Previous studies have suggested that the habenula (Hb) may be involved in the mechanism of obsessive-compulsive disorder (OCD). However, the specific role of Hb in OCD remains unclear. This study aimed to explore the structural and functional abnormalities of Hb in OCD and their relationship with the clinical symptoms.

Eighty patients with OCD and 85 healthy controls (HCs) were recruited as the primary dataset. The grey matter volume, resting-state functional connectivity (FC), and effective connectivity (EC) of the Hb were calculated and compared between OCD group and HCs. An independent replication dataset was used to verify the stability and robustness of the results.

Patients with OCD exhibited smaller Hb volume and increased FC of right Hb-left hippocampus than HCs. Dynamic causal model revealed an increased EC from left hippocampus to right Hb and a less inhibitory causal influence from the right Hb to left hippocampus in the OCD group compared to HCs. Similar results were found in the replication dataset.

This study suggested that abnormal structure of Hb and hippocampus-Hb connectivity may contribute to the pathological basis of OCD.

Thrombocytopenia occasionally occurs following the closure of some giant patent ductus arteriosus cases. Unfortunately, there is no associated research describing the associated risk factors for thrombocytopenia post-procedure.

We reviewed all patients who received occluders with sizes ≥10/12 mm between January 2013 and June 2019. All the data and information on the characteristics of the patients and their follow-up were recorded. Univariate analysis, receiver operating characteristic curves, and linear regression were used to analyse the risk factors for thrombocytopenia and the predictors of hospitalisation stay.

Finally, 32 patients (17.5%) suffered from thrombocytopenia. Univariate analysis revealed the ratio between occluder disc size (mm) and body weight (kg) (1.71 ± 0.51 versus 1.35 ± 0.53) as an independent predictive factor for thrombocytopenia, and the area under the curve of the ratio of occluder size and body weight for predicting thrombocytopenia post-closure was 0.691 (95% confidence interval: 0.589–0.792, p = 0.001). The best cut-off value for the ratio of occluder size and weight was 1.5895, with a sensitivity and specificity of 68.8 and 66.9%, respectively. Each unit of the ratio of occluder size and body weight predicted an average hospitalisation stay of 2.856 days (95% confidence interval: 1.380–4.332). Treatment with medication did not reduce the hospitalisation stay or benefit platelet restoration.

Once the ratio of occluder size and body weight is greater than 1.6, thrombocytopenia always exists. Every unit of the ratio of occluder size and body weight represents an additional 3 days of hospitalisation. Treatment does not reduce the duration of hospitalisation.