UCLA

Objectives

The aim of this study was to assess the prevalence of right-to-left (R to L) shunt in patients with visual aura and evaluate the effect of shunt closure on resolution of aura.

Background

Right-to-left shunting is associated with migraine headache (MH) with aura. Some patients present with visual aura without headaches. It is unclear whether visual aura without headache is a form of migraine or a transient neurologic dysfunction.

Methods

Of patients referred to the University of California, Los Angeles for suspected patent foramen ovale (PFO), 225 had visual aura with or without MH. Patients were assessed for a shunt and evaluated for MH and/or visual aura. They were divided into 3 groups: 1) visual aura associated with MH; 2) visual aura unrelated in time to MH; and 3) visual aura without MH. The frequency of R to L shunt was compared with a control group of 200 patients. Eighty patients underwent PFO closure. Residual shunts, MH, and visual aura were reassessed after 3 and 12 months.

Results

The prevalence of R to L shunt in Groups A, B, and C was 96%, 72%, and 67%, respectively, versus 18% in the control group (p < 0.0001). The frequency of shunting was similar in Group B versus Group C, but much higher in all 3 groups compared with control subjects. Twelve months after PFO closure, symptoms of aura were resolved in 52%, 75%, and 80% of patients in Groups A, B, and C, respectively (p = NS).

Conclusions

The similar distribution of R to L shunting in all 3 patient groups and the correlation between PFO closure and improvement of aura suggests a similar pathophysiology between the presence of PFO and the visual aura phenomenon, whether or not headache is present in the symptom complex.