Visual hallucinations after resection of cerebral metastases: two patients with complex phantom images

Purpose Complex visual hallucinations are rarely seen in neurooncology. They are commonly observed alongside psychotic symptoms in schizophrenia or dementia, in Parkinson’s or Lewy-body disease, after opioid medications or anesthesia, and, in particular, they appear with visual impairments. Methods Here we report two normal-sighted and mentally healthy patients with unusual visual hallucinations after the resection and irradiation of brain metastases, the main features of which were persistent colorful and meaningful images with hallucinatory perseveration. Results These cases demonstrate the occurrence of complex visual hallucinations after resection of visual cortices as an effect of deafferentation, so-called visual release hallucinations or phantom images, similar to phantom pain after amputation of a limb. Conclusion This case serves to heighten awareness in the radiooncology practitioner of the occurrence of visual release hallucinations (Charles Bonnet syndrome) related to multidisciplinary treatment of brain metastases.