My husband had an MRI done and was told he has "scattered white matter" in his brain. They made no indications of what this could be. They said nothing else. They did no further testing. What could this mean for my husband?

This is worth a read:

http://www.ctpost.com/news/article/White-matter-lesions-may-not-be-as-scary-as-they-2302110.php

Here's a quote from another internet source: the "presence of these white matter signal changes on brain MRI has to be correlated to the history, clinical examination and other ancillary investigations."

My impression is that the significance of "scattered white matter" in the brain as seen on an MRI can only be interpreted properly in the light of your husband's medical history and the symptoms he was having that prompted the doctor visit, as well as whatever additional tests your doctor seems appropriate.

(As an anecdote, I suffer from "blepharochalasis"---Scary, huh? Turns out that simply means that my right eyelid sags ever so slightly due to normal aging of the tissue in my body.  When someone asks me "what did the doctor say?"  I always start with  "blepharochalasis" and watch their horror type facial response. )