Tuesday, May 17, 2016

Messianic revelation with postictal psychosis

Arzy S, Schurr R. "God has sent me to you": Right temporal epilepsy, left prefrontal psychosis. Epilepsy Behav. 2016 May 10;60:7-10.

Religious experiences have long been documented in patients with epilepsy, though their exact underlying neural mechanisms are still unclear. Here, we had the rare opportunity to record a delusional religious conversion in real time in a patient with right temporal lobe epilepsy undergoing continuous video-EEG. In this patient, a messianic revelation experience occurred several hours after a complex partial seizure of temporal origin, compatible with postictal psychosis (PIP). We analyzed the recorded resting-state EEG epochs separately for each of the conventional frequency bands. Topographical analysis of the bandpass filtered EEG epochs revealed increased activity in the low-gamma range (30-40Hz) during religious conversion compared with activity during the patient's habitual state. The brain generator underlying this activity was localized to the left prefrontal cortex. This suggests that religious conversion in PIP is related to control mechanisms in the prefrontal lobe-related processes rather than medial temporal lobe-related processes.

From the paper:

Eight hours following the last seizure, while lying in bed, the patient abruptly “froze” and stared at the ceiling for several minutes, stating later that he felt that God was approaching him. He then started chanting prayers quietly, looked for his Kippa and put it on his head, chanting the prayers more excessively. Then, abruptly, he yelled “And you are Adonai (name of the Hebrew God) the Lord!”, stating later that god had revealed to him, ordering him to bring redemption to the people of Israel. The patient then stood up, detached the EEG electrodes from his skin, and went around the department trying to convince people to follow him, stating that “God has sent me to you”. When further questioned, he said that he does not have a concrete plan, but he is sure that God is going to instruct him what he and his followers should do on their way to redemption. In an in-depth psychiatric evaluation, the patient was diagnosed as suffering from postictal psychosis (PIP), with no other psychiatric illness. The patient was treated with olanzapine. The psychotic state resolved within several hours…

Comparison of EEG signals recorded in resting state during delusional religious conversion and with those during the nonpsychotic phase using power frequency analysis, and topographical statistical comparison tests revealed a significantly increased duration of a specific topographic FFT map in the low-gamma band (30–40 Hz; mean ± std of 180 ± 160 ms in the PIP phase compared with 3 ± 9 ms in the non-PIP phase; p < 0.01 after Bonferroni correction). Notably, only the map's duration, restricted to this frequency band, showed such a significant increased activity during religious conversion. The neural EEG generators underlying this map were localized to the left prefrontal cortex. No such differences were found in any other frequency band, nor in 12 control subjects in which the same analysis was conducted on two periods with the same time interval.

The pathophysiological mechanisms of PIP are poorly understood. As PIP occurs frequently in the framework of presurgical video-EEG monitoring, data are, nevertheless, available in the form of both continuous EEG recording as well as neuroimaging. With respect to EEG, several studies have reported frequent interictal discharges in patients with PIP, suggesting that ictal activity in the temporal lobe is directly related to this kind of psychosis.

Postictal psychosis appears almost exclusively in patients with temporal lobe epilepsy, predominantly with MTS . Most of the reported patients suffered from bilateral MTS/aberrant temporal activity, though unilateral MTS was also described . Our patient suffered from prominent right MTS with bilateral independent interictal discharges. The similarity between temporal lobe phenomena and psychotic symptoms does not necessarily imply common underlying mechanisms for the two sets . Moreover, the delusion of messianic conversion, as occurred in our patient, may be classified as beliefs of grandeur, reference, and religious significance, similar to schizophrenic delusions, which involve influence, persecution, and self-significance, rather than classical semiology of TLE. Taken together, the recurrent findings over studies of PIP revealing mesial temporal epilepsy and PFC aberrant activity during PIP point to a disturbance of a large-scale network, which encompasses both the PFC and the MTL. Such a network may be the default mode network (DMN), which manages self-referenced activity and mental orientation to the surrounding environment , and is known to be disturbed in psychosis.

Previous studies have speculated that PIP may be derived from repeated electrical discharges or that the epilepsy and psychosis share a common neuropathology that may be localized (with emphasis on temporal or frontal lobe).  Our study suggests an alternative explanation of a large-scale network disturbance underlying PIP.
Courtesy of a colleague.

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