White matter microstructural deficits in 22q11.2 deletion syndrome
David R Roalf1, J Eric Schmitt2, Simon N Vandekar3
1Brain Behavior Laboratory, Department of Psychiatry, Neuropsychiatry Section, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
Psychiatry Research. Neuroimaging
|September 3, 2017
Summary
Diffusion tensor imaging reveals white matter (WM) microstructure differences in 22q11.2 deletion syndrome (22q11DS). These brain abnormalities in 22q11DS are linked to psychosis spectrum symptoms.
Area of Science:
- Neuroimaging
- Neurogenetics
- Psychiatry
Background:
- 22q11.2 deletion syndrome (22q11DS) is a neurogenetic disorder linked to psychosis.
- Previous diffusion tensor imaging (DTI) studies show white matter (WM) aberrations in 22q11DS, similar to schizophrenia, but results are inconsistent.
Purpose of the Study:
- To compare WM microstructure in 22q11DS individuals and healthy controls (HC) using DTI.
- To explore WM differences in 22q11DS individuals with and without psychosis spectrum symptoms.
Main Methods:
- DTI scans were acquired at 3T using a 64-direction protocol in 39 22q11DS individuals and 39 age, sex, and race-matched HC.
- Analysis focused on fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) in various WM tracts.
Main Results:
- Individuals with 22q11DS showed lower FA and higher radial diffusivity in the cingulum bundle compared to HC.
- Lower MD was observed in the inferior longitudinal fasciculus, and lower AD in the cingulum bundle, forceps major, and other tracts in 22q11DS.
- 22q11DS individuals with psychosis spectrum symptoms had lower FA in the cingulum bundle and lower AD in the uncinate fasciculus compared to those without.
Conclusions:
- WM microstructure is aberrant in individuals with 22q11DS compared to HC.
- Subtle WM deficits in 22q11DS are associated with psychosis spectrum symptoms, suggesting a potential role in psychosis pathophysiology.
