Wernicke encephalopathy in a lung cancer patient during treatment with nivolumab

ObjectiveWernicke encephalopathy (WE) is a neuropsychiatric disorder caused by thiamine deficiency. It is recognized in various stages of the cancer trajectory but has not previously been recognized during nivolumab treatment.MethodFrom a series of WE patients with cancer, we report a lung cancer patient who developed WE during treatment with nivolumab.ResultA 78-year-old woman with lung cancer was referred to our psycho-oncology clinic because of depressed mood. Psychiatric examination revealed disorientation to time, date, and place, which had not been recognized 1 month previously. Her symptoms fulfilled the diagnostic criteria for delirium. No laboratory findings or drugs explaining her delirium were identified. WE was suspected as she experienced a loss of appetite lasting 4 weeks. This diagnosis was supported by abnormal serum thiamine and the disappearance of delirium after intravenous thiamine administration.Significance of resultsWe found WE in an advanced lung cancer patient receiving treatment with nivolumab. Further study revealed the association between nivolumab and thiamine deficiency. Oncologists should consider thiamine deficiency when a patient experiences a loss of appetite of more than 2 weeks regardless of the presence or absence of delirium.