Question: Select the statement that correctly describes multiple sclerosis?
A. This fatal disease leads to severe and progressive memory loss.
B. This fatal disease attacks the peripheral nervous system.
C. This nonfatal disease is characterized by severe memory loss.
D. This nonfatal disease disrupts the central nervous system (CNS).
The answer is option D. This nonfatal disease disrupts the central nervous system (CNS).
Explanation in full details
Multiple sclerosis (MS) is a long-lasting disease that affects the brain and spinal cord, known as the central nervous system. In MS, the immune system mistakenly attacks the nerves and a protective substance called myelin, which covers healthy nerve fibers. This causes inflammation and damages the nerves and myelin, disrupting electrical messages in the brain.
MS is unpredictable, and it varies from person to person. Some people may have mild symptoms like blurred vision or numbness and tingling in their limbs. Others might experience more severe effects like paralysis, vision loss, or trouble walking, but this is not common.
It’s hard to know the exact number of people with MS. The National Institute for Neurological Disorders and Stroke (NINDS) says around 250,000 to 350,000 people in the United States have MS. However, the National Multiple Sclerosis Society estimates the number could be closer to 1 million. There are different types or courses of MS that have been described.
Relapsing-Remitting Multiple Sclerosis (MS)
When doctors diagnose multiple sclerosis (MS), about 90% of patients will have the relapsing-remitting type of the disease. In this form of MS, people experience neurological symptoms that come and go over a few hours or days. Some common symptoms during a relapse may include:
- Tingling sensations
- Feeling weak
- Blurred vision, double vision, or losing vision
- Feeling very tired (fatigue)
- Numbness in parts of the body
- Having trouble walking steadily
These symptoms can last for days or weeks, and then they may go away partially or completely, either on their own or with treatment. After a relapse, patients may have weeks, months, or even years without any symptoms, which is called remission. If MS is not treated, most people will have more disease symptoms that gradually get worse over time, known as relapsing.
Secondary Progressive Multiple Sclerosis (MS)
If someone with relapsing-remitting MS goes through changes where they no longer have clear relapses and remissions, it means their disease has turned into secondary progressive MS. All people with secondary progressive MS initially had the relapsing-remitting type. In secondary progressive MS, symptoms keep getting worse without any periods of remission.
There might be times when the symptoms stay stable for a while, but overall, the condition keeps worsening over time. People may notice changes in their abilities when comparing how they are now to how they were in the past, even if they can’t point to a specific episode that caused the worsening. Sometimes, after having secondary progressive MS, a person might experience a relapse. In that case, their condition would be considered secondary progressive MS with relapses.
Primary Progressive Multiple Sclerosis (MS)
Around 10-15% of patients with MS have a type called primary progressive MS. In this form of MS, the symptoms gradually get worse right from the beginning of the disease. People with primary progressive MS may notice a slow change in their ability to move, especially when walking. They often feel heaviness and stiffness in their legs.
Unlike other types of MS, people with primary progressive MS almost never experience a relapse or exacerbation. However, if a relapse does happen after the primary progressive course has been established for some time, it is called Progressive-Relapsing MS.
Benign Multiple Sclerosis (MS)
Benign MS is a type of MS where a person has a mild form of the disease for about 15 years. This happens in about 5-10% of patients. There is no reliable way to know beforehand which patients will have this milder course of MS.
The only way to know if someone has benign MS is after they have had the MS diagnosis for at least 15 years and there is no sign of the disease getting worse. This includes both the person’s ability to do things and what is seen on MRI scans. Benign MS cannot be predicted when the person is first diagnosed with MS or even after a few years with the condition.