Open AccessBrain microstructural changes and cognitive correlates in patients with pure obsessive compulsive disorder
Author(s) -
Spalletta Gianfranco,
Piras Fabrizio,
Fagioli Sabrina,
Caltagirone Carlo,
Piras Federica
Publication year - 2014
Publication title -
brain and behavior
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.915
H-Index - 41
ISSN - 2162-3279
DOI - 10.1002/brb3.212
Subject(s) - fractional anisotropy , psychology , white matter , diffusion mri , corpus callosum , posterior cingulate , insula , neuroscience , audiology , medicine , cardiology , cognition , magnetic resonance imaging , radiology
Abstract Object The aim of this study was to investigate macrostructural and microstructural brain changes in patients with pure obsessive compulsive disorder ( OCD ) and to examine the relationship between brain structure and neuropsychological deficits. Method 20 patients with OCD underwent a comprehensive neuropsychological battery. A combined voxel‐based morphometry ( VBM ) and diffusion tensor imaging ( DTI ) analysis was used to capture gray matter ( GM ) and white matter changes in OCD patients as compared to pair‐matched healthy volunteers. Multiple regression designs explored the relationship between cognition and neuroimaging parameters. Results OCD patients had increased mean diffusivity ( MD ) in GM nodes of the orbitofronto‐striatal loop (left dorsal anterior cingulate [ Z = 3.67, P < 0.001] left insula [ Z = 3.35 P < 0.001] left thalamus [ Z = 3.59, P < 0.001] left parahippocampal gyrus [ Z = 3.77 P < 0.001]) and in lateral frontal and posterior associative cortices (right frontal operculum [ Z = 3.42 P < 0.001], right temporal lobe [ Z = 3.79 P < 0.001] left parietal lobe [ Z = 3.91 P < 0.001]). Decreased fractional anisotropy ( FA ) was detected in intrahemispheric (left superior longitudinal fasciculus [ Z = 4.07 P < 0.001]) and interhemispheric (body of corpus callosum [ CC , Z = 4.42 P < 0.001]) bundles. Concurrently, the semantic fluency score, a measure of executive control processes, significantly predicted OCD diagnosis (Odds Ratio = 1.37; 95% Confidence Intervals = 1.09–1.73; P = 0.0058), while variation in performance was correlated with increased MD in left temporal ( Z = 4.25 P < 0.001) and bilateral parietal regions (left Z = 3.94, right Z = 4.19 P < 0.001), and decreased FA in the right posterior corona radiata ( Z = 4.07 P < 0.001) and the left corticospinal tract ( Z = 3.95 P < 0.001). Conclusions The reported deficit in executive processes and the underlying microstructural alterations may qualify as behavioral and biological markers of OCD .