Brain structural changes in patients with cardio-facio-cutaneous syndrome: effects of BRAF gene mutation and epilepsy on brain development. Acase-control study by quantitative magnetic resonance imaging.

Abstract

To evaluate the brain volumetric changes caused by BRAF gene mutation in non-epileptic CFC patients and the influence of the age of epilepsy onset on brain development in 2 cohorts of epileptic CFC patients. We enrolled CFC patients carrying BRAF gene mutations without epilepsy (4 patients) and with epilepsy (16 patients). CFC epileptic patients were divided into two cohorts based on the age of seizure onset: early-age onset (7 children) and late-age onset (9 adolescents). All three cohorts of patients underwent 3D FSPGR T1-weighted imaging to assess supratentorial and infratentorial brain volumes. Moreover, for each compartment, gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) volumes were measured. All measurements were compared with those of age-matched controls without neuroimaging abnormalities. All CFC patients showed supratentorial and infratentorial WM reduction and supratentorial ventricular enlargement (p < 0.01). However, patients with early age of epilepsy onset, compared with the other two cohorts of CFC patients, showed both GM and a more pronounced WM volume reduction (p < 0.01). In non-epileptic CFC children, we demonstrated WM volumetric reduction suggesting a direct effect of BRAF gene mutation on brain development. Nevertheless, in CFC epileptic patients, the age of epilepsy onset may contribute to brain atrophy. Brain atrophy in CFC patients, in part due to the natural history of the disease, may be worsened by epilepsy when it begins in the early ages because of interference with brain growth at that critical age of development.