Whether you’re newly diagnosed, have had multiple sclerosis for a while, or have a friend or family member with the condition, it can be tough to absorb, understand, and remember the many terms associated with MS. We’ve tried to make it a little easier by creating this MS glossary as a reference for patients and their family members and friends. (If you’re looking for a term that’s not listed here, by all means email us at firstname.lastname@example.org and we’ll remedy that!)
Autoimmune Disease: A group of diseases characterized by the immune system malfunctioning and attacking healthy cells in the body. In MS, the immune cells attack myelin, a fatty substance that insulates the neurons (nerve cells) of the brain and spinal cord, causing damage to the central nervous system (CNS).
B Cells: A type of lymphocyte (white blood cell) that is made in the bone marrow. They are responsible for making antibodies, which fight foreign invaders (antigens).
Blood-brain barrier: A barrier between the blood vessels in the CNS and the delicate brain tissues. It serves to keep out cells and substances that would damage the brain. For unknown reasons, this barrier becomes “leaky” in MS, which allows immune cells to cross into brain tissue and attack myelin.
Central Nervous System (CNS): One of the two branches of the nervous system. It consists of the brain and the spinal cord, and is responsible for sensory and motor functions throughout the entire body. In MS, the immune system attacks the myelinated nerves of the CNS.
Cerebrospinal Fluid (CSF): Clear fluid that circulates through the brain and spinal cord. It maintains uniform pressure in the brain and spinal cord, and acts as a shock absorber.
Clinical trial: A research study done on human participants in order to test the effectiveness and safety of a disease intervention. Clinical trials must be approved by the Institutional Review Board (IRB) who ensures that the trial is ethical and protects the rights of the subjects. Trials are usually very expensive, and are funded by government organizations, biotechnology or pharmaceutical companies, or medical-device manufacturers. (To learn about how you can participate in research initiatives, click here.)
Clinical Trial Phases: Clinical trials for drug development are done in a series of phases, or steps:
- Phase 0: Researchers will give a low dose of the medication to the first human subject and observe how it is broken down and metabolized by the body, and what effects the drug has on the body.
- Phase 1: The drug is given to a small group of participants who are monitored for side effects and potential safety concerns.
- Phase 2: The drug is given to a larger group of participants to test its efficacy (effectiveness).
- Phase 3: The drug is given to an even larger group of participants and safety and efficacy is observed.
- Phase 4: If the drug is approved by the US Food and Drug Administration (FDA) and put on the market, then data on its effectiveness and side-effect profile will continue to be collected.
Demyelination: When the myelin sheaths (the protective coating around nerves) are damaged, this is called demyelination. Demyelination keeps the body’s nerves from sending and receiving signals smoothly, causing the symptoms of MS.
Double-blind trial: These are done to eliminate potential bias during a clinical trial, which would skew data. In a double-blind trial, information about the experiment is kept from the participants and the scientists until the completion of the trial. For example, to see if Drug A slows the progression of MS, a double-blind trial will be done. Half of the participants will receive a placebo and half will receive Drug A. Neither the doctors nor the participants know who’s receiving the drug or who’s receiving the placebo.
Glial Cells: Cells in the nervous system that act to support and protect the neurons.
Grey Matter: Brain tissue that contains few myelinated axons (neuron bodies), but many cell bodies that control memory, muscles, and sensation. There are also many small blood vessels called capillaries in grey matter. Over time grey matter atrophies (shrinks) leading to memory loss in the elderly. Atrophy may also be accelerated by diseases such as MS.
Inflammation: Inflammation is the body’s natural response to harmful stimuli, in order to heal an infection, wound, or other damage to the body. In the case of MS, inflammation is a response to the body’s immune system attacking the myelin that encases your nerves.
Myelin: The insulating coating that surrounds nerves and helps them conduct electrical signals (impulses) quickly and efficiently. Myelinated nerves have a myelin sheath that covers the axon (body of the nerve). Myelin is produced by oligodendrocytes in the CNS and is made up of water, protein, and fat.
Neurologist: A doctor who specializes in neurology, which covers all matters of the central nervous system (made up of the brain and spinal cord). This includes the diagnosis and treatment of ailments and injuries specific to these areas of the body.
Neuropsychology: Combining the sciences of both neurology and psychology, neuropsychology is the study of the anatomy and function of the brain and how it relates to physiological processes in the body.
Oligodendrocytes: A type of glial cell in the CNS that is responsible for producing myelin, which insulates nerves allowing them to effectively conduct electrical signals.
Relapse: The rapid onset of new or worsening MS symptoms that persist for more than 24 hours and cannot be attributed to any other cause such as illness or overheating. Relapses indicate that acute demyelination is occurring in the central nervous system. A relapse can also be referred to as an “attack” or “exacerbation.”
T Cells: Cells of the immune system known as lymphocytes (white blood cells). They are produced in the thymus and play a key role in the recognition and destruction of foreign invaders (such as bacteria and viruses) within the body.
White Matter: Brain tissue of the CNS that is made up of glial cells and myelinated axons. This is the area where demyelination occurs, and lesions are seen in people with MS.
Cognitive Function Testing: A test consisting of a series of questions and tasks that is administered to assess for cognitive deficits such as problems with memory and attention.
Enhancing Lesion: This is a lesion that shows up bright white after contrast dye is administered during an MRI. This indicates that there is new, active damage occurring as opposed to an old lesion from a previous attack.
Lesion: In MS, lesions are areas of demyelination that have scarred over and show up as a characteristic white spot on an MRI scan. They are caused by the body’s immune cells attacking the myelin sheaths that surround your nerve cells. Lesions make it more difficult or even impossible for nerve impulses to travel smoothly to and from the brain and through the spinal cord.
MRI: Magnetic Resonance Imaging (MRI) is used to obtain pictures of internal organs and structures. Neurologists use MRIs to look for MS lesions in the brain and spinal cord. Often, contrast dye is injected into a vein in order to get a clearer picture. MRIs use a magnetic field and pulses of energy from radio waves to take the pictures, and do not expose the person to radiation.
Oligoclonal Bands (O-Bands): Proteins that are present if there is inflammation present in the CNS. If two or more bands are found in the cerebrospinal fluid, but not in the blood, this can be suggestive of MS.
Spinal Tap: A spinal tap, also called a “lumbar puncture,” is a medical procedure where a needle is inserted between two vertebrae in a person’s lower back in order to retrieve a sample of cerebrospinal fluid (CSF). CSF is the protective liquid that surrounds your brain and spinal cord. This is usually done to confirm an MS diagnosis and/or to rule out other causes of neurological symptoms such as viral diseases.
Ataxia: Uncoordinated muscle movement that causes unsteady gait (walking).
Bladder Dysfunction: A common MS symptom caused by the disruption of nerve signals to the bladder. This can result in urinary frequency, urgency, hesitancy, incontinence, and nocturia.
Bowel Dysfunction: Disruption in normal defecation patterns caused by MS lesions and/or medications. This can include constipation, loss of bowel control, and diarrhea.
Clonus: Involuntary muscle spasms that are characterized by a series of rapid, rhythmic, and repetitive contractions and relaxations.
Cognition/Cognitive Changes: High-level brain functions that can be interrupted by MS lesions. Common cognitive changes include difficulty with memory, attention, concentration, processing information, planning, prioritizing information, spatial relations, and word finding. “Cog-fog” is a general term often used to describe the transient occurrence of a fuzzy, disconnected feeling during which it is extremely difficult to focus and process information.
Cognitive Function: An individual’s ability to absorb new information, process thoughts, remember things, and speak.
Diplopia: Double vision caused by muscle weakness. Can be temporarily brought on or worsened by fatigue or eye strain.
Dizziness: Feeling of being off balance or lightheaded.
Dysarthria: Difficulty with speech.
Dysphagia: Difficulty swallowing.
Emotional Changes: Symptoms that can be brought on by coping with chronic illness. It can also be a symptom of MS caused by demyelination, nerve damage, or as a side effect of medications. These include depression, anxiety, grief, stress, and/or mood swings.
Fatigue: Lack of energy or exhaustion that can have primary or secondary causes. Primary fatigue is a symptom of damage caused by MS and is not associated with lack of sleep, tiredness, or physical weakness. Secondary fatigue occurs as a result of another symptom such as insomnia, depression, overexertion, or heat intolerance.
Foot Drop: Weakness in the muscles of the leg and foot that results in the inability to lift the toes off the ground while walking. A normal step starts by lifting the foot and stepping down on the heel, but with foot drop the foot can’t be lifted and the front of the foot drags on the ground. Treatment includes muscle stimulators, AFO braces, and physical therapy.
Impaired Hearing: Decrease or loss of hearing.
Incontinence: The inability to hold in urine or stool, leading to leaks or accidents.
Lhermitte’s Sign: Sudden stabbing, electric-shock like pain that runs down the spine and occurs when the neck is bent forward.
MS Hug: Spasms of the intercostal muscles, which are located between the ribs. Results in an uncomfortable band-like feeling of constriction around the waist or chest.
Nocturia: Frequent nighttime urination.
Numbness: Decrease or loss of sensation. In MS, numbness often occurs in the face, hands, arms, and legs.
Nystagmus: Involuntary movements of the eye that occur when the eye moves up and down, or side to side. Neurologists will observe for this during an exam. In severe cases it can impair vision.
Optic Neuritis: Inflammation of the optic nerve, which results in blurred vision or even blindness. This is commonly one of the first symptoms of MS and it usually resolves itself over time.
Paralysis: Complete or partial loss of voluntary muscle movement.
Paresthesias/Dysesthesias: Abnormal sensations such as tingling, pruritus (itching), or pins and needles that are caused by nerve damage.
Pseudobulbar Affect (PBA): Unpredictable episodes of uncontrollable laughing and/or crying that occur at inappropriate times, or that have no relation to the person’s emotions. For instance, crying without feeling sad or laughing at situations that are not humorous. This is caused by lesions in areas of the brain that control emotion.
Restless Leg Syndrome: Uncomfortable sensations in the legs that are only relieved by movement. Frequently occurs at night, and can have a severe impact on sleep.
Seizure: Uncontrolled electrical activity of the brain that can result in tremors, physical convulsions, disruptions in thought, sensory disturbances, and/or loss of consciousness.
Sexual Dysfunction: Difficulty achieving orgasm or loss of libido. Can be secondary to a variety of MS symptoms such as incontinence, spasticity, emotional changes, or damage to nerve pathways that control the sexual response.
Spasticity: Increased muscle tone that results in stiffness or muscle rigidity, which can impact movement, walking, and speech.
Tremor: Involuntary shaking or twitching of the muscles.
Trigeminal Neuralgia: Stabbing, electric-shock like facial pain associated with damage to the trigeminal nerve.
Urinary Tract Infection (UTI): An infection of the urinary tract that is most often due to bacterial invasion of the (normally sterile) urinary system. Symptoms include burning with urination; dark-colored, foul smelling urine; and frequency/urgency with urinating. People with MS get UTIs more commonly than the general population for reasons that are not completely understood, but that are likely related to decreased sensation and/or urinary retention. UTIs can cause MS symptoms to acutely worsen, so many neurologists will order a urine sample to rule out UTI when acute neurological changes occur. UTIs are treated with antibiotics.
Vertigo: An interruption in the pathways that maintain equilibrium, which causes the sensation that a person’s surroundings are spinning, though it is different from dizziness. Vertigo is often accompanied by nausea and/or vomiting. It can be treated with drugs used for motion sickness and nausea.
Weakness: Decrease or loss of muscle strength.
Ampyra: Also known as “the walking drug,” Ampyra is an oral medication that is used to improve walking in MS patients. It works by blocking potassium channels in neurons, and allowing them to transmit electrical signals more effectively.
Anticholinergics: Medications that dry secretions and can be used in MS patients for symptomatic treatment of a variety of conditions. These are commonly used to treat vertigo (scopolamine) and bladder dysfunction (Enablex, Toviaz, Ditropan, Oxytrol, Vesicare, Tofranil, Detrol, and Sanctura). The most common side effects of anticholinergics include dry mouth, blurry vision, and constipation.
Anticonvulsants: Used to treat tremors and seizures. Also effective in the management of nerve pain, spasticity, restless leg syndrome, and paresthesias.
Antidepressants: Medications that are used to control depression. Also used to help alleviate chronic pain and insomnia.
Assistive Devices: Tools, devices, equipment, and technology that help to compensate for disability, and enables a person to perform everyday tasks independently. These devices include tools that grasp out-of-reach objects; AFO braces for foot drop; as well as canes, walkers, wheelchairs, and power chairs. Assistive devices help to maintain independence and reduce social isolation.
Botox: Botox is short for botulinum toxin, this treatment is made from bacteria. When injected into a muscle, it blocks the signal from nerves to that muscle, which effectively relieves muscle spasticity for a few months. Botox can also be used for bladder dysfunction.
Disease Modifying Drugs (DMD): Medications that are used to slow disability progression and reduce the rate of relapses in people with MS. Injectable drugs include Copaxone and Interferons (Rebif, Plegridy, Avonex, Betaseron, and Extavia). Oral DMDs include Gilenya, Aubagio, and Tecfidera. Finally, infusions, such as Tysabri and Lemtrada, are also available.
Immunosuppressants: A class of drugs that decreases, weakens, or prevents the body’s normal immune response. Cytoxan, Imuran, and Methotrexate are immunosuppressants that are used in the treatment of MS. People on immunosuppressants may be more vulnerable to infections.
Immunomodulators: A class of drugs that alters the body’s normal immune response. They have been shown to decrease the number of MS exacerbations and slow the progression of physical disability. These include Interferons, Lemtrada, Plegridy, Tysabri, Copaxone, Gilenya, Aubagio, and Tecfidera.
Muscle Relaxants: Medications used to treat muscle spasticity. The most common side effect of MR’s is drowsiness. Baclofen is the most commonly used muscle relaxant among MS patients, and it can be given orally or through an implanted pump.
Neudexta: An oral medication that is effective in controlling pseudobulbar affect. It is a combination of dextromethorphan (a cough medicine), and quinidine (an anti arrhythmic).
Occupational Therapy (OT): Therapy that is meant to help people perform everyday tasks without help in order to live as independently as possible. Certified OTs work with people with MS to help them regain the ability to do activities such as driving, dressing, grooming, eating, caregiving, home management, and tasks related to work, social, and recreational interests.
Physical Therapy (PT): In people with MS, physical therapy is the treatment of symptoms with physical interventions such as massage, hot/cold therapy, muscle strengthening, and muscle stimulation. Can be used for a variety of purposes, and often improves symptoms and the person’s quality of life. PT is most often used to enhance recovery from a relapse, increase muscle strength, improve balance, and treat foot drop. PT is administered by certified physical therapists and can be done inpatient, outpatient, or through home care services.
Speech/Swallow Therapy: Rehabilitative therapy that aims to improve the movement of the mouth to improve speech and swallowing. Can be used to treat slurred speech, voice changes, and difficulty swallowing foods or liquids. This therapy is done by certified speech/swallow therapists.
Steroids: Steroids are powerful anti-inflammatory drugs used to treat MS relapses by reducing inflammation in the body. Although they do not stop a relapse, they speed up the recovery by an average of two weeks. They can be given by mouth in pill form or via IV infusion.
Stephanie Buxhoeveden MSCN, FNP-BC
Stephanie is a nurse practitioner who was diagnosed with MS at age 25. Shortly after being diagnosed she realized she could use her experiences as a patient to make a difference in the lives of others, so she became a multiple sclerosis certified nurse. Stephanie completed her master’s in nursing at Rutgers University, and now specializes in the care of people with MS and other neurological diseases.
Her blog, www.justkeepsmyelin.com, offers a unique perspective on MS from both a healthcare provider’s point of view, and through the eyes of a person living with the disease every day. Her mission is to bring compassion, humor, and a deeper understanding of MS to anyone who reads it. She also writes for MultipleSclerosis.net, MSFocus Magazine, serves as a District Activist Leader for the National MS Society and is on the membership committee of iConquerMS.
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ms glossary, multiple sclerosis