Effect of Brain Tumor Size and Location on Seizure Risk Varies With Tumor Grade
Effect of Brain Tumor Size and Location on Seizure Risk Varies With Tumor Grade
Lee JW, Wen PY, Hurwitz S, Black P, Kesari S, et al
Arch Neurol. 2010;67:336-342
The goal of this retrospective imaging survey was to compare size and location for brain tumors presenting with seizures vs those presenting with nonseizure neurologic symptoms. At a university-affiliated teaching hospital, 124 patients with newly diagnosed supratentorial glial tumors underwent magnetic resonance imaging (MRI)-based morphometric analysis and nonparametric mapping.
For patients with high-grade gliomas, those presenting with seizures had smaller tumors than did those presenting with other neurologic symptoms, and tumor location maps showed that deep-seated tumors in the pericallosal regions were more likely to present with nonseizure neurologic symptoms. In contrast, among patients with low-grade gliomas, tumors presenting with seizures were larger, and tumors of the temporal lobe as well as the insular region were more likely to present with seizures.
Study limitations include retrospective design, heterogeneity in MRI parameters, small number of occipital tumors in this series, possible registration errors in patients with large tumors, and relative inability to detect intense focal signals. Nonetheless, this study suggests that the effect of size and location of brain tumors on their tendency to cause seizures varies with tumor grade.
Rapidly growing high-grade gliomas, especially those located in deeper structures, tend to present with nonseizure symptoms related to mass effect, such as headache, cognitive impairments, or focal weakness. In patients with low-grade gliomas, however, lesions in the temporal lobe or insula can grow large without causing other symptoms and ultimately present with seizures. Large tumor size in patients with low-grade gliomas may reflect long duration of silent growth, allowing more time for seizures to develop.
Future studies using volumetric imaging analysis may help identify patients who are at greater and lower risk for seizures, allowing early selection of patients for targeted antiepileptic drug therapy.
Abstract
Morphological Characteristics of Brain Tumors Causing Seizures
Lee JW, Wen PY, Hurwitz S, Black P, Kesari S, et al
Arch Neurol. 2010;67:336-342
Summary
The goal of this retrospective imaging survey was to compare size and location for brain tumors presenting with seizures vs those presenting with nonseizure neurologic symptoms. At a university-affiliated teaching hospital, 124 patients with newly diagnosed supratentorial glial tumors underwent magnetic resonance imaging (MRI)-based morphometric analysis and nonparametric mapping.
For patients with high-grade gliomas, those presenting with seizures had smaller tumors than did those presenting with other neurologic symptoms, and tumor location maps showed that deep-seated tumors in the pericallosal regions were more likely to present with nonseizure neurologic symptoms. In contrast, among patients with low-grade gliomas, tumors presenting with seizures were larger, and tumors of the temporal lobe as well as the insular region were more likely to present with seizures.
Viewpoint
Study limitations include retrospective design, heterogeneity in MRI parameters, small number of occipital tumors in this series, possible registration errors in patients with large tumors, and relative inability to detect intense focal signals. Nonetheless, this study suggests that the effect of size and location of brain tumors on their tendency to cause seizures varies with tumor grade.
Rapidly growing high-grade gliomas, especially those located in deeper structures, tend to present with nonseizure symptoms related to mass effect, such as headache, cognitive impairments, or focal weakness. In patients with low-grade gliomas, however, lesions in the temporal lobe or insula can grow large without causing other symptoms and ultimately present with seizures. Large tumor size in patients with low-grade gliomas may reflect long duration of silent growth, allowing more time for seizures to develop.
Future studies using volumetric imaging analysis may help identify patients who are at greater and lower risk for seizures, allowing early selection of patients for targeted antiepileptic drug therapy.
Abstract
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