I guess that definition would rule out optic neuritis which is a very common problem/exacerbation with MS patients. It was actually one of the key symptoms that led to my diagnosis.
Here's the definition given by the National MS Society:
The appearance of new symptoms or the aggravation of old ones, lasting at least twenty-four hours (synonymous with attack, relapse, flare-up, or worsening); usually associated with inflammation and demyelination in the brain or spinal cord.
You may be interested in reading this article, Is It an MS Attack—or Not?
which discusses transient worsening of symptoms, frequently due to heat or stress, which are often confused with an exacerbation.
In a nutshell, although I'm not qualified to give direct medical advice, I would get a new neurologist.