MRI diffusion tractography study in individuals with schizotypal features: a pilot study.
Diffusion tensor imaging (DTI) studies have identified changes in white matter tracts in schizophrenia patients and those at high risk of transition. Schizotypal samples represent a group on the schizophrenia continuum that share some aetiological risk factors but without the confounds of illness. The aim of the current study was to compare tract microstructural coherence as measured by fractional anisotropy (FA) between 12 psychometrically defined schizotypes and controls. We investigated bilaterally the uncinate and arcuate fasciculi (UF and AF) via a probabilistic tractography algorithm (PICo), with FA values compared between groups. Partial correlations were also examined between measures of subclinical hallucinatory/delusional experiences and FA values. Participants with schizotypal features were found to have increased FA values in the left hemisphere UF only. In the whole sample there was a positive correlation between FA values and measures of hallucinatory experience in the right AF. These findings suggest subtle changes in microstructural coherence are found in individuals with schizotypal features, but are not similar to changes predominantly observed in clinical samples. Correlations between mild hallucinatory experience and FA values could indicate increasing tract coherence could be associated with symptom formation.
Neuroscience and Psychiatry Unit, University of Manchester, Manchester M13 9PT, UK; School of Psychological Sciences, University of Manchester, Manchester, UK. Electronic address: richard.smallman@manchester.ac.uk.
Richard P
RP
Smallman
School of Psychology, University of Wollongong, Wollongong, NSW, Australia.
Emma
E
Barkus
Centre for Imaging Sciences, University of Manchester, Manchester, UK.
Hojjatollah
H
Azadbakht
School of Psychological Sciences, University of Manchester, Manchester, UK; Centre for Imaging Sciences, University of Manchester, Manchester, UK.
Karl V
KV
Embleton
Centre for Imaging Sciences, University of Manchester, Manchester, UK.
Hamied A
HA
Haroon
Institute of Brain, Behaviour and Mental Health, University of Manchester, Manchester, UK.
Shôn W
SW
Lewis
Centre for Imaging Sciences, University of Manchester, Manchester, UK.
David M
DM
Morris
Centre for Imaging Sciences, University of Manchester, Manchester, UK.
Geoffrey J
GJ
Parker
School of Psychology, Queen's University Belfast, Belfast, UK.
Teresa M
TM
Rushe
D000328:Adult; D000465:Algorithms; D016880:Anisotropy; D001921:Brain / Q000473:pathology / Q000503:physiopathology; D016022:Case-Control Studies; D056324:Diffusion Tensor Imaging / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D019580:Perforant Pathway; D010865:Pilot Projects; D011237:Predictive Value of Tests; D011618:Psychotic Disorders; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism*; D012569:Schizotypal Personality Disorder / Q000473:pathology*; D012680:Sensitivity and Specificity
Arcuate fasciculus; DTI; Launay–Slade; SPQ; Uncinate fasciculus