Editing CADASIL (section)

==Diagnosis==
[[Image:CADASIL - very high mag.jpg|thumb|A [[micrograph]] showing punctate [[immunostaining]] (brown) with a Notch 3 [[antibody]], as is characteristic in CADASIL.]]
MRIs show hypointensities on [[Magnetic resonance imaging|T1-weighted images]] and [[hyperintensities]] on [[Magnetic resonance imaging|T2-weighted images]], usually multiple confluent white matter lesions of various sizes, are characteristic. These lesions are concentrated around the [[basal ganglia]], peri-[[Ventricular system|ventricular]] [[white matter]] and the [[pons]] and are similar to those seen in [[Binswanger disease]].<ref name="Chabriat1995"/><ref>{{cite book |veditors=Ropper AH, Brown RH |chapter=Cerebrovascular Diseases |title=Adams and Victor's Principles of Neurology |publisher=McGraw-Hill |location=New York |year=2005 |isbn=978-0-07-141620-7}}</ref> These white matter lesions are also seen in asymptomatic individuals with the mutated gene.<ref>{{cite journal |vauthors=Tournier-Lasserve E, Joutel A, Melki J |title=Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy maps to chromosome 19q12 |journal=Nat. Genet. |volume=3 |issue=3 |pages=256–9 |date=March 1993 |pmid=8485581 |doi=10.1038/ng0393-256 |s2cid=13031278 |display-authors=etal}}</ref>  While MRI is not used to diagnose CADASIL, it can show the progression of white matter changes even decades before onset of symptoms.{{citation needed|date=December 2020}}

The definitive test is sequencing the whole ''NOTCH3'' gene, which can be done from a sample of blood. However, as this is quite expensive and CADASIL is a systemic [[arterial disease]], evidence of the mutation can be found in small and medium-size arteries. Therefore, skin biopsies are often used for the diagnosis.<ref>{{cite journal |vauthors=Joutel A, Favrole P, Labauge P |title=Skin biopsy immunostaining with a Notch3 monoclonal antibody for CADASIL diagnosis |journal=Lancet |volume=358 |issue=9298 |pages=2049–51 |date=December 2001 |pmid=11755616 |doi=10.1016/S0140-6736(01)07142-2 |s2cid=31459077 |display-authors=etal}}</ref><ref>{{cite journal |vauthors=Ueda M, Nakaguma R, Ando Y |title=[Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)] |language=Japanese |journal=Rinsho Byori |volume=57 |issue=3 |pages=242–51 |date=March 2009 |pmid=19363995 }}</ref>