Multiple Sclerosis

In MS, specific cells of the immune system invade the CNS which is composed o the rain an spinal cord, and destroy myelin (the fatty material that insulates the neurons in the brain and spinal cord).This leads to demyelination of the axon and damage to the axon itself. In response, other CNS cells produce a hardened sclerotic lesion (plaque) around the multiple demyelinated sites. Not all lesions are associated with neurological dysfunction and, depending on their location, areas of demyelination may not cause clinical symptoms or signs. Such lesions are referred to as "silent lesions."

Etiology of MS

The cause of MS remains unknown. Both genetic and environmental factors have been implicated in the disease. A combination of genetic susceptibility and one or more environmental triggers is sthe current theory.

Clinical Features of MS

Bladder Dysfunction
Bladder dysfunction, which occurs in almost two-thirds of patients within their disease course, can be a very disabling feature of MS. Symptoms include urinary frequency, urgency, hesitancy and incontinence. Retention, or the inability to empty the bladder completely increases the risk and frequency of urinary tract infections.

Fatigue
Fatigue is the single most common complaint of people with MS and one of the most debilitating symptoms. It occurs in as many as 75 percent of patients with MS and interferes with work, family and social life. Fatigue form MS commonly occurs late in the afternoon when the body and environmental temperatures rise, conversely, it often subsides in the early morning when temperatures fall. It can also occur as a result of over activity or over work. Relief from fatigue may be achieved by cooling off and resting.

Spasticity
Corticopspinal tract involvement, particularly spasticity occurs with the initial attack of MS in 30 to 40 percent of patients and is present in about 60 percent of patients with progressive disease. Spasticity occurs when opposing groups of muscles that are responsible for maintaining an upright posture, such as the calf, thigh, buttock, groin and occasionally the back, contract and relax at the same time. Most patients complain of heaviness stiffness or pain in an extremity. Usually the legs are more involved than the arms.

Sensory Problems/Pain
Sensory complaints occur in 20 to 60 percent of patients and are often the earliest symptoms of MS that bring the patient to the doctor. Symptoms such as disturbances in feeling in the extremities or in the trunk occur because sensory pathways in the spinal cord are impaired. These disturbancees, commonly called paresthesias, include tingling, swelling, crawling or tight-band sensations. It may also manifest as pain, which is often overlooked and under treated. Another common complaint is an electric sensation that radiates down the back and legs with forward flexion of the neck , this is called Lhermitte’s sign.

Cognitive and Emotional Dysfunction

Cognitive and emotional changes are common in MS, affecting approximately 50 percent of patients with MS. Of this group, approximately 40 percent have mild dysfunction, and 10 percent have severe dysfunction. There is controversy as to whether MS-related cognitive problems are a reaction to the emotional distress of the disease of a result of the lesions themselves. The most common cognitive deficits involve memory, reasoning, verbal fluency and speed of information processing. Cognitive dysfunction can significantly affect the patients’ employment or everyday activities, and it is important that these symptoms are discussed and treated.

Bowl Dysfunction
Constipation is common in patients with MS and is often aggravated by the patients’ reluctant to drink water because of associated urinary problems. Constipation can be prevented by adequate fluid intake and a high fiber diet. Fecal incontinence is less frequent and usually results from diarrhea secondary to other illness, such as over use of laxatives or improper diet.

Optic Neuritis
Optic neuritis occurs as the presenting symptoms in 5 to 20 percent of patients with MS. It rarely involves both eyes simultaneously, but may appear on one side followed by the other at a late date. Optic neuritis usually starts with blurred vision and is followed by vision loss, most often in one spot (scotoma) but sometimes in the entire field of vision. Complains often include dimming of vision, photophobia and pain that is aggravated by eye movement.

Balance Coordination
Gait and balance disturbances are common in patients with MS and are the initial complaint in about 15 percent of cases. They are more common in patients with progressive disease, with 50 percent reporting extremely ataxia (shaky movements or unsteady gait) or intention tremors.

Heat Sensitivity

Heat is a common aggravating factor in MS. With a one-degree elevation in temperature, new symptoms may appear or old ones may re-appear. The elevation in temperature may be due to environmental heat, fever from an infection or exercise. Although heat dose not bring on an attack, it is a good idea to avoid heat from sunbathing, saunas or hot showers.

Natural Course of MS

The natural course of MS is highly variable. It is impossible to predict the nature, severity or timing of progression in a given patient, however, there are a few guidelines to follow. For instance, a patient with numbness or tingling (sensory problems) tends to have a better prognosis than those with spasticity or paralysis (balance or coordination problems). Another factor that influences progress is age of onset. Disease progression tends to be more rapid in patients who experience their first symptoms after the age of 40. Other factors predictive of rapid progression include male gender, frequent attacks, and burden of disease as detected by magnetic resonance imaging (MRI). The course of MS of the first five years is largely predictive of the progression of the disease over the next 10 years. In a series of patients, 90 percent of those with minimal disability five years after disease onset were still ambulatory 15 years later.

Classifications of MS

Clinically definite MS is further categorized according to disease course. Relapsing-remitting MS is characterized by symptoms that develop over a period of a few hours to a few days, followed by recovery and a stable course between relapses. Approximately 80 percent of patients are initially diagnosed with relapsing-remitting MS. Almost 50 percent of these patients eventually develop secondary-progressive (SP) MS. This is characterized by gradual neurological deterioration with or without superimposed acute relapses. If there is continual disease progression from onset with only minor fluctuation, the classification becomes primary-progressive (PP) MS. PP-MS occurs in approximately 10 percent of patients, mainly those who are older than 40 year at onset. Progressive-relapsing MS, a rare form of the disease, is characterized by gradual neurological deterioration from the onset of symptoms and subsequent superimposed relapses.

A diagnosis of MS should be confirmed by a qualified neurologist who would subsequently recommend appropriate treatment.

Realistic Expectations

Despite being told that no disease-modifying drugs are a cure for MS, and that therapy is unlikely to reverse existing disabilities, patients with MS often hope that their disabilities will disappear and that no further exacerbation will occur. Failure to achieve these outcomes is likely to be very discouraging. Patients and their families require continual support and understanding. Education is crucial to maintaining patient compliance with treatment. In addition to the patient-support program provided by each drug supplier, the individual health care provider will be called upon for guidance on all aspects of treatment.

Additional Resources:

• Multiple Sclerosis Clinic, UI Hospitals and Clinics
• National Institute of Neurological Disorders and Stroke
• National Multiple Sclerosis Society
• Multiple Sclerosis Foundation
• Multiple Sclerosis Association of America

Last Reviewed 2008

Source: E. Torage Shivapour, M.D.
University of Iowa Hospitals and Clinics, Department of Neurology

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.