Wernicke-Korsakoff syndrome in Sydney hospitals: before and after thiamine enrichment of flour.

OBJECTIVE: To estimate the incidence of Wernicke-Korsakoff syndrome (WKS) before and after the introduction of thiamine enrichment of bread flour in 1991. DESIGN: Retrospective survey of hospital records. Patient records with the diagnostic codes for Wernicke's encephalopathy (WE) or Korsakoff's psychosis (KP) were reviewed and details of acceptable cases were entered onto a data form. SETTING: All 17 major public general hospitals in the Sydney area (New South Wales), between 1978 and 1993. OUTCOME MEASURES: Numbers of confirmed or probable diagnoses of WE, KP or WKS and associated deaths, patient demographic and social characteristics and alcohol intake. RESULTS: 1,267 patients with WKS were found, with 1,012 acute cases. Although numbers of acute cases may have started to fall before 1991, numbers for the last two years were the lowest of all the 16 years (P = 0.004). Cases of KP outnumbered those of WE by about 3:1 and men outnumbered women 4:1. The peak age was 60-64 years (17%) and beer was the most commonly cited alcoholic drink (71%). The red-cell transketolase test was seldom used for diagnosis (3% of acute cases). CONCLUSIONS: The lower number of "acute" cases in 1992 and 1993 is consistent with a preventive effect of mandatory enrichment of bread with thiamine, but is not conclusive evidence. Longer follow-up of Sydney hospitals, results of postmortem examinations and follow-up in other areas of Australia are required.

An international perspective on the prevalence of the Wernicke-Korsakoff syndrome.

In the Western world previous studies have shown that the majority of cases of the Wernicke-Korsakoff syndrome (WKS), which is caused by thiamine deficiency, occur in alcoholics. However, in France, a country with one of the highest per capita consumptions of alcohol, the prevalence of the WKS was found to be only 0.4% in a small retrospective autopsy study. This figure is compared with data sent to the authors by a number of neuropathologists from the U.S.A., Europe, Scandinavia and Australia. There was no obvious correlation between the prevalence rates of the WKS, which were highest in Australia (2.8%-previously published), and per capita consumption of alcohol. Other issues such as diet, National programs for supplementation of foods with thiamine, and drinking habits are considered. The pathological diagnosis of the WKS can often be made on macroscopic examination of the brain after fixation in formalin. The mammillary bodies are smaller than normal in most cases of chronic WKS. However in this study it was found that the most common causes of small mammillary bodies were Alzheimer's disease and atrophy due to transneuronal degeneration secondary to lesions in the hippocampus.

The Wernicke-Korsakoff syndrome: a reappraisal in Queensland with special reference to prevention.

The Wernicke-Korsakoff syndrome occurs most frequently in alcoholic patients when they become thiamin deficient. First admissions to psychiatric units with the chronic component of this syndrome, Korsakoff's psychosis, peaked in Queensland in 1975-1976. The fall in hospital admission rates since this time could relate to a decline in per-capita alcohol consumption in Australia, or to more awareness of the thiamin needs of drinkers. Alternatively, the improvement may be illusory: although many cases of Wernicke's encephalopathy are being diagnosed, many of these patients are not receiving psychiatric assessment and treatment, perhaps because admission to psychiatric hospital beds is more difficult than it was formerly. Patients who are diagnosed as having Korsakoff's psychosis fare badly in the community, and have a greatly increased mortality rate than do such patients in hospital. Optimal care for such patients is necessarily costly of medical resources. Of available preventive measures, evidence is presented to support the fortification of beer with thiamin and the provision of community educational programmes. The fortification of flour with thiamin may have little impact on the thiamin-deficiency syndromes that arise in problem drinkers in Queensland.