There are a few red flags on this one unless I missed something:
- The article did not link to the study (I looked it up, it's here:
https://www.neurology.org/doi/10.1212/WNL.0000000000210149)
- The quotes was attributed to "Amber Salter, from the varsity, and a member of the American Academy of Neurology". Odd wording, and in line with some other wording oddities in the write-up.
- Ms. Salter was quoted as speaking in absolutes (“This is good news for people with MS, that they do not need to worry about long-term worsening of their MS symptoms after a Covid-19 infection”) -- either she was misquoted, or she is irresponsible and not an objective researcher. There is no way to credibly make absolute statements about what is still a novel virus.
- The study's methodology was an experimental program for self-reporting of perceived symptoms by patients; additionally, whether or not a patient was infected with Covid during the study or ever had Covid was also a matter of self-reporting. No nucleocapsid testing was done to confirm or rule-out instances of asymptomatic infections amongst any of the participants.
- Much of the language in the study's write-up was... odd, for a neuro study in particular. Less formal than is typical, and not in a reader-comprehension way -- more an eliding-over-details way. Which may mean nothing, could just be the authors' style, but it was unusual.
- More than one of the study's authors had significant potential conflicts of interest in their disclosures, primarily financial.
So, I'd call this a curiosity, but definitely not definitive. This study, published in the same journal in January 2022, is an excellent example to contrast against the UT Southwestern study:
https://www.neurology.org/doi/full/10.1212/NXI.0000000000001118