Investigating mechanisms & monitoring outcomes in functional neurological disorder: The unrealised potential of digital remote monitoring technologies

Functional neurological disorder (FND) is characterised by involuntary, distressing neurological symptoms that are distinguishable from other neurological diagnoses in presentation, aetiology and mechanisms. Significant disability, impaired quality-of-life, and substantial healthcare resource utilisation often results from the disorder, yet its underlying mechanisms have not been proven empirically. Importantly, long-term clinical trajectories and predictive markers have been understudied in FND cohorts. Inadequate funding of large-scale mechanistic and longitudinal research, methodological limitations, and the absence of standardised outcome measures, necessitate development of innovative solutions. Digital remote monitoring technologies (dRMTs), which have been shown to be valuable across a range of other neurological and psychiatric disorders, may have unparalleled potential to address these research challenges in FND, yet this potential is currently unrealised. We propose that dRMTs could be harnessed to monitor subjective and/or objective functional neurological and associated symptoms, mechanistic variables, and important outcome domains, with excellent temporal precision, flexibility, and external validity. These methods could allow precise characterisation of both short- and long-term fluctuations in FND symptoms, the influences on them, and their impact on patients. Such data would strengthen mechanistic models, improve outcome prediction, and facilitate personalised FND clinical management in this underserved population.