Hi Curious2,
Welcome!
As a nurse you may be concerned about whether white matter disease means MS since MS is a disease of the white matter.. You might want to ask your doctor--though often as we get older, white matter disease that is age-related (but not MS) sets in.
Here is what WebMD has to say about it:
White Matter Disease: Causes, Symptoms, Treatment
And this is from Medical News Today:
White matter disease: Prognosis, symptoms, and treatment