Ictal “Doppelganger” Experience.

Purpose: To believe in another sclf (“Doppelganger” experience) connotes eithcr a sensation of another self being nearby (“leibhaftige BewuBtsein” type) or autoscopy. Such experiences can occur as a component of a simple partial seizure with psychic symptomatology. Ictal autoscopies are dividcd into (1) seeing another self as if in a familiar scene in the past (scene type): and (2) seeing another self as if in a mirror (mirror type). We here summarize features of patients with the ictal “Doppelganger” experience.

Method: Thirteen right-handed people with epilepsy with the ictal “Doppelganger” experience (3 men and 10 women: mean age, 42.5 years: range, 22–57 years) were studied.

Results: In any given seizure, “Doppelganger” experiences were preceded by I or more of subjective components, which, as depicted below, are listed in order of appearance and are linked by arrows: déjà vu → depersonalization 4 “Doppelganger” of “leibhaftige BewuBtsein” type (1 case), déjà vu depersonalization “Doppelganger” of “leibhaftige BewuBtsein” type → autoscopy of scene type (2 cases), déjà vu → depersonalization →“Doppelganger” of “leibhaftige Be- wuBtscin” type déjà autoscopy of mirror type (2 cases), déjà vu → dcpersoiialization → autoscopy of scene type (2 cases), déjà vu →“Doppelganger” of “leibhaftige BewuBtsein” type autoscopy of scene type (2 cases), déjà vu autoscopy of scene type (Icase), depersonalization 4 “Doppelganger” of “leibhaftige BewuBtsein” type (1 case), depersonalization →“Doppelganger” of “leibhaftige BewuBtsein” type → autoscopy of mirror type (Icase), elementary visual hallucination, visual illusion → autoscopy of mirror type (2cases). The interictal EEG showed temporal spike foci in 7cases with autoscopy of scene type and 2 cases with no seizure evolution further than “Doppelganger” of “leibhaftige BewuRtsein” type. Three of 4 cases of patients with seizures and the autoscopy of mirror type showed parietooccipital spike foci. Of 13 cases, the seizure focus was left in 6, right in 6, and bilateral in I. SPECT imaging revealed regions of hypoper- fusion, usually correlated to regions of EEG spiking.

Conclusion: Ictal Doppelganger experiences include features of déjà VLI depersonalization Doppelganger of leibhaftige BewuBtsein and autoscopy. SPECT imaging and interictal EEG demonstrate that the autoscopy of scene type is associated with temporal lobe foci, while autoscopy of mirror type usually is associated with parieto- occipital foci. Laterality borc no relevance to the ictal “Doppelganger” experience.