MRI Functional (fMRI) Head There is no relevant literature regarding the use of fMRI in the evaluation of known seizure disorder with changes in seizure semiology unless it is in the setting of presurgical planning. Seizures and Epilepsy MRI Head In the setting of interval changes of seizure semiology, MRI is the study of choice to evaluate for new structural lesions [17,34]. MRI is the modality of choice in assessment of the progression of known lesions, and as such is an important tool for prognostic considerations [17], and the use of specific protocols IV contrast considered depending on the underlying etiology. Some authors advocate neuroimaging only if there are focal findings on a neurologic examination [17]. One study, which evaluated repeat MRI in seizure patients, including those with change in seizure semiology, demonstrated a 21% increase of findings, which were not identified in initial MRI scans [32]. HMPAO SPECT or SPECT/CT Brain Ictal and Interictal There is no relevant literature regarding the use of SPECT or SPECT/CT in the evaluation of known seizure disorder with changes in seizure semiology unless it is in the setting of presurgical planning. Variant 5: Known seizure disorder. History of tumor. CT Head CT can assess for interval changes in tumor and associated edema, mass effect, hydrocephalus, and tumor- associated hemorrhage. These features can be assessed without IV contrast, often using secondary signs of underlying mass; however, adding IV contrast adds sensitivity and specificity to directly visualize smaller lesions. Overall, CT has decreased sensitivity and specificity to pathology in the brain with overall less gray-white matter differentiation compared with MRI [16,17,23]. CT is effective in the assessment of tumors that contain dystrophic calcifications, such as oligodendrogliomas and tuberous sclerosis [23].
Seizures and Epilepsy. MRI Functional (fMRI) Head There is no relevant literature regarding the use of fMRI in the evaluation of known seizure disorder with changes in seizure semiology unless it is in the setting of presurgical planning. Seizures and Epilepsy MRI Head In the setting of interval changes of seizure semiology, MRI is the study of choice to evaluate for new structural lesions [17,34]. MRI is the modality of choice in assessment of the progression of known lesions, and as such is an important tool for prognostic considerations [17], and the use of specific protocols IV contrast considered depending on the underlying etiology. Some authors advocate neuroimaging only if there are focal findings on a neurologic examination [17]. One study, which evaluated repeat MRI in seizure patients, including those with change in seizure semiology, demonstrated a 21% increase of findings, which were not identified in initial MRI scans [32]. HMPAO SPECT or SPECT/CT Brain Ictal and Interictal There is no relevant literature regarding the use of SPECT or SPECT/CT in the evaluation of known seizure disorder with changes in seizure semiology unless it is in the setting of presurgical planning. Variant 5: Known seizure disorder. History of tumor. CT Head CT can assess for interval changes in tumor and associated edema, mass effect, hydrocephalus, and tumor- associated hemorrhage. These features can be assessed without IV contrast, often using secondary signs of underlying mass; however, adding IV contrast adds sensitivity and specificity to directly visualize smaller lesions. Overall, CT has decreased sensitivity and specificity to pathology in the brain with overall less gray-white matter differentiation compared with MRI [16,17,23]. CT is effective in the assessment of tumors that contain dystrophic calcifications, such as oligodendrogliomas and tuberous sclerosis [23].