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FND Detective Series

The FND Detective Series is a collaborative initiative where volunteers dive into individual research projects focusing on Functional Neurological Disorder (FND) and its surrounding issues. Each volunteer researches a unique topic, producing detailed articles that offer fresh perspectives on FND.

The series has a mission with three distinct aims:

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  • Advocating for Policy Change: The research will assist in informing petitions that push for better healthcare policies and increased support for FND patients.

  • Building Future Research: By identifying gaps and generating new insights, the series paves the way for innovative research projects to improve FND treatment and understanding.

  • Enhancing Education: The series provides educational content aimed at raising awareness, educating healthcare professionals, and supporting individuals affected by FND.

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Through its focused research and advocacy, the FND Detective Series seeks to shape a future where FND is better understood, managed, and supported.

Want more details? See the blog post

You can find the articles on our blog, Medium, and Academia. Just choose the platform you prefer and click the corresponding link to read.

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How Technology Helps in Diagnosing Functional Neurological Disorder

Author: Zai Gao    Date: 01/08/2025

 

Technology has revolutionized how doctors diagnose and treat medical conditions. For many neurological disorders, tools like MRI scans and EEG tests provide detailed insights into the brain and nervous system, helping pinpoint structural or electrical issues that cause symptoms. For example, MRIs can reveal strokes, tumors, or multiple sclerosis, while EEGs can detect abnormal brain activity linked to epilepsy. These tools often give doctors clear, objective answers. But Functional Neurological Disorder (FND) is a little different.

 

FND doesn’t have a clear structural cause—there’s no visible damage to the brain or spinal cord, no tumor, no stroke (click here to learn more about symptoms of FND). It’s not something you can spot on an MRI like you would for some other conditions. However, recent studies have shown that there are some differences between the brains of FND patients and others, particularly in neurometabolites. These findings are promising, but further research is needed to explore the details. So, in general, just as there’s no single biomarker for FND, there’s also no single test that can definitively confirm, “This is FND.”

 

High-tech tools play an important role in diagnosing FND. They help rule out other conditions that might mimic FND and, in some cases, give subtle clues about what’s happening in the brain. This combination of advanced technology and skilled clinical observation is what makes diagnosing FND such a unique process. So, how do these tools work, and what can they really tell us about FND? Let’s explore!

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The Role of MRI in Diagnosing FND

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MRI, or Magnetic Resonance Imaging, is one of the most advanced tools doctors have for looking inside the brain and spinal cord (learn what happens during an MRI and how to prepare for an MRI here). It uses powerful magnets and radio waves to create detailed pictures, showing everything from soft tissues to blood vessels. For many neurological conditions, like strokes, brain tumors, or multiple sclerosis, an MRI can reveal structural damage or abnormalities that explain a patient’s symptoms (see which parts of body could go through a MRI scan here). But here’s the twist: when it comes to FND, MRI scans almost always come back normal. 

 

At first, this might feel frustrating or confusing—how can your symptoms be real if the test shows nothing wrong? But a normal MRI result is actually a critical step in diagnosing FND. Why? Because it helps rule out other serious conditions that could be causing similar symptoms. For instance, if someone experiences sudden muscle weakness, numbness, or tremors, an MRI can confirm that there’s no physical injury, tumor, or disease affecting the brain or spinal cord. This reassurance allows doctors to shift their focus to functional issues. It’s like crossing off other possibilities on the list, narrowing the path toward a better understanding of your condition.

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EEG: Testing Brain Activity

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Another tool doctors commonly use is an EEG, or Electroencephalogram (here is an EEG demonstration video if you’re curious). This test measures the brain’s electrical activity by placing small sensors on your scalp to detect and record patterns. It’s often used for patients who experience seizures, as it helps determine whether the seizures are caused by epilepsy or another condition.

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For epilepsy, an EEG typically shows abnormal electrical activity, such as spikes or waves, that indicate disruptions in how the brain is functioning. But with FND, the EEG usually shows normal brain activity—even during an episode. This difference is a key clue for doctors. It helps them rule out epilepsy and focus on diagnosing FND.

 

Doctors may even use EEGs alongside other tests, like video monitoring, to observe your symptoms in real-time. For example, if a functional seizure occurs during the EEG, the recording can show how your brain’s activity stays normal despite the outward symptoms. This combination of tools helps doctors better understand what’s happening and strengthens their confidence in the diagnosis.

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Functional MRI (fMRI) and Emerging Tools

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Functional MRI, or fMRI, takes traditional MRI to a whole new level by measuring brain activity in real time. Unlike a standard MRI, which captures detailed images of the brain’s structure, an fMRI tracks changes in blood flow, revealing which areas of the brain are more active during specific tasks. This allows doctors and researchers to "see" the brain in action. Although fMRI isn’t yet used as a routine diagnostic tool for FND, it’s opening up exciting possibilities for the future. Researchers are continuing to study these brain activity patterns, hoping to develop more precise ways to diagnose FND and tailor treatments based on how the brain functions in individual patients.

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fMRI isn’t the only emerging tool. Technologies like magnetoencephalography (MEG) are also being explored. MEG measures the magnetic fields produced by the brain’s electrical activity and can provide incredibly detailed maps of how the brain is working in real time. Other advanced neuroimaging techniques, like diffusion tensor imaging (DTI), which maps how different parts of the brain are connected, are also being studied. While these technologies aren’t widely available for diagnosing FND yet, they represent a glimpse of the future. Imagine a day when we can use these tools to not only understand the unique way your brain functions but also to develop personalized treatments that target the specific pathways involved in your symptoms. For now, emerging tools remain at the cutting edge of research, but their potential to transform how we understand and manage FND is truly inspiring.

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(For more information, here is a comprehensive study published in 2021 summarizes the output of the first International FND Neuroimaging Workgroup meeting on June 17th, 2020. It outlines many novel biologically and psychologically-informed treatments.)

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References

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“Epilepsy.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 14 Oct. 2023, www.mayoclinic.org/diseases-conditions/epilepsy/symptoms-causes/syc-20350093.

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“Functional Neurological Disorder (FND) | NHS Inform.” NHS INFORM, www.nhsinform.scot/illnesses-and-conditions/brain-nerves-and-spinal-cord/functional-neurological-disorder/. Accessed 9 Jan. 2025.

 

“Magnetic Resonance Imaging (MRI).” Johns Hopkins Medicine, 22 May 2024, www.hopkinsmedicine.org/health/treatment-tests-and-therapies/magnetic-resonance-imaging-mri.

 

“MRI.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 9 Sept. 2023, www.mayoclinic.org/tests-procedures/mri/about/pac-20384768.

 

Perez et al. “Neuroimaging in Functional Neurological Disorder: State of the Field and Research Agenda.” NeuroImage. Clinical, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/34215138/. Accessed 8 Jan. 2025.

 

UWGB Psychology. “Electroencephalogram (EEG) Demonstration.” YouTube, YouTube, www.youtube.com/watch?v=-5djHvFo7IQ. Accessed 8 Jan. 2025.

Why Diagnosing Functional Neurological Disorders is hard? 

Author: Zai Gao    Date: 12/16/2024

 

Diagnosing Functional Neurological Disorder (FND) can be really tough, and that’s because there isn’t a single test or biomarker that can give us a clear “yes” or “no” answer. Let’s break that down.

 

Imagine genetic testing. For some conditions, like sickle cell anemia, a simple test can confirm the diagnosis. According to the National Institutes of Health, sickle cell anemia is a blood disorder where red blood cells become rigid and shaped like sickles, causing pain and potential damage to organs (Check out more about sickle cell here). This disorder happens because of a mutation in one specific gene, so doctors can run a targeted genetic test to see if that mutation is there.

 

Now, what about biomarkers? Biomarkers are measurable signs in the body that give us clues about our health. Think of things like blood pressure, body temperature, pulse, or heart rate—these are examples of physiological biomarkers. There are also molecular biomarkers, like red blood cell counts or hormone levels. Take type 2 diabetes, for instance. It’s often diagnosed by measuring blood sugar levels, which is a clear, measurable indicator (Learn about how to diagnose type 2 diabetes here).

 

But with FND, it’s different. There isn’t a specific test result or biomarker that tells doctors if someone does or doesn’t have FND. Without a clear physical indicator, doctors have to consider lots of different factors. This is where things can get complicated, and sometimes mistakes happen.

 

What Are the DSM-5 and ICD-11, and Why Do They Matter in Diagnosing FND?

 

You may have heard of the DSM-5 or the ICD-11 when talking about medical or mental health diagnoses, but what exactly are these manuals, and why are they so important in diagnosing conditions like FND?

 

Let’s start with the DSM-5. The DSM-5 stands for the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. It’s basically the “bible” for mental health professionals in the United States and is published by the American Psychiatric Association. It covers everything from anxiety disorders to depression to FND. Think of it as a checklist that doctors use to figure out what condition a patient might have.

 

(If you want to dive into some medical jargon, you can check out the DSM online here. Note: this website is for educational purposes only, always consult a qualified doctor if you need medical advice or support.)

 

The ICD-11, on the other hand, stands for the International Classification of Diseases, 11th Revision, and it was created by the World Health Organization (WHO). Unlike the DSM-5, the ICD-11 is used all over the world and covers not only mental health disorders but also all kinds of medical conditions. It helps make sure that diseases and disorders are diagnosed in a standard way, no matter where you are. See ICD-11 for FND here

 

When doctors need to diagnose something tricky like FND, they turn to the DSM-5 or ICD-11. These manuals provide clear guidelines on what symptoms need to be present for a diagnosis. For example, if a patient shows signs like sudden muscle weakness or tremors, the doctor will check the DSM-5 or ICD-11 to see if the patient’s symptoms match the criteria for FND.

 

(If you’re interested in learning more about the criteria for FND from both manuals, take a look at this study here. For a quick and clear overview, head straight to Table 1.)

 

However, the DSM-5 and ICD-11 also have some downsides. The criteria in these manuals can be quite strict, and not everyone’s symptoms fit neatly into these categories, they also don’t always account for how cultural or background differences can influence how symptoms show up. For example, certain people express emotional distress through physical symptoms, like stomach pain or headaches, rather than describing feelings of anxiety or sadness. Additionally, labels can also oversimplify complex disorders. For instance, even though FND is a real disorder with physical symptoms, some people might wrongly think it’s “all in someone’s head.”

 

Common Tests for Diagnosing Functional Neurological Disorders

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Diagnosing FND involves specific tests that look for signs of a functional issue rather than a structural problem, like damage to nerves or muscles. Let’s explore some common tests doctors use and what they mean.

 

One of the most common tests is called Hoover’s Sign. This test is used to assess leg weakness. If someone says they can’t lift one of their legs, the doctor might ask them to press down with their other leg, as if stepping on a gas pedal. Normally, pressing down with one leg causes the other leg to lift automatically because of how our muscles work together. However, in someone with FND, the leg might not lift when asked to move intentionally, but it might still lift when the person is distracted by pressing down with the other leg. This inconsistency is a key feature of FND.

 

Another helpful test is for give-way weakness. In this test, the doctor applies steady resistance to the patient’s arm or leg and asks them to push or hold their strength. In someone with FND, the muscle might feel strong at first but then suddenly “give way” or weaken without warning. This weakness often comes and goes quickly. In contrast, weakness caused by a neurological condition like a stroke would stay consistent throughout the test.

 

There are many other possible tests depending on the patient’s symptoms, such as the Romberg test, Gait testing, etc. These tests are important because they help doctors identify positive signs of FND rather than just ruling out other conditions. This approach allows for a confident diagnosis and avoids unnecessary tests or treatments. 

 

It’s worth noting that FND is a real and treatable condition, even though it doesn’t have a structural cause like a damaged nerve or muscle. If you’re going through these tests, it’s natural to feel unsure or even nervous, but understanding what the doctor is looking for can make the process clearer. The goal is to understand your symptoms better and start the journey toward effective treatment.


 

References

more coming soon

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