In a recent interview, actress Christina Applegate shared her experience of being misdiagnosed with multiple sclerosis. We reached out to Dr. Sarah Sheldon, neuroimmunologist, Parkview Neurosciences, to better understand the complexities of this condition and why it is often misidentified.
An overview: What is MS?
Multiple sclerosis (MS) is a chronic autoimmune condition that affects the central nervous system (CNS), which includes the brain, spinal cord and optic nerves.
Characteristics
In MS, the immune system mistakenly attacks myelin, the protective covering surrounding nerve fibers. Myelin helps electrical signals travel efficiently between the brain and the rest of the body. When this shield is damaged, communication between nerve cells can slow down or become disrupted. MS can also damage the underlying nerve fibers. This damage can cause inflammation and scarring called “lesions” or “plaques,” leading to a variety of neurological symptoms.
MS can develop at any age but is most commonly diagnosed between 20 and 40. It is approximately three times more common in women than in men. Potential risk factors include:
- Genetic susceptibility
- Epstein–Barr virus infection
- Smoking
- Low vitamin D levels
Disease progression
MS affects each patient differently. Most patients initially experience relapsing-remitting multiple sclerosis (RRMS), the most common disease course, which accounts for approximately 85% of initial diagnoses. RRMS is characterized by episodes of new or worsening symptoms, called relapses, followed by periods of partial or complete recovery, known as remission.
In contrast, approximately 10–15% of patients with MS initially experience primary-progressive multiple sclerosis (PPMS), which is characterized by a gradual worsening of neurological function from the onset, rather than distinct relapses.
Some patients who initially have RRMS may eventually develop secondary-progressive multiple sclerosis (SPMS), characterized by a gradual progression of disability over time.
What are the common symptoms of MS?
MS symptoms also vary depending on which areas of the central nervous system are affected. Some patients experience a single prominent symptom, while others experience several symptoms that affect daily activities.
Common symptoms include:
- Vision changes: Blurred vision, double vision, pain with eye movement or reduced vision.
- Numbness or tingling: Unusual sensations in the arms, legs, face or other areas.
- Muscle weakness or stiffness: Difficulty with movement or walking.
- Balance and coordination problems: Unsteadiness, dizziness or tremor.
- Fatigue: Persistent, sometimes overwhelming exhaustion.
- Pain and muscle spasms: Neurological pain or involuntary muscle tightening.
- Bladder or bowel changes: Urgency, difficulty emptying the bladder or constipation.
- Cognitive changes: Difficulty with memory, concentration or processing information.
The type, severity and duration of MS symptoms vary from patient to patient. Symptoms may persist or fluctuate over time and may temporarily worsen with exposure to heat, fever or infection. This temporary worsening does not necessarily indicate new disease activity.
These symptoms are not unique to MS and can occur in a variety of other conditions. Experiencing one or more of these symptoms does not necessarily indicate MS; however, persistent, recurring or unexplained neurological symptoms warrant medical evaluation to determine the underlying cause.
How is MS diagnosed in an individual?
No single test confirms MS in every individual. A neurologist evaluates the patient's medical history, neurological exam findings and diagnostic test results to determine whether they meet established diagnostic criteria.
Magnetic resonance imaging (MRI) of the brain and, when appropriate, the spinal cord can identify lesions characteristic of MS. Additional testing, such as cerebrospinal fluid (CSF) analysis obtained through a lumbar puncture, visual pathway testing or blood tests to investigate alternative conditions, may also be performed. The diagnosis requires careful interpretation of these findings and consideration of other possible explanations for the symptoms.
How can MS be misdiagnosed?
MS can be challenging to diagnose because its symptoms overlap with those of many other neurological and medical conditions. Several factors can contribute to misdiagnosis:
- Symptoms that overlap with other conditions: Symptoms such as fatigue, dizziness, numbness/tingling and difficulty concentrating can occur for many reasons. Although these symptoms can occur in MS, they do not, by themselves, establish the diagnosis.
- Misinterpreting MRI findings: Small areas of abnormal signal in the brain can occur in a variety of conditions outside of MS, including but not limited to migraines, aging and small-vessel disease. It is important to understand that not every white matter lesion is caused by MS.
- Relying too heavily on one test: An isolated MRI finding or CSF test result, as well as an individual symptom, should not be interpreted without considering the broader clinical picture.
- Incomplete medical history: Clinicians may miss previous episodes of vision changes, weakness, sensory changes or other neurological symptoms if a patient does not recognize them as relevant to their history.
- Atypical symptoms or test results: Findings that do not fit the expected pattern of MS should prompt clinicians to reconsider the diagnosis.
- Not investigating alternative diagnoses: Conditions that mimic MS must be considered and appropriately evaluated before a diagnosis is made.
What other conditions can mimic MS?
Several conditions can produce symptoms or imaging findings that resemble MS. The most appropriate alternatives to investigate depend on a patient's symptoms, age, medical history, examination and test results.
Examples of alternative conditions to consider include:
- Neuromyelitis optica spectrum disorder (NMOSD): An inflammatory condition that can affect the optic nerves and spinal cord.
- MOG antibody-associated disease (MOGAD): An immune-mediated disorder that attacks myelin oligodendrocyte glycoprotein (MOG), which can cause inflammation of the optic nerves, spinal cord or brain.
- Migraine: Can cause visual disturbances, sensory symptoms, dizziness and white matter spots on MRI.
- Nutritional deficiencies: Vitamin B12 deficiency, copper deficiency, and, less commonly, vitamin E deficiency can cause neurological symptoms such as numbness, tingling, weakness and balance difficulties.
- Small-vessel disease of the brain: Can produce white matter abnormalities on MRI, particularly in individuals with underlying vascular risk factors.
- Cervical spine disorders: Compression of the spinal cord or nerves can cause weakness, numbness, tingling and difficulty walking.
- Other inflammatory and autoimmune conditions: Examples include systemic lupus erythematosus (SLE), Sjogren syndrome, Behcet’s disease and neurosarcoidosis. These conditions can affect the nervous system and sometimes produce overlapping neurological symptoms or imaging findings.
When should someone contact a healthcare provider?
Contact a healthcare provider if you experience new, persistent, recurrent or unexplained neurological symptoms, especially if they interfere with daily activities. Examples include:
- New numbness, tingling or weakness that persists or recurs.
- Unexplained changes in vision, including vision loss or pain with eye movement.
- New difficulties with balance, coordination or walking.
- Persistent neurological symptoms that have no clear explanation.
- Symptoms that worsen or return after a previous episode.
When appropriate, a primary care provider can begin the evaluation and refer the patient to a neurologist. If MS is suspected, a neurologist can determine whether additional testing is necessary.
It is important to be aware that sudden neurological symptoms, such as weakness on one side of the body, sudden vision loss or difficulty speaking, require immediate medical attention, as they may indicate a medical emergency, such as a stroke.
Are treatment options available for MS?
Although there is currently no cure for MS, several treatment options are available to help manage the disease.
Disease-modifying therapies (DMTs) can reduce relapse frequency, decrease new inflammatory activity in the central nervous system, and, depending on the treatment, slow disability accumulation over time.
Additional treatments can help manage specific symptoms and improve quality of life. Early diagnosis and appropriate treatment can play an important role in managing MS and reducing long-term disease activity. Treatment decisions should be individualized based on the patient's disease course, symptoms, and overall health, in consultation with a healthcare provider.
If you need assistance establishing care with a primary care provider, our Access Center can help. Call anytime at 877-PPG-TODAY or 877-774-8632 for assistance, or Find a Provider on our website.
Additional resources
National Library of Medicine: MedlinePlus: Multiple Sclerosis
The Lancet Neurology: Diagnosis of multiple sclerosis: 2024 revisions of the McDonald criteria
National Institute of Neurological Disorders and Stroke (NINDS): Multiple Sclerosis.
National Multiple Sclerosis Society. Multiple Sclerosis.
