01/11/2026
If your MRI is “normal” but your body isn’t, FND might be the missing explanation.
Functional Neurological Disorder (FND) is a real brain based condition where movement, sensation, speech, gait, or seizure like episodes malfunction without structural damage on routine scans. It’s not “faking,” and it’s not “just anxiety.” In neurology clinics it’s a top reason for referral (often 5 to 10% of new visits).
What research supports:
• Network disruption linking emotion (amygdala), salience/interoception (insula, cingulate), and sensorimotor control.
• Predictive processing gets stuck, expectations override real time signals, symptoms become involuntary and “learned.”
• Impaired sense of agency, the brain mislabels actions as not self generated.
• Autonomic imbalance is common (high arousal, lower vagal tone/HRV), which can fuel dizziness, tremor, shutdown, and faintness.
• Brainstem involvement, altered limbic to brainstem pathways tied to threat and autonomic regulation.
Now the piece most people skip: the upper neck.
Upper cervical proprioceptors feed the brainstem. After whiplash, hypermobility, chronic neck tension, or vestibular issues, that input can become noisy. In some people it perpetuates FND patterns, and in others it mimics them, so it must be assessed.
Misdiagnosis and overlap matter. FND can be mistaken for, or coexist with, epilepsy, stroke/TIA, MS, vestibular migraine/BPPV, and POTS or other dysautonomia. A solid FND diagnosis is based on positive clinical signs (like Hoover’s sign, tremor entrainment), not just “tests are normal.”
Who gets it more? In adult clinics, women are diagnosed more often (often around 60 to 80%), likely due to a mix of biology, stress load, trauma exposure, and bias. Men and kids can get it too.
I’m a chiropractor and global complex case consultant. I support complex cases by addressing brainstem inputs, neck proprioception, vestibular and visual coordination, breathing, autonomic regulation, and movement retraining, alongside neurology, PT/OT, and therapy when needed.
Want the deep dive? My Movability Masterclass on Substack breaks it down. Link at the top of my page.
— Dr. Sina