Cognitive impairment is a common symptom experienced by people with multiple sclerosis (MS), affecting quality of life and ability to work. Treatment strategies to manage cognitive dysfunction are an unmet need and viable solutions are still required. An area of considerable interest at the #ECTRIMS2018 congress was cognition and the importance of finding solutions to improve cognitive difficulties. Researchers addressed some important questions on this topic
What can alter cognitive function in people with MS?
Studies have shown that lifestyle and environmental factors might have an impact on cognitive function. Dr. Marianna Cortese from Harvard TH Chan School of Public Health (Boston), evaluated whether vitamin D levels, smoking, and EBV infection could predict changes in long-term cognitive function. 278 people with clinically isolated syndrome (CIS) who were enrolled in a Phase 3 trial called BENEFIT, were followed up for 11 years. The researchers evaluated whether environmental factors, such as vitamin D levels, smoking and viral infection might have an impact on cognition. Serum levels of vitamin D (measured with 25-hydroxy Vitamin D test), smoking (measured by a marker of smoking called cotinine) and Epstein-Barr virus (EBV; virus considered a risk factor for MS and measured by evaluating the levels of EBV nuclear antigen 1 in the serum) were measured, along with cognitive functions. Cognitive function was assessed by measuring the speed and flexibility of processing auditory information and calculation ability. Interestingly, the researchers discovered that higher vitamin D levels were associated with better cognitive function and lower neuronal damage while smoking status in the last three years was linked to worse cognitive function. Finally, viral infection was not associated with cognitive decline or neuronal damage.
Is early diagnosis of cognitive decline possible?
Dr. Wallace Brownlee from Herford County Hospital (London UK) presented a study that evaluated whether early brain or spinal cord lesions were associated with cognitive decline. In this study, 104 people with CIS were followed over 15 years. The individuals involved in the study had a brain and spinal cord magnetic resonance imaging (MRI) at the time CIS diagnosis and one year after diagnosis. After 15 years since being diagnosed with CIS, the researchers measured cognitive abilities (verbal and visual memory, attention and processing speed) and concluded that the MRI collected at the time of diagnosis could predict cognitive decline. The researchers discovered that MRI may be helpful in identifying individuals diagnosed with CIS who are at higher risk for developing cognitive difficulties 15 years later. Identifying people at-risk of developing cognitive difficulties is a priority and could be essential in helping people target this symptom early in their diagnosis to slow or prevent future cognitive impairments.
What new tools are available to identify people with cognitive impairments?
As cognitive impairment affects many people with MS, regular evaluation of cognition might help physicians to identify people earlier at risk to cognitive decline. To target this issue, Dr. Kunio Nakamura from the Cleveland Clinic (Ohio USA), and his colleagues developed a new test called the Processing Speed Test (PST), which evaluates the time that takes to process and react to information and that can be administered via an iPad application. The research team implemented the test into routine clinical care at their clinic. In 850 people diagnosed with MS, the score obtained with the PST correlated with brain lesions and patients reported outcomes of well-being and cognitive abilities. These results support the use of this test as a measure in clinical practice as well as in clinical trials.
What interventions are being tested to manage cognitive difficulties?
Non-pharmacological approaches to help with cognitive dysfunction are being studied. Dr. John DeLuca from the Kessler Foundation (New Jersey, USA) presented a handful of studies that showed very promising and clinically meaningful results using exercise and cognitive rehabilitation in MS. Interestingly, computer-based cognitive rehabilitation seems effective in improving memory but this type of rehabilitation should not be definitively considered as treatment for all patients. Exercise approaches have also been evaluated as a method to improve cognition. For instance, Dr. Brian Sandroff from University of Alabama at Birghman (USA) compared three (3) exercise- based training approaches using various levels of intensity of treadmill walking and observed that the intensity of the exercise is not a key factor to obtain positive outcomes in people with MS. Additionally, he reported that treadmill training improved self-perceived cognitive deficits and information processing speed.
Dr. Iris-Katharina Penner at the Heinrich-Heine-University and director of the COGITO Center for Applied Neurocognition and Neuropsychological Research (Düsseldorf, Germany), and colleagues performed a clinical trial during which 44 people affected by either relapsing-remitting or the secondary progressive MS, received one of the following interventions for three-months: physical exercise training twice a week for 45 minutes (treadmill walking), computer-based training twice a week for 45 minutes or a combination of both. The results showed that a combination of physical exercise and cognitive training improved patients’ self-perceived cognitive deficits and the ability to process information. Thus, physical exercise and computer-based cognitive training have the potential to improve cognitive performance in individuals diagnosed with MS. The study is still ongoing to assess other outcomes, including quality of life, fatigue, depression/anxiety.
Non- pharmacological approaches through exercise or cognitive training are still being developed. Well-designed clinical trials are needed to test the efficacy of these approaches. Nonetheless, it is encouraging to see an increasing number of studies on exercise and cognitive rehabilitation showing positive outcomes of the interventions. The MS Society of Canada recently announced support of research in this space by funding a $5 million clinical trial led by Dr. Anthony Feinstein from Sunnybrook Hospital. Check our previous post to have learn more information on the study.
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