Multiple sclerosis (MS) is a chronic medical condition that causes the progressive destruction of myelin---a type of tissue that protects the nerves that run throughout the central nervous system. An estimated 400,000 people in the United States have MS, based upon estimates provided by the Merck Manual, an online medical encyclopedia for healthcare professionals. MS symptoms are diverse and vary based upon the extent and type of nerve damage.
Vision Changes
Often, the initial symptoms of MS involve slight changes in vision, such as blurred or double vision. MS patients may also experience color blindness (red-green color distortion), which can develop into complete blindness in one or both eyes. Vision-related MS symptoms may resolve in later stages of the disease, though researchers at the National Institute of Neurological Disorders and Stroke (NINDS) in Bethesda, Maryland, are uncertain why this occurs.
Muscle Weakness
Muscle weakness is one of the predominate features of MS. This disease is characterized by the destruction of myelin throughout the body. Myelin damage interferes or prevents nerve signal transmission between the spinal column and the target tissue, muscle or organ. When this occurs, patients with MS can experience severe muscle weakness within certain regions of the body. Such symptoms can contribute to poor motor control, leading to difficulty walking or moving normally. As the disease progresses, some patients may become partially or completely paralyzed.
Muscle Spasticity
Patients with MS often experience muscle spasticity in addition to weakness. Muscle spasticity is a term used to describe abnormal muscle spasms or stiffness, which can prevent MS patients from moving about normally.
Fatigue
Fatigue is commonly experienced in patients with MS. The National MS Society estimates the fatigue occurs in approximately 80 percent of patients with MS and significantly interferes with a patient's ability to function normally.
Abnormal Skin Sensations
Nerve damage caused by MS can lead patients to experience abnormal skin sensations (paresthesias) as a symptom of this condition. These sensations can occur intermittently and are often characterized as feeling numb or prickly.
Decreased Cognitive Function
The NINDS estimates that 50 percent of MS patients experience some type of cognitive dysfunction. These symptoms tend to be mild but can include decreased attention, memory problems, difficulty concentrating or poor judgment. Patients may also develop difficulty speaking, which can cause him to slur his words or speak more slowly than usual.
