Reviewed for medical accuracy by Dr Evelyne Jonniaux, Medical Advisor
Last updated 17 September 2026
Migraine is the single most common wrong diagnosis in multiple sclerosis. In a 2019 study of patients referred to two academic MS centres with an established diagnosis, 17 to 19 percent did not have the disease. The most frequent alternative explanation was migraine.
The questions we get asked
How often is multiple sclerosis diagnosed by mistake?
The honest answer is that nobody knows the population rate. What is documented is the rate among patients referred to specialist centres, which is a filtered group: people whose course did not behave as expected, or whose treating physician wanted a second opinion. Kaisey and colleagues reviewed consecutive new referrals at two US academic centres in 2019 and found that 17 percent at one site and 19 percent at the other carried an MS diagnosis that the reviewing neurologists did not confirm. That figure cannot be read as “one in five people with MS do not have it”. It describes the yield of a second opinion in a selected population.
What replaces the diagnosis?
In the Kaisey series migraine was the leading alternative. Solomon and colleagues had reported the same pattern in 2016 in a multicentre case series of 110 misdiagnosed patients: migraine alone or in combination accounted for 22 percent. Fibromyalgia, non-specific white matter changes, and functional neurological disorder made up much of the remainder.
How long do these errors last?
This is the number that matters clinically. In the Solomon series, 33 percent of patients had carried the wrong diagnosis for ten years or more. Kaisey estimated roughly 110 patient-years of unnecessary disease-modifying therapy across the misdiagnosed patients in the two cohorts. These treatments carry real risk, including progressive multifocal leukoencephalopathy with some agents.
Why does it happen?
Two mechanisms recur. The first is misapplication of the McDonald criteria: white matter lesions on MRI that do not meet the required topography or dissemination rules are counted as if they did. The second is anchoring on the scan rather than the clinical history. White matter hyperintensities are common in migraine and increase with age and vascular risk factors, and they are not specific to demyelination.
What the figures say
| Finding | Figure | Source |
|---|---|---|
| Referred patients whose MS diagnosis was not confirmed | 17 to 19 percent | Kaisey et al., Mult Scler Relat Disord, 2019 |
| Migraine as the alternative diagnosis | 22 percent of the series | Solomon et al., Neurology, 2016 |
| Patients misdiagnosed for 10 years or more | 33 percent | Solomon et al., Neurology, 2016 |
| Unnecessary disease-modifying therapy | about 110 patient-years | Kaisey et al., 2019 |
These are case series from referral centres. They measure what a careful re-reading finds in patients who were already flagged as uncertain. They do not measure how often the diagnosis is wrong in the general population, and no published study does.
What Noria Health does, and does not do
We organise a neurological second opinion with a specialist team near Brussels: review of the existing MRI sequences, the clinical history, and the criteria actually applied. We confirm feasibility within 24 to 48 hours.
We do not make a diagnosis remotely, we do not comment on a treatment already in progress, and we do not advise stopping any medication. A change of diagnosis, when it happens, is a clinical decision taken in consultation.
Who reviewed this page
Noria Health editorial team.
See also: all our articles on neurology.
Have your case reviewed. Noria Health arranges a specialist consultation near Brussels and confirms feasibility within 24 to 48 hours. Open a case.