Cognitive decline is common in those with multiple sclerosis, but not everyone is so afflicted. What governs whether an individual will suffer cognitive impairment? One proposed factor is cognitive reserve, and a new study adds to the evidence that cognitive reserve does indeed help protect against cognitive decline, as it does with age-related decline.
The study involved 50 people with multiple sclerosis plus a control group included 157 clinically healthy adults of similar age and education level, and found that those with more education (defined as more than 13 years of schooling) were protected against cognitive impairment. This is not simply a matter of the more educated starting off from a higher base! MS patients with low education performed more poorly on a demanding cognitive test than healthy controls with the same level of education, while MS patients with high education performed at the same level as their matched controls.
On the other hand, occupation (also implicated as a factor in cognitive reserve, though a less important one than education) did not have an effect. Nor did fatigue.
Cognitive performance was evaluated using the Paced Auditory Serial Addition Test (PASAT), in which a series of single digit numbers are presented and the two most recent digits must be summed. This test has high sensitivity in detecting MS-related cognitive deficits as it relies strongly on working memory and information processing speed abilities. The poorer performance of low-education MS patients was only found at higher speeds.