Functional Motor Disorders in childhood and adolescence: clinical correlates of an emerging diagnostic challenge.

Background: Functional Neurological Disorders (FNDs) represent an emerging challenge also in childhood and adolescence neuropsychiatry. Clinical presentations of these cases are still vaguely characterized and often misdiagnosed in pediatric population. Even if, it represents a very common disorder in the clinical practice, till up the 5% of patients referred in neurological services, there are not yet common and defied diagnostic work up as well as therapeutic strategies mostly for pediatric neurology, causing important delay in early diagnosis and treatments with possible negative outcome and illness chronicization, causing severe disability on patient quality of life. This retrospective study was aimed to better-characterized Funtional Motor Disorders (FMDs) in a pediatric population: 1) describing FMDs clinical manifestations 2) analyzing clinical and demographic variables (i.e. cognitive and psychiatric profiles; life events) 3) analyzing short-term outcome in a subset of patients during the two pandemic years of follow up. Methods: 35 FMDs children and adolescents were selected (30F: 5M; age range: 9-18 years old), referred as neurological inpatients of the urban academic neuropsychiatric department of Rome Umberto I Hospital, during a timeframe of 5 years. For each patient, FMDs diagnosis was obtained (DSM-5 criteria) by a neurological diagnostic workout. As well, an extensive neurocognitive and neuropsychological evaluation was performed (Weschler Intelligence Scale for Children- WISC IV; Adolescent Dissociative experience Scale A-DES); Somatoform Dissociation Questionnaire SDQ-20); Children’s Depression Inventory CDI-2; Multidimensional Anxiety Scale for Children MASC 2). 15 out 35 of the described patients were enrolled during the last 2 years of pandemic (2019-2021) and were followed up with a multidisciplinary approach in psychotherapy and physiotherapy. Results: 1) epidemiological results highlighted FMDs mean age onset of 11,8 years with a prevalence in females (F:M=5:1). Clinical motor symptoms were characterized by hyperkinetic manifestations (60%) with a prevalence of combined pattern with other FNDs, as: PNES (40%), sensitive disorders (45%); weakness (30%) and generalized pain (65%). Among the motor manifestations the most expressed was a Gait Disorder (50%), Tremor (28%); Dystonia (22%) and Myoclonus/jerks (11%); Tic (5,5%) and Parkinson manifestations (2,8%) 2) Neurocognitive evaluation highlighted a heterogeneous profile between verbal ability (Verbal Comprehension Index- ICV) higher than the perceptual reasoning (Perceptual reasoning Index- IRP) in the 44% of cases. The Psychopathological evaluation underlined a higher prevalence of Anxiety (MASC2) and Mood Disorders (CDI2) than Dissociative/ Somatoform symptoms (A-DES; DSQ20). Traumatic Life Events and history of family illness were reported in the 65% and 85% of cases, respectively. 3) The early diagnosis and treatment with a multidisciplinary approach was related with a positive outcome in the 80% of patients. Conclusions: Hyperkinetic movements, presenting in combined pattern with further comorbid FNDs, were mainly reported in the pediatric population, showing higher prevalence of heterogeneous neurocognitive profiles associated with anxious/depressive symptoms. Traumatic Life events and a family history of illness seem to represent risk factors in the FMDs onset. An early diagnosis represents a clinical challenge to avoid a negative outcome.