L-dopa responsiveness in early Parkinson's disease is associated with the rate of motor progression

Malek, N. et al. (2019) L-dopa responsiveness in early Parkinson's disease is associated with the rate of motor progression. Parkinsonism and Related Disorders, 65, pp. 55-61. (doi: 10.1016/j.parkreldis.2019.05.022) (PMID:31105012)

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Abstract

BACKGROUND: L-dopa responsiveness in Parkinson's disease (PD) varies, but the clinical correlates and significance of this are ill-defined. METHODS: Patients were assessed before and after their usual morning L-dopa dose, using the MDS Unified PD Rating Scale Part 3 (MDS UPDRS 3), and rated as definite responders (≥24.5% improvement) or limited responders (<24.5%). RESULTS: 1007 cases, mean age 66.1 years (SD 9.1) at diagnosis, were assessed 3.4 (SD 0.9) years after diagnosis. The L-dopa response was definite in 614 cases (61.0%), median reduction in MDS UPDRS 3 scores was 42.0%, (IQR 33.3, 53.1), and was limited in 393 cases (39.0%), median reduction in MDS UPDRS 3 scores 11.5% (IQR 4.3, 18.2). Definite responders were younger (66.3 years at study entry, SD 9.3) than limited responders (69.2 years, SD 8.4, p < 0.001). The MDS UPDRS 3 score at study entry in definite responders (21.0, SD 10.5) was significantly lower than in limited responders (24.7, SD 13.4, p < 0.001). The MDS UPDRS 3 increase over 18 months was less in definite responders at 3.0 (SD 10.4), compared to limited responders (6.4, SD 11.0, p < 0.001). The levodopa equivalent daily dose (LEDD) was not significantly different at study entry (definite responders 317 mg, SD 199, vs limited responders 305 mg, SD 191, p = 0.53). However, LEDD was significantly higher at the time of the L-dopa challenge test in definite responders (541 mg, SD 293) compared to limited responders (485 mg, SD 215, p = 0.01). Responsiveness to L-dopa was unaffected by the challenge test dose (p = 0.54). CONCLUSIONS: The main determinants of variation in the L-dopa response in early PD are age and motor severity. A limited L-dopa response is associated with faster motor progression.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Grosset, Dr Donald and Pitz, Vanessa and Grosset, Dr Katherine
Authors: Malek, N., Kanavou, S., Lawton, M. A., Pitz, V., Grosset, K. A., Bajaj, N., Baker, R. A., Ben-Shlomo, Y., Burn, D. J., Foltynie, T., Hardy, J., Williams, N. M., Wood, N., Morris, H. R., and Grosset, D. G.
College/School:College of Medical Veterinary and Life Sciences > Institute of Neuroscience and Psychology
College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
Journal Name:Parkinsonism and Related Disorders
Publisher:Elsevier
ISSN:1353-8020
ISSN (Online):1873-5126
Published Online:14 May 2019
Copyright Holders:Copyright © 2019 Elsevier
First Published:First published in Parkinsonism and Related Disorders 65:55-61
Publisher Policy:Reproduced in accordance with the copyright policy of the publisher

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