Autoscopic phenomena: case report and review of literature

Abstract

Background: Autoscopic phenomena are psychic illusory visual experiences consisting of the perception of the image of one's own body or face within space, either from an internal point of view, as in a mirror or from an external point of view. Descriptions based on phenomenological criteria distinguish six types of autoscopic experiences: autoscopic hallucination, he-autoscopy or heautoscopic proper, feeling of a presence, out of body experience, negative and inner forms of autoscopy.

Methods and results: We report a case of a patient with he-autoscopic seizures. EEG recordings during the autoscopic experience showed a right parietal epileptic focus. This finding confirms the involvement of the temporo-parietal junction in the abnormal body perception during autoscopic phenomena. We discuss and review previous literature on the topic, as different localization of cortical areas are reported suggesting that out of body experience is generated in the right hemisphere while he-autoscopy involves left hemisphere structures.

Figure 1

Proton MR spectra from left and right temporo-parietal junction. The major metabolite peaks correspond to cholines (Cho) at 3.22 ppm, creatines (Cr) at 3.02 ppm, N-acetylaspartate (NAA) at 2.02 ppm. Axial T2 weighted MR image showing the voxel position at temporo-parietal junctions used for proton MR spectroscopy. Note that the splenium of corpus callosum is normal.

Figure 2

Interictal brain SPECT with 99mTC-ECD showed a cerebral hypometabolism in both right and left parietal and occipital lobes.

Figure 3

Autoscopic seizures. A: slow (3.5 Hz) right centro-parietal activity. Patient reported an unclear change in the awareness of her body, a feeling of strangeness. B: abrupt discharges constituted by polyspikes and sharp-waves of 100-120 uV in amplitude and in reversal phase at P4 lead. Patient reported a sudden appearance of her entire body exactly in front of her, in upright position. The double was at the same level of her real body, i.e. the real body was not felt elevated relatively to her double (unlike in out of body experience). She reported a bilocation state. The double was motionless and silent. C-D: after a few seconds the discharge involved right fronto-temporal channels and then left parieto-occipital channel. The discharge lasted about 30 seconds. We noted an impairment of consciousness. E: the final critic activity was constituted by right temporo-parietal spike and slow wave complexes (3.5-4 Hz). Patient reported again un unclear perception of her body, but the double had vanished. F: slow generalized interictal activity recorded by a previous EEG (3-3.5 Hz).