Introduction to clinical neuroscience

Question 1

What is the dura?

Answer 1

A thick membrane which surrounds the brain and spinal cord. It also keeps in the cerebrospinal fluid

Question 2

What is the function of the CSF?

Answer 2

Acts as a conduit for cleaning out toxins, and it acts as a cushion for the brain

Question 3

What are the different parts of the neuron?

Answer 3

1) Dendrites
receive signals from other neurons
2) Cell body
process these signals
3) Axon
transmits the signal to other cells

Question 4

What is the grey matter made up of?

Answer 4

• astrocytes
• glia
• neurons

Question 5

What is white matter made up of?

Answer 5

the bits of connectivity between the grey matter

Question 6

What is a glioblastoma?

Answer 6

A highly infiltrate brain tumour

Question 7

What is a haemorrhagic stroke?

Answer 7

When blood vessels to the brain are blocked and the part of the brain supplied by them is killed

Question 8

What is hippocampal sclerosis?

Answer 8

A structural change in the hippocampus which can cause seizures. It is found in Alzheimer’s and other dementias

Question 9

How does an X-ray work?

Answer 9

X-rays are beamed through the patient; those are detected on the other side. Thus, the brain is measured at different angles.

Can be processed by a computer to generate a 2D image

Question 10

How does an MRI work?

Answer 10

A radio frequency pulse is sent into the brain that interacts with all the positive protons of hydrogen molecules. These protons generate a signal from within the tissue that is picked up by frequency coils.

After some computer processing, it’s turned into the 2D image that we see.

Question 11

What is a T2 in MRis?

Answer 11

A T2 weighted image (T2WI) is one of the pulse sequences in MRI. The sequence weighting highlights differences in the T2 relaxation time of tissues

Question 12

What leads to an increased T2?

Answer 12

increases tissue water and loss of cellular structure

Question 13

What can we see as a result of increased specificity of MRIs?

Answer 13

• degenerative changes
• developmental abnormalities
• disease-specific changes

Question 14

How do MRIs show white/grey matter contrast?

Answer 14

In grey matter, water (in both the intra and extracellular compartments) has relatively free motion

In white matter, approximately 50% of the tissue volume is accounted for by myelin structures, within which T1 relaxation of hydrogen in lipid structures is very short

Question 15

What is diffusion MRI?

Answer 15

A type of MRI which uses the diffusion of water molecules to generate contrast in MR images.

Highlights white matter pathways and how they are connected

Question 16

How do we get a 3D MR angiogram of the brain?

Answer 16

• use very short TRs of about 10nm

- the inflowing blood provides a high signal against a darker background tissue signal

Question 17

What is the basis of fMRI?

Answer 17

Increased glucose and O2 extraction lead to increased blood flow, which leads to reduced haemoglobin and so an MRI signal increase.

Question 18

What is PET scanning?

Answer 18

Type of scan which enables us to image particular chemicals

Radionuclides are incorporated into pharmaceuticals that are specific for metabolic processes or cell receptors. The injected radiopharmaceutical generates a localised gamma ray signal relating to metabolism or cellular function.