Perinatal risk factors in Tourette's and chronic tic disorders: a total population sibling comparison study.

Adverse perinatal events may increase the risk of Tourette's and chronic tic disorders (TD/CTD), but previous studies have been unable to control for unmeasured environmental and genetic confounding. We aimed to prospectively investigate potential perinatal risk factors for TD/CTD, taking unmeasured factors shared between full siblings into account. A population-based birth cohort, consisting of all singletons born in Sweden in 1973-2003, was followed until December 2013. A total of 3 026 861 individuals were identified, 5597 of which had a registered TD/CTD diagnosis. We then studied differentially exposed full siblings from 947 942 families; of these, 3563 families included siblings that were discordant for TD/CTD. Perinatal data were collected from the Medical Birth Register and TD/CTD diagnoses were collected from the National Patient Register, using a previously validated algorithm. In the fully adjusted models, impaired fetal growth, preterm birth, breech presentation and cesarean section were associated with a higher risk of TD/CTD, largely independent from shared family confounders and measured covariates. Maternal smoking during pregnancy was associated with risk of TD/CTD in a dose-response manner but the association was no longer statistically significant in the sibling comparison models or after the exclusion of comorbid attention-deficit/hyperactivity disorder. A dose-response relationship between the number of adverse perinatal events and increased risk for TD/CTD was also observed, with hazard ratios ranging from 1.41 (95% confidence interval (CI): 1.33-1.50) for one event to 2.42 (95% CI: 1.65-3.53) for five or more events. These results pave the way for future gene by environment interaction and epigenetic studies in TD/CTD.

Suicide in obsessive-compulsive disorder: a population-based study of 36 788 Swedish patients.

The risk of death by suicide in individuals with obsessive-compulsive disorder (OCD) is largely unknown. Previous studies have been small and methodologically flawed. We analyzed data from the Swedish national registers to estimate the risk of suicide in OCD and identify the risk and protective factors associated with suicidal behavior in this group. We used a matched case-cohort design to estimate the risk of deaths by suicide and attempted suicide in individuals diagnosed with OCD, compared with matched general population controls (1:10). Cox regression models were used to study predictors of suicidal behavior. We identified 36 788 OCD patients in the Swedish National Patient Register between 1969 and 2013. Of these, 545 had died by suicide and 4297 had attempted suicide. In unadjusted models, individuals with OCD had an increased risk of both dying by suicide (odds ratio (OR)=9.83 (95% confidence interval (CI), 8.72-11.08)) and attempting suicide (OR=5.45 (95% CI, 5.24-5.67)), compared with matched controls. After adjusting for psychiatric comorbidities, the risk was reduced but remained substantial for both death by suicide and attempted suicide. Within the OCD cohort, a previous suicide attempt was the strongest predictor of death by suicide. Having a comorbid personality or substance use disorder also increased the risk of suicide. Being a woman, higher parental education and having a comorbid anxiety disorder were protective factors. We conclude that patients with OCD are at a substantial risk of suicide. Importantly, this risk remains substantial after adjusting for psychiatric comorbidities. Suicide risk should be carefully monitored in patients with OCD.

A less traumatic catheter for coronary arteriography.

A deformable soft-tipped angiographic catheter has been designed and developed to reduce vascular trauma during coronary arteriography. In order to test the ability of the catheter tip glide over vascular endothelium, the coefficient of resistance was tested using fresh human aortic tissue. The mean frictional coefficients of resistance (FRc) for the soft-tipped catheter, as compared with two commonly used catheters (N = 10/group), were .78 +/- .08 units for the soft-tipped catheter and 1.10 +/- .10 (p less than .006) and .98 +/- .10 (p less than .034) for the conventional catheters. This demonstrates a significant 23% reduction in FRc with the soft-tipped catheter. The ease of penetration into a wax media was also measured using the soft-tipped catheter and compared with the same two conventional catheters. The indentation depths for the soft-tipped catheter and the two other catheter groups (N = 7/group) were 140 +/- 18 micron, 246 +/- 15 micron and 318 +/- 20 micron, respectively. This represents a 56% decrease in indentation depth with the soft-tipped catheter. Histologic studies in canines have demonstrated considerably less endothelial damage and subsequent intimal proliferation in the aorta and coronary ostia with the soft-tipped catheters compared with control catheters. It is concluded that a soft-tipped angiographic catheter is less traumatic to vascular tissue and may offer a safer approach to intravascular studies.