Multiple sclerosis (MS) is an autoimmune disease that shares symptoms with many other conditions, which can mean people receive a misdiagnosis.

MS affects around 1 million people in the United States. However, experts believe that around 1 in 5 people with MS could have an incorrect diagnosis.

A conclusive diagnosis involves ruling out those conditions and checking for signs and symptoms that are specific to MS. Medical professionals refer to this process as a “differential diagnosis.”

This article describes what MS is, including its symptoms, causes, and treatment. We also investigate how common it is for doctors to misdiagnose MS and list some conditions with similar symptoms. Finally, we describe the protocol doctors use to draw a differential diagnosis.

Doctors discussing conditions that are similar to MS.Share on Pinterest
Tom Werner/Getty Images

MS is an autoimmune disease in which the immune system mistakenly attacks the myelin sheath that protects and insulates the nerves of the brain and spinal cord. This disrupts communication between the brain and other parts of the body.

According to the National Institute of Neurological Disorders and Stroke, the symptoms of MS can differ from person to person but may include:

  • vision problems, such as:
  • tingling, numbness, or pain in the face, torso, or limbs
  • muscle weakness in the hands and legs, sometimes with painful spasms
  • difficulties with balance and coordination
  • difficulty controlling the bladder
  • dizziness that may be intermittent or constant
  • cognitive difficulties and mental fatigue
  • mood changes, such as depression

The results of a 2019 study suggest that up to 1 in 5 people with MS may have a misdiagnosis.

The 2019 study investigated 241 patient evaluations across two separate clinics in the U.S. It found that up to 19% of people with a diagnosis of MS did not fulfill the McDonald criteria, which doctors use to diagnose MS.

The researchers concluded that these patients likely had conditions with symptoms similar to those of MS. The most common misdiagnoses were:

  • Migraine: 16%
  • Radiologically isolated syndrome: 9%
  • Spondylopathy: 7%
  • Neuropathy: 7%

According to another 2019 report investigating MS misdiagnoses, misdiagnosis may happen due to doctors:

  • incorrectly applying the McDonald criteria during diagnosis
  • diagnosing patients solely on the results of an MRI scan, without investigating the presence or lack of other symptoms
  • being reluctant to change a previous diagnosis of MS despite evidence to the contrary

Below is more information about the common misdiagnoses from the 2019 study.

Migraine is a complex neurological condition that causes moderate to severe throbbing headaches, typically on one side of the head. Other possible symptoms of migraine include:

  • nausea
  • feeling dizzy and off-balance
  • increased sensitivity to light and sound
  • visual disturbances, such as blurred vision or flashing lights
  • numbness in the hand that moves up the arm and into the face
  • mental fog

Experts do not know the exact cause of migraine. However, temporary changes to chemicals, nerves, and blood vessels inside the brain likely play a role.

Treatment

Although there is no cure for migraines, treatments can help to reduce their frequency and severity. Possible treatment options include:

Radiologically isolated syndrome (RIS) is a neurological condition characterized by changes or lesions in the brain or spinal cord. More than half of people with RIS go on to develop MS within 10 years of their initial diagnostic MRI scan.

Symptoms of RIS include:

  • headaches
  • loss of limb reflexes
  • weakness in the arms and legs
  • cognitive problems, such as memory loss or difficulty with comprehension
  • mood changes, such as anxiety and depression

Treatment

There is currently no cure for RIS. If there are no other symptoms present, a doctor may simply observe the patient for signs that MS is developing. Otherwise, a doctor will prescribe medications to treat the symptoms.

Spondylopathies are disorders that affect the individual bones or “vertebrae” of the spine. These conditions typically involve inflammation of the vertebrae. Examples include:

Spondylopathies typically involve the following symptoms:

  • stiffness in the spine
  • pain and inflammation in the lower back
  • hip pain
  • swelling in the arms and legs
  • eye pain and irritation
  • fatigue

Treatment

Spondylopathies are often chronic, meaning they are lifelong conditions. However, the following medications can help to manage these conditions and alleviate symptoms:

Neuropathy is the medical term for nerve damage or dysfunction. Causes include:

The symptoms of neuropathy depend on the type that a person has. Possible symptoms include:

Treatment

The treatment for neuropathy depends on the underlying cause and the symptoms a person experiences. Treatment options include:

CSVD affects the smaller blood vessels in the brain, causing lesions. It is a cause of vascular dementia and can also lead to strokes.

Although multiple factors may cause CSVD, the most common risk factors include:

Symptoms and complications of CSVD include:

Treatment

The treatment for CSVD focuses on medications that relax the small blood vessels, improve blood flow, and decrease blood pressure. Certain lifestyle changes can also help to manage CSVD. Examples include eating a healthy diet and performing regular physical activity.

According to the National Multiple Sclerosis Society (NMSS), there are many diseases and conditions that can cause symptoms similar to those of MS. Examples include:

According to NMSS, a doctor will confirm MS by ruling out other diseases and disorders that may have similar symptoms, as well as checking for signs and symptoms specific to MS. A doctor will also:

  • ask about a person’s medical history
  • ask about family history
  • perform a neurological exam

A doctor may then request the following tests:

  • blood tests to check for certain diseases or deficiencies
  • a lumbar puncture to analyze spinal fluid for antibody abnormalities associated with MS
  • an MRI scan to look for lesions on the brain and spinal cord
  • evoked potential tests, which measure how quickly information passes through nerve pathways

Despite advances in MS research, there is no single test for the condition. As such, diagnosis is not always a straightforward process.

MS affects around 1 million people in the U.S. However, research suggests that up to a fifth of these people may be living with a misdiagnosis.

Some conditions that doctors may commonly misdiagnose as MS include migraines, radiologically isolated syndrome, spondylopathies, and neuropathy.

In order to accurately diagnose MS, doctors must rule out conditions with similar symptoms and look for signs and symptoms specific to MS. As such, the process of diagnosing MS may be lengthy and complex. Nonetheless, an accurate diagnosis is essential to determine the most appropriate course of treatment.