SHORT COMMUNICATION Urinary profile of catecholamines and metabolites in Parkinson patients with deep brain stimulation J. Guimar ~ aes a,b,d , M. A. Vieira-Coelho c,d , E. Moura c,d , J. Afonso c , M. J. Rosas a , R. Vaz b,e and C. Garrett a,b,d a Neurology Department, Hospital de S~ ao Jo~ ao, Porto; b Neurology and Neurosurgery Unit of Clinical Neurosciences and Mental Health Department, Faculty of Medicine, University of Porto, Porto; c Department of Pharmacology and Therapeutics, Faculty of Medicine, Uni- versity of Porto, Porto; d Institute for Molecular and Cell Biology, University of Porto, Porto; and e Department of Neurosurgery, Hospital de S~ ao Jo~ ao, Porto, Portugal Keywords: catecholamines, deep brain stimulation, levodopa, Parkinson’s disease, subthalamic nucleus Received 2 November 2012 Accepted 28 February 2013 Background and purpose: Deep brain stimulation of the subthalamic nucleus (DBS- STN) is thought to continuously alter the activity of STN neurons in Parkinson’s disease (PD). A chronic decrease in the levodopa dose with continuous STN stimu- lation may induce plastic neuronal changes. Objective: The objective of this work was to study urinary excretion of catecholam- ines in patients with PD before and after DBS-STN. Methods: Twenty-three patients were submitted to DBS-STN, and evaluated before and after surgery with respect to catecholamines and metabolites in 24-h urine mea- sured by high-performance liquid chromatography with electrochemical detection. Results: Of the 23 patients evaluated, a significant decrease of about 60% in the urinary excretion of L-3,4-dihydroxyphenylalanine (L-DOPA; in nmol/mg creatinine/ 24 h) was observed 1 week after DBS-STN. Moreover, in 17 patients with a follow- up of 8 weeks after surgery, there was a further 50% decrease in urinary L-DOPA levels, dropping to about 75% of the values before surgery. There was also a signifi- cant decrease in dopamine (DA) and 3,4-dihydroxyphenylacetic acid (DOPAC) lev- els 1 week after DBS-STN that was no longer present 8 weeks after. A significant increase in the DA/L-DOPA ratio was observed 1 week after surgery, with a further increase 8 weeks after surgery. Conclusion: After DBS-STN, the DA/L-DOPA ratio, an indirect measure of DA synthesis, increased. These results show that DBS-STN may improve the efficacy of oral levodopa. Introduction The management of Parkinson’s disease (PD) is mainly pharmacological with levodopa, a precursor of dopamine (DA) and the other catecholamines. The concept of continuous dopaminergic stimulation is important in therapeutic strategies, and pulsatile administration of levodopa has been suggested to be mainly responsible for the development of motor fluc- tuations [1]. In recent years, surgery has been revital- ized for the treatment of patients with uncontrollable motor complications [2]. Deep brain stimulation (DBS) allowed a marked improvement in motor func- tion with a large reduction of levodopa intake. DBS of the subthalamic nucleus (STN) is thought to con- tinuously alter the activity of STN neurones in PD, whereas oral levodopa therapy has a pulsatile effect. Moro and colleagues [3] found that the persistence of pulsatile oral intake of levodopa after implantation might interfere with the beneficial effects of continu- ous STN stimulation. It seems that both the chronic decrease in the levodopa dose and the continuous STN stimulation can induce plastic neuronal changes that lead to improvement in levodopa-induced dyski- nesias. STN stimulation may induce a long-term mod- ification in the dopaminergic system. In the present study we evaluated urinary levels of L-3,4-dihydroxyphenylalanine (L-DOPA), of the cate- cholamines noradrenaline and DA, and of the cate- cholamine metabolites 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), 3-methoxytyramine (3-MT), from patients with PD receiving L-DOPA before Correspondence: Joana Guimar~ aes, Neurology Department, Faculty of Medicine, University of Porto, Hospital de S~ ao Jo~ ao, Alameda Professor Hern^ ani Monteiro, 4200 Porto, Portugal (tel./fax: 225511200; e-mail: jguimraes9@hotmail.com). © 2013 The Author(s) European Journal of Neurology © 2013 EFNS 1 European Journal of Neurology 2013 doi:10.1111/ene.12161