title: Factors predicting protracted improvement after pallidal DBS for primary dystonia: the role of age and disease duration.
abstract: In many patients, optimal results after pallidal deep brain stimulation (DBS) for primary dystonia may appear over several months, possibly beyond 1 year after implant. In order to elucidate the factors predicting such protracted clinical effect, we retrospectively reviewed the clinical records of 44 patients with primary dystonia and bilateral pallidal DBS implants. Patients with fixed skeletal deformities, as well as those with a history of prior ablative procedures, were excluded. The Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) scores at baseline, 1 and 3 years after DBS were used to evaluate clinical outcome. All subjects showed a significant improvement after DBS implants (mean BFMDRS improvement of 74.9% at 1 year and 82.6% at 3 years). Disease duration (DD, median 15 years, range 2-42) and age at surgery (AS, median 31 years, range 10-59) showed a significant negative correlation with DBS outcome at 1 and 3 years. A partition analysis, using DD and AS, clustered subjects into three groups: (1) younger subjects with shorter DD (n = 19, AS < 27, DD ≤ 17); (2) older subjects with shorter DD (n = 8, DD ≤ 17, AS ≥ 27); (3) older subjects with longer DD (n = 17, DD > 17, AS ≥ 27). Younger patients with short DD benefitted more and faster than older patients, who however continued to improve 10% on average 1 year after DBS implants. Our data suggest that subjects with short DD may expect to achieve a better general outcome than those with longer DD and that AS may influence the time necessary to achieve maximal clinical response.
authors.affiliation: Department of Neurology, Mount Sinai School of Medicine, New York, NY, USA. ioannis.isaias@unimi.it
authors.forename: Ioannis U
authors.initials: IU
authors.lastname: Isaias
authors.forename: Jens
authors.initials: J
authors.lastname: Volkmann
authors.forename: Andreas
authors.initials: A
authors.lastname: Kupsch
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Burgunder
authors.forename: Jill L
authors.initials: JL
authors.lastname: Ostrem
authors.forename: Ron L
authors.initials: RL
authors.lastname: Alterman
authors.forename: Hubertus Maximilian
authors.initials: HM
authors.lastname: Mehdorn
authors.forename: Thomas
authors.initials: T
authors.lastname: Schönecker
authors.forename: Joachim K
authors.initials: JK
authors.lastname: Krauss
authors.forename: Philip
authors.initials: P
authors.lastname: Starr
authors.forename: Rene
authors.initials: R
authors.lastname: Reese
authors.forename: Andrea A
authors.initials: AA
authors.lastname: Kühn
authors.forename: W M Michael
authors.initials: WM
authors.lastname: Schüpbach
authors.forename: Michele
authors.initials: M
authors.lastname: Tagliati
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D046690:Deep Brain Stimulation; D020821:Dystonic Disorders / Q000628:therapy*; D005260:Female; D005917:Globus Pallidus / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D020127:Recovery of Function; D012189:Retrospective Studies; D012720:Severity of Illness Index; D016896:Treatment Outcome; D055815:Young Adult