title: Side-effects of subthalamic stimulation in Parkinson's disease: clinical evolution and predictive factors.
abstract: Chronic bilateral high-frequency stimulation of the subthalamic nucleus (STN) is an alternative treatment for disabling forms of Parkinson's disease when on-off fluctuations and levodopa-induced dyskinesias compromise patients' quality of life. The aim of this study was to assess the evolution of side-effects during the first year of follow-up and search for clinical predictive factors accounting for their occurrence. We compared the frequency of side-effects at 3 and 12 months after surgery in a cohort of 44 patients. The off-medication scores of Unified Parkinson's Disease Rating Scale (UPDRS) II, III, axial symptoms, disease duration and age at surgery were retained for correlation analysis. Dysarthria/hypophonia, weight gain and postural instability were the most frequent chronic side-effects. Whereas dysarthria/hypophonia remained stable over time, weight gain and postural instability increased during the first year post-op. High axial and UPDRS II scores at surgery were predictive of dysarthria/hypophonia. Age and axial score at surgery were positively correlated with postural instability. Despite the occurrence of side-effects, the benefit/side-effects ratio of STN stimulation was largely positive during the first year of follow-up. Age, intensity of axial symptoms and UDPRS II off-medication score before surgery are predictive factors of dysarthria/hypophonia and postural instability after surgery.
authors.affiliation: Service de Neurophysiologie Clinique, Hôpital Pellegrin, Place Amélie-Rabat Léon, Bordeaux, France. dominique.guehl@umr5543.u-bordeaux2.fr
authors.forename: D
authors.initials: D
authors.lastname: Guehl
authors.forename: E
authors.initials: E
authors.lastname: Cuny
authors.forename: A
authors.initials: A
authors.lastname: Benazzouz
authors.forename: A
authors.initials: A
authors.lastname: Rougier
authors.forename: F
authors.initials: F
authors.lastname: Tison
authors.forename: S
authors.initials: S
authors.lastname: Machado
authors.forename: D
authors.initials: D
authors.lastname: Grabot
authors.forename: C
authors.initials: C
authors.lastname: Gross
authors.forename: B
authors.initials: B
authors.lastname: Bioulac
authors.forename: P
authors.initials: P
authors.lastname: Burbaud
mesh_terms: D000368:Aged; D046690:Deep Brain Stimulation / Q000009:adverse effects*; D004401:Dysarthria / Q000209:etiology; D020820:Dyskinesias / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000601:surgery*; D012189:Retrospective Studies; D020531:Subthalamic Nucleus / Q000503:physiopathology* / Q000528:radiation effects*; D016896:Treatment Outcome