We explain the impact on the neurological capacities of the person with MS.
It is a health condition whose diagnosis usually occurs at the end of the second decade of life or at the beginning of the third, at a time of effervescence in terms of personal projects.
In this article we will talk about cognitive impairment in multiple sclerosis, since it is one of the most disabling symptoms of the disease, but first we will stop to define what it consists of and how it is expressed.
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What is multiple sclerosis?
Multiple sclerosis is a neurological pathology, which stands as one of the most frequent causes of disability (due to disease) in young people.
It has important autoimmune and inflammatory components, both of which also contribute to its organic foundation . In general, this condition is characterized by the destruction of the myelin sheaths that cover the axons of neurons, which protect their integrity and allow their proper functioning.
This deterioration of the myelin sheaths has two fundamental consequences. The first is that it leaves the nerve itself exposed to possible damage, and the second is that it alters the saltatory electrical activity through which the neurons themselves can establish communication with each other (synapses). This effect is responsible for the various symptoms that accompany the pathology, for which it has often been called the “disease with a thousand faces”.
Most people with multiple sclerosis (85%) have the relapsing-remitting subtype, which manifests itself in the form of well-defined acute episodes in time, where the symptoms take on a preponderant entity and after which a partial physical recovery is seen. Disability would be the result of the sum of the residual symptoms that remain after these outbreaks, and that have a progressively greater impact on important bodily functions.
The remaining 15% of patients suffer from one of the progressive forms, namely: primary progressive, in which the symptoms evolve continuously from the moment the disease debuts; and secondary progressive, where an insidious progression of physical deterioration is manifested after a long period (around 15 years) in which it did so in the form of outbreaks. This last subtype generates a lot of anxiety, but it does not necessarily have to occur.
The most common symptoms of multiple sclerosis are motor and sensory. These include loss of muscle strength or difficulty walking; but also a series of sensations such as tingling or numbness, which can spread to any part of the body (but especially to the arms and legs). Another relatively common symptom is loss of visual acuity and double vision (as a result of optic neuritis), with pain around the affected eye.
Fatigue is the most common symptom in multiple sclerosis, and is closely associated with the negative impact of the pathology on work or academic life. Other symptoms that may appear are loss of balance, difficulties in controlling urinary/intestinal sphincters (incontinence or excessive restraint), pain (neuropathic or musculoskeletal), and psychological comorbidities (especially major depression ).
In this article we will focus on one of the most important: cognitive impairment .
Cognitive impairment in multiple sclerosis
Cognitive impairment in multiple sclerosis is one of the symptoms that is most closely related to the erosion of quality of life . Although there are discrepancies between authors, it is estimated that it occurs in a high percentage of patients (between 40% and 70%), being the result of lesions on the central nervous system (manifested as plaques or hardening of neural tissue at any point in the brain or spinal cord, but especially at the periventricular level).
It is more common in people who present some of the progressive forms of the pathology. This is because these patients show more extensive damage to the white matter (as a consequence of accumulated damage to the myelin sheaths and axons), but also to the gray matter and corpus callosum. However, in most cases, cognitive decline is slight and can be improved through personalized rehabilitation strategies.
Regarding specific brain structures related to cognitive impairment in multiple sclerosis; the cingulate gyrus, the insula and the temporobasal cortex stand out above all.
At this point, it is important to mention that the human brain has the plastic capacity to try to compensate for the damage that could be generated on it, and also has specific mechanisms to remyelinate axons whose integrity has been altered. This last restorative quality, however, has its limitations: the new generated pods are more vulnerable to new “attacks”, and are structurally more fragile than the original ones.
We proceed to know the cognitive functions that can be altered during the development of the disease .
Altered cognitive functions in multiple sclerosis
The cognitive functions that can be altered most frequently during the development of the disease are the speed of information processing, memory, attention and mental flexibility .
There are multiple studies that relate this deficit with mood disorders, such as major depression, in such a way that both realities seem to be associated in a bidirectional way.
If you are a person with multiple sclerosis and detect any of the alterations that we are going to address, consult your neurologist.
1. Information processing speed
The speed of information processing is a dimension of efficiency . It describes the ability of a person to distribute their cognitive resources in an appropriate way, with the purpose of developing tasks that require their management and a certain mental effort. Thus, this function describes the way in which we organize the limitations inherent to the human being, to optimize them according to the demands of a demanding situation in order to carry it out successfully.
People with difficulties in the speed of information processing may feel overwhelmed by physical environments in which there is an excess of sensory stimulation, or perceive that ambiguous environments (in which they could previously function without problems) overwhelm their cognitive resources and generate a special feeling of physical or mental exhaustion.
This function, however, supposes the contribution of many others (especially attention and concentration).
2. Memory
Memory is the ability to store information of different types, to be recalled later if necessary. It is a complex function, as there are many ways to describe each of its components, but among all of them the most commonly affected is long-term memory. In particular, problems can be seen in remembering events that happened a long time ago (episodic memory), which generates anguish in those who experience it.
Working memory can also be altered, a cognitive process that aims to store the necessary information (in the background) to carry out tasks that we are dealing with. One of the most common consequences of its affectation is the difficulty to follow the thread of those conversations that last for many minutes, or of relatively long stories that we read or watch on television.
3. Attention
Attention problems are common among patients who have lesions located in the prefrontal cortex. As was the case with memory, there is no single way to define attention, generally distinguishing three modalities: sustained (ability to attend to stimuli for long periods of time), divided (ability to attend to different stimuli or tasks simultaneously) and selective (ability to attend to a relevant stimulus that is immersed among others that should be ignored).
Multiple sclerosis patients may have problems sustaining attention for long periods of time , and even experience some difficulty in focusing their attentional resources on a single stimulus that is present in the environment. In some cases, in addition, it can refer to the feeling of having a “blank mind”.
4. Mental flexibility
Mental flexibility is the ability to adapt to changes in the situations in which we find ourselves immersed . It would also suppose the ability to stop doing what we were doing at a given moment, adapting (within the relevant time limits) our mental processes and actions in response to a situation that bursts into the environment and whose characteristics demand different skills.
Patients with multiple sclerosis may notice, in some cases, that they have difficulty adjusting to unforeseen events that suddenly appear, which implies a longer period of time to reorganize their resources and adapt them to new demands.
Important things to consider
The human brain has the ability to mobilize a series of processes aimed at optimizing the ability to adapt to the environment, in such a way that it takes advantage of the physical resources available to it to compensate for the deficiencies that may appear in a particular cognitive function. This phenomenon is known as neuroplasticity, and it is an essential mechanism in cognitive rehabilitation processes, which have been shown to be useful and effective in multiple sclerosis.
If you suffer from multiple sclerosis and perceive any of the cognitive problems that have been mentioned in this article, or any other that you consider relevant due to its ability to limit the normal development of your daily life, do not hesitate to contact a professional so that you can evaluate your case and articulate an individualized intervention program. Rehabilitation will help you make the most of your brain’s potential, optimizing all the resources it can deploy.
On the other hand, consider the possibility that certain cognitive difficulties may not necessarily be due to brain damage attributable to multiple sclerosis. Excessive stress (which increases cortisol levels in the body and in the long term leads to harmful effects on the hippocampus), depression, fatigue or even aging itself, may be important explanatory factors.
People with multiple sclerosis, despite the adversities they may experience in their daily lives, harbor the potential for a happy existence. Do not ignore the emotional problems that you may experience and seek specialized help, since scientific evidence supports the effectiveness of the different psychotherapeutic procedures in people with this disease.
Bibliographic references
- Guimaraes, J. y Sá, M.J. (2012). Cognitive Dysfunction in Multiple Sclerosis. Frontier in Neurology, 3:74.
- Matias-Guiu, JA, Cortés-Martínez, A., Valles-Salgado, M., Oreja-Guevara, C., Pytel, V., Montero, P. … Matias-Guiu, J. (2017). Functional Components of Cognitive Impairment in Multiple Sclerosis: A Cross-Sectional Investigation. Frontier in Neurology, 8, 643. doi: 10.3389/fneur.2017.00643
To the classic question “what do you do?” I always answer “basically I am a psychologist”. In fact, my academic training has revolved around the psychology of development, education and community, a field of study influenced my volunteer activities, as well as my first work experiences in personal services.
