Differences in cortical gyrification and fractional amplitude of low-frequency fluctuations between early- and late-onset obsessive-compulsive disorder.

backgroundObsessive-compulsive disorder (OCD) is heterogeneous, and differences in age at onset may be associated with important feature of distinct subtype. However, no studies have investigated the differences between early- and late-onset OCD using structural and functional multimodal neuroimaging methods that reflect different neurobiological backgrounds.

methodsStructural and resting-state functional magnetic resonance imaging data were obtained from 130 participants (76 medication-free patients with OCD and 54 healthy controls (HCs)). We investigated group differences among early- and late-onset OCD and HCs in the fractional amplitude of low-frequency fluctuation (fALFF) and local gyrification index (LGI).

resultsIn the fALFF analysis, group differences were detected in the left lateral occipital cortex and bilateral thalamus (a voxel-height threshold of LIMITATIONS: Our cross-sectional data could limit the interpretation of our results.

conclusionsOur results emphasize the importance of the thalamus in the pathophysiology regardless of the age-of-onset subtype of OCD. In addition, altered fALFF in the lateral occipital cortex, not accompanied by deficits of LGI, could represent a disruption of normal functional developmental processes resulting from the OCD onset at a young age. Future study should examine the relationship between the alteration of fALFF in lateral occipital cortex and clinical and treatment-refractory features of early-onset OCD, potentially improving therapeutic strategies.