Understanding Your Brain Stem and How MS Affects It

Many MS Symptoms Are Due to Brain Stem Damage

Section through a human brain
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Your brain stem, the “stem-like” part of the base of your brain, is located at the back of your skull. It’s connected to your spinal cord at its lower end and closely linked to your cerebellum (also called mini-brain), which controls many motor functions, at its top.

How Your Brain Stem “Runs”

You could think of your brain stem as resembling a bustling railway center with many “trains” passing through it to get to their destinations and return to where they started.

The “trains” are bundles of axons, message-carrying nerve fibers traveling through the “center” or brain stem on the way to and from your brain and spinal cord and, from there, out to the rest of your body.

Your brain stem is a very busy place, indeed. Within it lie many of the areas that control a large number of your body’s activities, including breathing, blood pressure, heart rate, swallowing, eye movements, hearing, balance, coordination, consciousness, and the feeling of being awake or sleepy.

How the Parts of Your Brain Stem Work Together

The parts of your brain stem include the medulla oblongata, the pons, the midbrain, and the reticular formation.

Medulla Oblongata. Located in the lower portion of your brain stem, the medulla oblongata is very important for your heart rate and blood pressure. It also controls many involuntary reflexes such as coughing, sneezing, and vomiting.

Pons. This major structure in the upper part of your brain stem has several important roles:

  • Regulation of breathing: controlling the amount of air you breathe and how often you breathe per minute (your breathing rate)
  • Transmission of signals to and from other structures in the brain, such as the cerebrum or the cerebellum, carrying messages regarding your hearing, taste, and balance
  • Regulation of deep sleep

    Midbrain. The midbrain, also called the mesencephalon, is a small region of the brain stem that:

    • Relays information about your body movements and the things you hear and see
    • Regulates autonomic (involuntary) functions, such as digestion, heart rate, and breathing rate, that your body takes care of without conscious thought on your part

    Reticular Formation. This dense network of nerve pathways in the brainstem connects your spinal cord, cerebrum (the part of your brain located in the front of your skull), and cerebellum and regulates your overall consciousness level.

    MS Symptoms Related to the Brain Stem and Cerebellum

    The list of MS symptoms that can be caused by damage to your brainstem (and its somewhat overlapping neighbor, your cerebellum) is surprisingly long. If you have MS, which, if any, of the following partial list of symptoms have you experienced?

    Vision: Double vision, oscillopsia (jumping images), jerky eye movements

    Movement and Coordination: Unsteady gait, ataxia (loss of control of body movements), incoordination (inability to move your body smoothly)

    Hearing and Balance: Vertigo, tinnitus, deafness, hyperacusis (inability to tolerate normal environmental sounds)

    Digestive Functions: Nausea, vomiting, bowel problems, hiccoughs

    Speech: Slurred speech

    Face and Throat: Swallowing problems, choking, loss of taste, facial pain, loss of sensation on the face or in the mouth

    Mental Health: Emotional incontinence (pseudobulbar effect -- inappropriate crying or laughing).

    Extremities: Weakness of the limbs

    Touch: Loss of skin sensation (perception of touch or being touched)

    As always, contact your doctor if any new symptom occurs to find out if it’s related to your MS or another cause. That way, you can be sure of getting the right treatment for your condition.

    Sources:

    “Predicting brainstem involvement.”  Multiple Sclerosis Research (2014).

    “Stroke education.” The Stroke Network (2014).

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