Ruling Out Other Conditions and Common Misdiagnoses

MS can present differently from person to person. It also has a wide variety of potential symptoms. This can make diagnosing MS tricky. When a doctor suspects MS, they will look for several similar conditions. These can be ruled out to eventually reach a diagnosis of MS.

What conditions are confused with MS?

There are many conditions that can be confused with MS. Some are also autoimmune or inflammatory conditions. Others are infections or vitamin deficiencies (like vitamin B12). Migraine and stroke can also look like MS.1,2

Mental health conditions can be confused with MS, too. For example, depression and anxiety can also have neurological symptoms. Several of these symptoms include dizziness, fatigue, balance issues, and trouble concentrating.

Getting to an MS diagnosis

MS is usually a clinical diagnosis. This means no single test confirms it. Instead, symptoms, personal characteristics, and imaging findings are considered together. Age, other health challenges, family history, and more can all be factored in.1

The timing of symptoms may also be a clue. For example, the sudden onset of one-sided weakness that does not improve may be a stroke. On the other hand, weakness that comes and goes, is on both sides of the body, and develops slowly may be MS.

Imaging tests like MRI (magnetic resonance imaging) can be helpful. People with MS often have visible lesions on their brain MRIs. These are bright spots on the image that represent demyelination and damage related to MS. These can help to separate MS from things like a stroke or brain mass. At the same time, these lesions can be related to a lot of things, or may even be normal.2,3

Other conditions to rule out with MS

When a person has 1 or more symptoms, their doctor will create a list of potential causes. This is called making a differential diagnosis. As mentioned, there are many conditions that can present like MS. Several of these are listed below.1-3

Inflammatory and autoimmune diseases

  • Acute disseminated encephalomyelitis (ADEM): Another myelin-damaging condition. ADEM is widespread and often develops rapidly. It also has symptoms like fever, stiff neck, and behavior changes.
  • Neuromyelitis optica (NMO): A spectrum of disorders that often involves the nerves of the eyes. Visual symptoms are similar to those in MS.
  • Transverse myelitis: Sudden inflammation of the spinal cord. This can happen after an infection or be autoimmune in nature. But the cause is often not found. Symptoms are widespread below the point of inflammation. Sometimes testing shows an underlying condition like NMO or MS.
  • Vasculitis: Inflammation of the blood vessels. Many conditions can affect the vessels in the CNS and cause neurologic symptoms. One example is Susac syndrome, which also causes hearing loss.
  • Sjorgren’s disease: An autoimmune condition affecting the saliva- and tear-producing glands.
  • Lupus: A widespread autoimmune condition that impacts the skin, joints, kidneys, lungs, and more.
  • Sarcoidosis: A condition that leads to growth and clustering of inflammatory cells. These clusters, called granulomas, can be present throughout the body. That includes in the lungs, CNS, and skin.

Infections

  • Lyme disease: An infection caused by tick bites. Most commonly from ticks found in the Eastern United States.
  • Syphilis: A sexually transmitted infection. Neurological symptoms can present years after infection.
  • Progressive multifocal leukoencephalopathy (PML): Caused by reactivation of a common virus called the JC virus. Occurs in people with a weak immune system.
  • Human immunodeficiency virus (HIV): A virus in the blood that can lead to acquired immunodeficiency syndrome (AIDS).
  • Human T-lymphotropic virus-1: A usually asymptomatic virus that can cause nervous system symptoms years later.

Genetic conditions

  • Leukodystrophies: A group of inherited conditions that progressively damage white matter.
  • Hereditary cerebellar degeneration: Another group of inherited conditions that affects the cerebellum in the brain. This causes progressive challenges with walking, speech, vision, and coordination.
  • Mitochondrial disease: A group of inherited conditions that cause problems with mitochondria. Mitochondria are in our body’s cells. They make energy. Without this energy, a person can have many symptoms, including neurologic symptoms.

Other neurologic conditions

  • Stroke
  • Transient ischemic attacks (TIA): stroke-like symptoms that come on suddenly and disappear quickly
  • Migraine

Malignancy

  • CNS lymphoma: cancer that starts in the CNS
  • Metastases: cancer that has spread from other places like the lungs or skin

Structural issues

  • Herniated discs: Slipped discs in the spinal cord can be caused by movement or trauma. These discs can press on nerves and cause neurologic symptoms.
  • Cervical spondylosis: Normal wear and tear related to aging in the neck (cervical spine). This can cause pressure on nerves in the neck and upper back.

This is not a complete list of all conditions that can seem like MS. It is also possible to have several conditions at once or illnesses that cause one another.

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Written by: Casey Hribar | Last reviewed: May 2021