Longitudinal Assessment of Enhancing Foci of Abnormal Signal Intensity in Neurofibromatosis Type 1

Abstract

BACKGROUND AND PURPOSE: Patients with neurofibromatosis 1 are at increased risk of developing brain tumors, and differentiation from contrast-enhancing foci of abnormal signal intensity can be challenging. We aimed to longitudinally characterize rare, enhancing foci of abnormal signal intensity based on location and demographics. MATERIALS AND METHODS:A total of 109 MR imaging datasets from 19 consecutive patients (7 male; mean age, 8.6 years; range, 2.3-16.8 years) with neurofibromatosis 1 and a total of 23 contrast-enhancing parenchymal lesions initially classified as foci of abnormal signal intensity were included. The mean follow-up period was 6.5 years (range, 1-13.8 years). Enhancing foci of abnormal signal intensity were followed up with respect to presence, location, and volume. Linear regression analysis was performed.

A new era for myelin research in Neurofibromatosis type 1

“…Nonetheless, limitations in this study include the small/heterogenous population studied with severe complication and diverse interventions. Further proposed FASI composition includes heterotopias, hamartomas, regions with demyelination or immature‐edematous myelin, and vacuolized/uncompacted myelin (Aoki et al, 1989; Hainc et al, 2021; Smirniotopoulos & Murphy, 1992). Also, the influence of FASI on decreased FA values has been broadly observed (Ferraz‐Filho et al, 2012).…”

“…Overall, Nf1 mutations impact brain structural/functional network properties, with putative strong influence from myelin. FASI are WM abnormalities that develop in most NF1 pediatric patients, typically arising in early childhood (3-3.5 YO) and resolving during adolescence (12-17 YO; Hainc et al, 2021;Itoh et al, 1994), which could indicate reorganization and/or repair of myelin (Alkan et al, 2005). FASI are MRI T2-weighted hyperintense lesions seen mostly in the brainstem, cerebellum, thalamus, basal ganglia, and CC of 43%-95% of NF1 pediatric patients (Itoh et al, 1994;Rosenbaum et al, 1999;Sevick et al, 1992).…”