Ictal visual hallucination intermittent photic stimulation: using evaluation of the clinical findings, ictal EEG, ictal SPECT, and rCBF]

A 43-year-old, right-handed woman experienced right hand paresthesias and a visual field abnormality. We attributed her symptoms to psychiatric abnormalities, due to the presence of delusions and auditory hallucinations. Upon photostimulation, she experienced left visual field hallucinations and demonstrated slow waves on the right parieto-occipital regions. The clinical and electro-encephalographic findings suggested that these episodes were epileptic seizures originating from the right occipital region. Ictal fear appeared at the end of the seizure, reflecting the spread of seizure activity to the mesial temporal region. Ictal SPECT images showed hyper-perfusion in the right occipital region and left cerebellar cortex. rCBF in the occipital lobe was significantly asymmetrical. When we encounter an epileptic patient with psychosis who has a visual hallucination, we should consider the possibility of epileptic seizure originating from the occipital lobe.