Osseous intramedullary signal alteration and enhancement in Sturge-Weber syndrome: an early diagnostic clue.

INTRODUCTION: Sturge-Weber syndrome (SWS) is a sporadic phakomatosis with variable intracranial involvement. Port-wine stain, choroidal angioma, and leptomeningeal angiomatosis typify the full disease spectrum. Disease manifestations generally evolve toward cerebral hemiatrophy and compensatory hemicalvarial enlargement. However, recognizable imaging correlates may be lacking early on. We have observed SWS-related marrow signal changes to be prevalent in patients of all ages. The purpose of this study is to evaluate bone marrow abnormalities in patients with Sturge-Weber syndrome.

METHODS: The MR imaging database at an academic children's hospital was queried for "Sturge-Weber" to build a cohort for retrospective analysis. Two board-certified neuroradiologists reviewed MR exams for abnormalities of the bone marrow, globes, susceptibility, and perfusion. A two-tailed Fisher's exact test was applied to evaluate the association between variables.

RESULTS: Twenty brain MR exams from 19 SWS patients, mean age 4.8 +/- 5.8 years (range 6 months-16 years), met the inclusion criteria. All patients with port-wine stains (18/20) had leptomeningeal enhancement, marrow T2 prolongation, and/or marrow enhancement ipsilaterally. Leptomeningeal enhancement was only present in 53%. Eighty percent had unilateral bone marrow abnormalities. In 37% (all <5 years), marrow abnormalities occurred without leptomeningeal angiomatosis. Thirty-five percent had facial bones involvement; 75% of these had ipsilateral choroidal angiomas.

CONCLUSION: Bone marrow signal abnormality and enhancement is common ipsilateral to the nevus flammeus in SWS. As this may be the sole brain MR abnormality in some patients, it may reflect mild phenotypes or an early disease manifestation, and could help stratify patients for early intervention.