Dystonia and Dopaminergic Therapy: Rationale Derived from Pediatric Neurotransmitter Diseases

The paucity of literature in pediatric neurotransmitter diseases indicates a gap in our understanding of neurochemistry and the clinical phenomenology. However, the dramatic clinical responses to dopaminergic therapy in dopa-responsive dystonias opened avenues for rationalizing this therapeutic approach in other pediatric neurotransmitter disorders. This chapter aims to link up dopaminergic therapy, dystonia and other pediatric neurotransmitter diseases. It was in 1971 that Segawa (Segawa et al., 1971, 1976) reported patients with child-onset periodic dystonia, whose dystonia had diurnal variation, with towards evening being worse with walking. The symptom was recovered in the morning. Unlike other dystonic disorders, levodopa was effective to alleviate involuntary movements in those patients. (Tarsy et al., 2006) This disease was later named as Dopa responsive dystonia (DRD), DYT-5, or Segawa disease. (Nygaard et al., 1988)