Demographic, clinical and brain imaging characteristics between migraine patients with and without PFO
The demographic, clinical and brain imaging characteristics were compared in migraine patients with and without PFO and described in table 1. The study included a total of 424 patients with migraine for analysis, of whom 244 patients (57.5%) had PFO. The mean age was 44.39±12.06 years. There were more females (62.7%) in the patient cohort, but there was no sex difference between patients with and without PFO. The other clinical characteristics, including hypertension, diabetes, dyslipidemia and current smoking, was also not different between patients with and without PFO.
Of 424 patients, 58% had DWI lesion. Among them, 9.4% had single lesion and 48.6% had multiple lesions. They all presented as small scattered lesion, of which 50.9% were cortical lesion (cortical only or both cortical and non-cortical lesion) and 50.2%% were from anterior vascular territory. In the analyses that compared the difference of DWI pattern between patients with and without PFO, the presence or absence of DWI lesion, lesion number and lesion location (cortical or non-cortical) were all not associated with the presence or absence of PFO. However, the proportion of PFO-positive was higher than that of PFO-negative in patients with single DWI lesion (11.9% vs 6.1%). Moreover, DWI lesion was more likely to come from anterior or multiple vascular territory instead of posterior vascular territory in PFO positive patients compared with PFO negative patients (p=0.033).
DWI lesion and its association with PFO presence
Multivariate logistics regression analysis revealed no association between the PFO prevalence and the presence or absence of brain DWI lesion (OR 0.499, 95% CI 0.236-1.052). We then tested the association between DWI lesion and PFO presence in different age groups (table 2). All patients were divided into four age groups: 1) age<34 years; 2) 34 years≤age<46 years; 3) 46 years≤age< 55 years; 4) age≥55 years. DWI lesion was found in 246 patients (58%) and the incidence of DWI lesion increased with age (from 5.4% in group of age<34 years to 24.3% in group of age≥55 years).
In DWI lesion-positive patients, the proportion of PFO presence was significantly higher than that of PFO absence in group of patients who were younger than 46 years (13% vs 4%, p<0.017, in group of age<34 years; and 25.3% vs 11%, p<0.005, in group of 34 years≤age<46 years, respectively). In turn, in group of 46 years≤age< 55 years, the proportion of PFO-negative and PFO-positive patients was not significantly different (30% vs 28.8%, p=0.835). Interestingly, in group of age≥55 years, the proportion of PFO-positive patients was inversely lower than that of PFO-negative patients (32.9% vs 55%, p<0.0005). Consistently, regression analysis by age found that the odds of PFO presence in patients with DWI lesion were diminished by older age (table 3). The OR value was 3.614 in group of age<34 years, 3.132 in group of 34 years≤age<46 years, 1.071 in 46 years≤age< 55 years and 0.727 in group of age≥55. In comparison, in DWI lesion-negative patients, there was no difference between the proportion of PFO-negative and PFO-positive patients for all four age groups.
These findings suggest that the association of DWI lesion with the presence of PFO in migraine patients is age dependant. The association is significant only in patients younger than 46 years but not in those equal to or older than 46 years.
DWI lesion and its association with RLS amounts
We tested the association between brain DWI lesion and RLS amounts. In 244 patients (57.5%)who had PFO, the RLS amounts were distributed as 1) 47 (19.3 %), small RLS and 2) 197 (80.7%), large RLS. Multivariate logistics regression analysis found the association between different RLS amounts and the single or multiple brain DWI lesion was negative (OR 1.020, 95% CI 0.993-1.047). In addition, the odds of PFO with large RLS amounts in patients with DWI lesion were also age dependant and diminished by older age (table 4). The OR value was 4.000 in group of age<34 years, 2.738 in group of 34 years≤age<46 years, 1.021 in 46 years≤age< 55 years and 0.709 in group of age≥55. To confirm the results, we performed univariate analysis in patients who were aged less than 46 years, there was still no difference for the probability of brain lesion between large-RLS and small-RLS (OR 0.939, 95% CI 0.390-2.260) (table 5). In comparison, OR was 3.049 (95% CI 1.540-6.036) between large-RLS and RLS negative, and 3.248 (95% CI 1.231-8.570) between small-RLS and RLS negative (table 5). The results revealed that the association between the PFO and DWI lesion is probably independent of RLS amounts in migraine patients.