Thiamine deficiency in the outpatient psychiatric oncology setting: A case series

B vitamins are essential for the functioning of the nervous system. Vitamin B1 (thiamine) deficiency is associated with neuropsychiatric syndromes such as Wernicke's encephalopathy (WE), which, if untreated, has an estimated mortality of 17-20%. Although the prevalence of thiamine deficiency in the general population is difficult to estimate, it is being increasingly recognized in oncology, especially in the inpatient setting. We describe three cases of thiamine deficiency (TD) in the outpatient psychiatric oncology setting.

Retrospective chart review of three adult patients, who were seen in the psychiatric oncology clinic and found to have TD on laboratory testing, was done. Patient, disease, and thiamine treatment-related information were obtained, and descriptive statistics were used to analyze the data.

The average age was 59 years, mean body mass index (BMI) was 22.00 ± 4.58 (mean ± SD), and mean thiamine level was 59.10 ± 7.69 that ranged from 45 to 68 nmol/L (normal thiamine level reference: 70-180 nmol/L). None of the patients had brain imaging nor cerebrospinal fluid analysis. Risk factors such as unbalanced nutrition, prior GI surgery, renal disease, and chemotherapy were noted.

TD can have a multifactorial etiology in oncology. Identification of TD in both inpatient and outpatient setting is important. Our report highlights how early identification of TD in the outpatient setting can help prevent further clinical progression.