Methodological Issues in Right-to-Left Shunt Detection in CADASIL Patients
To the Editor:
With regard to the article from Zigari et al,1 we would like to add some comments to the authors’ reply2 to our letter.3 The authors are very welcome to read our data that have indeed been published on an international, peer-reviewed journal.4 As to the second point of their reply, in our article we systematically referred to contrast enhanced transcranial Doppler diagnosis of right-to-left shunt instead of patent foramen ovale. We still believe that contrast enhanced transcranial Doppler is the most sensitive tool to detect right-to-left shunt, which is sustained by a patent foramen ovale in 95% of cases. Nevertheless, we think that if a relation is to be demonstrated between such a complex disease as CADASIL and interatrial septal abnormalities due to mutated Notch3-induced developmental disorders, these have at least to be documented anatomically. Otherwise, we could be left to suspect that 5% of the patients reported by Zicari et al1 had conditions other than a patent foramen ovale, such as a pulmonary arteriovenous malformation.
Zicari E, Tassi R, Stromillo ML, Pellegrini M, Bianchi S, Cevenini G, Gistri M, De Stefano N, Federico A, Dotti MT. Right-to-left shunt in CADASIL patients: prevalence and correlation with clinical and MRI findings. Stroke. 2008; 39: 2155–2157.
Zicari E, Tassi R, De Stefano N, Dotti MT. Response to letter by Mazzucco et al. Stroke. 2008; 39: e151.
Mazzucco S, Anzola GP, Rizzuto N. Right-to-left shunt in CADASIL patients: a comorbidity factor? Stroke. 2008; 39: e150.
Mazzucco S, Anzola GP, Ferrarini M, Taioli F, Olivato S, Burlina AP, Fabrizi GM, Rizzuto N. Cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy and right-to-left shunt: lack of evidence for an association in a prevalence study. Eur Neurol. 2008; 61: 46–49.