RM ENFERMEDADES NEURODEGENERATIVAS

1. MD
Logan Hospital
Brisbane, Australia
Xiangyun "Xavier" Zhu

2. Understand and
apply common
scoring systems
for assessment of
dementia
1
Recognise and
correlate specific
MRI signs to
neurodegenerative
diseases
2
Form a systematic
approach to
assess for
neurodegenerative
disease on MRI
3
Learning Objectives

3. Common Scoring Systems
Common Scoring Systems
Posterior atrophy score of parietal atrophy (Koedam score) - for Alzheimer's disease (AD)
Medial temporal lobe atrophy (MTA) score - for Alzheimer's/frontotemporal dementia
Entorhinal cortical atrophy (ERICA) score - for Alzheimer's disease
Fazekas scale - for vascular dementia
Global cortical atrophy (GCA) scale - for vascular dementia/Alzheimer's disease
Case: Frank Gaillard rID: 10770

4. Grade 0: closed sulci, no cortical atrophy
Grade 1: mild sulci widening, mild cortical atrophy
Grade 2: moderate sulci widening, moderate cortical
atrophy
Grade 3: marked sulci widening of posterior cingulate
sulcus and parieto-occipital sulcus, marked "knife
blade" cortical atrophy of parietal lobe
The Koedam score, otherwise known as the posterior
atrophy score of parietal atrophy, assesses for evidence
of Alzheimer's disease, specifically the visual variant,
posterior cortical atrophy (PCA). The parietal lobe,
posterior cingulate sulcus and parieto-occipital sulcus
are reviewed in all three planes.
Koedam Score
Koedam Score
Case: Gabrielle Matta rID: 43384
Case: Royal Melbourne Hospital Neuropsychiatry Unit
rID: 24746

5. Score 0: no CSF around hippocampus
Score 1: widening of choroid fissure
Score 2: also widening of temporal horn of lateral
ventricle
Score 3: also moderate loss of hippocampal height
Score 4: marked increase in all above findings
< 75 years of age: score 2 or more is abnormal.
> 75 years of age: score 3 or more is abnormal.
The medial temporal lobe atrophy (MTA) score
considers three features: the width of the choroid
fissure, the width of the temporal horn, and the height
of the hippocampal formation. This score mainly
assesses for Alzheimer's disease. The sequence used is
coronal T1-weighted, through the hippocampus at the
level of the anterior pons.
MTA Score
MTA Score
Case: Bruno Di Muzio rID: 42027

6. Score 0: normal volume of entorhinal cortex and parahippocampal gyrus
Score 1: widening of collateral sulcus; mild atrophy of entorhinal cortex and
parahippocampal gyrus
Score 2: detachment of entorhinal cortex from cerebellar tentorium; moderate
atrophy of entorhinal cortex and parahippocampal gyrus
Score 3: wide cleft between detachment, marked atrophy of entorhinal cortex and
parahippocampal gyrus (image on right)
The entorhinal cortical atrophy
(ERICA) score is used to identify
Alzheimer's disease in its early
stages, even prior to visible
changes of the hippocampus. It is
assessed in the coronal plane, at
the level of the mammillary bodies.
Score 2 or 3 suggests
Alzheimer's disease, with a
sensitivity of 83% and
specificity of 98%
ERICA Score
ERICA Score
Case: Frank Gaillard rID: 40748 Case: Frank Gaillard rID: 22196
1

7. Deep white matter
Fazekas 0 - none
Fazekas 1 - punctate lesion
Fazekas 2 - beginning confluence (bridging)
Fazekas 3 - large confluent lesions
The Fazekas scale quantifies the amount of white
matter hyperintensities in the brain that can be
attributed to chronic small vessel ischemia.
Specifically, it is the white matter change in deep white
matter that is important in assessing for vascular
dementia. The best sequence is T2-weighted images.
Fazekas Scale
Fazekas Scale
Case: Bruno Di Muzio rID: 36927
White matter hyperintensities are often found in
vascular dementia, but can also be a part of normal
aging (Fazekas 1 is generally normal in elderly, while 2
and 3 are pathological).

8. Score 0: normal sulci size or no ventricular
enlargement
Score 1: wider sulci or mild ventricular enlargement
Score 2: volume loss of gyri or moderate ventricular
enlargement
Score 3: severe volume loss of gyri "knife blade" or
severe ventricular enlargement
The global cortical atrophy (GCA) scale assesses the
sulcal and ventricular dilatation in the following regions:
frontal, parieto-occipital, temporal, and third ventricle.
The score gives an indication of general cerebral atrophy.
It is important to note that some neurodegenerative
disorders have asymmetry or region specific atrophy,
such as frontotemporal lobar degeneration (FTLD).
GCA Scale
GCA Scale
Case: Frank Gaillard rID: 10738

9. Disease Summary (1)
Disease Summary (1)
MTA and ERICA scores; often associated with cerebral amyloid angiopathy
Classically, elderly with progressive short term memory loss (especially antegrade)
Treatment: cholinesterase inhibitors and NMDA receptor antagonists
Clinical significance of early identification includes advance care planning and
potential use of disease modifying treatments to slow progression (monoclonal
antibodies)
Alzheimer's Disease
Koedam score
"visual variant" Alzheimer, where patients are typically
younger (50-65 years) and have more pronounced
visual symptoms (apraxia especially)
Treatment is same as Alzheimer disease, with
nonpharmacological visual aids playing a key role
Posterior Cortical Atrophy
2

10. Disease Summary (2)
Disease Summary (2)
2 main variants: behavioural and language. This reflects the typical presentation, and
location of anatomical abnormality on scans (frontal lobe area for behaviour and
temporal lobe area/Broca's/Wernicke's areas for language)
Typically asymmetric atrophy L>R
Treatment is mainly symptomatic control, and also nonpharmacological management
(speech pathology for instance)
Frontotemporal Lobar Degeneration
Fazekas Scale, largely symmetric deep white matter lesions
(however not perfectly symmetric). Perfectly symmetric
white matter changes favour leukodystrophies and toxic
encephalopathies, while completely random white matter
changes are suggestive of diseases such as multiple
sclerosis, vasculitis or metastatic lesions
Usually has temporal lobe sparing (in contrast to CADASIL)
Typically there is stepwise clinical deterioration
Clinical significance of early identification is vascular risk
factor optimisation
Vascular Dementia

11. Hummingbird sign - progressive supranuclear palsy (PSP)
Mickey Mouse sign - progressive supranuclear palsy
Hot cross bun sign - multiple system atrophy, cerebellar type (MSA-C)
Bright putaminal rim sign - multiple system atrophy, parkinsonian type (MSA-P)
Mammillary body high T2 - Wernicke encephalopathy
Hockey stick sign - Creutzfeldt-Jacob disease (CJD)
Caudate head atrophy - Huntington's disease
Specific Sign Correlations
Specific Sign Correlations
Case: Frank Gaillard rID: 13007

12. Hummingbird Sign
Hummingbird Sign
Case: Prashant Gupta rID: 18863 Case: Craig Hacking rID: 76531
The appearance of the brainstem in progressive supranuclear palsy typically resembles a hummingbird.
This sign arises from atrophy of the midbrain (the "head") with a normal structure of the pons (the "body").

13. In progressive supranuclear palsy (PSP), there is atrophy of the midbrain, causing reduction in the
anteroposterior midline midbrain diameter (<12 mm), with a deep interpeduncular cistern and
concavity of the lateral margin of the midbrain. This Mickey Mouse sign appears in the axial view at
the level of the superior colliculi.
Mickey Mouse Sign
Mickey Mouse Sign
Case: Roberto Schubert rID: 16914
Normal axial MRI
FLAIR
PSP axial MRI
FLAIR
Case: Bruno Di Muzio rID: 41113

14. Putaminal Rim
Putaminal Rim
Sign - MSA-P
Sign - MSA-P
Multiple system atrophy - parkinsonian type (MSA-P), can
manifest with T2 hyperintensity of the lateral putamen
border; the bright putaminal rim sign. It is important to
note that this sign may be normal in 3T MRI, but not in 1.5T.
Hot Cross Bun
Hot Cross Bun
Sign - MSA-C
Sign - MSA-C
Classically, multiple system atrophy - cerebellar type
(MSA-C), can manifest with degeneration and T2
hyperintensity of the transverse pontocerebellar tracts
and median pontine raphe nuclei. This causes a
characteristic cross appearance on the axial view of the
pons; the hot cross bun sign.
Case: Frank Gaillard rID: 5465 Case: Andrew Dixon rID: 14451
3

15. In Wernicke encephalopathy, there is abnormally increased signal intensity of
the mammillary bodies on T2 MRI compared to normal.
Mammillary Body High T2
Mammillary Body High T2
Case: Frank Gaillard rID: 42777 Case: Yves Leonard Voss rID: 56413
Normal MRI T2 Sequence MRI T2 Sequence of Wernicke encephalopathy

16. The appearance of the thalamic
nuclei in Creutzfeldt-Jakob
disease typically resembles a
hockey stick. This sign arises from
hyperintensity of the pulvinar
thalamic nuclei and the
dorsomedial thalamic nuclei.
Hyperintensity of the pulvinar
thalamic nuclei ONLY is aptly
named the pulvinar sign
Hockey Stick
Hockey Stick
Sign
Sign
Case: Bruno Di Muzio rID: 39311
Case: Brad Hayhow rID: 43970
Case: Daniel J Bell rID: 57294
Normal MRI FLAIR Sequence
MRI FLAIR Sequence of
Creutzfeldt-Jacob disease

17. In Huntington's disease, there is atrophy of the caudate head. This is quantified by measuring the
frontal horn width (FH), intercaudate distance (CC) and inner table width (IT), on the same axial
plane as the anterior commissure - posterior commissure line.
FH: distance between the lateral margins of the frontal horns. CC: closest distance between caudate
heads. IT: distance between inner table of the skull.
Huntington's disease case: CC/IT = 0.26.
Normal CC/IT ratio is 0.09 - 0.12
Huntington's disease case: FH/CC = 1.46.
Normal FH/CC ratio is 2.2 - 2.6
Caudate Head Atrophy
Caudate Head Atrophy
Case: Ammar Haouimi rID: 98523
Case: Frank Gaillard rID: 10768 Case: Ammar Haouimi rID: 98523

18. Disease Summary (3)
Disease Summary (3)
Hummingbird and Mickey Mouse sign
Classic presentation is of cognitive decline with abnormal eye movements (especially
upward gaze paralysis) and parkinsonian symptoms
Treatment is symptomatic, for example with parkinsonian symptoms, L-Dopa can be used
Progress Supranuclear Palsy
Two main types -> MSA-P and MSA-C
MSA-P: putaminal rim sign, T2 signal in globus pallidus>putamen (opposite
to normal), parkinsonian symptoms
MSA-C: hot cross bun sign, cerebellar atrophy, symptoms of cerebellar
dysfunction (eg. ataxia)
Treatment for both is symptomatic management. Again with parkinsonian
symptoms, L-Dopa can be trialed. Physical and occupational therapy is
important for cerebellar symptoms, especially ataxia
Multiple System Atrophy

19. Disease Summary (4)
Disease Summary (4)
T2 hyperintensity of mammillary body, and also dorsomedial thalami and midbrain
Classically presents with confusion, ataxia and visual disturbance, commonly in the
context of alcohol use/malnutrition contributing to thiamine deficiency
Treatment is with thiamine replacement
Clinical significance of early detection is prevention of Korsakoff syndrome
Wernicke Encephalopathy
Caudate head atrophy; FH/CC<2.2 and CC/IT>0.12
Classically choreiform movements, dementia, psychiatric disturbance,
rigidity, hypokinesia
No treatment options, progressive decline
Clinical significance: familial inheritance - autosomal dominant
Huntington's Disease
Hockey stick sign, DWI hyperintensity (cortical, basal ganglia)
Rapidly progressive cognitive decline
No treatment options
Clinical significance: infection control; notifiable condition
Creutzfeldt-Jakob Disease

20. T1 Sagittal
Coronal
Axial FLAIR & T2
T2*
DWI
1) Corpus callosum
Anterior half should be thicker than posterior half. If not,
consider frontal lobe atrophy
2) Midbrain and pons
PSP: hummingbird sign
MSA-C: disproportionate atrophy in cerebellum and
brainstem
Note: MSA-P is disproportionate atrophy in putamen instead
3) Medial surfaces of frontal, parietal, occipital
lobes
AD: Koedam score (parietal lobe/precuneus, posterior
cingulate sulcus, parieto-occipital sulcus); hippocampal
volume
FTLD: anterior-posterior sulcal size (larger anteriorly)
4) Lateral surfaces
General regional atrophy
Systematic Approach
Systematic Approach

21. T1 Sagittal
Coronal
Axial FLAIR & T2
T2*
DWI
1) MTA score and ERICA score
Size of hippocampus and surrounding fissures
2) Symmetry in atrophy
FTLD: L>R
AD: L=R
4) Region of atrophy
FTLD: more frontal and temporal lobe involvement
AD: more hippocampus and parahippocampal gyrus involvement
3) Anterior vs posterior atrophy
5) Mammillary body size, signal, symmetry
FTLD: anterior atrophy > posterior
Wernicke encephalopathy: atrophy, high T2 signal, symmetry
Systematic Approach
Systematic Approach

22. T1 Sagittal
Coronal
Axial FLAIR & T2
T2*
DWI
1) General gyral atrophy and sulcus size
GCA scale and Koedam score
2) Basal ganglia and surrounding structures
Huntington's disease: caudate head atrophy
MSA-P: putaminal rim sign
Wernicke encephalopathy: hyperintensity in mammillary
bodies symmetrically; also in medial thalamus
CJD: hockey stick sign
3) Posterior fossa
MSA-C: hot cross bun sign of pons
PSP: Mickey mouse sign of midbrain
4) White matter T2 hyperintensities
Vascular dementia/chronic small vessel ischaemia - Fazekas
scale
5) Previous infarcts, assess intracranial arteries
Systematic Approach
Systematic Approach

23. T1 Sagittal
Coronal
Axial FLAIR & T2
T2*
DWI
1) Peripheral microhaemorrhages
Suggestive of cerebral amyloid angiopathy which is
associated with AD
2) Central microhaemorrhages
Suggestive of chronic hypertensive encephalopathy
Systematic Approach
Systematic Approach
DWI
T2*
1) CJD
Hyperintensity in cerebral grey matter (cortex, basal ganglia,
thalamus)
2) Acute ischaemic stroke

24. Scoring systems
Koedam Score
MTA Score
ERICA Score
Fazekas Scale
GCA Scale
1
Specific signs
Hummingbird sign
Mickey mouse sign
Hot cross bun sign
Putaminal rim sign
Mammillary body T2
Hockey stick sign
Caudate head atrophy
2
Approach
T1 sagittal
Coronal
Axial FLAIR and T2
T2*
DWI
3
Take Home Points

25. References
1) Enkirch S, Traschütz A, Müller A et al. The ERICA Score: An MR Imaging–based Visual Scoring System for the
Assessment of Entorhinal Cortex Atrophy in Alzheimer Disease. Radiology. 2018;288(1):226-333.
doi:10.1148/radiol.2018171888
2) Perneczky R, Jessen F, Grimmer T et al. Anti-Amyloid Antibody Therapies in Alzheimer’s Disease. Brain.
2023;146(3):842-9. doi:10.1093/brain/awad005
3) Wei-Hsing Lee, Chau-Chin Lee, Woei-Cherng Shyu, Pau-Nyen Chong, Shinn-Zong Lin. Hyperintense Putaminal Rim
Sign Is Not a Hallmark of Multiple System Atrophy at 3T. AJNR Am J Neuroradiol. 2005;26(9):2238-42.
https://www.ncbi.nlm.nih.gov/pubmed/16219828