title: Neurobiological underpinnings of bipolar disorder focusing on findings of diffusion tensor imaging: a systematic review.
abstract: OBJECTIVE
  To review the available data on diffusion tensor imaging (DTI) of subjects with bipolar disorder (BD), with a particular focus on fractional anisotropy (FA) in white matter (WM) tracts.
  
  
  METHODS
  The PubMed/MEDLINE database was searched for relevant articles, which were included in a systematic review of the literature. FA reductions and WM abnormalities were divided anatomically into three groups: commissural tracts, association tracts, and projection tracts.
  
  
  RESULTS
  Eighteen studies met the inclusion criteria. The corpus callosum was the main impaired commissural tract as demonstrated by FA reductions. Five studies reported FA reductions in the cingulum. Two studies reported decreased FA in the anterior thalamic radiation, and one in the corticospinal tract. Conversely, three studies found increased FA values in WM tracts involved in BD pathophysiology.
  
  
  CONCLUSIONS
  Despite considerable heterogeneity, these results indicate a direct link between executive cognitive functioning and abnormal WM microstructural integrity of fronto-limbic tracts in patients with remitted BD, providing further evidence of the neuronal disruption that underlies BD symptomatology.
authors.affiliation: Laboratório de Psiquiatria Molecular, Instituto Nacional de Ciência e Tecnologia - Medicina Translacional (INCT-TM), Hospital de Clínicas de Porto Alegre (HCPA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto AlegreRS, Brazil, Laboratório de Psiquiatria Molecular, Instituto Nacional de Ciência e Tecnologia - Medicina Translacional (INCT-TM), Hospital de Clínicas de Porto Alegre (HCPA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.|Departamento de Radiologia e Ressonância Magnética, HCPA, Porto Alegre RS , Brazil, Departamento de Radiologia e Ressonância Magnética, HCPA, Porto Alegre, RS, Brazil.|Tomoclínica, Canoas RS , Brazil, Tomoclínica, Canoas, RS, Brazil.
authors.forename: Juliana A
authors.initials: JA
authors.lastname: Duarte
authors.affiliation: Tomoclínica, Canoas RS , Brazil, Tomoclínica, Canoas, RS, Brazil.
authors.forename: Jaisa Q
authors.initials: JQ
authors.lastname: de Araújo E Silva
authors.affiliation: Laboratório de Psiquiatria Molecular, Instituto Nacional de Ciência e Tecnologia - Medicina Translacional (INCT-TM), Hospital de Clínicas de Porto Alegre (HCPA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto AlegreRS, Brazil, Laboratório de Psiquiatria Molecular, Instituto Nacional de Ciência e Tecnologia - Medicina Translacional (INCT-TM), Hospital de Clínicas de Porto Alegre (HCPA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
authors.forename: André A
authors.initials: AA
authors.lastname: Goldani
authors.affiliation: Laboratório de Psiquiatria Molecular, Instituto Nacional de Ciência e Tecnologia - Medicina Translacional (INCT-TM), Hospital de Clínicas de Porto Alegre (HCPA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto AlegreRS, Brazil, Laboratório de Psiquiatria Molecular, Instituto Nacional de Ciência e Tecnologia - Medicina Translacional (INCT-TM), Hospital de Clínicas de Porto Alegre (HCPA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.|UFRGS, Universidade Federal do Rio Grande do Sul, Porto Alegre RS , Brazil, UFRGS, Porto Alegre, RS, Brazil.|Departamento de Psiquiatria, Universidade Federal do Paraná (UFPR), Universidade Federal do Paraná, Curitiba PR , Brazil, Departamento de Psiquiatria, Universidade Federal do Paraná (UFPR), Curitiba, PR, Brazil.
authors.forename: Raffael
authors.initials: R
authors.lastname: Massuda
authors.affiliation: Laboratório de Psiquiatria Molecular, Instituto Nacional de Ciência e Tecnologia - Medicina Translacional (INCT-TM), Hospital de Clínicas de Porto Alegre (HCPA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto AlegreRS, Brazil, Laboratório de Psiquiatria Molecular, Instituto Nacional de Ciência e Tecnologia - Medicina Translacional (INCT-TM), Hospital de Clínicas de Porto Alegre (HCPA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
authors.forename: Clarissa S
authors.initials: CS
authors.lastname: Gama
mesh_terms: D016880:Anisotropy; D001714:Bipolar Disorder / Q000000981:diagnostic imaging* / Q000503:physiopathology; D056324:Diffusion Tensor Imaging; D056344:Executive Function / Q000502:physiology; D006801:Humans; D009434:Neural Pathways / Q000503:physiopathology; D066127:White Matter / Q000000981:diagnostic imaging / Q000503:physiopathology