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 unchanged seizure semiology. Variant 4: Known seizure disorder. Change in seizure semiology or new neurologic deficit or no return to previous neurologic baseline. CT Head CT can rapidly assess for intracranial hemorrhage, stroke, vascular malformation, hydrocephalus, or progression of tumors in the setting of changes in seizure semiology or new neurologic deficit. However, CT has decreased sensitivity and specificity to pathology in the brain with overall less gray-white matter differentiation compared with MRI [16,17,23]. FDG-PET/CT Brain Changes in seizure semiology may be secondary to interval changes in an epileptogenic focus, and as such, FDG- PET may identify these changes and can provide additional information regarding the functional status of the uninvolved brain, including assessment of the functional deficit zone. Reported sensitivities of PET in the assessment of TLE ranges from 87% to 90% and extra-TLE ranges from 38% to 55% [24-27]. FDG when combined with perfusion ictal-interictal SPECT and subtraction ictal SPECT co-registered to MRI demonstrated improved detection of the epileptogenic zone [28]. A major limitation of interictal FDG-PET is that it cannot precisely identify the surgical margin because the area of hypometabolism often extends beyond the epileptogenic zone [8]. FDG- PET allows for higher-resolution and better-quality images compared with SPECT [29]. FDG-PET is an effective problem-solving tool in the workup of seizures in the setting of a negative MRI scan [30]. MEG There is no relevant literature regarding the use of MEG in the evaluation of known seizure disorder with changes in seizure semiology unless it is in the setting of presurgical planning.
Seizures and Epilepsy. 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 unchanged seizure semiology. Variant 4: Known seizure disorder. Change in seizure semiology or new neurologic deficit or no return to previous neurologic baseline. CT Head CT can rapidly assess for intracranial hemorrhage, stroke, vascular malformation, hydrocephalus, or progression of tumors in the setting of changes in seizure semiology or new neurologic deficit. However, CT has decreased sensitivity and specificity to pathology in the brain with overall less gray-white matter differentiation compared with MRI [16,17,23]. FDG-PET/CT Brain Changes in seizure semiology may be secondary to interval changes in an epileptogenic focus, and as such, FDG- PET may identify these changes and can provide additional information regarding the functional status of the uninvolved brain, including assessment of the functional deficit zone. Reported sensitivities of PET in the assessment of TLE ranges from 87% to 90% and extra-TLE ranges from 38% to 55% [24-27]. FDG when combined with perfusion ictal-interictal SPECT and subtraction ictal SPECT co-registered to MRI demonstrated improved detection of the epileptogenic zone [28]. A major limitation of interictal FDG-PET is that it cannot precisely identify the surgical margin because the area of hypometabolism often extends beyond the epileptogenic zone [8]. FDG- PET allows for higher-resolution and better-quality images compared with SPECT [29]. FDG-PET is an effective problem-solving tool in the workup of seizures in the setting of a negative MRI scan [30]. MEG There is no relevant literature regarding the use of MEG in the evaluation of known seizure disorder with changes in seizure semiology unless it is in the setting of presurgical planning.