What Multiple Sclerosis Looks Like in Your Brain?


Multiple Sclerosis is a highly debilitating disease that affects the central nervous system (CNS), i.e., the brain and spinal cord.

By affecting how the brain and spinal cord function, it also impacts the ability of the central nervous system to send and receive information from different parts of the body.

This can, therefore, present as a range of consequences in various parts of the body. But since the brain is the focal target of the illness it is important to know how exactly, multiple sclerosis impacts the brain and how this impact looks in the brain as well.

Symptoms of Multiple Sclerosis

As previously stated, multiple sclerosis first targets the central nervous system which in turn causes a malfunction in various parts of the body. The characteristic symptoms include −

  • Tingling/pins-and-needles sensations in the body

  • Numbness or a prickling sensation, particularly in the extremities

  • Loss of balance

  • Difficulty in coordination

  • Memory loss

  • Brain fog or confusion

  • Vision problems

  • Hearing loss

  • Speech problems i.e., aphasia

  • Difficulty swallowing or dysphagia

  • Muscle weakness

  • Tremors

  • Bladder and bowel problems, for example, incontinence

What does Multiple Sclerosis Do to the Brain?

Multiple sclerosis causes lesions in the brain and along the spinal cord (what these lesions are exactly, and how they are formed will be explored in the next section).

Lesion formation takes place over a while, as the illness aggravates and declines in phases. New lesions are formed from time to time. However, just the formation of lesions doesn’t necessarily mean that the symptoms will manifest in the patient either.

Research shows that anywhere between 6% to 82% of people diagnosed with MS may have brain lesions that are identified through brain scans or MRIs. Of the people who have brain lesions or spinal cord lesions, only 1/10th of these lesions will actually precipitate a symptom.

However, because these lesions can spread, regular MRI scans are crucial to track their development, and also so the neurologist can later customize your disease-modifying therapies (DMTs) accordingly.

DMTs can be in the form of oral pills, injectables, or infusions – there are about a dozen of these medications. So, while MS can’t be cured, it can be managed by slowing the growth of lesions.

Where do Multiple Sclerosis Lesions Occur in the Brain?

Cerebral lesions occur most commonly in diagnosed patients, but they cause the least symptoms, especially during the early phases of the disease. These lesions could be on the frontal, parietal (middle), occipital (back), or temporal (lower) lobes of the cerebrum i.e., the outer part of the cerebrum that forms the grey matter or the cortex.

Usually, these are not large enough to affect the eloquent regions of the brain i.e., the regions associated with speech, vision, language, and motor function; or more normally they don't occur in these areas.

When the cortical lesions are large, they spread out over different parts of the cerebrum resulting in clinically visible symptoms such as cognitive impairment, mood disorders like bipolar, schizoaffective, and depressive disorders, and aphasia - a problem of jumbled speech, difficulty articulating, drawing and writing.

The problem is that the prevalence of these symptoms across many other illnesses makes them hard to pin down as being a consequence of just MS.

Brain lesions can also occur on the brainstem, which controls motor function and sensory abilities. When the lesions affect the brainstem and the white matter therein, it also affects other parts of the brain and the spinal cord as many nerve pathways that connect different components are located in this region.

In particular brain stem lesions can damage the cranial nerves resulting in different symptoms from MS lesions in other parts of the brain.

These could include facial pain, facial muscle weakness, ear problems like tinnitus or reduced sound tolerance, difficulty sleeping, reduced ability to taste, double visions, spasmodic eye movements, and very rarely, fluctuation in blood pressure and breathing trouble.

How are Multiple Sclerosis Lesions Formed in the Brain?

Lesions are a characteristic symptom and indicator of MS, which is first triggered by an outbreak of white blood cells that turn on the body’s own central nervous system and attack nerves.

It could be mediated by a glitch in the immune system or due to a viral infection. Once set off, the white blood cells cause inflammation which gradually erodes the protective myelin sheath of your nerve fibers i.e., axons causing difficulties in transmitting the information.

The damage to the axons presents as the fibers becoming rigid scar tissue which blocks the flow of information between nerves, muscles, and the brain. This stiff scar tissue is called a lesion or plaque, and the formation of many of these is what becomes known as multiple scars i.e., multiple sclerosis.

In addition to destroying myelin, the inflammation also destroys the glial cells that help to insulate nerve cells and repair and restore myelin when it is damaged. Hence, the destruction of glial cells prevents the reconstruction of new myelin and makes the damage worse.

It is only during periods of remission, that the nerve cells have the opportunity to rebuild themselves, but for people with frequent relapses, the scope of restoration is very low.

The most worrying consequence of the destruction of nerve cells and associated grey and white matter is that the brain atrophies or decreases in volume, much faster than the rate associated with normal aging and thus has very serious repercussions for cognitions and other key functions.

Conclusion

Living with multiple sclerosis or caring for a family member with this illness can be extremely difficult both physically and mentally. It is important to get pain management, physical therapy, moderate exercise, and time in the sun to reduce stiffness and motor difficulties.

Rehabilitation for speech and writing, adapting your house fixtures for safety and better mobility, and taking medications for depression or muscle relaxants are key to reclaiming different aspects of your life. So is attending a support group or meeting a counselor for emotional help, getting good sleep, keeping your body cool, and eating a balanced diet.

Someswar Pal
Someswar Pal

Studying Mtech/ AI- ML

Updated on: 24-Apr-2023

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