Clinical Evaluation of HRV Biofeedback in Functional Neurological Disorders Compared to Placebo

Although Functional Neurological Disorders (FND) represent one of the most common reasons for consultation in Neurology, the pathological mechanisms remain unexplained. Recent studies suggest disrupted emotional processes in patients with FND and disturbed autonomic nervous system profiles, highligting the hypothesis of autonomic endophenotypes among the FND population.

The Heart Rate Variability Biofeedback (HRV-BFB) is an innovative and non-invasive approach, based on the self-regulation of autonomic physiological processes. It has shown promising results in clinical and non-clinical populations but has never been assessed in an adult FND population.

Therefore, this approach appears particularly promising for understanding the mechanisms underlying FND and developing personalized therapy.

The main objective is to investigate the clinical effects of HRV-BFB on FND patients compared to placebo in a single-blind crossover design.

The investigators predict that depending on their autonomic profile, patients will respond to HRV-BFB to varying degrees.

Firstly, patients with FND will prospectively undergo an comprehensive clinical evaluation considering symptoms, functional capacity, quality of life, and an assessment of the physical and psychological comorbidities. Then patients will complete an emotional task and undergo multimodal autonomic measures. Cluster analyses will be conducted to identify both dysfunctional and functional autonomic profiles associated with the clinical exploration, enabling confirmation of the endophenotypes hypothesis and allowing for specific characterization of the profils. The clinical evaluation of the beneficial effects of HRV BFB will rely on repeated mesures of symptoms, functional capacity, and quality of life at scheduled points in time before and after the both interventions (HRV-BFB and pseudo-BFB). The emotional task and autonomic measures will be repeated simultaneously.