[COMPLEX REGIONAL PAIN SYNDROME AND FUNCTIONAL NEUROLOGICAL DISORDER IN CHILDREN AND ADOLESCENTS: UNITY IN DIVERSITY].

Introduction: Functional neurological disorder (FND) and complex regional pain syndrome (CRPS) are disorders that affect quality of life. CRPS diagnosis is based on Budapest criteria that include various signs/symptoms. Despite the similarity in the etiology/pathophysiology of FND and CRPS, the joint prevalence of these two conditions in youth has not yet been reported. Given that both phenomena are less familiar among pediatric patients, it is crucial to thoroughly characterize them and establish a clear differential diagnosis. This, in turn, holds significant implications for guiding therapeutic interventions.

Objectives: We aimed to examine: 1) the clinical profile of children with FND; 2) the prevalence of CRPS among children with FND; and 3) differences in clinical characteristics and in Budapest's symptoms/signs between children with FND and those with a co-diagnosis of FND and CRPS.

Methods: Sixty-one children (mean age: 13.70+2.93 years; 75.4% females) diagnosed with FND were studied. Sample's demographic, clinical characteristics and the Budapest CRPS classification criteria were collected from medical files.

Results: Most children with FND reported sensory (67%) and motor (88%) symptoms. Forty-four percent had a co-diagnosis of FND and CRPS. Among these children, 100% reported sensory and motor/tropical, 74% vasomotor, and 65% sudomotor symptoms. The prevalence of Budapest symptoms, except for motor-function impairment, was significantly higher among children with a co-diagnosis compared to children with FND alone.

Conclusions: The high frequency of symptoms and clinical signs in children with co-incidence of CRPS and FND may indicate a shared developmental mechanism and is important for the development of appropriate rehabilitation interventions.