Migraine is common in childhood with a prevalence of 6 %, and aura is present in almost half of these cases [20]. There are limited studies in children mirroring adult data demonstrating that the prevalence of PFO in children with migraine with aura (50 %) is significantly greater than in children without aura (27 %) or in controls (25 %) [21]. No robust data on the effect of closure however has been reported in this age group and thus, extrapolation from adult data is necessary with a large randomized clinical trial suggesting some reduction in headache burden but no curative effect of PFO closure on adult migraine sufferers [22]. Singular reports of resolution of symptoms in a child with hemiplegic migraine have been published [23] and it may be reasonable to screen for PFO with RLS in children with severe symptoms not controlled with medication. It may be that closure in these uncommon circumstances may provide reduction in headache burden however evidence is anecdotal and may not be supported financially.

An association between PFO and neurological and cutaneous decompression illness has been reported. Divers with these types of decompression illness have a higher prevalence of significant right-to-left shunt than do controls, and those with the largest shunts appear to be at greatest risk [24, 25]. An increased prevalence of brain lesions has also been reported in divers, with a right-to-left shunt present in all those with multiple brain lesions [26]. Although there are no published guidelines, for divers who dive with an open PFO, it is usually recommended to remain shallower than 15 m [16]. If parents wish to take their child diving it would seem logical to limit depth to less than 15 m, as this should be at an acceptable risk even if there is a PFO. There is currently no clear consensus on screening; however, any adolescent expressing an interest in diving professionally or as part of a school course, might want to consider PFO screening as part of an overall medical examination process. It may be inappropriate to close a PFO in a child below the age of 16 for the sole purpose of diving. Nevertheless, knowing about the presence of a PFO so that diving can be modified would provide an indication for testing as above.

Considering a reported wide variability in attitudes of pediatric neurologists to the impact of PFO to childhood AIS, with an equally wide variability in how the presence of intracardiac RLS is assessed by pediatric cardiologists [16], a consolidated approach is warranted to ensure that an optimal screening examination is performed once it has been requested. Similar diagnostic challenges exist within the pediatric population as in adults. Transesophageal echocardiography although considered the “Gold Standard” may not permit the patient (particularly a child where general anesthesia is usually required) to perform an adequate Valsalva. Transthoracic echocardiographic images are often clearer in children and for many, this has been the approach of choice in this age group [13, 16, 27]. Clear imaging of the atrial septum and pulmonary veins (to rule out false positive results via intrapulmonary shunting) is usually achievable with no impediment to Valsalva, although explaining the technical aspects of the maneuver itself may be challenging with younger patients. A variety of improvisations have been used for smaller children down to 3 years of age to improve compliance including blowing into a straw or balloon [13, 16]. The use of transcranial Doppler (TCD) has also been described in the assessment of RLS in children [13], with some degree of shunt quantification achievable with this approach however this may not be tolerated in smaller children (<5 years) when significant head movement may impact upon the quality of the test.

There is some variability in the reported saline/blood/air mix for children and it may be that in smaller children with smaller intravenous access (obtained as close to the heart as possible), blood withdrawal through the cannula is not possible. Either way the important indicators of an adequate study include Valsalva leading to reduction in the size of the left atrium, and release of Valsalva when the right atrium is filled with bubble contrast. It may be necessary to repeat the test on up to five occasions to ensure the test is adequate [16].

Procedural approach is similar to that in adults. General anesthesia may be preferable in younger patients although conscious sedation has been used successfully in this setting. Both TEE and intracardiac echocardiography (ICE) have been used in children and optimal modality may be dictated by operator preference. Although PFO closure is not common in children, transcatheter closure of large atrial septal defects in children less than 20 kg has been reported without complication [28], and thus technical difficulties should not be an issue. More relevant factors may relate to ensuring full closure and minimizing longer-term impact on the heart. Randomized studies comparing closure rates with available devices have been reported in adults and support non-randomized comparative trials suggest better early closure rates and less event recurrences with the Amplatzer device (St Jude Medical, Plymouth, MN) versus the Helex Septal Occluder (WL Gore and Associates, Flagstaff, AZ) [29, 30]. This needs to be balanced against complication rates with both devices (which are very low) however erosion has been reported with the Amplatzer PFO device in adults [31], and this may be a “psychological” concern for interventionalists when implanting in younger patients. The largest reported study to-date exclusively in children that included information regarding implanted device, outlined closure in eight patients using the Amplatzer PFO device [32]. There were no procedural complications and no stroke recurrences after median follow-up of 15 months. One patient had residual shunt at 6-month follow-up. A larger cohort evaluating ASD and PFO closure in 45 patients including children has been published using both Amplatzer devices (ASD and PFO) and the Cardioseal device (NMT, Medical, Boston, MA). Excellent closure rates were seen however residual symptoms and shunt were reported in one of the seven patients receiving the Cardioseal device [33]. Further anecdotal reports have described closure with the Amplatzer device [19, 34]. Limited published experience exists regarding use of the Helex device for PFO closure in children however we have used this in our practice for this indication (Fig. 19.1). Reports using the newer generation Gore Septal Occluder (WL Gore and Associates) for PFO closure are evolving with patients less than 18 years included in one large study to date [35]. This study suggested improved early closure rates (when compared to previous reports with the original Helex device) of 89 % in those undergoing bubble contrast study with Valsalva. It is too early as yet to determine longer-term clinical outcomes with this device.