The next tier of cognitive domains, or next most prevalent deficits, is in the area of visual spatial perception and problem solving, where we see from 12 to 19 percent of the patients showing impairment, and problems with language or attention span are relative. In this case, for her it was visual spatial abilities in sustaining attention. Even though she complained of impairment, she had relatively little impairment on formal testing. This would be deficits in verbal memory, and processing speed, or concentration, but normal performance in other cognitive domains. We really don't know a lot about what happens in terms of patient's cognitive functions over time.
Some studies show relatively little change in the patient's performance over four years.
It wasn't broken down into subgroups, but there was deterioration in overall performance of the MS group. A Finnish group has stratified people based on whether they were intact at the initial observation or whether they were impaired. Whereas, the members of the group that was impaired continued to get more impaired, although at variable rates. The bottom line is much the same answer we have to give them in terms of their physical progression over time. We really can't say with an individual patient.