Neuroimaging in dementia

Question 1

Describe what Dementia is.

Answer 1

Dementia refers to a decline in cognitive function, in which awareness of the environment is preserved.

Question 2

List Manifestations of Executive Dysfunction:

Answer 2

Poor Planning and Problem Solving
Impulsivity
Difficulty in Task Switching
Disorganized Thought

Question 3

List the clinical features of Dementia

Answer 3

cognitive dysfunction
Memory loss
Loss of higher cognitive processes. E.g. executive function, visuospatial ability and language.
Challenges in planning or solving problems
Changes in mood, social behaviour, emotional control and personality.

Question 4

What does the frontal lobe control

Answer 4

Executive functions

Question 5

what does the temporal lobe control

Answer 5

Learning and memory

Question 6

What does the partial lobe control

Answer 6

Visuospatial functions

Question 7

State frontal lobe dysfunction symptoms/ how does dementia affect the frontal lobe

Answer 7

Executive dysfunction
Alterations in behaviour and personality
Expressive dysphasia

Question 8

State temporal lobe dysfunction symptoms/ how does dementia affect the temporal lobe

Answer 8

Mood changes
Episodic memory loss
Receptive dysphasia

Question 9

State parietal lobe dysfunction symptoms

Answer 9

Visuospatial dysfunction
Dyslexia
Dyscalculla

difficulties with reading, writing, math, dyslexia and distinguishing left from right.

Question 10

Why are screening tests performed for dementia?

Answer 10

Screening tests can be performed to assess cognitive impairment and suspected cognitive decline

Question 11

List exams of cognitive tests used for dementia assessment

Answer 11

mini-mental state examination (MMSE)

Montreal cognitive assessment (MoCA)

Clinical Dementia Rating (CDR) scale

CLOX test

Question 12

How can premorbid intelligence be measured?

Answer 12

using the national adult reading test (NART)
This is a measure of intellectual ability level prior to the onset of disorders

Question 13

List the types of dementia

Answer 13

Alzheimer’s disease
Vascular dementia
Lewy body dementia
Frontotemporal dementia

Question 14

List the risk factors of Alzheimer’s disease

Answer 14

Age, Vascular Risk Factors, Family History, APOE 4
allele status

Question 15

Define Alzheimers disease

Answer 15

Alzheimer’s disease: characterised by the deposition of amyloid-beta plaques and tau protein tangles in the brain.

Question 16

List the clinical features of AD

Answer 16

Depression & Anxiety, Social withdrawal, Aggression,
Wandering.

Question 17

List pharmacological interventions for AD

Answer 17

Donepezil, a centrally acting reversible acetylcholinesterase inhibitor
(increasing acetylcholine concentrations at cholinergic synapses).
Memantine, an NMDA receptor antagonist (blocks the effects of glutamate,
reducing neuronal excitability).

Question 18

List the different types of dementia

Answer 18

Alzheimer’s Disease (AD)
Vascular Dementia
Lewy Body Dementia (LBD)
Frontotemporal Dementia (FTD)

Question 19

State the characteristics and cause of AD

Answer 19

Characteristics: The most common form of dementia, Alzheimer’s is characterized by the progressive loss of memory and cognitive functions.

Causes: It is associated with the accumulation of amyloid-beta plaques and tau tangles in the brain, leading to neuronal damage.

Question 20

State the characteristics and cause of Vascular Dementia

Answer 20

Characteristics: Caused by impaired blood flow to the brain, leading to cell damage or death.

Causes: Often results from stroke, atherosclerosis, or other conditions that damage blood vessels and reduce circulation, leading to multiple infarcts in the brain.

Question 21

State the characteristics and cause of Lewy Body Dementia (LBD)

Answer 21

Characteristics: Dementia with Lewy bodies is marked by the presence of Lewy bodies (abnormal deposits of the protein alpha-synuclein) in brain cells.

Causes: The exact cause is unknown, but genetic factors may play a role.

Question 22

State the characteristics and cause of Frontotemporal Dementia (FTD)

Answer 22

Characteristics: Affects the frontal and temporal lobes of the brain, typically seen in a younger age group compared to other dementias.

Causes: Involves degeneration of the frontal and/or temporal lobes. Genetics play a significant role, with many cases linked to specific gene mutations.

Question 23

What assessments can be performed for Frontotemporal Dementia (FTD)

Answer 23

MMSE
MoCA

Question 24

What assessments can be performed for Vascular Dementia

Answer 24

MMSE
MoCA
MRI

Question 25

What is a PET scan

Answer 25

Positron Emission Tomography

PET scans can reveal reduced metabolic activity in areas of the brain typically affected by Alzheimer’s disease and other dementias.

A radionuclide is administered into a vein through an intravenous line. The PET scanner detects the amount of the radionuclide collected in the tissue, affecting how brightly the tissue appears on the image and indicating the level of organ or tissue function.

Question 26

What is a SPECT scan

Answer 26

Single-photon Emission Computed Tomography

Vascular Dementia: SPECT can detect blood flow abnormalities throughout the brain, which are common in vascular dementia.

Uses gamma emitting radioisotopes. SPECT shows alterations in the dopamine transporter (DAT), reflecting reduced binding in the striatum, which indicates dysfunction or loss of nerve terminals in the substantia nigra. Neurons expressing DAT are concentrated in the caudate and putamen.

Question 27

What is a FLAIR MRI

Answer 27

Fluid-Attenuated Inversion Recovery MRI

Brain Lesions: FLAIR MRI can show shrinkage or atrophy in specific regions like the hippocampus in Alzheimer’s disease, or widespread cortical atrophy in FTD.

An MRI technique that suppresses the signal of fluids like CSF to enhance the visibility of lesions, particularly in the brain. FLAIR MRI is effective in highlighting lesions against the suppressed background of CSF, making it excellent for detecting brain pathologies such as multiple sclerosis plaques.

Question 28

What is a SWI scan

Answer 28

Susceptibility Weighted Imaging (Quantitative Susceptibility Imaging)

Neurodegenerative Diseases: SWI is valuable in studying diseases such as Alzheimer’s where iron deposition in the brain is a marker of disease progression. It can quantify these iron deposits more accurately than other methods. Also, SWI can detect and differentiate between blood degradation products (like hemosiderin) following microbleeds or haemorrhagic strokes, crucial for stroke assessment and treatment planning

This MRI technique focuses on the magnetic susceptibility differences of tissues, providing detailed images that reveal variations in tissue composition, particularly iron and other paramagnetic substances.

Question 29

Identifying Dementia types on Brain Specimens

Answer 29

Alzheimer’s: Amyloid plaques, neurofibrillary tangles.
Vascular: Infarcts, blood vessel changes.
Lewy Body: Lewy bodies in the cortex.
FTD: Frontal/temporal atrophy, sometimes with Pick bodies.

Question 30

Pharmacological Management of Dementia

Answer 30

Acetylcholinesterase inhibitors (e.g., Donepezil) for Alzheimer’s. (mild-to-moderate)
Memantine for moderate to severe dementia.
SSRIs for mood symptoms, sleep aids for disrupted sleep.

Question 31

what are the characteristics of Lewy body dementia

Answer 31

marked by the presence of Lewy bodies (abnormal deposits of the protein alpha-synuclein) in brain cell

Question 32

symptoms of Lewy body dementia

Answer 32

sleep disturbances, visual hallucinations, fluctuations in cognitive ability

Question 33

describe what executive function is

Answer 33

Executive function refers to a set of cognitive processes that are essential for controlling behavior and thought processes, allowing individuals to plan, focus attention, remember instructions, and manage multiple tasks successfully. These functions are crucial for goal-directed behavior and are primarily managed by the frontal lobes of the brain, particularly the prefrontal cortex.