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Updated: Jun 17, 2026

Induction and Assessment of Levodopa-induced Dyskinesias in a Rat Model of Parkinson's Disease
Published on: October 14, 2021
Hyperhomocysteinemia recurrence in levodopa-treated Parkinson's disease patients
V Belcastro1, L Pierguidi, A Castrioto
1Neurology Clinic, University of Perugia, S. Maria della Misericordia Hospital, Perugia, Italy. vincenzobelcastro@libero.it
Background:
Patients with Parkinson's disease (PD) and chronically treated with L-DOPA exhibit, in a percentage of 10-30%, supra-physiological levels of plasma total homocysteinemia (tHcy). In this study, we have investigated, in a group of hyper-homocysteinemic PD patients, the time of hyper-tHcy recurrence after discontinuation of 1-month folate supplementation given to normalize plasma tHcy levels.
Methods:
Plasma tHcy, cobalamin and folate were assayed before and after 1-month folate supplementation (5 mg/day), and after 2 and 4 months after folate discontinuation in 29 PD patients (16M/13F, mean age 69.4 +/- 6.9 years) stabilized on a mean L-DOPA dose of 509.4 +/- 312.1 mg/day.
Results:
After folate supplementation, plasma tHcy levels fell within the normal range in all patients. At the 2-month control after folate discontinuation, plasma tHcy remained within physiological values in 25 out of 29 patients. Conversely, 4 months after folate discontinuation, all patients exhibited hyper-tHcy.
Conclusions:
One-month intake of 5 mg/day folate normalizes plasma tHcy levels in all hyper-homocysteinemic PD patients. Following folate discontinuation, hyper-tHcy recurs in all patients within 4 months. Knowledge of this time interval is useful to optimize pulses of folate therapy in hyper-homocysteinemic patients with PD.
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