title: Effect of tetrabenazine on motor function in patients with huntington disease.
abstract: BACKGROUND
  Tetrabenazine (TBZ) reduces chorea related to Huntington disease (HD); however, it is uncertain whether this effect improves functionally relevant motor skills such as hand coordination and balance. The objective of this study was to provide pilot data regarding three motor function tests, which might be useful in monitoring symptom progression and therapeutic response, pending formal validation.
  
  
  METHODS
  The authors assessed 11 ambulatory patients with HD-related chorea on two occasions: (1) while off TBZ (either prior to starting therapy or following a >24 h washout) and (2) when on a stable dose of TBZ, titrated to optimal effect. Study evaluations included the Jebsen-Taylor Hand Function Test (JTHFT) and Berg Balance Scale, a timed 25-foot walk, the Montreal Cognitive Assessment (MoCA) and the complete United Huntington Disease Rating Scale (UHDRS).
  
  
  RESULTS
  Maximal chorea scores (UHDRS item 12) improved from 11.1 ± 2.9 to 8.5 ± 3.9 while on TBZ (P = 0.03), but we could not detect an improvement in functional measures while on TBZ in this small cohort. Scores of the JTHFT were globally slower than published normative data and correlated with MoCA summary scores, but not UHDRS chorea scores.
  
  
  CONCLUSIONS
  This pilot study did not detect significant functional gains with chorea suppression. The fact that performance on tests of hand function correlates with MoCA but not UHDRS chorea scores highlights the need for additional treatments targeted toward the cognitive aspects of HD.
authors.affiliation: Movement Disorder Clinic, Virginia Tech Carilion School of Medicine and Research Institute, Roanoke, VA USA.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Ferrara
authors.affiliation: Department of Neurology, Parkinson Disease Center and Movement Disorders Clinic, Baylor College of Medicine, Houston, TX USA.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Mostile
authors.affiliation: Department of Neurology, Parkinson Disease Center and Movement Disorders Clinic, Baylor College of Medicine, Houston, TX USA.
authors.forename: Christine
authors.initials: C
authors.lastname: Hunter
authors.affiliation: Division of Neurology, Naval Medical Center, Portsmouth, VI USA.
authors.forename: Octavian R
authors.initials: OR
authors.lastname: Adam
authors.affiliation: Department of Neurology, Parkinson Disease Center and Movement Disorders Clinic, Baylor College of Medicine, Houston, TX USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Jankovic
keywords: Berg Balance Scale; Chorea; Huntington disease; Jebsen-Taylor Hand Function Test; Tetrabenazine