Multiple sclerosis

Multiple sclerosis (MS) is a chronic disease that affects the brain and spinal cord. MS can cause a variety of symptoms, including changes in sensation, visual problems, muscle weakness, depression, and difficulties with coordination and speech. Although many patients lead full and rewarding lives, MS can cause impaired mobility and disability in the more severe cases. more...

Multiple sclerosis affects neurons, the cells of the brain and spinal cord that carry information, create thought and perception and allow the brain to control the body. Surrounding and protecting these neurons is a fatty layer known as the myelin sheath, which helps neurons carry electrical signals. MS causes gradual destruction of myelin (demyelination) and transection of neuron axons in patches throughout the brain and spinal cord, causing various symptoms depending upon which signals are interrupted. The name multiple sclerosis refers to the multiple scars (or scleroses) on the myelin sheaths. It is thought that MS results from attacks by an individual's immune system on the nervous system and is therefore categorized as an autoimmune disease.

Multiple sclerosis may take several different forms, with new symptoms occurring in discrete attacks or slowly accruing over time. Between attacks, symptoms may resolve completely, but permanent neurologic problems often persist. Although much is known about how MS causes damage, its exact cause remains unknown. MS currently does not have a cure, though several treatments are available which may slow the appearance of new symptoms. MS primarily affects adults, with an age of onset typically between 20 and 40 years, and is more common in women than in men.

Signs and symptoms

Individuals with multiple sclerosis may experience a wide variety of symptoms. The initial attacks are often transient, mild (or asymptomatic), and self-limited. They often do not prompt a health care visit and sometimes are only identified in retrospect once the diagnosis has been made based on further attacks. The most common initial symptoms reported are: changes in sensation in the arms, legs or face (33%), complete or partial vision loss (optic neuritis) (16%), weakness (13%), double vision (7%), unsteadiness when walking (5%), and balance problems (3%). Fifteen percent of individuals have multiple symptoms when they first seek medical attention. Most people find their initial MS symptoms occur over a period of hours to weeks. For some people the initial MS attack is preceded by infection, trauma or strenuous physical effort.

Other symptoms and physical findings common in multiple sclerosis are flickering eye movements (nystagmus), speech difficulties, tremor, clumsiness of the hands, abnormal muscle spasms, bladder and bowel difficulties, and sexual dysfunction. Cognitive impairments are also common, such as difficulty performing multiple tasks at once, difficulty following detailed instructions, loss of short term memory, emotional instability, and fatigue. Emotional symptoms are common and can be the normal response to having a debilitating disease or the result of damage to the nerves that generate and control emotions. The most common condition, clinical depression, is a product of both causes. Feelings such as anger, anxiety, frustration, and hopelessness are also common, and suicide is a very real threat.

Read more at Wikipedia.org