Session Information
Date: Tuesday, June 21, 2016
Session Title: Drug-induced movement disorders
Session Time: 12:30pm-2:00pm
Location: Exhibit Hall located in Hall B, Level 2
Objective: To provide a critical review of the existing literature on valproate-associated parkinsonism and to discuss possible mechanisms.
Background: Valproate was first approved as an antiepileptic drug in 1962 and has since also become established as a mood stabiliser and as prophylaxis for migraine. In 1979, Lautin published the first description of a valproate-associated extrapyramidal syndrome. Many cases of valproate-associated parkinsonism have subsequently been published, but uncertainties remain concerning its prevalence, risk factors and prognosis.
Methods: Medline/PubMed was searched systematically. The quality of the evidence was assessed and probability of causation was examined using the Naranjo score (≥ 9 = definite adverse drug reaction, 5-8 = probable, 1-4 = possible, 0 = doubtful).
Results: We identified a total of 109 patients with valproate-associated parkinsonism published in case reports, case series and systematic analyses. Prevalence rates ranged widely, between 1.4% and 75% of patients on valproate. There was great heterogeneity with regard to clinical presentation, age of onset, valproate dose, concomitant conditions and imaging findings. In all patients apart from two, valproate plasma levels were within the recommended reference range when the parkinsonism occurred. Parkinsonism was reversible in the majority of patients, although recovery was often prolonged and sometimes incomplete. A dopaminergic deficit was confirmed in two of four patients investigated with dopamine transporter imaging. Five of 13 patients who were treated with dopaminergic medication had a good response. The Naranjo score ranged from 0 to 7 (median: 5.0).
Conclusions: The features of valproate-associated parkinsonism are heterogeneous, and not yet well established. Several pathophysiological mechanisms could theoretically lead to valproate-associated parkinsonism. Further studies are warranted to elucidate this entity and its underlying pathophysiology.
To cite this abstract in AMA style:
F. Brugger, K.P. Bhatia, F.M.C. Besag. Valproate-associated parkinsonism – A critical review of the literature [abstract]. Mov Disord. 2016; 31 (suppl 2). https://www.mdsabstracts.org/abstract/valproate-associated-parkinsonism-a-critical-review-of-the-literature/. Accessed May 13, 2025.« Back to 2016 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/valproate-associated-parkinsonism-a-critical-review-of-the-literature/