Motor skills and neurological soft signs: Are they only clinical differences or reflection of distinct etiopathogenesis in tic disorder and primary stereotypic movement disorder?

Background

While tic disorders and stereotypic movement disorder are commonly comorbid in pediatric clinics, their clinical and etiological differences remain poorly understood.

Objectives

We aimed to investigate the clinical features that differentiate between tic disorders and primary stereotypic movement disorder by evaluating neurological soft signs and motor skills.

Methods

The Kiddie-Schedule for Affective Disorders and Schizophrenia for School Age Children-Present and Lifetime Version DSM-5 and Sociodemographic and Clinical Data Form were administered to the children. The clinician completed Yale Global Tic Severity Scale, Repetitive Behavior Scale-Revised and Neurological Evaluation Scale. Nine-Hole Peg Test was used for fine motor skills, 1-Minute Sit-to-Stand Test for gross motor skills, Flamingo Balance Test for static balance, Finger-to-Nose Test for bilateral coordination. Parents completed the Conners Parent Rating Scale-Revised Short Form and the Revised Developmental Coordination Disorder Questionnaire.

Results

Our sample consisted of 20 tic disorders, 20 primary stereotypic movement disorder, 13 attention deficit hyperactivity disorder patients, and 20 healthy controls. Sequencing of the complex motor acts scores of Neurological Evaluation Scale were significantly higher in the primary stereotypy group than in healthy controls. The primary stereotypy group demonstrated significantly lower dominant hand performance on the Nine-Hole Peg Test than the tic group. Children with stereotypy had significantly lower scores of 1-min sit-to-stand test; higher total and subscale scores of Revised Developmental Coordination Disorder Questionnaire. and higher developmental coordination disorder risk than healthy controls.

Conclusions

Our findings offer valuable insights into the distinct etiopathogenesis of tic disorders and primary stereotypic movement disorder, providing a foundation for future neurobiological research.