Persistent Idiopathic Facial Pain Associated with Patent Foramen Ovale with Right- to-Left Shunt and Hyperhomocysteinaemia: When a Symptom Can Save a Life ^†

1. Background

The association of Persistent Idiopathic Facial Pain (PIFP) and a congenital heart abnormality has never previously been reported. We report a case in which the diagnostic workup performed for PIFP revealed a Patent Foramen Ovale (PFO), with right-to-left shunt (RLS) and hyperhomocysteinaemia due to a polymorphism in the gene coding for 5,10 Methylene TetraHydroFolate Reductase (MTHFR) (c677) with a homozygous mutation.

2. Presentation of the Case

A 48-year-old female patient presented at the Oral Medicine Unit with a 10-month history of left-side facial pain. The pain was deep, occurring daily and diffuse to the upper teeth irradiating to the ipsilateral jaw without any paroxysms. She had undergone several investigations and tooth extractions without any relief and had been unsuccessfully treated with amitriptyline, pregabalin and triptan. She had a history of venous thromboembolism occurring at the age of 32 years and never evaluated. Gliosis and carotid siphons tortuosity were found on Magnetic Resonance Imaging (MRI) of the brain (Figure 1a) and hyperhomocysteinaemia (18 μmol/L) was identified. Transcranial Doppler Ultrasonography (TCD) with an agitated saline test was performed and showed a high degree of RLS (Figure 1b) while Transesophageal Echocardiography detected an interatrial septum aneurysm with PFO. Complete thrombophilia screening revealed a homozygosis mutation for MTHFR (c677, Ala--> Val).

A complete remission of pain was reported three months after the percutaneous closure of the PFO and therapy with antiplatelet and folic acid supplementation. After six months the patient continues to stay in well-being only undergoing this treatment without the need for any selective drugs for PIFP.

3. Conclusions

To the best of our knowledge, this is the first case described of facial pain secondary to a RLS due to an asymptomatic PFO in a patient with a prothrombotic state in which the disappearance of pain after the percutaneous closure of the PFO supports the possible association between a RLS and PIFP. PFO with RLS has been suggested as a risk factors for cryptogenic stroke in younger patients. Therefore, in our case, the early detection could be considered a possible lifesaver. However, the study leaves an unresolved question: namely whether the association is coincidental or causal. To address this point, the mechanism of action has to be further elucidated. This report shows that a careful evaluation of the clinical history, together with an interdisciplinary collaboration and a specific work up including neuroimaging studies is recommended in every case of facial pain in order both to achieve a more accurate and early recognition and to avoid diagnostic delay, which could sometimes be fatal for the patient.