Hemorrhage is common in
brain tumors. Due to characteristic magnetic field changes induced by
hemosiderin it can be detected using susceptibility weighted MRI (SWI). Its relevance to clinical syndromes is unclear. Here we investigated the patterns of intra-tumoral SWI positivity (SWI(pos)) as a surrogate for
hemosiderin with regard to the prevalence of
epilepsy. We report on 105 patients with newly diagnosed supra-tentorial
gliomas and brain
metastasis. The following parameters were recorded from pre-operative MRI: (1) SWI(pos) defined as dot-like or fine linear signal changes; (2) allocation of SWI(pos) to
tumor compartments (contrast enhancement, central hypointensity, non-enhancing area outside contrast-enhancement); (3) allocation of SWI(pos) to include the cortex, or SWI(pos) in subcortical
tumor parts only; (4)
tumor size on T2 weighted and
gadolinium-enhanced T1 images. 80
tumors (76 %) showed SWI(pos) (4/14 diffuse
astrocytoma WHO II, 5/9
anaplastic astrocytoma WHO III, 41/46
glioblastoma WHO IV, 30/36
metastasis). The presence of SWI(pos) depended on
tumor size but not on patient's age, medication with
antiplatelet drugs or anticoagulation.
Seizures occurred in 60 % of patients. Cortical SWI(pos) significantly correlated with
seizures in brain
metastasis (p = 0.044), and as a trend in
glioblastoma (p = 0.062). Cortical SWI(pos) may confer a risk for
seizures in patients with newly diagnosed brain
metastasis and
glioblastoma. Whether development of cortical SWI(pos) induced by treatment or by the natural course of
tumors also leads to the new onset of
seizures has to be addressed in longitudinal studies in larger patient cohorts.