neurodegenerative disease and radiology

Question 1

skull = neurocranium + viscerocranum, what are these

Answer 1

neurocranium (which protects the brain) and the viscerocranium (which forms the face)

Question 2

purpose of frontal, parietal, occipital, temporal lobe, insula, limbic complex, cerebellum, brain steam

Answer 2

frontal = higher cognitive function

parietal = sensory input, spatial discrimination, taste and receptive speech

temporal = auditory, spoken language, body language

occipital = visual input and processing

insula = (medial to temporal lobe) influences vestibular function(balance), some language, perception of visceral sensations, emotions and limbic function

limbic = emotions and some autonomic functions

cerebellum = coordinates smooth motor activities

brain stem = convey motor and sensory info from body and autonomic/motor info from higher centres to peripheral targets

Question 3

limbic lobe/complex = more functional than anatomical lobe. e.g basal ganglia, hypothalamus, amygdalla etc

Question 4

what are the 7 parts of the limbic system?

Answer 4

amygdala = emotion response (fear and aggression) + memory

hippocampus = long term memory

thalamus = major relay station for sensory info to cerebrum

hypothalamus = controls bodily function e.g hormone release

basal ganglia = motor control, reward and motivation

cingulate gyrus = above corpus callous, emotion, attention, cognitive control

olfactory bulb = receives sensory input in nose and sends to other parts of brain (small)

Question 5

AGAIN, know all the important sulcus, lobes, fissures, components e.g limbic system, what they look like, where they are found in Brain

Question 6

what are the 2 common clinical manifestations of neurogenerative diseases

Answer 6

dementia
movement disorder e.g parkinsons

Question 7

what is ataxia and chorea

Answer 7

Ataxia describes poor muscle control that causes clumsy movements

Chorea is a symptom that causes involuntary, irregular or unpredictable muscle movements

Question 8

most neurodegenerative conditions are A SPECTRUM.

what is most common dementia related disorder

Answer 8

alzheimers

• then vascular demntia

Question 9

what is the age range, risk factors, clinical presentations and pathological cause of alzheimers

Answer 9

• increased incidence with increasing age
• family history
• dementia, loss of higher cognitive function, gradually progressive
• clumps of beta-amyloid protein built up b/w nerve cells (disrupting cell function) and OR tau build up in nerve cells (disrupting nutrient transportation system= cell death)

(know what it looks like on imaging, although cannot be diagnosed from imaging alone)

Question 10

what does Alzheimer brain look like vs normal

Answer 10

shrunken, loss of volume (grey and white matter)

Question 11

Lewy body dementia accounts for what percentage of dementia disorder

Answer 11

20%

Question 12

what is the age range, risk factors, clinical presentations and pathological cause of vascular dementia

Answer 12

• increased incidence with increasing age
• atherosclerosis, hypertension causes it
• dementia, loss of higher cognitive function, can be progressive or stepwise (in distance stages)
• due to cortical infarcts (brain damage = cognitive decline) or white matter lesions (disrupting connections b/w different brain regions)

Question 13

what does vascular dementia look like on imaging T2 MRI

Answer 13

• little symmetry between hemisphere
• white matter hyperintensity seen across cortex in t2 weighting (suggesting small vessel ischaemia, but not definitive)
• thinned out corpus callosum
• cerebral volume loss ESP in frontal/anterior temporal
• overal blood volume looks reduced

Question 14

what is the age range, risk factors, clinical presentations and pathological cause of lewy body dementia

Answer 14

• increased incidence with increasing age
• family history, including PD
• dementia, loss of higher cognitive function, Parkinson’s, hallucinations
• Lewy body (clumps of alpha-synuclein protein) presence disrupts normal brain function, commonly found in brainstem and cortex (basal ganglia) thus affecting production and function of important neurotransmitters crucial for cognitive function, movement and mood regulation

KNOW WHAT IT LOOKS LIKE ON IMAGING

Question 15

what does Lewy body dementia look like on imaging

Answer 15

• subtle and non-specific thus, imaging is done to only EXCLUDE other causes of dementia such as Alzheimers

Question 16

posterior cortical atrophy is a diagnostic sign of what disease

Answer 16

variant of alzheimers disease

Question 17

what is the age range, risk factors, clinical presentations and pathological cause of frontotemporal dementia

Answer 17

• 45-65 yrs
• family history
• dementia, typically personality/behaviour issues, aphasia before memory loss
• abnormal accumulation tau protein deposits in brain cells, tau becomes tangled and disrupts cell function

Question 18

what is aphasia

Answer 18

inability (or impaired ability) to understand or produce speech, as a result of brain damage.

Question 19

tau protein NORMALLY helps stabilise microtubules, essential for cell structure and transport

Question 20

how can u identify frontotemporal dementia with imaging, what does it look like

Answer 20

brain perfusion scan

• severe HYPOperfusion seen in frontal/temporal lobes
• increase sulcus gap
• HYPOperfusion of basal ganglia and midbrain BUT NOT CEREBELLUM

Question 21

what is the age range, risk factors, clinical presentations and pathological cause of Parkinson’s disease

Answer 21

increase chance with increase age

• family history
• tremor, dementia, sleep issues, bowel issues, dizziness
• due to loss of neurones in substantial niagra (a part of your brain that helps control your movements. It’s part of the basal ganglia,)

know what it looks like

Question 22

what is Parkinson’s plus syndrome, what are the 3 things included

Answer 22

Parkinson-plus syndromes are a group of neurodegenerative diseases featuring the classical features of Parkinson’s disease with additional features that distinguish them from simple idiopathic Parkinson’s disease. Parkinson-plus syndromes are either inherited genetically or occur sporadically.

1. profressive supra nuclear palsy

(gradual deterioration and death of specific volumes of the brain. The condition leads to symptoms including loss of balance, slowing of movement, difficulty moving the eyes, and cognitive impairment.)

2. multiple system atrophy

(a rare condition that’s caused by a loss of nerve cells in the brain. This can lead to a wide range of problems with muscle control and movement)

3. corticobasal degeneration (disease that causes areas of the brain to shrink)

Question 23

MRI is modality of choice for assessing corticobasal degeneration

Question 24

what sign seen on MRI shows progressive supranucelar palsy? whuy

Answer 24

humming bird sign (on sagittal MRI)

• due to loss of volume in brainstem

Question 25

what is Huntington's disease, cause and symptoms

Answer 25

- progressive brain disorder due to defective gene on chromosome 4 = abnormal protein production = causes nerve cell in brain to degenerate - symptoms = chorea, cognitive decline, psychiatric disorder , ultimately fatal as its incurable

Question 26

what does Huntington's disease look like on imaging

Answer 26

loss of GABAergic neurones in basal ganglia = atrophy of putamen and caudate nucleus (look up to remember what it looks like) (dorsal striatum)

Question 27

what is friedricks ataxia

Answer 27

- genetic disease = progressive damage to nervous system leading to symptoms ranging from muscle weakness to heart disease - mutation in FXN gene on chromosome 9 = decreased production of FRATAXIN (needed for proper function of mitochondria) - mainly affects spinal chord and peripheral nerves and cerebellum (area of balance and coordination) thus - ATAXIA (poor walking and balance), loss of coordinations, slurred speech, fatigue, cardiomyopathy, diabetes, scoliosis - wheel chair bound within 5 yrs, dead within 40-50 yrs

Question 28

what does firebricks ataxia look like on imaging

Answer 28

ENLARGED sulk b/w folia of cerebellum ENLARGED 6th ventricle atrophied cerebellum (both hemispheres and vermis)

Question 29

whats ALS, cause and effect

Answer 29

amyotrophic lateral sclerosis (most common form of motor neurone disease (MND)) - progressive disease affecting nerve cells in Brain and spinal cord (UMN upper motor neurones affected) - sporadic ( cause can be due to many things not just genetics), toxic protein accumulation - progressive weakness and eventual death due to respiratory insufficiency

Question 30

early sign of ALS = asymmetric weakness of Hands, difficulty performing motor neurone tasks, cramping frequently etc MOST PATIENTS HAVE LOSS OF UMN AND LMN (upper lower motor neurones)

Question 31

signs of ALS on mri imaing

Answer 31

hyperintensity in the corticospinal tracts, which run from the motor cortex to the spinal cord. These will show up as brighter areas on MRI images.

Question 32

whats prion disease, cause and effect

Answer 32

abnormal protein ' prions' cause rapid progressive neurodegeneration - can be sporadic, familial or transmitted - types include CJD (Creutzfeldt-jakob disease) (CJD typical imaging looks like diffused cortical 'ribbon' in DWI imaging often involving basal ganglia