Experimental data suggest that memory-retraining exercises and other cognitive rehabilitation techniques may improve memory acquisition and retention in patients with multiple sclerosis.
One of the distinguishing features of multiple sclerosis is that it is a disease that frequently affects people during the prime of their lives. Recent data indicate that approximately 80% of multiple sclerosis patients retire early from their careers as a result of physical and cognitive impairments.
According to John DeLuca, PhD, vice president of the Kessler Foundation Research Center, most cognitive impairment studies have focused on associations with stroke or traumatic brain injury, but not multiple sclerosis (MS). Approximately 325 studies focused on TBI and cognitive impairment were published over the past 25 years. By comparison, fewer than 20 studies were focused on cognitive impairment in multiple sclerosis. However, over 50% of patients diagnosed with multiple sclerosis suffer from specific cognitive impairments in processing speed and visual memory.
At CMCC-ACTRIMS 2013, DeLuca described several studies focused on how cognitive rehabilitation may provide benefits toward improving the quality of life of patients with multiple sclerosis. They revealed that objective measures of cognitive impairment predicted actual functional impairment in everyday life for the MS patient. Also, significantly, data obtained from self-reporting only predicted emotional stress.
Since objective cognitive impairment can be measured, the investigators then asked whether memory-retraining exercises that have been previously established to improve cognitive function might help to improve everyday life functional activities. The two key aspects to memory are acquisition and retrieval. Researchers determined that the biggest memory problem for patients with MS is associated with the acquisition step.
Then they initiated attempts to improve cognition in patients with MS. These methods are known as self-generation, spacing effects, or combinations of both. The generation effect is simply that the data is obtained via the individual self as opposed to being offered by someone else. The space effect refers to learning two things at times or places spaced apart as opposed to learning two different things together. DeLuca explained that the spacing effect explains why we do not remember so much of the hard things we learned in college, such as calculus, because we crammed it all together in study sessions. Ultimately, DeLuca said these studies revealed that both self-generation and the spacing memory exercises could improve learning in MS patients and that this may translate into benefits for the everyday life of the MS patient.
A newer cognitive rehabilitation model known as “testing effect of spaced retrieval” was also examined and determined to measurably improve cognitive function. This method involved reviewing information, taking a pretest, and then taking a test as opposed to reviewing the information twice followed by taking a test. It has been proven that the testing effect leads to better memory retention.
Visual imagery was also examined in a randomized controlled study involving multiple sclerosis patients with memory problems. Fourteen MS patients were treated with a modified story memory technique incorporating context and imagery and a control group of 14 MS patients were untreated. The results indicated a dramatic improvement in total learning change score for the treated patients, with little to no change in the untreated patients.
Neuroimaging functional MRI studies published in 2012 have detected changes in cerebral activation after performing memory-retraining techniques in multiple sclerosis patients. These results strongly validate the utility of cognitive rehabilitation for treating MS patients.
Ultimately, DeLuca said that these experimental data suggest that cognitive rehabilitation techniques may improve the everyday function of multiple sclerosis patients. It is difficult to determine the best way to measure function in everyday life of multiple sclerosis patients, so this remains one of the ongoing basic challenges to this research. Studies on cognitive rehabilitation for MS patients are ongoing with funding support from the National Institutes of Health.