Revising a diagnosis of functional neurological disorder—a case report

We report a case of a 62-year-old female diagnosed with functional neurological disorder (FND), where the diagnosis was eventually revised to progressive supranuclear palsy 3 years after symptom onset. FND is a commonly encountered condition and can be diagnosed with a considerable degree of confidence in most cases. FND is associated with significant functional impairment and may occur alongside other neurological disorders, and there is now a growing evidence base for symptom-specific FND treatments. Charting clinical progression of symptoms and serial neuroimaging were useful in refining the diagnosis in this case. Alhough the diagnosis was ultimately revised to a neurodegenerative disorder, a degree of functional overlay likely remained present. The case highlights the importance of recognizing and avoiding diagnostic overshadowing in those with FND.