Background: Behavioral disturbances following chemotherapy with cisplatin are rare. Here, we report a patient with temporary loss of moral behavior in the setting of cisplatin-based chemotherapy for treatment of tonsillar cancer. Case presentation: A 66-year-old Caucasian male with no psychiatric or violent history was started on chemotherapy with cisplatin for treatment of tonsillar cancer. During the following weeks, the patient developed profound personality changes involving volatile emotions and impulsive aggression with verbal and physical assaults on others. Admitted to the hospital, the patient lacked any awareness that his behavior was wrong. Chemotherapy was discontinued and the patient was prescribed risperidone. Aside from mild cognitive impairment, comprehensive neuropsychological, neuroradiological and lab testing were unremarkable. Three weeks following cessation of chemotherapy, the patient had recovered to his original mental state and he was completely aware of his wrongdoing and social misconduct. Conclusion: Since neurotoxic effects of chemotherapeutics on the brain are not yet sufficiently elucidated, our case emphasizes that early signs of behavioral abnormalities in patients receiving chemotherapy should trigger comprehensive psychiatric evaluation and ongoing monitoring of the patients’ mental state.

Background: Behavioral disturbances following chemotherapy with cisplatin are rare. Here, we report a patient with temporary loss of moral behavior in the setting of cisplatin-based chemotherapy for treatment of tonsillar cancer. Case presentation: A 66-year-old Caucasian male with no psychiatric or violent history was started on chemotherapy with cisplatin for treatment of tonsillar cancer. During the following weeks, the patient developed profound personality changes involving volatile emotions and impulsive aggression with verbal and physical assaults on others. Admitted to the hospital, the patient lacked any awareness that his behavior was wrong. Chemotherapy was discontinued and the patient was prescribed risperidone. Aside from mild cognitive impairment, comprehensive neuropsychological, neuroradiological and lab testing were unremarkable. Three weeks following cessation of chemotherapy, the patient had recovered to his original mental state and he was completely aware of his wrongdoing and social misconduct. Conclusion: Since neurotoxic effects of chemotherapeutics on the brain are not yet sufficiently elucidated, our case emphasizes that early signs of behavioral abnormalities in patients receiving chemotherapy should trigger comprehensive psychiatric evaluation and ongoing monitoring of the patients’ mental state.