Medical News Today: What do brain lesions mean in multiple sclerosis?

Magnetic resonance imaging is an important diagnostic tool for multiple sclerosis because it produces images of lesions in the brain and spinal cord. These lesions can appear as the condition progresses, and they may have a bearing on the symptoms that occur.

Also, MRI scans are useful in monitoring disease status and how well a person is responding to treatment.

If someone shows symptoms of multiple sclerosis (MS), their doctor may order an MRI scan, which is a safe and painless test.

The MRI scanner uses a strong magnetic field and radio waves directed at the individual to produce 2- or 3-D images.

Using MRI to diagnose MS

MRI scans provide a significant amount of information that doctors use to diagnose MS and to assess the status of people who already have the condition.

MRI scans can detect damage in the central nervous system, which comprises the brain and spinal cord. MS-related lesions appear on MRI images as either bright or dark spots, depending on the type of MRI used.

This imaging technique is useful because it shows active inflammation and helps doctors determine the age of the lesions.

Specific lesion types might indicate a flare-up or reveal damage occurring in the brain. It is a good idea to have regular scans so that a doctor can assess the progression of the disease.

Below, we list some of the main types of MRI scanning techniques.

T1-weighted MRI scan

This MRI technique provides information about the current status of MS. A T1-weighted MRI reveals areas of active inflammation, which represent lesions that are either new or growing. This type of scan is particularly useful for the early diagnosis of MS.

In a T1-weighted MRI scan, areas of the brain that are permanently damaged appear as dark spots, or “black holes.”

The appearance of new or expanding lesions captured by a T1-weighted MRI scan might indicate progression of the condition.

T2-weighted MRI scan

A T2-weighted MRI scan shows the number of old and new lesions in a specific part of the brain or spinal cord. This information helps doctors determine the long-term impact of MS.

MS lesions appear as bright spots in a T2-weighted MRI scan. More T2-hyperintense lesions identified by a T2-weighted MRIs may mean higher levels of disability.

One study revealed that the long-term outcome of the condition in people who developed three or more T2-hyperintense lesions within the first 2 years of onset was likely to be unfavorable.

Pictures

Location and symptoms

The location of the lesions determines the status of MS.

Symptoms also depend on the type and location of the lesions. However, some lesions may appear in areas of the brain that do not produce symptoms.

Some lesion locations and the MS symptoms they may trigger include:

Cerebellum (back part of the brain)

• impaired balance and coordination

Optic nerve (nerve behind the eye)

• problems associated with vision

Spinal cord

• muscle stiffness
• numbness and tingling
• pain in the arms, legs, or both
• problems passing urine or having bowel movements

Disappearing lesions

New research suggests that brain lesion atrophy, or shrinkage, could be a good indicator of how MS will progress.

Scientists typically evaluate new MS medications based on their ability to reduce the number of brain lesions. However, a 2018 study looked at whether a reduction in the number of brain lesions means that the condition is progressing rather than improving.

The researchers used MRI scans to observe brain lesion shrinkage in 192 people with MS. They found that people with relapsing-remitting MS, the most common type of MS, had the highest number of new lesions. However, the lesions atrophied at higher rates in people who had more severe progressive forms of MS.

The researchers concluded that brain lesion atrophy is a better predictor of disease progression than the appearance of new or growing lesions.

Treatments for MS lesions

Currently, there is no cure for MS. Available treatment options focus on managing symptoms.

There are several types of disease-modifying therapies available to treat relapsing forms of MS.

These include:

• Corticosteroids. These reduce nerve inflammation. Side effects may include raised blood pressure, weight gain, and sleeping problems.
• Plasma exchange (plasmapheresis). This involves removing and separating plasma (the liquid part of blood) from the blood cells. Scientists then mix the blood cells with a protein solution and return the liquid to the body.

A doctor may suggest a plasma exchange when symptoms are new, get worse, and do not improve to corticosteroids.

Procedure

Before someone has an MRI scan, they should eat and take their usual medications as normal, unless their doctor says otherwise.

Once inside the exam room, the individual may need to put on a hospital gown. They will need to remove any items that might affect the magnetic imaging, such as:

• eyeglasses
• hairpins
• watches
• jewelry
• dentures
• hearing aids
• wigs
• bras with underwiring

Before the scan, a healthcare professional may inject a chemical substance called gadolinium through an intravenous line into a vein in a person’s hand or arm.

Also called an MRI contrast media or dye, gadolinium improves the quality of the images and improves the diagnostic accuracy of the MRI.

An MRI machine is a long, narrow tube. The individual will lie down on a table that slides into the tube. A technician will monitor the examination process from a separate room.

During the scan, the internal part of the magnet produces loud, repetitive noises, such as tapping and thumping. The technician may provide earplugs or music to help with blocking out the noise.

Outlook

There is currently no cure for MS. However, people who have the condition will have a similar life expectancy to people who do not. Life expectancy for people with MS has increased. This may be a result of better treatment, more accurate diagnostic tools, or lifestyle changes.

In many instances, MS significantly impacts a person’s quality of life. MS treatment programs will focus on managing symptoms and speeding up recovery from relapses to make a person’s life as comfortable as possible.

The severity and symptoms of MS vary from person to person. MS is very unpredictable, which means that people with MS do not always know when they will have a relapse or experience symptoms.

MS brain lesions, as captured by an MRI scan, can help a doctor determine the current status of the condition and how it might progress.

People with MS can manage their symptoms by supplementing their current treatments with stretching, light aerobic exercise, and dietary changes.