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Updated: Jul 18, 2026

Rating L-DOPA-Induced Dyskinesias in the Unilaterally 6-OHDA-Lesioned Rat Model of Parkinson's Disease
Published on: October 4, 2021
Dihydropteridine reductase deficiency: levodopa's long-term effectiveness without dyskinesia
1Fédération des maladies du système nerveux, Groupe Hospitalier Pitié-Salpêtrière, 47 Boulevard de l'Hôpital, 75651 Paris cedex 13, France. frederic.sedel@psl.ap-hop-paris.fr
Abstract:
We report an adult patient lacking endogenous synthesis of monoamines (dopamine, serotonin, and catecholamines) due to a severe dihydropteridine reductase (DHPR) deficiency. With levodopa and 5-hydroxytryptophan (5HTP) supplementation, the patient exhibited moderate mental retardation, acute episodes of parkinsonism, and episodes of depression. Despite the use of levodopa from age 3 months, he exhibited no dyskinesia or dopaminergic cell loss as suggested by normal PET imaging of the dopamine transporter.
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