“Today my attention moves in fits and starts. My memory has broken legs, perhaps it will remain compromised. My words may be unfaithful” [1]. In these lines, Francesca Mannocchi portrays her cognitive challenges while living with multiple sclerosis (MS). She is a journalist, a war correspondent, a writer. Her private endeavor is invisible to someone looking from the outside. And this is also part of the problem. The difficulties she faces resonate with most people – nearly two-thirds – with MS [2].
People with MS often find that the speed at which they can handle information slows – this is known as slow processing speed. Furthermore, the abilities to learn and remember something over an extended period (long-term memory) and to briefly hold and manipulate a small amount of information for an immediate task (working memory) can be affected [3]. People with MS can experience difficulties in high-level language abilities. For example, they can have problems in word finding [4]. Attention and executive functioning – i.e. a group of mental processes which serve to organise and monitor behavior to achieve desired goals – can also be compromised [3]. These impairments can have a profound impact on different facets of daily life. Many consider quitting their jobs. Indeed, the unemployment rate among individuals with MS with cognitive impairment is significantly higher, compared to patients without cognitive difficulties [5].
Early and regular assessment of cognition in people with MS can therefore help to detect or anticipate limitations and tailor interventions [6].
Personal experiences and cognitive assessment
How do individuals with MS recognise they have a cognitive problem? We asked this question to John DeLuca, PhD, senior vice president of Research and Training at Kessler Foundation and a professor at Rutgers New Jersey Medical School. “Usually, when the patients feel that something is going on cognitively, they complain about memory. Typically, they would say: ‘I cannot think like I used to’ or ‘My memory does not seem as good as it used to be.’ However, this is not always the case. Occasionally, the self-report may not define the correspondent deficit. There may be problems other than memory, that the patients do not know how to describe. We need to identify the problem first to effectively intervene.”
Screening tools like the Brief International Cognitive Assessment for MS (BICAMS) can be used to assess processing speed, verbal and visuospatial memory [7]. This enables to narrow down the problem, further investigate it, and plan the targeted intervention.
Currently, it is not possible to manage MS-related cognitive impairment with medications approved by health authorities [8]. In fact, the evidence supporting the efficacy of pharmacological treatment for cognitive difficulties in MS is not compelling. A systematic review of eighty-seven articles – published between 1990 and 2020 – found mixed results, possibly due to methodological limitations [9]. A treatment approach that is gaining increasing support is cognitive rehabilitation. Cognitive rehabilitation is based on behavioral approaches that are designed to restore skills or compensate for cognitive difficulties [10].
Understanding the problem to cope with it
“With cognitive rehabilitation, we mostly try to alleviate cognitive challenges and their impact in everyday life”, Dr. DeLuca continues, “If the issue is related to slow information processing speed, the patients need to understand what this means and entails. This means that they can have difficulties to elaborate all the pieces of information presented to them. Therefore, since they do not get the information in the first place, they cannot possibly remember it. One approach is for patients to take control of their environment to help ensure they received the information. For example, whenever they find it hard to hold a conversation, they can momentarily stop their interlocutor to seek clarification: ‘Excuse me, let me please better understand what you are telling me.’ This increases the chances to acquire the complete information, rather than losing it or getting only a fraction of it.”
In other cases, cognitive dysfunction in people with MS is related to difficulties in the initial acquisition of novel information [11]. Indeed, our ability to remember information for extended duration is dependent on different phases. First, we create an internal representation of the novel information. Over time, we integrate this representation with what we already know, consolidating it in a way that can be accessed later [12, 13]. There is a variety of ways in which the initial phase of acquisition can be enhanced. One of them is using visual imagery – i.e. the ability to form mental images. This technique can strengthen certain types of memories, related for instance to stories and appointments [14, 15]. For this effect to occur and last over time, patients need to be trained to actively use mental images to facilitate learning [14].
Solid evidence and methodologically robust studies suggest that patients living with MS can benefit from memory rehabilitation. The most recent Cochrane review about memory rehabilitation in patients with MS evaluated 44 good-quality studies and observed substantial progress in the field. Over a period of 6 months, memory functioning and quality of life – but not anxiety and daily activities – improved in people with MS who had memory rehabilitation [16].
Physical activity can also contribute to manage cognitive dysfunction in MS. A recent review observed a significant effect of high-intensity interval training (HIIT) on verbal memory. HIIT includes brief high-intensity activity of 30-60 seconds, alternated with periods of active recovery [17]. Walking is also an interesting activity to consider, as it is common in daily life and easy to measure with wearable sensors. A recent study assessed the volume – number of steps per day – and the intensity – number of steps per minute – of walking and the possible association of these indicators with better cognitive performance. The researchers measured the “peak cadence” to capture the maximum intensity at which one walks during the day. People living with MS who walked at higher intensity levels showed better performance in verbal and visuospatial learning and memory. The intensity of walking was more strongly associated with improvements in cognition in MS, compared to the overall quantity of steps [18].
A broad perspective on the patient
The skills obtained through cognitive rehabilitation should be observed as part of patients’ everyday life activities. Therefore, it is crucial to see the patients in their entirety, considering different aspects of their lives. Potential obstacles that could prevent the usage of the new skills in real-life should be evaluated on a case-by-case basis. The Cochrane review – on memory rehabilitation in MS – highlighted an important concern regarding the insufficient description of the samples. Only 5 out of 44 studies provided information on participants’ ethnicity and no paper reported whether participants had co-morbidities or if they faced economic disadvantages [16]. These are some of the aspects that can importantly influence health outcomes [19].
Hanneke Hulst, PhD, newly appointed scientific director of the Institute of Psychology at Leiden University, explained to us, “It is crucial to take a full picture of the patient and determine what fits best at that moment in time. In the context of cognitive rehabilitation, there are many factors that need to be considered beyond the cognitive functioning – social network, private life, community support, working environment. The patients need to integrate new practices in their routine, maybe plan some activities differently. Therefore, it is fundamental to have a broad perspective on the individual and to personalise cognitive rehabilitation. Interdisciplinary collaboration is fundamental in broadening the perspective and seeing the global picture when designing these interventions.”
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Written by Stefania de Vito
Special thanks to John DeLuca, PhD (Kessler Foundation), and Hanneke Hulst, PhD (Leiden University), for their insights.
References
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