Cerebral abscesses among Danish patients with hereditary haemorrhagic telangiectasia

Background Hereditary haemorrhagic telangiectasia (HHT) is a dominantly inherited disease characterized by a wide variety of clinical manifestations, including pulmonary arteriovenous malformations (PAVMs), which due to paradoxical embolization may cause cerebral abscess. Objective To estimate the risk of cerebral abscess among patients with HHT. Methods All patients with HHT included in the Danish HHT data base, between January 1995 and October 2012, have been clinically evaluated for the presence of neurological symptoms and history of previous cerebral abscess. Results A total of 337 patients with HHT have been included in the Danish database. Of these, 264 were screened for the presence of PAVM. In 117 patients, a PAVM was diagnosed; among these, we identified nine patients with a history of cerebral abscess. The prevalence of cerebral abscess among patients with HHT and PAVM was therefore 7.8%. The patients with a history of cerebral abscess were genetically evaluated, and seven had ENG mutations, one had an ALK1 mutation, and in one case, a mutation could not be identified. Conclusion Patients with untreated PAVM have a considerable risk of sustaining cerebral abscesses. A cerebral abscess may be the first symptom leading to an HHT diagnosis. Patients with unexplained cerebral abscess should be evaluated for HHT and PAVM.