Prevalence and Association of Generalized Joint Hypermobility in Children with Functional Neurological Disorder: A Retrospective Study

Aims: Functional neurological disorder (FND) etiology is multifactorial. This study aimed to examine: (1) generalized joint hypermobility (GJH) prevalence in children diagnosed with FND and (2) the association between GJH and FND severity, activity level, and participation. Methods: Participated in this study 53 children with FND (mean age 14.2 ± 2.7 years; 73.6% female). GJH was assessed using the Beighton score. FND severity was evaluated with the 24-item Children’s Somatic Symptoms Inventory (CSSI-24), number of limbs affected, and pain following the six-minute walk test (6MWT). Results: GJH was identified in 43% (Beighton ≥4) and 24% (Beighton ≥6) of participants. Elbow hyperextension was the most common feature (56.6%). The total Beighton score was independently associated with CSSI-24 (R²=.25, p<.01) and with the number of limbs involved (R²=.15, p<.01). A positive association was observed between Beighton score and pain post-6MWT. Conclusion: Regardless of the Beighton cutoff used, GJH prevalence remained high, with at least 1 in 4 participants presenting GJH even at the strictest threshold (≥6). GJH was associated with increased CSSI-24 and motor involvement. These findings suggest that GJH may represent a somatic vulnerability factor within the biopsychosocial model of FND. Routine assessment could help identify meaningful subgroups and guide individualized treatment.