MRI Head MRI is effective in assessing for traumatic pathology; however, because of the longer duration of the examination compared with CT and the additional evaluation necessary for safety clearance, MRI has a secondary role in the acute traumatic setting [15,16,18]. Nevertheless, MRI is recommended in patients with acute TBI if noncontrast CT is normal and there are persistent unexplained neurologic findings [19]. Compared with CT, MRI is more sensitive in assessment of smaller hemorrhages related to contusions and microhemorrhages related to diffuse axonal injury due to the use of GRE, with susceptibility-weighted imaging, which is even more sensitive. In addition, diffusion- weighted images are sensitive in detection of nonhemorrhagic diffuse axonal injury lesions [21]. The identification of microhemorrhages is important as it may predict injury severity and outcome; however, this is controversial [19,22]. In the setting of seizures with history of trauma, MRI can be considered if there are focal neurologic findings [17] as MRI is effective in the assessment of chronic blood deposition, gliosis, and encephalomacia. There is no indication for IV contrast in the setting of TBI; however, subacute contusions can enhance because of disruption of the blood-brain barrier [19]. HMPAO SPECT or SPECT/CT Brain Ictal and Interictal There is no relevant literature regarding the use of SPECT or SPECT/CT as an initial imaging study in the evaluation of new-onset seizure with history of trauma. Variant 3: Known seizure disorder. Unchanged seizure semiology. CT Head CT is less sensitive to focal pathologies when compared with MRI and is less specific in its characterization of findings, limiting its utility in the setting of known seizures that are unchanged [16,23]. However, CT can be helpful for characterizing structural findings in seizure etiologies that contain dystrophic calcifications, such as with oligodendrogliomas and tuberous sclerosis. [23]. Seizures and Epilepsy
Seizures and Epilepsy. MRI Head MRI is effective in assessing for traumatic pathology; however, because of the longer duration of the examination compared with CT and the additional evaluation necessary for safety clearance, MRI has a secondary role in the acute traumatic setting [15,16,18]. Nevertheless, MRI is recommended in patients with acute TBI if noncontrast CT is normal and there are persistent unexplained neurologic findings [19]. Compared with CT, MRI is more sensitive in assessment of smaller hemorrhages related to contusions and microhemorrhages related to diffuse axonal injury due to the use of GRE, with susceptibility-weighted imaging, which is even more sensitive. In addition, diffusion- weighted images are sensitive in detection of nonhemorrhagic diffuse axonal injury lesions [21]. The identification of microhemorrhages is important as it may predict injury severity and outcome; however, this is controversial [19,22]. In the setting of seizures with history of trauma, MRI can be considered if there are focal neurologic findings [17] as MRI is effective in the assessment of chronic blood deposition, gliosis, and encephalomacia. There is no indication for IV contrast in the setting of TBI; however, subacute contusions can enhance because of disruption of the blood-brain barrier [19]. HMPAO SPECT or SPECT/CT Brain Ictal and Interictal There is no relevant literature regarding the use of SPECT or SPECT/CT as an initial imaging study in the evaluation of new-onset seizure with history of trauma. Variant 3: Known seizure disorder. Unchanged seizure semiology. CT Head CT is less sensitive to focal pathologies when compared with MRI and is less specific in its characterization of findings, limiting its utility in the setting of known seizures that are unchanged [16,23]. However, CT can be helpful for characterizing structural findings in seizure etiologies that contain dystrophic calcifications, such as with oligodendrogliomas and tuberous sclerosis. [23]. Seizures and Epilepsy