The symptoms of thiamine deficiency vary considerably and asymptomatic cases; i.e., subclinical thiamine deficiency (SCTD), are known to exist. However, there is no information available on the treatment of SCTD.

We report a patient who underwent intravenous thiamine replacement therapy for about a month after being diagnosed with SCTD, but who developed SCTD again about three weeks after finishing the treatment.

The patient was a 64-year-old woman who, after starting treatment for cervical cancer, complained of anxiety and underwent an initial psychiatric examination. The psychiatric diagnosis was an adjustment disorder. Based on the possibility of SCTD complications due to her decreased appetite and weight loss, her serum thiamine concentration was measured and found to be low. Therefore, thiamine was administered intravenously for 29 days. At the end of treatment, thiamine administration was discontinued as there were no apparent neuropsychiatric symptoms or problems with appetite. Twenty-three days later, there were still no problems with appetite or neuropsychiatric symptoms, but a follow-up blood sample revealed that her serum thiamine was again below the normal range.

Currently, there is no information available regarding the diagnosis and treatment of SCTD in cancer patients. In some cases, such as this case, the deficiency recurs without any symptoms indicative of SCTD; therefore, further examination for diagnosis and treatment is necessary.

Nivolumab has become an effective treatment option for cancer in various sites; however, this drug may cause immune-related adverse effects due to its mechanism of action. Furthermore, little has been reported on thiamine deficiency (TD) in patients receiving nivolumab treatment.

From a series of cancer patients, we reported a patient with recurrent renal cell carcinoma who developed TD after the start of nivolumab treatment.

A 74-year-old man with recurrent renal cell carcinoma was referred to the psycho-oncology department as he had lost about 4 kg and displayed a loss of energy after four cycles of nivolumab treatment. Psychiatric interviews revealed a decrease in energy. Neurological examination did not reveal any impairment in consciousness, ataxia, or ocular symptoms. He did not develop appetite loss. The malabsorption or overconsumption of some nutrients is thought to occur due to the rapid loss of weight; thus, a reduction in vitamin B1, which has a short storage period in the body and is often deficient in cancer patients, was suspected. The diagnosis of TD was supported by the patient's abnormally low serum thiamine level.

In patients treated with nivolumab, it is necessary to pay careful attention to TD when proceeding with the treatment. It is hoped that future research may reveal the link between nivolumab administration and TD.

Thiamine deficiency (TD) is recognized in various kinds of disease with associated loss of appetite including cancer. However, it has not been recognized to date in bereaved partners after spousal loss from cancer.

From a series of bereaved partners who lost a spouse to cancer, we report on those who developed TD after bereavement.

Case 1 was a 57-year-old woman who sought consultation at our “bereavement clinic.” Her husband had been diagnosed with pancreatic cancer one year earlier and had died one month previously. At the first visit, she was observed to suffer depression, anxiety, and decreased appetite. Neurological, blood, and biochemical examinations did not reveal any noteworthy findings. She was diagnosed with uncomplicated bereavement. Detailed examination revealed that her appetite had been markedly decreased for approximately five weeks. The diagnosis of TD was supported by her abnormally low serum thiamine level. Case 2 was a bereaved 73-year-old male who had lost his wife to hypopharyngeal cancer one month previously after a five-year illness. He had shown a lack of energy for the month preceding his wife's death, but because there was no improvement after her death, his family recommended he seek consultation at our “bereavement clinic.” He was suffering from major depressive disorder. Detailed examination revealed that his appetite had been decreased for more than two weeks. Again, the diagnosis of TD was supported by his abnormally low serum thiamine level.

These reports demonstrate that there is a possibility that bereaved could develop TD after the loss of a loved one. TD should be considered whenever there is a loss of appetite lasting for more than 2 weeks, and medical staff should pay careful attention to the physical condition of the bereaved to prevent complications because of TD.

Thiamine deficiency (TD) is recognized in various kinds of disease with associated loss of appetite including cancer; however, TD has not been recognized in the family caregivers of cancer patients to date.

From a series of cancer patient caregivers, we reported an aged family caregiver who developed TD while caring for the cancer patient.

The caregiver was a 90-year-old male. He had been accompanying his wife, who was diagnosed with colon cancer 4 years previously, on hospital visits as the primary caregiver, but because of psychological issues, he was recommended to visit the psycho-oncology department's “caregiver's clinic” for a consultation. Detailed examination revealed that his appetite had been only about 50% of usual from about one year before, and he had lost 12 kg in weight in one year. The diagnosis of TD was supported by his abnormally low serum thiamine level.

This report demonstrates that there is a possibility that care providers could develop TD from the burdens associated with caregiving. TD should be considered whenever there is a loss of appetite lasting for more than 2 weeks, and medical staff should pay careful attention to the physical condition of care providers to prevent complications resulting from TD.

Although thiamine deficiency (TD) and Wernicke encephalopathy (WE) are not rare in cancer patients, the cases reported to date developed TD and/or WE after treatment had started.

From a series of cancer patients, we report a patient diagnosed with TD without the typical clinical symptoms of WE at the preoperative psychiatric examination.

A 43-year-old woman with ovarian cancer was referred by her oncologist to the psycho-oncology outpatient clinic for preoperative psychiatric evaluation. Her tumor had been growing rapidly before the referral. Although she did not develop delirium, cerebellar signs, or eye symptoms, we suspected she might have developed TD because of her 2-month loss of appetite as the storage capacity of thiamine in the body is approximately 18 days. The diagnosis of TD was supported by abnormally low serum thiamine levels.

Cancer therapists need to be aware that thiamine deficiency may occur even before the start of cancer treatment. In cases with a loss of appetite of more than 2 weeks’ duration, in particular, thiamine deficiency should be considered if the tumor is rapidly increasing, regardless of the presence or absence of delirium.

Wernicke 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.

From a series of WE patients with cancer, we report a lung cancer patient who developed WE during treatment with nivolumab.

A 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.

We 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.

Wernicke encephalopathy (WE) is a neuropsychiatric disorder caused by thiamine deficiency, and is sometimes overlooked because of the diversity of clinical symptoms.

From a series of WE patients with cancer, we report a lung cancer patient who developed WE, the main symptom of which was agitation.

A 50-year-old woman with lung cancer was referred to our psycho-oncology clinic because of agitation lasting for three days. No laboratory findings or drugs explaining her agitation were identified. Although the patient did not develop delirium, ophthalmoplegia, or ataxia, WE was suspected because she experienced a loss of appetite loss lasting 5 weeks. This diagnosis was supported by abnormal serum thiamine and disappearance of agitation one hour after intravenous thiamine administration.

This report emphasizes the clinical diversity of WE and indicates the limits of the ability to diagnose WE from typical clinical symptoms. The presence of a loss of appetite for more than two weeks may be the key to the accurate diagnosis of WE.

Wernicke's encephalopathy (WE) is a neuropsychiatric disorder caused by a thiamine deficiency. Although WE has been recognized in cancer patients, it can be overlooked because many patients do not exhibit symptoms that are typical of WE, such as delirium, ataxia, or ocular palsy. Furthermore, outpatients with WE who intermittently present at psycho-oncology clinics have not been described as far as we can ascertain.

This report describes two patients who did not exhibit the complete classic triad of symptoms among a series with cancer and WE, and who attended a psycho-oncology outpatient clinic.

Case 1, a 76-year-old woman with pancreatic cancer and liver metastasis, periodically attended a psycho-oncology outpatient clinic. She presented with delirium and ataxia as well as appetite loss that had persisted for 8 weeks. We suspected WE, which was confirmed by low serum thiamine levels and the disappearance of delirium after thiamine administration. Case 2, a 79-year-old man with advanced stomach cancer, was referred to a psycho-oncology outpatient clinic with depression that had persisted for about 1 month. He also had appetite loss that had persisted for several weeks. He became delirious during the first visit to the outpatient clinic. Our initial suspicion of WE was confirmed by low serum thiamine levels and the disappearance of delirium after thiamine administration. The key indicator of a diagnosis of WE in both patients was appetite loss.

This report emphasizes awareness of WE in the outpatient setting, even when patients do not exhibit the classical triad of WE. Appetite loss might be the key to a diagnosis of WE in the absence of other causes of delirium.

Thiamine is an essential coenzyme for oxidative metabolisms; however, it is not synthesized in the human body, and the average thiamine storage capacity is approximately 18 days. Therefore, thiamine deficiency (TD) can occur in any condition of unbalanced nutrition. If TD is left untreated, it causes the neuropsychiatric disorder Wernicke encephalopathy (WE). Although WE is a medical emergency, it is sometimes overlooked because most patients with WE do not exhibit all of the typical symptoms, including delirium, ataxia, and ophthalmoplegia. If all of the typical clinical symptoms of WE are absent, diagnosis of TD or WE becomes more difficult.

From a series of cancer patients, we reported three patients who developed TD without the typical clinical symptoms of WE.

A 69-year-old woman with pancreatic body cancer receiving chemotherapy with paclitaxel and gemcitabine for six months. Her performance status (PS) was 1. A detailed interview revealed that she had appetite loss for six months. Another 69-year-old woman with ovarian cancer received nedaplatin; her PS was 0. A detailed interview revealed that she had appetite loss for three months. A 67-year-old woman with colon cancer receiving ramucirumab in combination with second-line fluorouracil with folinic acid and irinotecan. Her PS was 1. A detailed interview revealed that she had appetite loss for three weeks. None exhibited typical clinical signs of WE, but they developed appetite loss for six months, three months, and three weeks, respectively. The diagnosis of TD was supported by abnormally low serum thiamine levels.

This report emphasizes the possibility of TD in cancer patients even when patients do not develop typical clinical signs of WE. The presence of appetite loss for more than two weeks may aid in diagnosing TD. Patients receiving chemotherapy may be at greater risk for developing TD.

Wernicke encephalopathy (WE) is a neuropsychiatric disorder caused by thiamine deficiency. Several reports of WE in cancer patients are known. WE is sometimes overlooked because most patients do not exhibit its typical symptoms (e.g., delirium, ataxia, ocular palsy). If delirium is not present, a diagnosis of WE is difficult because delirium is the hallmark symptom of WE.

Taken from a series on WE in cancer, we report two patients who developed WE without delirium during periodic psycho-oncology outpatient visits.

Case 1. A 61-year-old woman with non-Hodgkin lymphoma who was periodically attending a psycho-oncology outpatient clinic developed an unsteady gait. WE was suspected because she also developed appetite loss for two weeks, and we could find no other laboratory findings to explain her unsteady gait. Our diagnosis was supported by abnormal serum thiamine and disappearance of the gait disturbance after intravenous thiamine administration. Case 2. A 50-year-old woman with breast carcinoma with bone metastasis developed an unsteady gait. WE was suspected because she also developed loss of appetite for two weeks, and no other laboratory findings could explain her unsteady gait. The diagnosis was supported by abnormal serum thiamine and disappearance of the gait disturbance after administration of intravenous thiamine.

Our report emphasizes the importance of being aware of WE, even when patients do not present with delirium. The presence of loss of appetite for more than two weeks may be the key to a diagnosis of WE.

Few reports of Wernicke encephalopathy in oncological settings have been published. Some cases of Wernicke encephalopathy are related to appetite loss; however, the degree to which loss of appetite leads to thiamine deficiency is not known.

A 63-year-old female with advanced cancer of the external genitalia was referred for psychiatric consultation because of disorientation, insomnia, and bizarre behaviors. Her symptoms fulfilled the diagnostic criteria for delirium. Routine laboratory examinations did not reveal the cause of the delirium. Thiamine deficiency was suspected because appetite loss had continued for 19 days since she had been admitted to hospital.

Intravenous administration of thiamine resulted in recovery from the delirium within three days. Serum thiamine level was found to be 16 ng/ml (normal range: 24–66 ng/ml). The clinical findings, the low level of thiamine in the serum, and the effective alleviation of delirious symptoms after thiamine administration fulfilled Francis's criteria for delirium induced by thiamine deficiency.

Clinicians must be aware of the possibility of Wernicke encephalopathy in cancer patients, especially in those with loss of appetite for longer than 18 days. The degree of appetite loss in such patients might serve as a reference. Early detection and intervention may alleviate the symptoms of delirium and prevent irreversible brain damage.

The death of a loved one is one of the most stressful events of life, and such stress affects the physical and psychological well-being of the bereaved. Dissociative amnesia is characterized by an inability to recall important autobiographical information. Dissociative amnesia in the bereaved who have lost a loved one to cancer has not been previously reported. We discuss herein the case of a patient who developed dissociative amnesia the day after the death of here beloved husband.

A 38-year-old woman was referred for psychiatric consultation because of restlessness and abnormal behavior. Her 44-year-old husband had died of pancreatic cancer the day before the consultation. On the day of the death, she looked upset and began to hyperventilate. The next day, she behaved as if the deceased were still alive, which embarrassed her family. At her initial psychiatric consultation, she talked and behaved as if her husband was still alive and in the hospital.

Her psychiatric features fulfilled the DSM–V criteria for dissociative amnesia. The death of her husband had been very traumatic for her and was considered to have been one of the causes of this dissociation.

This report adds to the list of psychiatric symptoms in the bereaved who have lost a loved one to cancer. In an oncology setting, we should consider the impact of death, the concomitant defense mechanisms, and the background of the families.

Family caregivers of cancer patients suffer from physical, psychological, and social distress and therefore are often referred to as second order patients. Akathisia is a common side effect of antipsychotics and antidepressants that causes great discomfort and even agitation and is often described by patients administered these drugs as the most distressing side effect of their treatment. Several studies of akathisia as a cause of distress in cancer patients have been reported. However, akathisia has not been reported as a cause of distress in family caregivers of cancer patients.

A 74-year-old spouse caregiver who was under treatment for major depressive disorder was not able to visit the hospital where her husband, a terminally ill cancer patient, was being treated. Initially, the spouse caregiver thought that she could not visit the hospital because of the symptoms of her depression and her grief about losing her husband. However, careful clinical examination revealed that she was suffering from akathisia in addition to her grief.

Discontinuation of her sulpiride treatment resulted in the disappearance of her akathisia symptoms, and therefore she became able to visit the hospital and care for her terminally ill husband.

Drug induced akathisia is a cause of distress in spouse caregivers taking certain drugs. It is important for clinicians to realize that family caregivers might suffer from not only socioeconomic, physical, and psychological problems but also side effects of medication.

Akathisia is a common adverse effect of antipsychotics and, less commonly, antidepressants. Akathisia can cause great discomfort and is often described by the patient as a most distressing sensation; however, the condition is often underdiagnosed or misdiagnosed. In oncological settings, neuroleptics and antidepressants that induce akathisia are also administered. However, reports of akathisia in oncology settings are few and a case of akathisia in a bedridden patient has not been reported as far as we know.

A 72-year-old man with esophageal cancer who could not sit down or stand up was administered 5 mg/day haloperidol to relieve agitation as a symptom of major depressive disorder. Three days after the administration of haloperidol, the agitation had become worse. Careful observation revealed that the patient sometimes showed slight rubbing movement of the lower extremities and slight twisting movements of the body, which were not observed before the administration of haloperidol. The patient moved his body and lower extremities to relieve restlessness, which had developed after the administration of haloperidol. Although symptoms were atypical, akathisia was suspected and discontinuation of haloperidol resolved the symptoms.

In patients with poor performance status, clues leading to the correct diagnosis of akathisia might be absent, which would not be the case in patients who were able to walk, stand up, or sit down. Careful observations of patients before and after the administration of drugs that may cause akathisia may be required to ensure correct diagnosis.

The death of a person is a stressful event. Such stress affects the physical and psychological well-being of the bereaved. As an associated mental disorder, major depressive disorder (MDD) is common. Some dream of the deceased, and these dreams are called bereavement dreams. Some MDD patients also experience dreams. These two types of dreams are sometimes difficult to differentiate. The dream of the bereaved might be only a bereavement-related dream, yet it might be a symptom of MDD. Herein, we report one patient who had distressing dreams after the death of her mother.

A 63-year-old woman was referred for psychiatric consultation because of generalized fatigue and insomnia. Questioning her about recent events, she said that her mother had died of colonic carcinoma 5 months previously. Two months after the death, she suddenly started dreaming of her mother, getting angry with her almost every night. Generalized fatigue, insomnia, and distressing dreams appeared simultaneously. The dream caused much distress, making her afraid to fall asleep.

Her psychiatric features fulfilled the DSM-IV-TR criteria for MDD, single episode. The death of her mother was considered to be one of the causes of MDD. She was administered 25 mg/day of sertraline hydrochloride. After that, her symptoms gradually disappeared, and the frequency of distressing dreams was reduced. Five months later, physical and psychiatric symptoms of MDD were completely resolved. Subsequently, she has not suffered from any distressing dreams of her mother.

This case indicates that dreams experienced after the death of a loved one should not be regarded simply as bereavement dreams. Some of the dreams may be symptoms of MDD. If the dreams are the symptoms of MDD, antidepressant treatment as well as psychotherapy may be useful. Therefore, we should avoid regarding symptoms of MDD as reactions to bereavement.