Pediatric parkinsonism: clinical review and a proposed clinical algorithm.

Pediatric parkinsonism (PP) is a rare but disabling movement disorder characterized by bradykinesia and rigidity, with tremor being less frequent. Additional features include gait disturbances and impaired postural reflexes. In younger children, hypotonia is often a predominant sign. Clinical expression evolves with neurodevelopment and is frequently associated with other movement abnormalities, such as dystonia. The condition may arise from a variety of pathophysiological mechanisms and multiple etiologies, with genetic causes being particularly prominent. A classification system has been proposed based on age of onset, clinical features, prognosis and etiology, comprising: Developmental parkinsonism, Infantile degenerative parkinsonism, Parkinsonism in the setting of postnatal neurodevelopmental disorders, Parkinsonism associated with multisystemic brain diseases, Juvenile parkinsonism and dystonia-parkinsonism and Acquired parkinsonism. A specific assessment tool-the Infantile Parkinsonism-Dystonia Rating Scale-has recently been developed and primarily validated to quantify severity, monitor disease progression and assess treatment response. This review aims to provide a comprehensive overview of the clinical features, pathophysiology, etiologies and treatment approaches of pediatric parkinsonism. In addition, we propose a diagnostic algorithm to support clinical decision-making.