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Cognitive Issues
Cognition refers to a range of high-level brain functions including the ability to learn and remember information, organize, plan and problem-solve, focus, maintain and shift attention, understand and use language, accurately perceive the environment, and perform calculations.

About half of those with multiple sclerosis (MS) will experience some form of cognitive dysfunction, or impaired thinking in the high-level brain functions. For the majority of those with cognitive dysfunction, this means slowed thinking, decreased concentration, or decreased memory. Most of the time, difficulties with cognition occur later in the course of the disease; however, there are times where it occurs much earlier, and occasionally it's present with the onset of MS.

The loss of myelin around nerve fibers can cause difficulty with transporting memories to storage areas of the brain or retrieving them from storage areas. In MS, certain functions are more likely to be affected than others:
Memory (acquiring, retaining and retrieving new information)
Attention and concentration (particularly divided attention)
Information processing (dealing with information gathered by the five senses)
Executive functions (planning and prioritizing)
Visuospatial functions (visual perception and constructional abilities)
Verbal fluency (word-finding)

A cognitive deficit is a large category that includes recent memory recall, attention and concentration, information processing speed, executive functions (including multitasking, reasoning, problem solving and visuospatial perception). Any compromise in cognition has the potential for vast effects on a person's life. Unlike those with cortical dementias, such as Alzheimer's disease, MS patients seldom exhibit accelerated forgetfulness over time. Memory failures in MS are likely related, in part, to impairments in other areas, such as processing speed and higher executive function, which impact encoding processes.

A person may experience difficulties in only one or two areas of cognitive functioning or in several. Certain functions including general intellect, long-term (remote) memory, conversational skill and reading comprehension are likely to remain intact.

Cognitive impairments occur in about up to 70% of patients with MS. At times referred to as brain fog, impairments may present at the beginning of the disease. In MS, after the first attack but before a secondary confirmatory one, up to 50% of patients have impairment at onset. In only about 10% of MS patients is this dysfunction so severe that it significantly impairs their ability to carry out daily living tasks. In very rare instances, cognitive dysfunction may become so severe that the person can no longer be cared for at home.

Common MS-Related Cognitive Problems:
Problems with Abstract Conceptualization
A difficulty with figuring things out in the "abstract" or in a way that is going to lead to a desired outcome. Easily overwhelmed if something is too complex, as it's hard to organize thoughts and tasks, to apply lessons learned from multiple past experiences, and to be flexible enough in thinking to come up with alternate solutions if a problem arises. This can negatively impact judgment.

Short-Term Memory Deficits
This most common form usually manifests in things like forgetting the phone number just dialed, walking into a room and not knowing what you went there for, or being unable to remember if you took your pills or not. You may also find yourself repeating a sentence or part of a story to someone that you just told it to, not aware that you already had.

Attention Difficulties
This can manifest as "distractibility" or simply the inability to keep your mind on a task or focus. You may find that you are unable to multitask or that even minor ambient noise, like the television or music, can make it virtually impossible to concentrate on things like reading or performing sequential tasks, like those involved in cooking.

Slower Speed of Information Processing
This includes all the aforementioned symptoms, and it means that the brain simply can't take in and prioritize all of the information coming at a person at once. This includes problems processing language (spoken or written), sensory information (visual, sounds, smells, touch), spatial information (like that involved in navigating while driving), or more abstract things like social cues and reading people's emotions.

Cognitive problems such as having trouble concentrating and solving problems affect about 50% of those with MS. It's not uncommon for more people with MS to leave work because of such cognitive difficulties than because of physical problems. In about 10% of cases, mental dysfunction has been severe and resembles dementia. The severity of such mental changes appears to be associated with the degree of loss of brain tissue. This offers another argument for early treatment as medications may improve these symptoms.

Some of the most common deficits are in recent memory, attention, processing speed, visual-spatial abilities and executive function. Symptoms related to cognition include emotional instability, and fatigue, including purely neurological fatigue. Cognitive deficits are independent of physical disability, and can even occur in the absence of neurological dysfunction.

Impairment can be a major predictor of low quality of life, unemployment, caregiver distress, and difficulty driving. The limitations in a patient's social and work activities are found to correlate with the extent of impairment.

How MS Affects Cognition

Because cognitive difficulties are the result of the disease pathology, they too are individual and unpredictable. The measurement and treatment of cognitive difficulties is usually done by a neuropsychologist. Cognitive issues are very complex and in the past, physicians seemed to have felt more comfortable denying its existence to their patients. Rather than placing cognitive issues in the same category as fatigue and depression, it's now studied on its own. Cognitive evaluation techniques have improved greatly and now proper studies into cognitive dysfunction in MS can be done.

Measures of tissue atrophy are well correlated with and can predict cognitive dysfunction. Cognitive impairment is the result of not only tissue damage, but tissue repair and adaptive functional reorganization.

Cognitive dysfunction in MS seems to correlate with more permanent destruction of brain tissue, such as "black holes" and atrophy. Therefore, cognitive dysfunction tends to be worse in people with progressive forms of MS than in people with relapsing-remitting MS (RRMS). In general, those with progressive MS seem to be more severely affected, but as mentioned, even those people with very little disability can experience some degree of cognitive dysfunction.

Cognition, however, can also be made worse temporarily by other symptoms of MS such as: Depression, fatigue, and MS-related heat intolerance.

Pronounced Cognitive Dysfunction With:
More T1-Weighted Lesions
T1-weighted lesions in MS are areas that appear dark on MRI scans. These "black holes" indicate that there has been destruction of nerve fibers called axons, not just demyelination.

Atrophy of Corpus Callosum
This means that the bundle of nerve fibers that connect the right and left hemispheres of the brain has shrunk, due to destruction of nerve cells.

Language Issues

Those with MS often have cognitive impairments which affect speech, resulting in word-finding delays or problems remembering how to spell words. This is most often classified as dysphasia (difficulty understanding or using language), which is less severe than aphasia (difficulty understanding the speech of other people and/or expressing oneself verbally). True aphasia is an uncommon symptom of MS but can result from damage to the part of the brain that is responsible for language, specifically the cerebral cortex.

Forms of language dysfunction can occur where verbal expression is badly hampered causing the words to be lost. "Finding the right word" is a phrase used often, but for people with MS it can be a fact of everyday life. Language problems can be mild and intermittent, with the sufferer experiencing some minor difficulty with word recall; where the correct word is "in there somewhere" or "on the tip of the tongue", but still proves elusive nonetheless.

Substitution of an alternative word is a typical action taken by the person experiencing these difficulties, but they can't hide the fact that there is a problem. This all can break the fluency of a conversation, leading to a reluctance to participate and a sense of isolation.

Recognition of Cognitive Issues

Early recognition, assessment and treatment are important because cognitive changes, along with other factors, can significantly affect a person's quality of life and are the primary cause of early departure from the workforce. The first signs of cognitive dysfunction are usually subtle enough that they are typically noticed first by the person with MS or by a family member.

The first signs of cognitive dysfunction will typically be:
Difficulty in finding the right words
Trouble remembering what to do at work or at home
Difficulty making decisions or showing poor judgment
Difficulty keeping up with tasks or conversations

It's important to talk to your doctor if you are concerned that cognitive dysfunction is occuring. If you or your doctor think you may be developing cognitive problems, you will be referred to a rehabilitation specialist for an evaluation. A neuropsychologist, speech/ language pathologist or occupational therapist can administer a battery of tests and careful evaluate determine the cause(s) of changes. It's important that everyone is aware of your current state of health since cognitive function can also be affected by aging, medications, depression, anxiety, stress and fatigue.

Cognitive rehabilitation is typically offered at a center that specializes in MS care, at a rehabilitation clinic, or through individual private practices. Depending on what the evaluation reveals, one of three approaches may be adopted, including (1) a general stimulation approach, in which cognitive processing is stimulated by playing word games or listening to stories; (2) a process-specific approach, in which you carry out a series of cognitive exercises of increasing difficulty; or (3) a functional adaptation approach, in which rehabilitation tasks are performed at home or in a work environment.

Treatment of Cognitive Issues

Based on the test findings, including cognitive deficits and strengths, the need for cognitive rehabilitation therapy (CRT) may be in order. CRT is a broad term used to describe treatments that address the cognitive problems that can arise after a brain injury. Given the wide range of symptoms and severity of cognitive problems in individuals with brain injury, CRT doesn't refer to a specific approach to treatment. CRT may include a combination of restorative and compensatory activities.

Restorative treatments are aimed directly at improving, strengthening, or normalizing specific impaired cognitive functions. Such treatments frequently have an "exercise-like" aspect in that they may involve intensive and repetitive use of a particular cognitive process while gradually increasing the level of difficulty or the processing demands. Patients with attention deficits may, as an example, be provided with a series of computer tasks that require detection of targets on the screen at an increasing pace. Such tasks may increase in difficulty along a number of dimensions, and the difficulty along each dimension increases as performance improves.

Restorative techniques (return or restore what is lost) may include learning and memory exercises:
Combine modes of learning: You will be more likely to remember something if you "see it, say it, hear it, write it, do it."
Repeat & verify: Repeat what you hear and verify that it's correct to improve your attention and memory.
Spaced rehearsal: Repeat and practice information at intervals spread out over time to improve your ability to store information.
Build associations: Use memory aids such as remembering the name of someone you just met and associate their name with a friend or family member of the same name, or with a place, color or event that sounds like the new name.

Compensatory treatments, in contrast, seek to provide alternative strategies for carrying out important activities of daily living despite residual cognitive impairment. The compensations may be internal, as when a person with memory impairment learns mental strategies for organizing material for better recall such as learning to group items to be remembered in categories as an aide to retrieval, or external, as when such a person adopts the use of electronic reminder technology.

Compensatory techniques (to make up or compensate for functions that are weakened) include:
Consolidate and centralize: Designate one place in your home as the information center. Include your master calendar, mail, bills, phone messages, to-do lists, keys, wallet, shopping lists and any addition information that is important.
Plan: Post a calendar large enough to display everyone's appointments or activities and reminders. Keep pens available so you can write down information as it arises. Or use a computer program or app set up with reminders for routine tasks. Synchronize all of your devices so you have your appointments with you.
Record: Dictate your to-do list, notes or other things to remember on a digital voice recorder.
Remind: Use checklists, the alarm on your watch or phone, your kitchen timer, and more.
Eliminate or remove yourself from distractions: Turn off the TV, music and whatever else is "on" when speaking with someone in person or on the phone. Background visual and noise distractions can make learning or remembering more difficult. If you can't eliminate the distractionthen ask if you can talk in a quieter place.
Take a break: If you are having difficulty concentrating, take a breath and refresh.
Do one thing at a time: Avoid switching back and forth from one topic or task to another. Finish or find an appropriate stopping place in what you're working on before you switch to something else.

Conclusions

Memory difficulties for people with MS are well known and, like the general effects of poor reasoning in MS, their effects are insidious. A marked feature of the pattern of memory deficits in MS is that recall, or unprompted remembering, is more adversely affected than recognition, or prompted remembering. This leads those with MS to respond appropriately to reminders, but when not prompted, MS patients with this type of difficulty may fail to remember. People with MS are less likely to volunteer problems to caregivers or doctors unless that particular aspect is probed by a specific question.

In MS, a very commonly observed feature of the many cognitive dysfunctions is that performance accuracy is rarely affected. What tends to be affected is the speed of ones action. It may take longer to accomplish a task, but the task will typically be done with greater accuracy. This may be the case since MS is a white matter disease and rarely affects the grey matter.

Recall memory can also let people down when it comes to the initiation of activity. They may report that everything is fine when asked, because the question made them consider the problems that they are experiencing in everyday life.

It's also important to be aware of the possibility that those with MS could have been using cognitive reserves for some time in the early and mid stages of the disease. Due to this, the actual damage may be more extensive than is apparent before measurable cognitive deficits appear. Those that have a cognitive reserve available don't know that it's there and there isn't a label that will show up on an MRI, so it comes down to everyone's best judgment as to the extent of any damage.