Do small- and moderate-size right-to-left shunts identified by saline contrast echocardiography are normal and unrelated to migraine headache?
When using modern ultrasound technology combined with a rigorous SCE technique, the majority of healthy subjects demonstrate some degree of RLS. PAVM in an otherwise healthy population is common. Small- and moderate-size RLSs do not appear to be significantly associated with migraine headache.
Future studies of M. ulcerans would benefit from consideration of local structure of the local stream network in future sampling, and further work is needed on the reasons for notable differences in the distribution of this species from one region to another. This work represents a first step in the identification of large-scale environmental drivers of this species, for the purposes of disease risk mapping.