Your brain feels foggy

Questions about memory, focus, and thinking changes

Is this brain fog from MS, or could something else be doing it — sleep, B12, depression, medication?
Could any of my medications be contributing to cognitive issues?
If I'm on an infusion DMT like Ocrevus, could my brain fog be worse in the weeks before my next dose (the 'crap gap')? Should we adjust the timing?
Can you refer me for formal memory and thinking testing — a neuropsych evaluation?
What actually helps protect my thinking — cognitive rehab, lifestyle, anything else?
Will my cognitive function keep getting worse over time?
Does MS lead to dementia?