1. CADASIL Mary Quiceno, M.D. Clinical Assistant Professor
Department of Neurology
UT Southwestern Medical Center

2. Neuropathology report on NP36015
What is CADASIL?

3. CADASIL Cerebral Autosomal Dominant Arteriopathy with Subcortical
Infarcts &
Leuko-encephalopathy
Inherited small vessel disease causing stroke and subcortical vascular dementia that starts in early adulthood and progresses over time.
This is a nonatherosclerotic, nonamyloid angiopathy involving small arteries and capillaries of the brain and other organs.
Caused by missense mutations in the Notch3 gene on chromosome 19p13.
Inherited small vessel disease causing stroke and subcortical vascular dementia that starts in early adulthood and progresses over time. This is a nonatherosclerotic, nonamyloid angiopathy involving small varteries and capillaries of the brain and other organs caused by missense mutations in the Notch3 gene on chromosome 19p13.

4. CADASIL 1977: family w/hereditary, multi-infarct dementia syndrome
Presents in mid-20s to age 45
Stroke, dementia, migraine with aura, mood disorders
Shortened life span
Most die by age 65
Unknown prevalence
400 families world-wide
2/100,000
Largely undiagnosed
A clinical syndrome consistent with CADASIL was originally described by Van Bogaert in 1955 and by Sourander and Walinder in 1977 in
a case series describing the autopsy findings of 5 patients who had recurrent ischemic strokes prior to age 40. There was an autosomal dominant transmission, and 4 of the 5 had dementia. Pathologic changes were observed in the cerebral microvasculature. Also in 1977, Stevens et al described a similar syndrome which they termed chronic familial vascular encephalopathy.
400 familes world-wide have mutation.
Estimates at prevalance: 2/100,000.
Largely uindiagnosed.

5. Case Studies Most reported cases from Europe
105 people from 33 affected families
Vascular risk factors are uncommon
Mean age of initial symptom onset years
Migraine in 40% ( yrs)
Stroke/ TIA 43% ( yrs)
Depression 8%
Cognitive decline 6%
Seizure 3%
A pooled analysis of published cases found 105 symptomatic people from 33 families.
-even split between males and females
-most patients from europe, 13 from US, 2 from El Salvador, 1 from Japan
-Vascular RF uncommon (8 had HTN)
-mean age of symptom onset was years.
-Stroke/TIA was initial symptom in 45 (mean age on onset years) (43%)
-Migraine was initial symptom in 42 patients (younger mean age of onset years) (40%). Most w/aura.
-9 had depression as initial symptom (8.5%) and 6 (5.7%) had cognitive decline, and 3 had seizure (2.8%) -

6. overall, 67% had a TIA or stroke
overall, 42% had dementia
>30% with migraine w/aura and 15% w/mood d/o
overall, age of death, in the 20% of the cohort that was deceased, was years
Course is heterogeneous even in the same family: some remain asymptomatic until their 70s whereas others are severely affected by the age of 50.

7. MIGRAINE with aura Often initial feature 1/3 of families
Occurs earlier as compared to stroke
Consider CADASIL in migraineur with diffuse white matter lesions on MRI
Not small, scattered hyperintensities, which can be seen in migraineurs (16%) who don’t have CADASIL
16% have WM lesions
If <50 years old with no stroke risk factors, then 6% have UBOs
Increase in frequency with age and RF
In study of 1000 MRIs in normals who had studies done for research purposes, 0.5% had a solitary white matter hyperintensity. Mean and median age was about 30 yrs (all subjects were 3-83 yrs old).
WMLs in 10% of people in 4th decade and 80% of people in 8th decade

8. STROKE TIAs and subcortical ischemic strokes
Accumulating sensory, motor, and cognitive deficits
Most common feature
Typical stroke risk factors NOT present
Cerebral non-atherosclerotic, nonamyloid angiopathy
Primarily affecting small vessels that penetrate white matter and basal ganglia

9. MOOD DISORDERS Depression Bipolar disorder
Like migraine, CADASIL should only be considered when MRI changes are present
Tend to predate cognitive decline

10. Mood Disorders in an affected family
29 yr old son
4th psychiatric hosp. admission
Depression and psychosis
52 yr old father
Migraines, stroke
Antisocial and withdrawn
72 yr old paternal grandmother
Depression at age 50
Dementia at age 61
Frontal lobe dysfunction
Retrieval deficits

11. COGNITIVE DEFICITS
Slowly progressive in addition to stepwise deterioration
Typically appears after stroke symptoms appear
Can be presenting feature
Frontal lobe dysfunction
Memory impairment
Pseudobulbar palsy, gait disturbances, pyramidal signs, sphincter incontinence
Subcortical dementia
Vascular dementia

12. Cognitive profile CADASIL compared to normals
Impaired on executive function and speed measures
Delis-Kaplan Executive Function System (D-KEFS)
Trails motor speed subtest from the D-KEFS
CADASIL w/stroke and cerebral small vessel disease (SVD)
SVD typically older
Both impaired similarly on executive fx and speed
CADASIL worse on verbal fluency (letter)
refers to a wide range of central control processes in the brain that connect, prioritize,
and integrate operation of subordinate brain functions
this central management system, often attributed to operations in the prefrontal
cortex, is crucial to organizing and integrating cognitive processes over time and plays an
increasingly important role as we mature
visualize executive function as the conductor of a symphony orchestra, who does not play
a musical instrument in the orchestra but does play a critical role by enabling the
orchestra to produce complex music. The conductor organizes, activates, focuses,
integrates, and directs the musicians as they play. The brain’s executive functions, in like
fashion, organize, activate, focus, integrate, and direct, allowing the brain to perform both
routine and creative work.
Executive functions require several higher-level cognitive abilities for successful performance.
These can be assessed with tasks that require:
– initiation of effortful and novel thinking
– isolation of a common feature or attribute from among the array of target stimuli
– formation of a higher-level concept that captures the defining properties of those common features
– flexibility of thinking in order to abandon one conceptual relationship in order to apprehend new ones
Delis-Kaplan Executive Function System
􀂉 Ages 8- adulthood
􀂉 D-KEFS is the first nationally standardized set of tests to evaluate executive functions
􀂉 Assesses higher level thinking and cognitive flexibility
􀂉 Two forms are available to limit practice effects when used for pre- and post-testing.
Comprehensive Evaluation Using 9 Tests
􀂉 Card Sorting Test
– Evaluates problem-solving, verbal and spatial concept formation, flexibility of thinking on a
conceptual task
􀂉 Trail Making Test
– Evaluates flexibility of thinking on a visual-motor task
􀂉 Verbal Fluency Test
– Evaluates fluent productivity in the verbal domain
􀂉 Design Fluency Test
– Evaluates fluent productivity in the spatial domain
􀂉 Color-Word Interference Test
– Evaluates verbal inhibition
􀂉 Tower Test
– Evaluates planning and reasoning in the spatial modality; impulsivity
􀂉 20 Questions Test
– Hypothesis testing; evaluates verbal and spatial abstract thinking; impulsivity
􀂉 Word Context Test
– Evaluates deductive reasoning; verbal abstract thinking
􀂉 Proverb Test
– Evaluates metaphorical thinking; generating versus comprehending abstract thought
Correlated
􀂉 with Wechsler Abbreviated Scale of Intelligence (WASI)
􀂉 with California Verbal Learning Test
􀂉 Provides information concerning the role of intellectual ability and memory
on D-KEFS performance

13. Executive Function
refers to a wide range of central control processes in the brain that connect, prioritize, and integrate operation of subordinate brain functions
this central management system, often attributed to operations in the prefrontal cortex, is crucial to organizing and integrating cognitive processes over time and plays an increasingly important role as we mature
organizes, activates, focuses, integrates, and directs
Executive functions require several higher-level cognitive abilities for successful performance.
These can be assessed with tasks that require:
– initiation of effortful and novel thinking
– isolation of a common feature or attribute from among the array of target stimuli
– formation of a higher-level concept that captures the defining properties of those common features
– flexibility of thinking in order to abandon one conceptual relationship in order to apprehend new ones

14. Other organ disease In some patients w/CADASIL
silent retinal microvascular circulatory changes
18 pts: No visual symptoms. VA was normal in all. Ophthalmologic abnormalities were found in 8 patients.
FE and FA revealed silent retinal abnormalities in CADASIL patients with nerve fiber loss in 22% and cotton wool spots in 17%.
may be considered as peripheral markers of this genetic disease.
high frequency of myocardial infarction in a single series of Dutch patients
Distinct from CADASIL, hereditary endotheliopathy with retinopathy, nephropathy, and stroke (HERNS) is an autosomal dominant multi-infarct syndrome with systemic involvement.
We describe a Chinese American family with a hereditary syndrome consisting of retinopathy, nephropathy, and stroke, affecting 11 members spanning three generations. Ophthalmologic evaluations revealed macular edema with capillary dropout and perifoveal microangiopathic telangiectases. Several members had renal abnormalities with proteinuria and hematuria. Initial manifestations were visual impairment and renal dysfunction; neurologic deficits occurred in the third or fourth decade of life. Symptoms included migraine-like headache, psychiatric disturbance, dysarthria, hemiparesis, and apraxia. Neuroimaging consistently demonstrated contrast- enhancing subcortical lesions with surrounding edema. Ultrastructural studies showed distinctive multilaminated vascular basement membranes in the brain and in other tissues, including the kidney, stomach, appendix, omentum, and skin. Genetic analysis ruled out linkage to the CADASIL locus on chromosome 19. Distinct from CADASIL, hereditary endotheliopathy with retinopathy, nephropathy, and stroke (HERNS) is an autosomal dominant multi-infarct syndrome with systemic involvement.

15. Brain Imaging in CADASIL
Diffuse white matter hyperintensities on T2 and FLAIR weighted images
Subcortical white matter
Basal ganglia
Changes on MRI may be evident in persons who are in their 20s
Penetrance complete by age 35 and all will have MRI findings
The syndrome may not be suspected until affected individuals are in their 50s or older
Lesion volume is inversely correlated with cognitive function

16. MRI Changes Axial FLAIR images 59 yr old woman
Multiple confluent hyperintensities in deep and periventricular white matter

17. MRI
Most specific finding to differentiate CADASIL from ischemic leukoaraiosis
T2 hyperintenisties in anterior temporal pole

18. MRI in CADASIL w/characteristic MRI findings of involvement of the external capsule and anterior temporal lobes.

19. Differentiating CADASIL from other diseases affecting the white matter
Ischemic small-vessel disease
Usually occurs after fifth decade
Vascular risk factors present
Multiple Sclerosis
More likely to see spinal cord and corpus callosum lesions
Periventricular lesions are ovoid and/or oriented perpendicular to lateral ventricles
Others in the differential
ADEM
Binswnger’s disease (hypertensive atherosclerotic encephalopathy)
Amyloid angiopathy
Progressive multifocal leurkoencephalopathy
Mitochondrial disprders
vasculitis

20. When to consider MRI in migraineur
Consider MRI if
Migraine attacks with aura begin in mid-adulthood
Atypical aura
Hemiplegic, basilar, prolonged
Family history of stroke, dementia, depression
Focal neurological signs
In 771 migraineurs with nl exam, significant abnormalities on MRI were found in <1%.
26% with “complicated migraines” (prolonged aura that was difficult to distinguish from a TIA/CVA, had an abnormal MRI.
White matter hyperintense lesions (multiple, small, punctate lesions in deep white matter as seen on T2 or FLAIR imaging are common in general population (up to 10% in fourth decade and 80% in eight decade). There is an increased prevelance in people with vascular disease risk factors, h/o CAD, stroke, dementia, and advancing age. People with migraine are four times more likely to have WMH than non-migraine, age-matched controls, independent of vascular risk factors. Aura or no aura are the same. Women with more than 1 migraine a month may be at higher risk for the development of WMH. Putative mechanisms include migraine-related hypoperfusion and embolism.

21. When to Suspect CADASIL
Recurrent subcortical ischemic strokes
Esp. <60 yrs old
Esp. in absence of vascular risk factors
Early cognitive decline
Migraine with aura
Comorbid psychiatric symptoms
Depression
Bipolar

22. When to Suspect CADASIL
Abnormal MRI
Significant white matter lesions before age 35
Multiple T2 hyperintensities w/o vascular risk factors
Bilateral T2 hyperintensities in white matter, esp. w/lesions in ant. Temporal poles
Family history
Stroke, dementia, depression, migraine w/aura, other white matter diseases (which may be misdiagnosed)
Premature CAD

23. Diagnostic Approach History
MRI with involvement of anterior temporal poles OR external capsule ***
&
Positive gene testing ***
Sensitivity of 100% with Hx, MRI, & gene test in one study from England
Figure. Fluid-attenuated inversion recovery MRI scans from a patient with a notch3 mutation shows typical involvement of the anterior temporal poles (arrow in A) and the external capsule (arrow in B), and characteristic images at the level of the lateral ventricles

24. Biopsy
Skin biopsy was positive in approximately half of the 18 patients tested
Skin biopsy was negative in all of the gene negative patients
Sensitivity of 100%
Granular osmiophilic material seen on EM
Sensitivity 50%, specificity 100%
Tissue samples stained with monoclonal Ab top Notch3 protein
Sensitivity 96%, specificity 100%

25. The hallmark of the disease is the presence of granular osmiophilic material which is seen adjacent to the basement membrane of the smooth muscle cells of arterioles on electron microscopy.
This is pathognomic for CADASIL.
The deposition of GOM in skin arterioles may vary depending on the exact mutation involved.
The vascular defects are present in every tissue and may be detected histologically by examining arterioles in skin biopsy, where accumulation of granular and osmiophilic material within the smooth muscle cell basement membrane and the surrounding extracellular matrix.

26. Blood vessels in CADASIL
w/ basophilic granular material (below)
EM (to right)
The hallmark of the disease is the presence of granular osmiophilic material which is seen adjacent to the basement membrane of the smooth muscle cells of arterioles on electron microscopy. This is pathognomic for CADASIL. The deposition of GOM in skin arterioles may vary depending on the exact mutation involved.
The vascular defects are present in every tissue and may be detected histologically by examining arterioles in skin biopsy, where accumulation of granular and osmiophilic material within the smooth muscle cell basement membrane and the surrounding extracellular matrix.

27. Blood vessels in CADASIL
2 types of changes in arteries, veins in body
Basophilic degeneration and thickening of the media (top picture)
Fibrinoid necrosis of the media sometimes associated with delicate perivascular inflammatory infiltrates (bottom picture)
Basophilic degeneration and fibrinoid necrosis have been found in arteries and veins of internal organs as well as vessels from skin, muscle, and nerve biopsy.
The nature of the granular basophilic changes in vessel walls has not been identified. It may be debris of degenerated smooth muscles cells and/or basal lamina.
In some cases of CADASIL, eosinophilc necrosis of tunica media and perivascular inflammatory infiltrates have been seen. Notch 3 gene may influence the development or reactivity of the immune system. Notch signalling directs early development of T and B cell lineages and is involved in the maturation of CD4 and CD8 T cells in the thymus. The notch pathway contributes to the regulation of the peripheral immune system and regulates the decision between immunity and tolerance.

28. Notch3 ab in brain blood vessels
Notch3 immunoreactivity in vascular smooth muscle cells
Normal controls on left (a, c, e)
CADASIL patients on right (b, d, f)

29. What leads to CADASIL? Mutations in notch3 gene
Odd number of cysteine residues in Notch3 receptor extracellular domain
Impaired clearance of cleavage product
Alterations of vascular smooth muscle
Presence of granular osmiophilic deposits

30. Notch3 gene mutation Usually missense mutation
More than 50 have been found
Spontaneous mutations have been described
The protein folds incorrectly
Leads to accumulation of protein in membranes of smooth muscles and, ultimately, fibrosis and luminal narrowing of them

31. Notch3 gene Mutation in Notch3 gene on chromosome 19
Just downstream from a mutation found in familial hemiplegic migraine
Notch 3 gene encodes a transmembrane receptor
Functions in signaling pathways essential for maturation of blood vessels
In adults, it is maximally expressed in vascular smooth muscle in small to medium arteries
Interaction of notch receptor with its ligand leads to cleavage of the transmembrane receptor which migrates into the nucleus and, associated with a transcription factor, activates transcription of primary target genes.
Notch genes code for large transmembrane receptors involved in cell fate decision during embryonic development.
Interaction of notch receptor with its ligand leads to cleavage of the transmembrane receptor which migrates into the nucleus and, associated with a transcription factor, activates transcription of primary target genes. (fig 2b)
Like all notch receprtos, notch3 contains a large number of tandemly arranged epidermal growth factor-like repeat domains which account for most of the extracellular portion. The gene has 34 exons and all of them may have pathogenetic mutations. No geneotype-phenotype relationship has been observed.
All CADASIL related mutations occur in exons that encode one of the EGF-repeat domains. 100 different nutations in Notch3 have been reported. 95% are missense point mutations. Almost all mutations result in an odd number of cysteine residues which may cause protein misfolding, causing changes in receptor activation and abnormal signal trasnduction. The mechanism by which CADASIL mutations become pathogenic are unknown.

32. The notch in the Drosophila wing
In fruit fly heterozygotes for Notch3 gene have a “notch” in their wing
The mutation is lethal in homozygotes
Notch proteins
Encode transmembrane receptors involved in determination of cell fate during development
Proliferation, differentiation, apoptosis

33. Pathogenic Hypothesis
Notch 3 expression is limited to vascular smooth muscle cells
Mature vascular smooth muscle cells require continued function of the Notch 3 pathway
Continued survival
Blood vessels are narrowed and weak and do not react to fluctuations of CO2 and BP
Capillaries, veins are involved
Generalized vasculopathy

34. Brain Predilection
Cerebral vessels have fewer smooth muscle cells than vessels of other organs
Increased susceptibility
Limited ability for regeneration of CNS tissue
White matter predilection
Insufficient collateral circulation
Density less than in grey matter

35. What can be done for these patients?
Treatment
Control vascular disease risk factors BP
Increased SBP independent risk factor for progression of CADASIL
Cholesterol DM
Smoking
Obesity
Avoid OCP, HRT

36. Treatment Antiplatelet therapy Cholinesterase inhibitors
Investigate for other causes of stroke (cardiac, afib, hypercoag state, etc.)
Cholinesterase inhibitors
Work in vascular dementia
Screen for mood disorders, cognitive decline, seizure
Life expectancy may be shortened by 6 years

37. NP36015 The key finding Differential diagnosis
Abundant basophilic (blue on H&E), PAS positive, osmiophilic (black on EM) granular material seen in the markedly thickened blood vessel walls
Differential diagnosis
Atheroscerotic disease
Blood vessel walls are also thickened
Granular material is not usually present (if present, it differs from that seen in CADASIL)

38. No treatment
Screening not indicated, unless family member is affected
Family may wish to seek genetic counseling
Control vascular risk factors
Do not smoke
Screen for mood disorders, cognitive decline, focal neurologic signs, seizure

39. Questions?