As the disease progresses, other symptoms may include muscle spasms, sensitivity to heat, fatigue, changes in thinking or perception, and sexual disturbances.
- Fatigue . This is a characteristic and common symptom of MS. It is typically present in the mid afternoon and may consist of increased muscle weakness, mental fatigue, sleepiness, or drowsiness. Physical exhaustion is not related to the amount of work performed; and many patients with MS complain of extreme fatigue even after a good night's sleep.
- Heat sensitivity . Heat sensitivity (the appearance or worsening of symptoms when exposed to heat, like a hot shower) occurs in most people with MS.
- Spasticity . Muscle spasms are a common and often debilitating symptom of MS. Spasticity usually affects the muscles of the legs and arms, and may interfere with a persons ability to move those muscles freely.
- Dizziness. Many people with MS complain of feeling "off balance" or lightheaded. Occasionally they may experience the feeling that they or their surroundings are spinning; this is called vertigo. These symptoms are caused by damage in the complex nerve pathways that coordinate vision and other inputs into the brain that are needed to maintain balance.
- Impaired thinking . Problems with thinking occur in about half of people with MS. For most, this means slowed thinking, decreased concentration, or decreased memory. Approximately 10% of people with the disease have severe impairment that significantly impairs their ability to carry out tasks of daily living.
- Vision problems . Vision problems are relatively common in people with MS. In fact, one vision problem, optic neuritis, occurs in 55% of people with the condition.This can result in blurring or graying of vision or blindness in one eye. However ,most vision problems in MS do not lead to blindness.
- Abnormal sensations. Many people with MS experience abnormal sensations such as "pins and needles," numbness, itching, burning, stabbing, or tearing pains. Fortunately, most of these symptoms, while aggravating, are not life-threatening or debilitating and can be managed or treated.
- Speech and swallowing problems . People with MS often have swallowing difficulties. In many cases, they are associated with speech problems as well. They are caused by damaged nerves that normally aid in performing these tasks.
- Tremors . Fairly common in people with MS, tremors can be debilitating and difficult to treat.
- Difficulty walking. Gait disturbances are amongst the most common symptoms of MS. Mostly this problem is related to muscle weakness and/or spasticity, but having balance problems or numbness in your feet can also make walking difficult.
What Are the Types of Symptoms?
It is helpful to divide the symptoms into three categories: primary, secondary, and tertiary.
Primary symptoms are a direct result of the demyelination process. This impairs the transmission of electrical signals to muscles (to allow them to move appropriately) and the organs of the body (allowing them to perform normal functions.) The symptoms include: weakness, tremors, tingling, numbness, loss of balance, vision impairment, paralysis, and bladder or bowel problems. Medication, rehabilitation, and other treatments can help keep many of these symptoms under control.
Secondary symptoms result from primary symptoms. For example, paralysis (a primary symptom) can lead to bedsores (pressure sores) and bladder or urinary incontinence problems can cause frequent, recurring urinary tract infections. These symptoms can be treated, but the ideal goal is to avoid them by treating the primary symptoms.
Tertiary symptoms are the social, psychological, and vocational complications associated with the primary and secondary symptoms. Depression, for example, is a common problem among people with MS.
What Causes the Symptoms?
Demyelination, or deterioration of the protective sheath that surrounds nerve fibers, can occur in any part of the brain or spinal cord. The symptoms that people with MS experience depend on the affected area. Demyelination in the nerves that send messages to the muscles causes problems with movement (motor symptoms), while demyelination along the nerves that carry sensory messages to the brain causes disturbances in sensation.
Are Symptoms the Same in Every Person?
Multiple sclerosis follows a varied and unpredictable course. In many people, the disease starts with a single symptom, followed by months or even years without any progression of symptoms. In others, the symptoms become worse within weeks or months.
There are four courses that MS takes:- Relapsing-remitting MS: characterized by unpredictable acute attacks, called "exacerbations," with worsening of symptoms followed by full, partial, or no recovery of some function. These attacks appear to evolve over several days to weeks. Recovery from an attack takes weeks sometimes months. The disease does not worsen in the periods between the attacks. This pattern usually occurs early in the course of MS in most people.
- Primary-progressive MS: characterized by a gradual but steady progression of disability, without any obvious relapses and remissions. This form of disease occurs in just 15% of all people with MS, but it is the most common type of MS in people who develop the disease after the age of 40.
- Secondary-progressive MS: initially begins with a relapsing-remitting course, but later evolves into progressive disease. The progressive part of the disease may begin shortly after the onset of MS, or it may occur years or decades later.
- Progressive-relapsing MS: This is the least common form of the disease and is characterized by a steady progression in disability with acute attacks that may or may not be followed by some recovery. People with progressive relapsing MS initially appear to have primary progressive MS.
A true exacerbation of multiple sclerosis is caused by an area of inflammation (swelling) in the nerves of the brain and spinal cord system followed by something called demyelination, which is the destruction of myelin. The myelin is the fatty sheath that surrounds and protects the nerve fibers.
Demyelination results in the formation of an abnormal area called a plaque within the brain and/or spinal cord. A plaque causes the nerve impulses to be slowed, distorted, or halted, producing the symptoms of MS. One example of an exacerbation of MS would be the development of optic neuritis, an inflammation of the optic nerve (which is in the back of the eye) that impairs vision.
An exacerbation of MS may be mild and not cause a noticeable impairment in functioning or may significantly interfere with a person's daily life. Exacerbations usually last from several days to several weeks, although they may extend into months.
Exacerbations or relapses of MS are often treated with medications calledcorticosteroids. These drugs reduce inflammation. It is generally accepted that taking corticosteroids for a short amount of time will shorten an exacerbation and/or reduce the severity.