Multiple Sclerosis: It’s Effect on the Nervous System

Multiple Sclerosis: It’s Effect on the Nervous System

    Multiple sclerosis (MS) is a complex autoimmune disease that affects the central nervous system (CNS) through damage to the myelin sheaths of nerve cells, which can cause severe physical or cognitive disabilities, as well as neurological defects. Although the direct causes for MS are unclear, research has suggested it is multifactorial– environmental factors coinciding with a genetic predisposition. These components are what can trigger a series of events in the immune system leading to neuronal cell death, demyelination, and dysfunction throughout the CNS. The objective of this STEAM project is to demonstrate how MS affects the various key structures and components of the nervous system through art and research. 

    In MS, damage to the white and gray matter tissue found throughout the CNS can be attributed to inflammation caused by focal immune cell infiltration (T-lymphocytes and macrophages) and their cytokines (Ghasemi et al., 2016), which results in both macroscopic and microscopic injury. Lesions, or plaques, can be macroscopic injuries found throughout the white matter of the CNS, the most frequently affected sites being the optic nerves, the brainstem, the cerebellum, and the spinal cord. Within these plaques are macrophages and T cells, as well as myelin debris and a reduced oligodendrocyte count (Hafler, 2004). Oligodendrocytes are the myelinating cells of neurons present in the CNS and in MS are one of the primary targets of the immune system, along with the myelin sheaths that normally insulate and protect the axonal nerve cells. This process is known as demyelination, and can lead to various issues regarding the transmission of nerve impulses and action potentials. 

    Demyelination “readily explain[s] conduction failure within the affected axon” (Coggan et al,. 2015) and even if conduction does not entirely fail, the speed at which conduction occurs across different axons can be drastically slowed down. Axons that are demyelinated may become closer in proximity as well, which can cause crosstalk and ephaptic interactions (indirect communication between neurons). During demyelination, disruption to transmembrane Na+, K+, and Ca2+  ions and their corresponding ion channels can also reduce the efficiency of action potentials due to hyperexcitability. To compensate for this, a process known as homeostatic plasticity alters the neuronal excitability. However, this process can be attributed to different symptoms observed in MS due to abnormal “burst-type spiking” (Coggan et al,. 2015). 

    MS may present itself through a very wide variety of symptoms, varying in severity depending on many factors such as the location of an attack and the amount of tissue damage. Symptoms of MS include but  are not limited to:

• Muscle symptoms:
  • difficulties in movement, walking, and/or coordination
  • muscle spasms
  • weakness and tremors in one or more arms or legs
  • pain, numbness, and/or other abnormal sensations 
• Bowel and bladder symptoms:
  • constipation and/or diarrhea 
  • urinary retention and/or incontinence 
  • frequent urination
• Eye symptoms:
  • double vision
  • eye discomfort 
  • uncontrollable eye movements 
  • vision loss
• Cognitive symptoms:
  • decreased attention span and judgement 
  • memory loss
  • difficulty reasoning and problem solving 
• Psychiatric symptoms:
  • depression or feelings of sadness
  • anxiety 
• Other symptoms:
  • vertigo and/or dizziness
  • hearing loss 
  • sexual dysfunction 
  • difficulty in speech 
  • trouble swallowing 

 (MedlinePlus, 2022). 

    Since MS can affect various regions of the CNS, it presents itself through a very broad spectrum of neurological symptoms, mimicking other neurological issues. MS can be identified however by acute relapses which typically develop in young adults (Tafti et al., 2022) and a gradual progression of the disease which can lead to permanent disability. MRIs are also used to detect and identify plaques found throughout the brain and spinal cord. 

    Currently, there is no known cure for MS, but there are some treatment methods that can slow the progression of the disease. Medications may be prescribed long-term to slow the disease, decrease the severity of attacks, or manage symptoms. Physical and speech therapy may be helpful in those who have undergone severe neurological damage, as well as assistive devices in the case of permanent disability. Avoiding extreme temperatures, stress, and illness is recommended for those with MS, as these factors could trigger an attack. Like many other diseases, having a healthy lifestyle with a balanced diet, rest, and physical activity can greatly decrease the severity of symptoms as well. Research has suggested that those with MS may be deficient in vitamins D and B12 as well, and those with MS who have taken vitamins have reported it being beneficial (Ghasemi et al., 2016). Overall, treatment for MS mainly involves management of the symptoms present and removing risk factors that may trigger another attack. 

    In conclusion, MS is a chronic autoimmune disease that affects the brain and spinal cord of an individual which can lead to a wide array of symptoms in an MS patient. These symptoms are attributed to the immune system attacking myelin sheaths and oligodendrocytes, leading to dysfunction and conduction failure throughout the CNS. This disruption leads to further complications, such as abnormal excitability within the neurons, causing even more to go awry. MS is a very complicated disease, especially on the microscopic level, with much more to be understood about it, but through research and art I have learned a lot about MS and how it affects the various key structures and components in the nervous system. 

Works Cited:

Tafti , D., Ehsan , M., & Xixis , K. L. (2022, January-). Multiple sclerosis – statpearls – NCBI bookshelf. StatPearls. Retrieved November 18, 2022, from https://www.ncbi.nlm.nih.gov/books/NBK499849/

Coggan, J. S., Bittner, S., Stiefel, K. M., Meuth, S. G., & Prescott, S. A. (2015, September 7). Physiological Dynamics in demyelinating diseases: Unraveling complex relationships through computer modeling. International journal of molecular sciences. Retrieved November 18, 2022, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4613250/

Ghasemi, N., Razavi, S., & Nikzad, E. (2016, December 21). Multiple sclerosis: Pathogenesis, symptoms, diagnoses and cell-based therapy. Cell journal. Retrieved November 10, 2022, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5241505/

Hafler, D. A. (2004, March 15). Multiple sclerosis. The Journal of Clinical Investigation. Retrieved November 10, 2022, from https://www.jci.org/articles/view/21357

U.S. National Library of Medicine. (n.d.). Multiple sclerosis: Medlineplus medical encyclopedia. MedlinePlus. Retrieved November 20, 2022, from https://medlineplus.gov/ency/article/000737.htm