FOCAL AREAS OF HIGH-SIGNAL INTENSITY ON BRAIN T2-WEIGHTED MAGNETIC RESONANCE IMAGING SCANS ARE SIGNIFICANT FOR THE DIAGNOSIS OF NEUROFIBROMATOSIS VON RECKLINGHAUSEN TYPE 1

Abstract

INTRODUCTION: Neurofibromatosis von Recklinghausen type 1 (NF1) is characterized by the following National Institutes of Health (NIH) diagnostic criteria: café au lait spots, freckling, neurofibromas, Lisch nodules, optic glioma, distinct osseous lesions, and first-degree relative with NF1. Focal areas of high-signal intensity (FASI) in white matter and deep gray matter are typical brain MRI findings in children with NF1. OBJECTIVE: This study evaluated the frequency of FASI and the possibility of using FASI as a diagnostic criterion. METHODS: In a group of 160 children, the diagnosis of NF1 was confirmed in keeping with the NIH criteria. All children had MRI examination of the brain. The MRI findings of FASI in the children with NF1 were compared both with the brain MRI findings of the control group of 160 children with different diagnoses and with frequencies of the NIH diagnostic criteria. RESULTS: In 137 (86%) patients with NF1, ≥1 FASI were found. The difference between frequency of FASI in the NF1 group and in the control group (14 [9%]) is highly significant. The frequencies of the diagnostic criteria were as follows: café au lait spots: 157 (98%); freckling: 123 (77%); neurofibromas: 112 (70%); NF1 relatives: 89 (56%); Lisch nodules: 71 (44%); optic glioma: 45 (28%); and osseous lesions: 15 (9%; only partial examination of the group). CONCLUSIONS: The findings of FASI in T2-weighted images of the brain MRI are significantly frequent in children with NF1. Frequency of FASI is comparable with frequency of NIH diagnostic criteria. FASI could be proposed as an additional or new criterion for the NF1, mainly in childhood.