Current-source Analysis of Interictal Spikes in a Patient With Ictal Crying

Ictal crying has been associated with ictal activities in the medial frontal or medial temporal area of the nondominant hemisphere. We applied current-source analysis to the interictal spikes of a patient with episodes of ictal crying without sad feelings, but fear sensation. The current sources were in the medial frontal area of both cerebral hemispheres, the temporal area and the posterior cingulate gyrus of the right hemisphere.

Currrent Source Analysis of Interictal Spikes in a Patient With Ictal Grimacing

Facial grimacing can be a manifestation of complex partial seizures from the temporal lobe. We observed a case of seizure with facial grimacing and partial loss of consciousness during an electroencephalography recording. The recording revealed interictal spikes on the left-sided inferior temporal electrodes and ictal discharges starting on the same electrodes. The current source appeared to be in the inferior and lateral temporal areas of the left cerebral hemisphere. These results show that it is possible to localize the current sources responsible for interictal spikes.

Correlation of FDG PET Hypometabolism with Interictal Spike Frequency during FDG Distribution Phase in Temporal Lobe Epilepsy

BACKGROUND: Although hypometabolism of positron emission tomography (PET) helps lateralization of epileptic focus in temporal lobe epilepsy (TLE), the mechanism of PET hypometabolism (PET-Hypo) is still controversial. We investigated whether interictal spike frequency during distribution phase of 18F-fluorodeoxyglucose (DP-FDG) correlates with the degree of PET-Hypo in TLE. METHODS: FDG PET was performed in 21 TLE patients. In PET, polar, mesial, anterior, middle and posterior temporal ROIs (region of interests) were determined in superior, middle and inferior transtemporal planes. PET Asymmetry index (AI) of each ROI was obtained by (right-left)/(right+left) x 2. Scalp EEG was recorded from 30 min prior to FDG injection until the end of scanning. Interictal spikes on temporal electrodes (F7, F8, FT9, FT10, T3, T4, T5 and T6) were counted during DP-FDG. Left-Right difference of spike numbers on electrodes of both temporal regions was obtained by subtracting spike number of right temporal region from that of left side. RESULTS: Average number of interictal spikes during FDG-DP was 11.5 per patient. Distributions of spikes were anterior temporal (F7, F8, FT9, FT10):70.7%, mid-temporal (T3,T4):29.3%, posterior temporal (T5,T6):0%. Left-Right difference of spike number was strongly correlated with PET AI of whole temporal region (r=0.655, p=0.002). Lateralization of all PET-Hypo was concordant to that of interictal spike dominance during DP-FDG although 2 cases showed false lateralization of epileptic focus by PET. CONCLUSIONS: FDG PET hypometabolism was significantly correlated with DP-FDG interictal spike numbers. Anterior and polar temporal regions showed the best correlation. PET-Hypo may reflect not only permanent functional deficit but also transient regional cerebral dysfunction.

Modulation of Interictal Spikes by Sleep Structure in Complex Partial Seizure

We analyzed interictal spikes of complex partial seizure by two parameters of sleep structure. They are macrostrure and microstructure of sleep. The macrostructure of sleep is traditional parameter and includes REM and NREM sleep. The microstructure of sleep is recently identified modalities of arousal control during NREM sleep: (a) the cyclic alternating pattern (CAP) expressed by alternating and successive phasic fluctuation of sleep; and (b) non-CAP(NCAP) characterized by prolonged stable periods of EEG. We performed polygraphical analysis of extended daytime-sleep of eight patients with complex partial seizure. The mean spike index(SI) was 4.9+3.6. The percentage of CAP time in total NREM was 50.7+5.8 and phase A in CAP time was 32.5+4.2. Significant increase in discharge rates was observed in NREM compared with REM sleep (pO. 05). Spiking activities were significantly enhanced during CAP sleep. Patients showed significant SI differences between CAP and NCAP sleep (p