Magnetic Resonance Imaging Lesion Analysis in Neurofibromatosis Type 1

Abstract

High-signal T2 lesions on MRI in patients with NF-1 evolve over time. The evolution of the NF-1 lesion is region specific and may relate to preferential region-specific effects of the NF-1 gene product.

Longitudinal evolution of unidentified bright objects in children with neurofibromatosis‐1

“…A similar pattern of evolution can be seen in Figures 2 and 4. Ramsby, 1998]. Despite this general agreement, we found a different and complex pattern of evolution of UBOs.…”

“…These UBOs have been recognized as a distinctive feature of NF-1 since the late 1980s [Aoki et al, 1989;Goldstein et al, 1989;Mirowitz et al, 1989;Yamanouchi et al, 1995;North, 2000]. Cross-sectional analyses, and more recently longitudinal evaluations, indicate that UBOs tend to regress during adolescence [Itoh et al, 1994, DiMario andRamsby, 1998;North, 2000]. The first major serial study of UBOs included 13 subjects with two observations each, and assessed volume of UBOs in five locations: cerebral white matter, basal ganglia, brainstem, dentate nucleus, and cerebellar white matter [Itoh et al, 1994].…”

“…The histologic nature of the abnormalities remains obscure, although the limited available pathologic material suggests that the signal abnormalities reflect spongiform changes in the white matter [DiPaolo et al, 1995], compatible predominantly with intramyelinic edema. At least two groups have evaluated the evolution of these foci over time [Itoh et al, 1994;DiMario and Ramsby, 1998], and have found that, in general, the UBO burden tends to decrease over time, but that the patterns of change over time vary by brain region. In one of the previous studies, in which patients were examined serially, seven patients were studied at more than two time points [DiMario and Ramsby, 1998].…”

“…At least two groups have evaluated the evolution of these foci over time [Itoh et al, 1994;DiMario and Ramsby, 1998], and have found that, in general, the UBO burden tends to decrease over time, but that the patterns of change over time vary by brain region. In one of the previous studies, in which patients were examined serially, seven patients were studied at more than two time points [DiMario and Ramsby, 1998]. Those results were reported in a framework of an anatomic parcellation in which the locations of all the foci were assigned to cerebral hemisphere, brainstem (diencephalic UBOs were included in this compartment) or cerebellum; using this parcellation scheme, the UBOs were found to occur most often in the cerebellum and in the globus pallidus.…”

Diffuse Pontine Lesions in Children with Neurofibromatosis Type 1: Making a Case for Unidentified Bright Objects

“…Four of these patients presented with symptoms referable to the brainstem and 4 were found incidentally on a screening MRI. DiMario and Ramsby [25] found that UBOs in the cerebellum and basal ganglia tend to decrease in number and size with increasing patient age, while brainstem UBOs demonstrated either no change or slight increase in size.…”