Among the possible consequences of the disruption are loss of muscular coordination, impaired vision and incontinence. The symptoms of the disease are diverse, depending on where in the brain, spinal cord or optic nerve these patches of demyelination are located.
The most prominent symptoms are:
Visual Problems--Ranging from blurred vision to more serious visual impairment, often a symptom which disappears later. Blindness in MS is rare.
Ataxia--Difficulties in controlling the strength and precision of movements, so that holding things is a problem; balance and coordination may be impaired.
Sensory Problems--Numbness, tingling and sensitivity to heat or cold.
Bladder--Control problems and urinary tract infections.
Mood Swings--Ranging from depression to euphoria.
Fatigue--Mild to severe fatigue and weakness.
Cognitive Problems--Most people with MS do not show any evidence of intellectual deficits. However, it is estimated that about 40 percent of people with MS have mild cognitive dysfunction and another 10 percent have moderate to severe cognitive impairment. Among those individuals affected by cognitive impairment, the most common problems include the following:
Memory recall, particularly remembering recent events.
Slowness in learning and processing new information.
Difficulty with abstract reasoning, such as analyzing a situation, planning a course of action, and following through.
Impaired verbal fluency, such as slowed speech or difficulty coming up with a word during conversation.
Cognitive problems associated with MS are not related to a person's level of physical disability and can potentially affect people with few physical symptoms of MS. In addition, cognitive problems can develop rapidly during an exacerbation of the disease. In these cases, the cognitive deficits can improve as the person comes to a remission. It is important to stress that cognitive impairment in MS bears little resemblance to the intellectual decline in Alzheimer's disease. People with MS virtually never experience severe, progressive cognitive decline. Cognitive impairment in MS is typically mild and may stabilize at any time.
Individuals with MS and their families should be aware of potential cognitive problems. Recognizing and learning about certain deficits can dispel misunderstandings about a person's apparent forgetfulness, carelessness, or seeming indifference. Families can be supportive and help the person compensate. Understanding deficits can alleviate fears about losing one's capacities. If cognitive impairment is suspected, this topic should be discussed with the person's doctor. In some cases, depression or medications can mimic cognitive problems. These can be treated separately. A neurologist can perform a brief evaluation to test for pronounced (severe) cognitive deficits. However, a neuropsychologist (preferably one with experience with MS) may be recommended to perform a more complete evaluation to test for subtle cognitive changes. If deficits are found, the neuropsychologist can follow up to help individuals and their families cope with cognitive problems and to work on cognitive rehabilitation.
There are a number of compensatory strategies individuals can use to cope with mild cognitive problems. These include memory aides such as writing down all appointments, making check lists, or using memory "tricks" (e.g., visual images or rhymes) to help remember. Practicing concentration and focus when listening will also minimize distractions and help the person retain new information.
The initial attack occurring as early as the teen-age years may be brief and mild, and may not even be recognized. The symptoms temporarily abate or disappear for reasons that are not known, but recurrence is highly likely although usually after a long latency period. Generally the first full-fledged bout, lasting weeks or months, takes place between the ages of 20 and 40, and further attacks follow at erratic intervals. The repeated inflammation of the nerves produces scarring (sclerosis), and although myelin can normally repair itself, the scarring happens too rapidly for healing to take place; the effects of the lesions become permanent. As a result of such lasting damage, 77 percent of MS sufferers are limited to some degree in their activities, and about 25 percent become wheelchair-bound.
The first attack is generally mild, lasts only a few days, and is followed by a long period of remission perhaps years before the next episode. Symptoms vary considerably. They include:
Weakness, stiffness (spasticity), or numbness in one or more limbs.
Sensations of tingling, pins and needles, heaviness, or a band-like tightness around one or more limbs or the trunk of the body.
Tremors, instability, or a lack of balance or coordination.
Loss of vision in one or both eyes, blurred or double vision, or rapid, involuntary eye movement.
Bowel or bladder incontinence.
Fatigue: either a feeling of general tiredness or extreme exhaustion.