If the optic nerve is involved, the patient may have blurred or reduced vision. Patients with demyelination of the brain stem, a region that controls eye movement, commonly have double vision, since each eye may no longer focus on the same object. If the illness has impaired the spinal cord, in addition to losing leg strength, the patient may lose bladder control, become constipated, or become impotent. One common feature of multiple sclerosis is that many symptoms worsen when patients are exposed to heat. Conversely, a cold bath can sometimes temporarily relieve symptoms or reduce some of the fatigue multiple sclerosis patients often feel.
Neurologists divide multiple sclerosis into two types.
The first, known as exacerbating-remitting disease, is characterized by fluctuations in nerve function. Periods of deteriorating ability are followed by periods of recovery, although, as time passes, recovery often becomes less and less complete. The second form of the illness, chronic progressive disease, has more of a steady downhill course, typically without periods of temporary recovery. Frequently, people who initially have the fluctuating form of multiple sclerosis go on to develop the chronic form. There are two basic strategies for treating multiple sclerosis.