Relationship between right-to-left shunt detected by c-TCD and clinical characteristics in migraine patients

Objectives: To explore the relationship between the presence or parameters of right-to-left shunt (RLS) detected by c-TCD and attack clinical features in migraine patients with aura (MA+) or without aura (MA-). Methods: Migraine patients with aura and migraine patients without aura (MA-) were recruited consecutively. The RLS was assessed by a c-TCD examination. Results: A total of 528 migraine patients and 71 healthy were included. The prevalence of RLS especially of mild shunts was higher in patients with migraine. Patients of MA+ developed migraine earlier and experienced more severe pain, more frequent photophobia and phonophobia, although the yearly frequency, duration and degree of pain or type and size of shunt was similar. Moreover, patients with MA+ and RLS (MA+RLS+) also experienced more photophobia and phonophobia than that without RLS (MA+RLS-). The result was similar in MA-RLS+ group. Patients with moderate or massive of RLS experience longer duration of pain in both MA+RLS+ and MA-RLS+ groups. The sex distribution was only significantly different in MA+RLS+ group, in which women were more likely to suffer from RLS especially mild shunt. Conclusion: A higher prevalence and severity of RLS was found in the migraine patients, especially those with aura. MA+ patients develop earlier and experience more severe pain. The duration was consistent with the shunt size in both MA+RLS+ and MA-RLS+ groups.