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PubMed This is a summary of 20 peer-reviewed journal articles Updated
Neurology · Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy

Decoding Your MRI and Genetic Test Reports

At a Glance

CADASIL is typically confirmed through a NOTCH3 genetic test showing a cysteine-altering mutation, or an MRI revealing white matter changes in the anterior temporal poles. If genetic results are unclear, a skin biopsy looking for GOM deposits can definitively confirm the diagnosis.

Reviewing your medical reports can feel like reading a foreign language. However, once you understand a few key terms, these documents become powerful tools that help you and your care team track the health of your brain’s blood vessels [1].

Deciphering Your MRI Report

Magnetic Resonance Imaging (MRI) is the primary way doctors see the physical effects of CADASIL. When you read your report, look for these specific “hallmarks”:

  • White Matter Hyperintensities (WMH): These are often described as “bright spots” or “increased signal” [2]. In CADASIL, these spots represent areas where the brain’s “wiring” has been affected by reduced blood flow [3].
  • The “CADASIL Signature”: While many conditions cause white matter spots, CADASIL has a unique preference for two specific locations:
    • Anterior Temporal Poles: This is the front part of the brain near your temples. Finding spots here is a classic sign of CADASIL [2][4].
    • External Capsules: These are thin layers of white matter deep in the brain. Involvement here further points toward a CADASIL diagnosis [2][5].
  • Lacunar Infarcts: These are the medical terms for very small strokes that occur in the deep parts of the brain [2][6]. Your report may list a “burden” or count of these [7].
  • Cerebral Microbleeds (CMB): These are tiny, old leaks from fragile blood vessels [8]. They are usually seen on a specific type of MRI sequence called “SWI” or “T2*” [9].

Understanding Your Genetic Test

A NOTCH3 genetic test is the “gold standard” for confirming CADASIL [1]. It looks for an error in the instructions for building blood vessel proteins [10].

  • Exons: These are like “chapters” in a book. While mutations can happen in any chapter from 2 to 24, they are most common in Exons 4, 8, and 11 [11][12].
  • The Cysteine Rule: The most important word to look for is cysteine. In classic CADASIL, the mutation usually results in the gain or loss of a “cysteine residue” [13][14]. If your report says “cysteine-altering,” it strongly confirms the diagnosis [15].
  • Variants of Uncertain Significance (VUS): Sometimes the test finds a change, but science doesn’t yet know if it causes disease [16]. In these cases, your doctor may look at your family history or order a skin biopsy [17].

The Role of Skin Biopsies

If genetic testing is unclear, a doctor may perform a skin biopsy. They take a tiny sample of skin and look at the small blood vessels under a powerful microscope [18][19].

  • GOM Deposits: They are looking for Granular Osmiophilic Material (GOM)—the protein clumps that are the physical fingerprint of CADASIL [13][20]. Finding GOM is 100% specific to CADASIL [20].

Your Diagnostic Vocabulary File

To ensure you can advocate for yourself effectively, make sure you understand the following variables in your file:

  1. Your specific NOTCH3 mutation and exon number.
  2. Whether your MRI report mentions the “temporal poles.”
  3. The general count of microbleeds or lacunar infarcts mentioned in your latest scans.

Common questions in this guide

What does a NOTCH3 test look for in CADASIL?
A NOTCH3 genetic test is the standard for confirming CADASIL. It looks for specific errors, typically a gain or loss of a cysteine residue, in the instructions for building blood vessel proteins.
Why do doctors look at the anterior temporal poles on an MRI?
Finding white matter changes, often called bright spots, in the anterior temporal poles is a classic hallmark of CADASIL. This specific brain location helps doctors distinguish CADASIL from other conditions that cause similar spots.
What is the purpose of a skin biopsy for CADASIL?
If genetic testing results are unclear, a skin biopsy can look for Granular Osmiophilic Material (GOM) deposits. Finding these protein clumps in the small blood vessels of the skin is a definitive sign of CADASIL.
What are lacunar infarcts on my MRI report?
Lacunar infarcts are very small strokes that occur deep within the brain. Your MRI report will often mention the count or burden of these, which helps doctors track how the condition is affecting your brain.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.My report mentions 'hyperintensities'—how extensive are these compared to my previous scans?
  2. 2.Does my MRI show involvement of the temporal poles? If not, does that change your confidence in the CADASIL diagnosis?
  3. 3.How many 'lacunar infarcts' or 'microbleeds' are currently visible, and what does this number mean for my stroke risk?
  4. 4.My genetic test identifies a mutation in a specific exon. Does this particular location suggest a milder or more severe course?
  5. 5.If we aren't sure about the genetic results, would a skin biopsy help clarify the diagnosis?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References

References (20)
  1. 1

    Hereditary Haemorrhagic Cerebrovascular Disease: Implications for Clinical Management.

    Hou W, Hou Y, Ren X, Liu J

    Annals of neurosciences 2025; 09727531241308346 doi:10.1177/09727531241308346.

    PMID: 40115281
  2. 2

    [The hereditary vessel disease CADASIL].

    Sveinsson OA, Arkink EB, Thors B

    Laeknabladid 2024; (110(7)):360-364 doi:10.17992/lbl.2024.0708.801.

    PMID: 38934718
  3. 3

    Recurrent transient global amnesia as presenting symptoms of CADASIL.

    Pradotto L, Orsi L, Mencarelli M, et al.

    Clinical case reports 2016; (4(11)):1045-1048 doi:10.1002/ccr3.666.

    PMID: 27830070
  4. 4

    Update on the Epidemiology, Pathogenesis, and Biomarkers of Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy.

    Yamamoto Y, Liao YC, Lee YC, et al.

    Journal of clinical neurology (Seoul, Korea) 2023; (19(1)):12-27 doi:10.3988/jcn.2023.19.1.12.

    PMID: 36606642
  5. 5

    Recurrent generalized seizures as the prominent manifestation in a patient with CADASIL: a case report and literature review.

    Pan L, Chen Y, Zhao S

    BMC neurology 2022; (22(1)):375 doi:10.1186/s12883-022-02889-7.

    PMID: 36180846
  6. 6

    Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) - Still to be Considered in the Presence of Vascular Risk Factors.

    Ganesan DN, Coste T, Venketasubramanian N

    Case reports in neurology 2020; (12(Suppl 1)):196-201 doi:10.1159/000507542.

    PMID: 33505295
  7. 7

    Imaging Characteristics for Predicting Cognitive Impairment in Patients With Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy.

    Taniguchi A, Shindo A, Tabei KI, et al.

    Frontiers in aging neuroscience 2022; (14()):876437 doi:10.3389/fnagi.2022.876437.

    PMID: 35754959
  8. 8

    Intracerebral Hemorrhage in Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy: Prevalence, Clinical and Neuroimaging Features and Risk Factors.

    Liao YC, Hu YC, Chung CP, et al.

    Stroke 2021; (52(3)):985-993 doi:10.1161/STROKEAHA.120.030664.

    PMID: 33535780
  9. 9

    Occurrence of Intracranial Hemorrhage and Associated Risk Factors in Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy: A Systematic Review and Meta-Analysis.

    Lai QL, Zhang YX, Wang JJ, et al.

    Journal of clinical neurology (Seoul, Korea) 2022; (18(5)):499-506 doi:10.3988/jcn.2022.18.5.499.

    PMID: 36062766
  10. 10

    Role of NOTCH3 Mutations in the Cerebral Small Vessel Disease Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy.

    Coupland K, Lendahl U, Karlström H

    Stroke 2018; (49(11)):2793-2800 doi:10.1161/STROKEAHA.118.021560.

    PMID: 30355220
  11. 11

    NOTCH3 mutations in a cohort of Portuguese patients within CADASIL spectrum phenotype.

    Almeida MR, Elias I, Fernandes C, et al.

    Neurogenetics 2022; (23(1)):1-9 doi:10.1007/s10048-021-00679-w.

    PMID: 34851492
  12. 12

    First report of a homozygous mutation on exon 24 of the NOTCH3 gene in a paucisymptomatic CADASIL elderly patient.

    Ragno M, Pianese L, Tiberi S, et al.

    Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology 2022; (43(2)):1457-1458 doi:10.1007/s10072-021-05706-0.

    PMID: 34739617
  13. 13

    Most common NOTCH3 mutations causing CADASIL or CADASIL-like cerebral small vessel disease: A systematic review.

    Boston G, Jobson D, Mizuno T, et al.

    Cerebral circulation - cognition and behavior 2024; (6()):100227 doi:10.1016/j.cccb.2024.100227.

    PMID: 38966425
  14. 14

    Top-NOTCH3 Variants in the Population at Large.

    Kalaria RN, Kittner SJ

    Stroke 2020; (51(12)):3482-3484 doi:10.1161/STROKEAHA.120.031609.

    PMID: 33161845
  15. 15

    Blood vessel organoids generated by base editing and harboring single nucleotide variation in Notch3 effectively recapitulate CADASIL-related pathogenesis.

    Ahn Y, An JH, Yang HJ, et al.

    Molecular neurobiology 2024; (61(11)):9171-9183 doi:10.1007/s12035-024-04141-4.

    PMID: 38592587
  16. 16

    Homozygous NOTCH3 p.R587C mutation in Chinese patients with CADASIL: a case report.

    He R, Li H, Sun Y, et al.

    BMC neurology 2020; (20(1)):72 doi:10.1186/s12883-020-01660-0.

    PMID: 32122318
  17. 17

    The role of clinical and neuroimaging features in the diagnosis of CADASIL.

    Bersano A, Bedini G, Markus HS, et al.

    Journal of neurology 2018; (265(12)):2934-2943 doi:10.1007/s00415-018-9072-8.

    PMID: 30311053
  18. 18

    Detection of Vascular Notch3 Deposits in Unfixed Frozen Skin Biopsy Sample in CADASIL.

    Ueda A, Nakajima M, Misumi Y, et al.

    Frontiers in neurology 2022; (13()):881528 doi:10.3389/fneur.2022.881528.

    PMID: 35775048
  19. 19

    Novel dot-blot assay for detection of vascular Notch3 aggregates in patients with CADASIL.

    Ma Y, Ueda M, Ueda A, et al.

    Journal of the neurological sciences 2020; (415()):116931 doi:10.1016/j.jns.2020.116931.

    PMID: 32470649
  20. 20

    Clinical presentation of Y189C mutation of the NOTCH3 gene in the Polish family with CADASIL.

    Dorszewska J, Kowalska M, Grzegorski T, et al.

    Folia neuropathologica 2020; (58(1)):83-92 doi:10.5114/fn.2020.94009.

    PMID: 32337960

This page explains CADASIL MRI and genetic testing terminology for educational purposes. Your neurologist and genetic counselor are the best sources for interpreting your specific medical reports.

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