Regional Relationships Between Focal Abnormalities on SPECTs and High Power Zones on EEG Topographies of Background H Activities in Adult Patients with Partial Epilepsies

Abstract

Purpose: In previous studics regarding adult patients with partial epilepsies, we statistically found that the relativc power of 8 band with power spectral analysis of their hackground EEGs showed significant inverse correlation with absolute rCBF values with 123Tc‐HMPAO SPECT or the binding potential of benzodiaapinc receptors with 1211 ‐ iomazcnil SPECT, i n each cerebral region including epileptic foci or even in the whole cerebral regions. As ii series of study aiming at iuvcstigating the utility of SPECT scans for the clinic of epilepsy, we examined with visual inspection whether thcrc were regional relationships between EEG topographies of H hand i n the background EEGs and focal ahnormalitics on 123Tc‐HMPAO SPECT or 2I‐iomazenil SPECT i n adult patients with partial epilepsies. Methods: Subjects were 27 adult epilcptic patients, composed of I4 mcn and I women, age range of 20–57 years old. Or the 27 patients, 6, 14, 2, and I patients had frontal, temporal, parietal, and occipital lobe epilepsies, respectively. The remaining 4 patients had u n tial epilepsies. Furthermore, 16 o l the 27 patients had intractable epilcpsics with seizure interval of days or weeks. All the subjects received 123Tc‐HMPAO SPECT and 99mI‐iomazenil SPECT scans and EEG examinations in the interictal periods, once an each within two weeks. MRI examinations were performed on 24 patients. EEG topographies of 0 band in background EEG activities were produced in the torm of 2‐dimensional brain mapping based on a quantitative analysis of the discontinuous monopolar recording of 24 sessions per EEG, each of which consisted of a continuous record of 5 second duration without artifacts or seizurc discharges. Results: Epileptic foci on EEG were definitely dctcrmiiicd in 24 of the 27 patients, and 18 of the 24 patients (75.0%) showed a regional agrccment between the epileptic EEG foci and the highest or higher power zones in the topographies of H band in background EEG. Thirteen of the 27 patients showed focal abnormalities consisting of hypoperfusion images in 123Tc‐HMPAO SPECT scans. Eight of the 13 patients (6 I .5%) had a regional agreement between the hypoperfusion areas and the highest or higher 0 power m i e s in EEG topographies, whereas 9 of the 13 patients (69.2%) showed a regional agreement between the hypoperfusion areas and epilcptic EEG foci. 99m1‐ iomazenil SPECT scans revealed focal hypoaccumulation images i n 17 of thc 27 patients. Twelve of thc 17 patients (70.6%) showed a regional agreement between the hypoaccumulation areas and the highest or higher H power xones i n EEG topographies, although 10 of the 17 patients (58.8%1) had a regional agreement between the hypoaccumulation areas and epileptic EEG foci. In addition, MRI showed focal organic lesions in 9 of the 24 patients, and 4 of the 9 patients (44.4%J) showed a regional agreement between the lesions and the highest or higher 0 power zones in EEG topographies.