Wernicke encephalopathy in patients with depression: A systematic review
Erik Oudman
Abstract
Depression is a psychiatric disorder occurring most frequently in those who have significant health problems.1-4 Depression is associated with high rates of health-care utilization and severe limitation in daily functioning.3-5 Poor intake of food is common in depression6 and nutrition can play a key role in the onset and severity of depression.7 In fact, a number of studies have shown an inverse association between thiamine (vitamin B1) levels and symptoms of depression in adults.8 A possible side-effect of prolonged vitamin B1 deficiency is Wernicke's encephalopathy (WE), a neuropsychiatric disorder characterized by ataxia, muscle incoordination, memory loss, delirium, confusion, and ocular abnormalities. The classic triad of WE symptoms consists of ataxia, ocular abnormalities, and mental status change.3 Although the most common cause of WE is vitamin B1 deficiency after severe alcoholism, other causes have also been described in the literature. As descriptions in the literature have not yet been reviewed in detail, and it is relatively unknown that malnutrition in depression can lead to WE, the aim of this study was to review the clinical characteristics of WE that have developed in the context of depression in the absence of an alcohol use disorder. The methods, flow-chart of article selection, and references to all included case studies are presented in Appendix S1. We identified 21 case descriptions in the published literature. The average age in case descriptions was 47.2 years (SD: 16.7 years), with a range between 20 and 79 years, suggesting that both young and older patients with depression could be at risk for WE. In seven patients, diminished food intake was the primary etiology for WE in depression. In six patients, a loss of vitamins because of vomiting was the primary etiology of WE in depression. Three cases had diarrhea leading to WE, due to a loss of vitamins. Five patients had forms of cancer and a depression leading to WE, due to an increased demand for thiamine. In nine cases, weight loss was reported in detail, with an average weight loss of 14.9 kg (SD: 10.5 kg). All cases are reported in Table 1. Depression with a suicide attempt, renal failure, total gastrectomy for gastric cancer Depression, hypogammaglobulinemia, pyelonephritis, pneumonia, and severe urticarial A full WE triad was present in eight out of 21 cases. This relative occurrence of WE cases presenting with a full triad following depression seems to be higher than that seen earlier in alcoholics with WE (16%).3 In 20 out of 21 cases, mental status change, such as amnesia, loss of consciousness, or disorientation, was reported. In 16 out of 21 cases, ataxia was reported. Here, eight out of 21 cases were reported to show ocular signs. In 10 out of 15 case descriptions, MRI revealed radiological alterations in the thalamic area of the brain. In 12 patients, treatment of WE was described in detail. Of importance, low levels of thiamine were given in five patients (<500 mg/day), possibly causing residual cognitive decline in three patients. Just one patient receiving higher doses of thiamine developed Korsakoff's syndrome. None of the patients received optimal thiamine dosing of three times 500 mg i.v. or i.m. per day.9 Depression is characterized by diminished or increased food intake.8 Rapidly losing weight and somatic comorbidity can lead to severe complications of depression. Patients diagnosed with depression are at risk for malnutrition. Severe malnutrition can lead to WE. Nine cases reported WE in relatively uncomplicated depression, and 12 cases reported WE in depression with somatic comorbidity. Patients diagnosed with WE should be treated with 500 mg of thiamine i.v. or i.m./three times per day, according to recent guidelines.3, 9 Korsakoff's syndrome, a chronic neuropsychiatric disorder, developed in three out of five WE patients receiving less than 500 mg thiamine per day. Of seven WE patients who received more than 500 mg per day, only one developed Korsakoff's syndrome. A limitation of this review is that the diagnosis of depression was not substantiated with DSM classification in the majority of reports. The nature and extent of the depression is therefore not clear in the reviewed cases. In conclusion, depression is a risk factor for developing malnourishment. Malnourishment-related WE is a rare but severe and preventable consequence of depression, following starvation, vomiting, or diarrhea. WE can be fully prevented by supplying prophylactic thiamine given parenterally in patients with depression. After onset of symptoms, rapid treatment with high doses of thiamine is still a life-saving measure, directly influencing the core symptoms of WE. There are no conflicts of interest for the author. Appendix S1. Supporting information. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.