Multiple Sclerosis Misdiagnosis in Florida: When MRI Findings Are Read as MS and When MS Is Missed

Magnetic resonance imaging has transformed the way neurologists see the brain and spinal cord, making it possible to detect demyelinating lesions long before a patient's symptoms become disabling. That said, the same scan that reveals multiple sclerosis can also mislead a clinician who reads every bright spot as disease — or who never orders the scan at all.

Multiple sclerosis (MS) is a chronic immune-mediated disease in which the body attacks the myelin that insulates nerve fibers in the central nervous system. Because no single blood test or image confirms it, the diagnosis rests on clinical judgment applied to a defined set of criteria, and that judgment can fail in either direction.

If you or a loved one were told you have MS and later learned you never did, or if your symptoms were dismissed for years before a neurologist finally confirmed the disease, we understand how disorienting that can be. You may have spent years on medication you did not need, or lost a treatment window you cannot get back. This guide explains what the standard of care requires, how each kind of error happens, and how a claim moves through Florida's presuit process.

Neurologists in the United States and abroad diagnose MS using the McDonald criteria, a framework first published in 2001 and revised several times since, most notably in 2017. The core idea has stayed constant: the clinician must show that damage to the central nervous system has occurred in more than one place and at more than one point in time.

Under the 2017 revision, those two requirements break down as follows:

• Dissemination in space. The patient must have at least one characteristic T2-hyperintense lesion in at least two of four regions: periventricular, cortical or juxtacortical, infratentorial, and the spinal cord. Location matters as much as number, because lesions scattered randomly through deep white matter do not satisfy this requirement.
• Dissemination in time. The clinician must show that lesions formed at different times. This can be met by a second clinical attack, by a scan showing both enhancing and non-enhancing lesions at once, by a new lesion on a follow-up MRI, or — a change introduced in 2017 — by cerebrospinal fluid-specific oligoclonal bands.
• No better explanation. The criteria apply to patients with a typical clinically isolated syndrome, such as optic neuritis or a partial myelitis, and only after alternative diagnoses have been considered and reasonably excluded.

That third element is where many errors begin. In fact, the McDonald authors have repeatedly cautioned that the criteria were never designed to be applied to patients with vague or atypical symptoms whose MRI happens to show white-matter changes.

Keep in mind that the criteria continue to evolve. A further revision presented in 2024 proposed additions such as the optic nerve as a fifth lesion region and imaging markers like the central vein sign, so the version that governed your care depends on when you were diagnosed — confirm the applicable standard with counsel and a qualified expert.

All of this matters in a malpractice case because the McDonald criteria give an expert a concrete benchmark. Florida law measures a physician against the prevailing professional standard of care under Florida Statute § 766.102, and a documented departure from widely accepted diagnostic criteria can be strong evidence of a breach.

Small areas of increased signal on T2 and FLAIR sequences are common on brain MRI, particularly as people age. These spots can reflect migraine, small vessel ischemic disease related to high blood pressure or diabetes, prior infection, vitamin B12 deficiency, or no clinically meaningful process at all.

When a radiologist describes such findings as consistent with demyelinating disease, and a treating clinician accepts that phrase without applying the McDonald criteria, a patient can leave the office with a lifelong diagnosis they do not have. Published research has documented this pattern, including a 2016 multicenter study in Neurology that examined patients misdiagnosed with MS at academic referral centers and identified migraine and fibromyalgia among the conditions most often mistaken for the disease.

Overdiagnosis frequently traces back to a few recurring missteps, including but not limited to:

• Counting lesions without weighing location. Nonspecific subcortical spots do not carry the same diagnostic weight as periventricular lesions abutting the ventricles or lesions in the spinal cord.
• Treating atypical symptoms as a clinical attack. Headache, fatigue, dizziness, or diffuse pain without objective neurological findings generally do not qualify as a typical demyelinating event.
• Skipping the mimic workup. Conditions such as neuromyelitis optica spectrum disorder (NMOSD), MOG antibody-associated disease, neurosarcoidosis, CNS vasculitis, and Lyme disease can produce overlapping imaging and call for targeted testing.
• Anchoring on a prior label. Once MS appears in a chart, later clinicians may continue treatment without independently revisiting whether the original diagnosis was sound.

The consequences of overdiagnosis extend well beyond the emotional weight of the label. Disease-modifying therapies carry real risks — some require ongoing laboratory monitoring, and certain agents have been associated with serious infections such as progressive multifocal leukoencephalopathy.

What's more, several MS therapies are known to be ineffective or even harmful in NMOSD, so a patient misdiagnosed with MS may receive treatment that worsens the disease they actually have. Accordingly, overdiagnosis cases often involve two layers of harm: the injury caused by unnecessary treatment and the injury caused by leaving the true condition untreated.

Radiology errors frequently sit at the center of these cases. Our guide to unreported and misread radiology findings explains how a radiologist's report can shape every decision that follows, and why the images themselves — not just the written report — need independent review.

The opposite error is just as consequential. Early MS often presents with symptoms that come and go, such as blurred or painful vision in one eye, numbness or tingling in a limb, an electric-shock sensation down the spine when bending the neck, or a sudden loss of balance.

Because these episodes may resolve on their own within days or weeks, they are easy to attribute to stress, anxiety, a pinched nerve, carpal tunnel syndrome, or an inner-ear problem. However, a clinician who sees a younger adult with painful monocular vision loss or a sensory level on the trunk should consider demyelinating disease and order appropriate imaging.

Missed-MS cases tend to follow recognizable patterns. Some examples include:

• Optic neuritis treated as an eye-only problem. An ophthalmologist or emergency physician may address the vision loss without referring the patient for brain MRI or neurological evaluation.
• Spinal cord symptoms imaged at the wrong level. Numbness from a cervical cord lesion can be mistaken for a lumbar or peripheral problem, leading to imaging that never captures the lesion.
• Symptoms attributed to a psychiatric cause. Women in particular report having neurological complaints dismissed as anxiety or conversion disorder before an eventual MS diagnosis.
• Abnormal imaging never followed up. An MRI ordered for headaches or trauma may note lesions suggestive of demyelination, yet no one communicates the finding or arranges neurology follow-up.

After all, the value of an early diagnosis lies in early treatment. Modern disease-modifying therapies aim to reduce relapses and the accumulation of new lesions, and delay can allow damage to build that later treatment may not reverse.

That said, missed-MS claims carry a demanding causation question. Florida follows the more-likely-than-not standard affirmed in Gooding v. University Hospital Building, Inc. (Fla. 1984), so a claimant generally must show that timely diagnosis and treatment would probably have produced a better outcome, not merely that it offered some chance of one.

Overlap with emergency care is common as well. Patients who present with sudden neurological symptoms often pass through an emergency department first, and our overview of suing a Florida hospital explains how institutional liability and staff-physician relationships affect who can be named in a claim.

Florida does not allow a medical negligence lawsuit to be filed until the claimant completes a mandatory presuit process under Chapter 766. Each step carries its own requirements, and missing one can jeopardize the entire claim.

Here is how the process generally unfolds:

• Presuit investigation. Under Florida Statute § 766.203, the claimant must conduct a reasonable investigation and obtain a verified written medical expert opinion corroborating that there are reasonable grounds to believe a provider was negligent and that the negligence caused injury.
• The right expert. Section 766.102 requires, in most cases, that an expert testifying against a specialist practice in the same specialty. A claim against a neurologist generally calls for a neurologist, while a claim against a radiologist generally calls for a radiologist.
• Notice of intent. Under Florida Statute § 766.106, the claimant serves a notice of intent to initiate litigation on each prospective defendant, which opens a 90-day period during which the defendants investigate and may respond.
• Informal discovery. During presuit, the parties may exchange records and take unsworn statements, and § 766.204 gives claimants a right to obtain copies of relevant medical records.
• Response and resolution. Before the 90 days close, each defendant may reject the claim, make a settlement offer, or offer to admit liability and arbitrate damages.

Timing deserves special attention. Under Florida Statute § 95.11(4)(b), a medical malpractice claim generally must be brought within two years from when the incident occurred or when it was discovered, or should have been discovered with due diligence, subject to a four-year outer limit from the incident itself, with narrow exceptions for fraud, concealment, and certain claims involving minors.

Discovery dates can be genuinely contested in MS cases, because the moment a patient learns the diagnosis was wrong — or that it was missed — may come long after the original error. Serving a notice of intent tolls the limitations period during the 90-day presuit window, and § 766.104 allows an automatic 90-day extension by petition, but these mechanics are technical, so confirm your specific dates with counsel. Our guide to the Florida malpractice filing deadline walks through these rules in more detail.

Evidence in an MS misdiagnosis case is heavily image-driven. Remember that a second reader can only evaluate what the first reader saw, so the complete DICOM image files from every MRI, along with neurology notes, lumbar puncture results, antibody testing, and pharmacy records, form the backbone of the expert review.

Damages depend on which direction the error ran. In an overdiagnosis case, losses may include the cost and side effects of unnecessary therapy, harm from a missed alternative condition, and emotional distress; in a missed-diagnosis case, they may include disability progression, lost earning capacity, future care costs, and diminished quality of life.

An MS diagnosis reshapes how a person plans a career, a family, and a future, and learning that the diagnosis was wrong — or came years too late — can be just as life-altering. We understand the far-reaching impact of that discovery, and we are here to help you make sense of it.

Our team works with board-certified neurologists and neuroradiologists to review imaging and records against the McDonald criteria in effect at the time of your care. Together, we can determine whether a departure from the standard of care occurred and whether it caused the harm you have suffered.

If you believe a neurologist, radiologist, or other clinician misread your scans or overlooked your symptoms, you may want to consider a confidential case review. You can learn more about related claims in our wrong diagnosis malpractice hub, including how misdiagnosis cases differ from treatment-error cases.

Free consultation. No fee unless we recover — and because Florida's limitations clock may already be running, please do not wait to have your records reviewed.

This article is for informational purposes and does not constitute legal or medical advice. Consult a qualified attorney in your jurisdiction about your specific situation.