Abstract: Objective To investigate the incidence and structure of mental disability in children with movement disorders. Methods 157 children with movement disorders (103 with cerebral palsy and 54 with mental retardation) were assessed with Gesell developmental schedules,and mental disability was identified as development quotient (DQ)<75. Results The incidence of intelligence disability was 92.2% in children with cerebral palsy, including 91.2% in spastic type, and 100% in dyskinetic, mixed or dystonic type. The development of gross motor was retarded in children with spastic cerebral palsy, and gross and fine motor in children with dyskinetic cerebral palsy, compared with those with mental retardation. Conclusion It is important to focus the mental development in children with movement disorders, especially the dyskinetic cerebral palsy. Gesell developmental schedules should be used carefully to assess the mental development in children with movement disorder.

Key words: movement disorder, development quotient, mental disability, cerebral palsy, children, Gesell developmental schedules