CADASIL may occasionally present with MS-like inflammatory features, and the term 'inflammatory CADASIL' can be considered when such red flags are present in atypical MS patients.
A systematic literature review identified 12 reports describing 19 cases of CADASIL with inflammatory or MS-like features.
Sensory manifestations were the most prevalent clinical feature among CADASIL patients with MS-like presentations.
The majority of reviewed CADASIL patients with MS-like features had small vessel disease, demyelinating lesions, or both on neuroimaging.
Both originally reported cases in this study were CADASIL patients who were misdiagnosed with Multiple Sclerosis.
The authors propose the term 'inflammatory CADASIL' to describe CADASIL presentations with MS-like inflammatory features.
Genetic testing was identified as imperative for cases of suspected CADASIL, particularly those presenting with atypical MS features.
This research examines a diagnostic overlap between two neurological conditions: CADASIL, a rare inherited disease affecting small blood vessels in the brain, and Multiple Sclerosis (MS), an autoimmune disease that damages nerve fibers. The authors reported two patients who had CADASIL but were initially diagnosed with MS, and they also reviewed the existing medical literature, finding 19 previously published cases where CADASIL patients showed symptoms or brain scan findings that resembled MS. Common features in these cases included sensory problems (like numbness or tingling), motor difficulties, problems with walking, and migraine headaches. Nearly all patients (over 90%) had brain imaging findings associated with either small vessel disease, demyelinating (nerve-damaging) lesions, or both — the kinds of findings that can make CADASIL look like MS on a scan. The researchers propose using the term 'inflammatory CADASIL' to describe cases where CADASIL presents with these MS-like features, suggesting this may represent a recognized pattern worth naming. They emphasize that when a patient appears to have atypical MS — especially with features like small vessel disease or a family history suggesting a hereditary condition — clinicians should consider the possibility that CADASIL could be the true underlying diagnosis. Genetic testing, which can definitively confirm a CADASIL diagnosis by identifying mutations in the NOTCH3 gene, is highlighted as essential in such situations. This research suggests that CADASIL can mimic MS closely enough to lead to misdiagnosis, which matters because the two conditions require very different management approaches. Treating a CADASIL patient as though they have MS could mean missing the correct diagnosis and potentially exposing patients to unnecessary or inappropriate treatments. Awareness of the overlap between these two conditions, and a low threshold for genetic testing in atypical cases, may help reduce misdiagnosis.
Ahmed A, Mistry N, Gehad A, Hassan A. (2026). Inflammatory CADASIL: the cross-link between CADASIL and multiple sclerosis: a report of two cases and systematic review of the literature.. BMC neurology. https://doi.org/10.1186/s12883-026-04772-1