia (less dopamine w/ this disease → can see if medications are working)
* PET can also be used to show brain tumors (show oxygen uptake → white = where the tumor is) -Used to determine the boundaries and location

Front 19

Functional Magnetic Resonance Imaging (fMRI)

Back 19

Tracks blood flow in the brain → Can determine which parts of the brain is working harder for different functions

Front 20

What is Neurovascular coupling

Back 20

Neurovascular coupling: strong relationship b/w neural activity and blood flow (more oxygen needed @ areas being used)

Front 21

What is fMRI good for?

Back 21

* Great for exploring brain networks and precisely localizations regions involved in a certain cognitive task
* Also useful for determining how brain networks have been disrupted after injury or recovery from injury

Front 22

What is TMS?

Back 22

Transcranial magnetic stimulation (TMS)
* Way to induce a temporary lesion in the brain by stimulating the brain

Front 23

What would prevent one from getting a TMS?

Back 23

History of seizures

Front 24

Is TMS used as a treatment?

Back 24

used to treat depression (stimulating the frontal lobes has therapeutic effects and improves mood)