Cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy vs. multiple sclerosis. Either one or sometimes both?

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL), is the most common cause of inherited cerebral small vessel disease, inherited stroke and inherited vascular dementia. It is not infrequent for CADASIL to be mistaken and mistreated for multiple sclerosis (MS). A much less frequent but existing scenario is the co-occurrence of CADASIL and MS (or MS-like inflammatory condition). Such patients may present with spinal cord lesions, brain or spinal cord enhancing lesions, positive oligoclonal bands and high IgG index in the cerebrospinal fluid and good response to corticosteroids or immunomodulating treatments. CADASIL through various mechanisms may trigger or modulate autoimmune reactions, and either be complicated by an inflammatory component or cause an MS-like disorder.