title: Relationship between movement disorders and obsessive-compulsive disorder: beyond the obsessive-compulsive-tic phenotype. A systematic review.
abstract: BACKGROUND
  Obsessive-compulsive disorder (OCD) and symptoms (OC symptoms) are associated with tic disorders and share an aetiological relationship. The extent to which OCD/OC symptoms are correlated with other hyperkinetic movement disorders is unclear. The aim of this review was to investigate this co-occurrence and the extent to which OCD/OC symptoms and hyperkinetic movement disorders share a neurobiological basis.
  
  
  METHODS
  A systematic review was performed, specifically searching for OCD/OC symptom comorbidity in hyperkinetic movement disorders using case control studies, longitudinal studies and family based studies. The literature search was conducted using PubMed and PsycINFO databases.
  
  
  RESULTS
  Heterogeneity of measurement instruments to detect OCD diagnosis and OC symptoms decreased comparability between studies. The most convincing evidence for a relationship was found between the choreas (Huntington's disease and Sydenham's chorea) and OCD/OC symptoms. Furthermore, elevated frequencies of OC symptoms were found in small case control series of dystonias. Small family based studies in dystonia subtypes modestly suggest shared familial/genetic relationships between OC symptoms and dystonia.
  
  
  CONCLUSIONS
  Current data indicate a relationship between OCD/OC symptoms and the choreas. As OCD and the choreas have been associated with dysfunctional frontal-striatal circuits, the observed relationships might converge at the level of dysfunctions of these circuits. However, paucity of longitudinal and family studies hampers strong conclusions on the nature of the relationship.
  
  
  CONCLUSIONS
  The relationship between OCD and movement disorders needs further elaboration using larger family based longitudinal studies and sound instruments to characterise OC symptomatology. This could lead to better understanding of the shared pathology between OCD and hyperkinetic movement disorders.
authors.affiliation: Department of Psychiatry, VU Medical Centre and GGZinGeest, AJ Ernststraat 1187, Amsterdam 1081HL, The Netherlands.
authors.forename: Lieneke A
authors.initials: LA
authors.lastname: Fibbe
authors.forename: Danielle C
authors.initials: DC
authors.lastname: Cath
authors.forename: Odile A
authors.initials: OA
authors.lastname: van den Heuvel
authors.forename: Dick J
authors.initials: DJ
authors.lastname: Veltman
authors.forename: Marina A J
authors.initials: MA
authors.lastname: Tijssen
authors.forename: Anton J L M
authors.initials: AJ
authors.lastname: van Balkom
mesh_terms: D002819:Chorea / Q000453:epidemiology*; D015897:Comorbidity; D006801:Humans; D009069:Movement Disorders / Q000175:diagnosis / Q000453:epidemiology*; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis / Q000453:epidemiology*; D013981:Tic Disorders / Q000175:diagnosis / Q000453:epidemiology*