Unpleasant emotional response evoked by visual disperceptions after temporo-insular stroke

Background. Emotional processes are underestimated in stroke patients because they are often hidden by the massive clinical picture of large hemispheric strokes [1]. We describe a patient exhibiting an altered emotional response evoked by visual disperceptions after an ischemic temporo-insular stroke. A 62-years-old man came to our attention complaining feeling of disgust and fear for daily activities or circumstances that previously did not evoke negative emotions. Two years before, he had a sudden confusional state associated with spatial-temporal disorientation, dizziness, postural instability, vomiting, psychomotor agitation and photophobia. There was no familiar or personal history of psychiatric disorders or exposure to psychotropic drugs. The neurological examination showed mild left hemiparesis along with facial expression of disgust and fear with abnormal visceromotor reaction and orripilation after seeing pictures of objects or animals containing curved or tangled lines (fig. 1). Extensive blood test, cardiologic, neuropsychological and ophthalmological evaluations were normal. Electroencephalography showed intermittent theta-activity in right fronto-temporal areas. Ultrasonography detected unstable plaque in right internal carotid artery. Magnetic resonance imaging showed evidence of past ischemic infarction involving right temporo-insular regions (fig.2). Discussion: Several studies demonstrated a crucial role for the anterior insula in transforming unpleasant sensory input into visceromotor reactions and the accompanying feeling of disgust [2]. It is also known that temporal pole modulates visceral emotional functions in response to emotionally evocative perceptual stimuli. Therefore, the involvement of temporal pole could cause a decoupling of visceral emotional response to complex visual stimuli [3]. Disturbance of socioemotional behaviour negatively impacts quality of life of stroke patients.