Wernicke's encephalopathy: a more common disease than realised. A neuropathological study of 51 cases

Mechanisms of neuronal cell death in Wernicke's encephalopathy

Wernicke's Encephalopathy (WE) is a serious neurological disorder resulting from thiamine deficiency, encountered in chronic alcoholics and in patients with grossly impaired nutritional status. Neuropathologic studies as well as Magnetic Resonance Imaging reveal selective diencephalic and brainstem lesions in patients with WE. The last decade has witnessed major advances in the understanding of pathophysiologic mechanisms linking thiamine deficiency to the selective brain lesions characteristic of WE. Activities of the thiamine-dependent enzyme alpha-ketoglutarate dehydrogenase, a rate-limiting tricarboxylic acid cycle enzyme are significantly reduced in autopsied brain tissue from patients with WE and from rats treated with the central thiamine antagonist, pyrithiamine. In the animal studies, evidence suggests that such enzyme deficits result in focal lactic acidosis, cerebral energy impairment and depolarization resulting from increased release of glutamate in vulnerable brain structures. It has been proposed that this depolarization may result in N-Methyl-D-Aspartate receptor-mediated excitotoxicity as well as increased expression of immediate early genes such as c-fos and c-jun resulting in apoptotic cell death. Other mechanisms involved in thiamine deficiency-induced cell loss may involve free radicals and alterations of the blood-brain barrier. Additional studies are still required to identify the site of the initial cellular insult and to explain the predilection of diencephalic and brainstem structures due to thiamine deficiency.

Wernicke-Korsakoff syndrome in Sydney hospitals after 6 years of thiamin enrichment of bread

OBJECTIVES

To estimate the incidence of Wernicke's encephalopathy (WE) and Korsakoff's psychosis (KP) before and after the introduction of thiamin enrichment of bread in Australia.

DESIGN AND SUBJECTS

Inpatient records were examined in 17 major public general hospitals in greater Sydney for the 4 years 1993-96 (inclusive) with the International Classification of Diseases (ICD) 9 diagnoses 265.1 (WE), 291.1 and 294.0 (KP). Relevant clinical data were recorded on a specially designed form so that cases could be classified as confirmed or probable WE, confirmed or probable KP, confirmed or probable Wernicke-Korsakoff syndrome (WE + KP) or not WE or KP. The average number of cases of WE + KP was 38 acute (new) cases and 69 total (acute + chronic) cases per annum for all the hospitals combined.

RESULTS

This study used the same methods as our earlier retrospective examination of Wernicke-Korsakoff cases in essentially the same hospitals for 1978-93. Records for 1993 were thus pulled twice and, while individual cases (using hospital index number) did not always coincide, the total numbers for 1993 were 69 and 70. For the 5 years after 1991 the number of acute cases of WE and KP in Sydney hospitals was 61% of the number for the 5 years before 1991 (P<0.01). There is, however, no continuing downward trend.

CONCLUSIONS

These results are consistent with a 40% reduction of the incidence of acute WE and KP since bread has been enriched with thiamin. The disease complex has, however, not been eliminated. To achieve this, further public health action would be needed, such as addition of thiamin to beer.

Prevalence of Wernicke-Korsakoff syndrome in Australia: has thiamine fortification made a difference?

OBJECTIVE

To determine the prevalence of the Wernicke-Korsakoff syndrome (WKS) in Australia and compare this with previous studies.

DESIGN AND SETTING

Prospective autopsy study at the New South Wales Institute of Forensic Medicine, 1996-1997.

METHODS

Brains of deceased people (aged over 15 years) derived from 2212 sequential autopsies performed between 1 January 1996 and 31 December 1997 were studied macroscopically and microscopically to identify cases of WKS.

MAIN OUTCOME MEASURES

Standard histological criteria for WKS and any available clinical data.

RESULTS

Twenty-five cases of WKS were identified (prevalence, 1.1%), mostly among the 5.9% of the 2212 people who had a history suggestive of alcohol abuse. Only four cases (16%) had been diagnosed during life.

CONCLUSIONS

There has been a significant reduction in the prevalence of WKS in Australia since the introduction of thiamine enrichment of bread flour. While the prevalence is still higher than in most other Western countries, further research is needed before adding thiamine to alcoholic beverages can be recommended.

Pharmacotherapies for alcohol abuse. Withdrawal and treatment

Pharmacologic management of alcoholism is only one part of the management of both alcohol dependence and withdrawal, which also includes the provision of a calm, quiet environment; reassurance; ongoing reassessment; attention to fluid and electrolyte disorders; treatment of coexisting addictions and common medical, surgical, and psychiatric comorbidities; and referral for ongoing psychosocial and medical treatment. For further discussion of these topics, the reader is referred to previously published sources. A survey of alcoholism treatment programs revealed that although benzodiazepines were the most commonly used drugs, standardized monitoring of patients' withdrawal severity was not common practice, and a significant minority of clinicians were using a variety of other drugs, some not known to prevent or treat the complications of withdrawal. Treatment should be based on the available evidence (Working Group on Pharmacological Management of Alcohol Withdrawal: American Society of Addiction Medicine Committee on Practice Guidelines: Pharmacological management of alcohol withdrawal: An evidence-based practice guideline. Unpublished draft, 1997). Patients with significant symptoms, patients with complications such as seizures or delirium tremens, and patients at higher risk for complications of alcohol withdrawal should receive benzodiazepines, particularly chlordiazepoxide, diazepam, or lorazepam, because of their safety and documented efficacy in preventing and treating the most serious complications of alcohol withdrawal. These drugs may be dosed on a fixed schedule for a predetermined number of doses on a tapering schedule over several days, or they may be administered by front-loading. An alternative approach for selected patients without seizures or acute comorbidity is symptom-triggered therapy, which individualizes treatment and decreases the duration and dose of medication administration. With either of the regimens, patients should have their withdrawal severity monitored until symptoms are resolving. Once withdrawal from alcohol is safely completed, the focus should turn to helping to prevent relapse. Disulfiram may be useful in highly motivated subsets of patients and when compliance-enhancing strategies are used. Naltrexone is useful in the broader population of patients entering treatment for alcohol dependence. These pharmacologic interventions should be given in the context of ongoing psychosocial support. There is substantial evidence that pharmacologic management of alcohol abuse and dependence is effective. As would be predicted from alcohol's myriad cellular effects, no panacea exists for alcoholism. For alcohol withdrawal, however, although treatment regimens have only recently been refined, evidence for effective treatment of symptoms and prevention of complications with benzodiazepines has been available for decades. Within the last decade, effective treatments, including naltrexone, have been shown to reduce alcohol intake in alcohol-dependent persons. Given the prevalence and cost of alcohol-related problems, all effective therapies (including pharmacologic treatments) should be considered to treat alcohol abuse and dependence.

Wernicke's encephalopathy with ballooned neurons in the mamillary bodies: an immunohistochemical study

Two cases of Wernicke's encephalopathy with the rare phenomenon of ballooned neurons in the mamillary bodies are reported. Both patients suffered from acute Wernicke's symptoms starting approximately two weeks before death. The mamillary bodies contained grossly enlarged, ballooned neurons, in one case associated with focal necrosis. The affected neurons were immunoreactive for phosphorylated neurofilament (160 and 200 kDa), and synaptophysin. Ubiquitin and alpha beta-crystallin expression were not detected. The mamillo-thalamic tract appeared normal in both cases. There was a marked associated microglial reaction, as shown by the antibody Ki-MIP. It is concluded that the ballooning of mamillary neurons reflects an acute retrograde reaction to primarily axonal damage. Rather than being a rare manifestation of the disease, these cases may constitute a typical intermediate early stage (10-15 days) in the development of Wernicke's encephalopathy).

Operational criteria for the classification of chronic alcoholics: identification of Wernicke's encephalopathy

OBJECTIVES

To establish better operational criteria for the diagnosis of Wernicke's encephalopathy. Current criteria for diagnosing Wernicke's encephalopathy require the presence of three clinical signs (oculomotor abnormalities, cerebellar dysfunction, and an altered mental state), although it has often been reported that most patients do not fulfil all these criteria.

METHODS

The clinical histories of 28 alcoholics with neurological and neuropsychological assessments and definitive neuropathological diagnoses were examined to determine clinical signs for use in a screening schedule. Operational criteria were then proposed for differentiating patients with Wernicke's encephalopathy alone or in combination with Korsakoff's psychosis or hepatic encephalopathy. The new criteria for Wernicke's encephalopathy require two of the following four signs; (1) dietary deficiencies, (2) oculomotor abnormalities, (3) cerebellar dysfunction, and (4) either an altered mental state or mild memory impairment. Reproducibility and validity testing of these criteria were performed on 106 alcoholics screened from a large necropsy sample.

RESULTS

Despite rater variability with regard to specific symptoms, within and between rater reliability for diagnostic classification using the criteria retrospectively on patient records was 100% for three independent raters. Validity testing showed that Wernicke's encephalopathy was underrecognized only when occurring with hepatic encephalopathy (50% sensitivity).

CONCLUSIONS

By contrast with current criteria, the proposed operational criteria show that the antemortem identification of Wernicke's encephalopathy can be achieved with a high degree of specificity.

Mammillary body and cerebellar shrinkage in chronic alcoholics with and without amnesia

Mammillary body and cerebellar atrophy have been described as postmorten neuropathologic markers of Korsakoff's syndrome. This study examined whether shrinkage in the mammillary bodies and cerebellum is present consistently in amnesic chronic alcoholics during life and whether the degree of abnormality in these patients differs from that in nonamnesic alcoholic and healthy controls. The severity of shrinkage in the mammillary bodies, cerebellar hemispheres, and cerebellar vermis visualizable on MRI scans was rated on a three-point scale in 33 chronic nonamnesic alcoholics, 9 amnesic alcoholics, and 20 healthy controls. Although both alcoholic groups showed significant mammillary body and cerebellar shrinkage relative to controls, the two patient groups did not differ from each other. Furthermore, four of eight amnesic patients in our sample did not demonstrate clinically significant mammillary body atrophy. These results suggest that alcoholism is associated with mammillary body and cerebellar tissue volume loss but do not provide evidence that these markers distinguish accurately between amnesic and nonamnesic patients. In addition, they suggest that visualizable mammillary body atrophy is not necessary for the development of amnesia in alcoholic patients.

Chronic alcoholism in the absence of Wernicke-Korsakoff syndrome and cirrhosis does not result in the loss of serotonergic neurons from the median raphe nucleus

Previous studies have identified alcohol, thiamine deficiency and liver disease as contributing to the neuropathology of alcohol-related brain damage. In order to examine the effects of alcohol toxicity and thiamine deficiency on serotonergic neurons in the median raphe nucleus (MnR), alcoholic and previously published Wernicke-Korsakoff syndrome (WKS) cases without liver disease, were compared with age-matched non-alcoholic controls. While there was no difference between the estimated number of serotonergic neurons in either controls or alcoholics without WKS (means of 63,010 +/- 8,900 and 59,560 +/- 8,010 respectively), a substantial loss of serotonergic neurons was previously found in WKS cases (mean of 19,050 +/- 13,140). Further analysis revealed a significant difference in the maximum daily alcohol consumption between these groups. However, analysis of covariance showed that the number or serotonergic neurons in the MnR did not correlate with the amount of alcohol consumed. Therefore, our results suggest that cell loss in the MnR can be attributed to thiamine deficiency rather than alcohol per se.

Preventing the Wernicke-Korsakoff syndrome in Australia: cost-effectiveness of thiamin-supplementation alternatives

Alcoholic Wernicke's encephalopathy has been commonplace in Australia for many years and, as this syndrome is attributed to a deficiency in the diet, it should be preventable. This study employs conventional cost-effectiveness methodology to compare the economic efficiency of several thiamin-supplementation alternatives that have been proposed for the prevention of Wernicke's encephalopathy. A series of rankings of these measures is derived from an estimated cost per case averted for each of the alternatives studied. These rankings identify the least cost-effective thiamin-supplementation alternative as that of enriching bread-making flour with thiamin.

Neuropathology of thiamine deficiency disorders

The Wernicke-Korsakoff syndrome (WKS) is the most frequently encountered manifestation of thiamine deficiency in Western society. It is commonly seen in alcoholic patients, but may also occur in patients with impaired nutrition from other causes, such as those with gastrointestinal disease or AIDS. The pathology is restricted to the central nervous system and is characterised by neuronal loss, gliosis and vascular damage in regions surrounding the third and fourth ventricles and the cerebral aqueduct. In addition to WKS, thiamine deficiency may also result in beriberi, a cardiac and peripheral nervous system disease, and it has been implicated in the pathogenesis of cerebellar degeneration and peripheral neuropathy. Thus thiamine deficiency results in significant nervous system pathology and vigilance should be maintained in the diagnosis and treatment of this readily preventable cause of disease.

Chronic alcoholics without Wernicke-Korsakoff syndrome or cirrhosis do not lose serotonergic neurons in the dorsal raphe nucleus

Despite the considerable evidence that alcoholics have perturbation of serotonergic function, there is little pathological evidence for alcohol directly affecting the nervous system. The present study aims to assess neuronal loss that occurs as a consequence of alcohol neurotoxicity in the serotonergic dorsal raphe nucleus (DRN). To that end, the brains of eight alcoholics and eight age-matched control cases were carefully screened to eliminate serious liver disease, the sequela of thiamine deficiency, Wernicke-Korsakoff syndrome (WKS), and other pathological abnormalities. Brains were formalin-fixed for 2 weeks, cut, and then immunohistochemically stained using a monoclonal PH8 antibody specific for the rate-limiting enzyme of serotonin synthesis, tryptophan hydroxylase. The morphology of the serotonin-synthesizing neurons and their average size was similar in all cases. However, there was a reduction in the staining intensity of the reaction product in the DRN serotonergic neurons of most alcoholics. Neuronal counts on spaced serial sections revealed that there were an estimated average total of 106,100 +/- 19,500 serotonergic neurons in the DRN of alcoholics and 108,300 +/- 11,800 in the DRN of controls, indicating that in most alcoholics there is no reduction in the number of these neurons. Therefore, the effect of chronic alcohol consumption on the serotonergic system, in the absence of WKS or liver disease, seems to be functional rather than neuropathological.

Wernicke's disease and schizophrenia: a case report and review of the literature

OBJECTIVES

A review of the neuropathology literature in schizophrenia suggests that some patients with this disease exhibit periventricular gliosis at postmortem examination. Several researchers have speculated that this finding is the remnant of either a prior viral infection or a gestational intraventricular hemorrhage. The present article uses a case report to hypothesize and discuss an alternate possibility to the putative gliosis, namely Wernicke's disease.

METHOD

Based on the pathological findings of our patient and a review of the literature, the author summarizes several reasons why Wernicke's disease may occur, and still be unnoticed, in some schizophrenic patients.

RESULTS

Inefficient self-care and homelessness predisposes some patients with schizophrenia to poor dietary habits and malnutrition. Similarly, the high prevalence of concurrent alcoholism in patients with schizophrenia may propitiate thiamine deficiency. The resulting brain insult may be compounded by disturbances of carbohydrate metabolism which may be peculiar to the schizophrenic process itself, or acquired, as in coincidental diabetes.

CONCLUSIONS

Since symptoms accrued to Wernicke's may often be subtle and obscured by other schizophreniform manifestations, clinicians should lower their threshold for suspecting this potentially fatal complication. The diagnostic possibility of Wernicke's should be especially entertained in schizophrenic patients who are alcoholics and/or diabetics.

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.

Alcoholism and dementia

This article reviews epidemiological, neurological, cognitive, and imaging data on alcohol-induced dementia. Recent studies indicate that "heavy alcohol use" (variously defined) is a contributing factor in 21-24% of cases of dementia. Research difficulties include lack of positive diagnostic criteria, few post-mortem studies, and no accepted pathological mechanism. Sulcal widening and ventricular enlargement (occasionally reversible) are the strongest findings in patients with alcohol-induced dementia. There is evidence for peripheral neuropathy, ataxia, sparing of language, and improved prognosis when patients with alcohol-induced dementia are compared to other dements. Case examples, etiologic theories, and recommendations for research, training, and clinical practice are included.

Severe intraventricular haemorrhage shown by computed tomography as an unusual manifestation of Wernicke's encephalopathy

Images

Acute Wernicke's encephalopathy associated with hyperemesis gravidarum: magnetic resonance imaging findings

A 25-year-old woman with hyperemesis gravidarum developed acute Wernicke's encephalopathy during prolonged intravenous fluid therapy without vitamin supplements. Delay in diagnosis led to a persistent severe neurological deficit, including coma. Gadolinium-diethylenetriaminepentaacetic acid-enhanced magnetic resonance imaging revealed symmetrical lesions around the aqueduct and fourth ventricle, which resolved after treatment with thiamine. She did not regain consciousness. This report demonstrates the diagnostic value of enhanced magnetic resonance imaging in acute Wernicke's encephalopathy.

Impaired melatonin secretion in patients with Wernicke-Korsakoff syndrome

OBJECTIVES

Melatonin (MT) undergoes circadian changes in response to external light conditions and has been implicated in the control of other circadian hormone variations. Alcohol inhibits MT secretion in healthy subjects. The purpose of the present investigation was to elucidate whether patients with Wernicke-Korsakoff syndrome (WKS) also have impaired MT secretion after a period of prolonged alcohol abstention. If so, it would be of interest to find out whether this affects cortisol rhythmicity.

DESIGN

Seven patients with WKS and 8 healthy controls were included in the study. Venous blood was sampled every 2nd h between 18.00 and 08.00 hours, and urine collected between 22.00 and 07.00 hours.

SETTING

Department of Internal Medicine, Endocrinology Section, Södersjukhuset, Stockholm.

MAIN OUTCOME MEASURES

Peak serum MT values during the night, total nocturnal MT secretion (estimated by MT incremental areas), and urinary excretion of MT were determined in each participant. Serum cortisol levels were determined in the patients at 18.00, 02.00 and 08.00 hours.

RESULTS

Patients with WKS had a markedly reduced nocturnal secretion of MT compared to healthy volunteers (MT incremental areas 0.33 +/- 0.21 vs. 1.60 +/- 0.29 nmol L-1 h-1, mean +/- SEM; P < 0.005). Amongst the patients, the serum cortisol level was higher in the morning than in the afternoon (331 +/- 46 vs. 240 +/- 52 nmol L-1; P < 0.01), and showed a nadir during the night (138 +/- 45 nmol L-1) as in normal individuals.

CONCLUSION

Patients with WKS have markedly reduced nocturnal secretion of MT. The exact mechanism behind this finding has to be further elucidated. However, it is of interest to note that despite the lack of clearcut circadian MT changes. WKS patients retain normal cortisol secretion, thus suggesting that MT rhythm may not be obligatory for the proper control of circadian cortisol rhythmicity.

Mechanisms of cell death in cholinergic basal forebrain neurons in chronic alcoholics

Tau immunoreactivity was examined in post mortem tissue from patients in three groups: neurologically-asymptomatic and neuropathologically normal alcoholics, alcoholics with Wernicke's Encephalopathy (WE) and age matched non-alcoholic controls. Tau-positive granular and fibrillary inclusions were frequently observed within the magnocellular neurons of the cholinergic nucleus basalis, within occasional nucleus basalis neurons in non-WE alcoholics, but not in controls. Tau immunoreactivity was not however observed in cortical, brainstem, diencephalic or non-cholinergic forebrain structures. Peroxidase activity was also examined within the nucleus basalis using diaminobenzidine as an indicator. The majority of neurons in the basal forebrain showed increased peroxidase activity in all WE alcoholics and in some nucleus basalis neurons of non-WE alcoholics, but was rarely seen in controls. Neighboring astrocytes also showed increased peroxidase activity. These results suggest a link between peroxidase activity and the abnormal accumulation of phosphorylated tau. The presence of tau in the nucleus basalis of alcoholics with WE suggests a thiamine-dependent mechanism in tau accumulation and cell death in the cholinergic basal forebrain.

The Korsakoff syndrome

BACKGROUND

Investigations of the Korsakoff syndrome by researchers from different disciplines have proliferated in recent years, making it apposite to review the various findings.

METHOD

This review is based on the author's knowledge of reports in the major clinical and neuropsychological journals, supplemented by Medline searches to update particular subtopics.

RESULTS

The Korsakoff syndrome is defined as a disproportionate impairment in memory, relative to other aspects of cognitive function, resulting from a nutritional (thiamine) depletion. The initial manifestations of the disorder are variable, and a persistent memory impairment can result from a non-alcoholic aetiology, although this seems to happen much less commonly than in the past - presumably because of generally higher standards of nutrition. Although there is agreement on the underlying neuropathology, the critical lesion sites for memory disorder have been debated. Recent evidence suggests that the circuit involving the mammillary bodies, the mammillo-thalamic tract and the anterior thalamus, rather than the medial dorsal nucleus of the thalamus, is particularly critical in the formation of new memories. The relationship of these deficits to thiamine depletion remains a topic of current investigation, as does the purported role of neurotransmitter depletions in the cholinergic, glutamate/GABA and catecholamine and serotonergic systems. Neuro-imaging studies have confirmed autopsy findings of more widespread structural and metabolic abnormalities, particularly involving the frontal lobes.

CONCLUSIONS

The relationship of these neuropathological, neurochemical, and metabolic abnormalities to cognitive functioning, with particular reference to specific aspects of memory processing, has been considered in some detail. Whereas structural and/or neurochemical abnormalities within the limbic/diencephalic circuits account for anterograde amnesia, some other factor, such as frontal lobe dysfunction, must underlie the severe retrograde memory loss which is characteristically found in this syndrome.

Reversible neurological deficits in a chronic alcohol abuser: a case report of Wernicke's encephalopathy

The abuse of alcohol presents daily challenges for the emergency medicine physician. Wernicke's encephalopathy represents one of the metabolic complications associated with alcoholism. A classic presentation of Wernicke's encephalopathy is reported. The patient presented to the emergency department with the chief complaint of confusion, difficulty ambulating, and visual disturbances. Following administration of intravenous thiamine, the patient's symptoms spontaneously resolved. The pathophysiology, clinical presentation and therapy of this classic disorder are discussed.

Increased densities of binding sites for the "peripheral-type" benzodiazepine receptor ligand [3H]PK11195 in vulnerable regions of the rat brain in thiamine deficiency encephalopathy

Quantitative receptor autoradiography was used to evaluate the density of high-affinity binding sites for the "peripheral-type" benzodiazepine receptor (PTBR) ligand [3H]PK11195 in brain regions of the rat at different stages of pyrithiamine-induced thiamine deficiency encephalopathy, an experimental model of the Wernicke-Korsakoff syndrome (WKS). Assessment of the density of [3H]PK11195 binding sites in thiamine-deficient animals showing no neurologic signs of thiamine deficiency encephalopathy, and revealed no significant alterations compared with pair-fed control animals in any brain region studied. Densities of [3H]PK11195 binding sites were, however, significantly increased in brain regions of the rat at the symptomatic stage, where increased densities were seen in the inferior colliculus (233% increase, p < 0.001), inferior olivary nucleus (154% increase, p < 0.001) and thalamus (up to 107% increase, p < 0.001). Histologic studies of these same brain regions revealed evidence of neuronal cell loss and concomitant gliosis. Densities of [3H]PK11195 binding sites in nonvulnerable brain regions that showed no histologic evidence of neuronal loss, such as the cerebral cortex, hippocampus, and caudate-putamen, were not significantly different from those in control animals. Increased densities of binding sites for the PTBR ligand probably reflect glial proliferation and are consistent with an excitotoxic mechanism in the pathogenesis of neuronal cell loss in thiamine deficiency encephalopathy. Positron emission tomography (PET) using [11C]PK11195 could offer a potentially useful diagnostic tool in WKS in humans.

Wernicke's encephalopathy complicating schizophrenia

Wernicke's encephalopathy producing an altered mental state may occur in malnourished psychiatric patients even in the absence of alcohol abuse. A case is reported of a woman, aged 61 years, with schizophrenia who refused her medication for four months, had the delusion she was dying from a tumour, and withdrew to her bed with a neglect of her nutrition. She was committed to hospital in a mute unresponsive state and after taking some food and fluids for four days lapsed into coma. She responded within three hours to the administration of thiamine. Clinicians need to remain vigilant to the possibility that an altered mental state in malnourished patients may be due to thiamine deficiency rather than to the primary psychiatric disorder. If doubt exists as to the presence of Wernicke's encephalopathy, then parenteral thiamine should be administered.

Thalamic vacuolation in acute Wernicke's encephalopathy [corrected]

Two patients with acute Wernicke's encephalopathy, with the diagnosis confirmed pathologically at autopsy, showed substantial vacuolation and neuronal degeneration in discrete nuclei of the thalamus. Thalamic vacuolation has not been described previously in acute Wernicke's encephalopathy. The use of frozen sections to minimize processing artifact was fundamental in demonstrating this pathology. The pathogenic mechanism underlying this change appears to be different to that seen in the more typical periventricular, mamillary body and brainstem lesions. We hypothesize that a specific neural pathway may be involved and suggest that this pathway could be the ascending nitric oxide-containing cholinergic pathway from the brainstem.

Brain lesions in alcoholics

Brain lesions in alcoholics are multifactorial in origin. Ethanol neurotoxicity, Wernicke's encephalopathy, hepatocerebral degeneration, head trauma, central pontine myelinolysis, Marchiafava-Bignami syndrome, pellagra, and premorbid pathological conditions, such as fetal alcohol syndrome, may all contribute to cognitive dysfunction in alcoholics. With the exception of ethanol neurotoxicity, all of these conditions are associated with specific neuropathological lesions. Wernicke's encephalopathy, the neurological syndrome of thiamine deficiency, is frequently overlooked during life and may cause global dementia as well as the more familiar Korsakoff's amnestic syndrome. Distinguishing ethanol neurotoxicity from nutritional deficiency can be facilitated by magnetic resonance imaging, which can visualize some of the specific macroscopic lesions of Wernicke's encephalopathy, central pontine myelinolysis, cerebellar degeneration, and Marchiafava-Bignami syndrome. Computerized morphometric studies of alcoholic brains have revealed ventricular enlargement, selective loss of subcortical white matter, and alterations in neuronal size, number, architecture, and synaptic complexity. These lesions tend to be more severe when there is coexisting nutritional deficiency or liver disease, suggesting that ethanol neurotoxicity may not be the sole cause. A search for similar lesions in nonalcoholic Wernicke's encephalopathy and nonalcoholic liver disease will help determine the specificity of these lesions.

Hypothermia, Wernicke encephalopathy and multiple sclerosis

Neurological exacerbation observed in MS patients is usually related to a demyelinating process. We report two patients where hypothermia (32.4 degrees C and 32.5 degrees C) and neurological exacerbation were probably due to a Wernicke encephalopathy (WE). The clinical features and the rapid efficiency of parenteral thiamine were suggestive of WE. Hypothermia is an exceptional symptom observed in MS and has been considered as resulting from hypothalamic demyelination; these two cases showed that WE which is another cause of reversible hypothermia, can be associated with MS.

Coma and death in unrecognized Wernicke's encephalopathy. An autopsy study

Eleven out of 36 autopsied cases of Wernicke's encephalopathy had developed coma. None of these patients had the diagnosis during life. There were six men and five women with ages ranging from 26 to 50 years (mean 36.6). Seven of these patients were heavy drinkers, three exhibited signs of severe malnutrition, whereas one was being evaluated for a disseminated gastric cancer and one was in treatment of hyperemesis gravidarum. Two patients were brought to the hospital after found unconscious at home. Neuropathological examination disclosed gross changes in the mammillary bodies in eight cases and microscopic changes in all cases. In one case there was atrophy of the anterior superior part of the vermis. Petechial hemorrhages were observed particularly in the walls of the third ventricle. Microscopically there were in addition to hemorrhages, glial proliferation, endothelial hypertrophy and necrosis of nerve cells and myelin. Central pontine myelinolysis was observed in one case. Wernicke's encephalopathy is a clinically underdiagnosed condition. Coma may mask its classical clinical picture or even be the sole manifestation. Although coma points to a poor outlook it may be reversed by thiamine administration. Any patient with coma of unknown etiology should be given parenteral thiamine.

Thiamine deficiency and Wernicke's encephalopathy in AIDS

Several neuropathological reports in the last 5 years have described brain lesions characteristic of Wernicke's Encephalopathy in patients with AIDS. Using the erythrocyte transketolase activation assay, we now report biochemical evidence of thiamine deficiency in 9/39 (23%) of patients with AIDS or AIDS-related complex. In no cases was there history of alcohol abuse nor were there clinical signs of Wernicke's Encephalopathy. Thiamine deficiency in these patients most likely results from the cachexia and catabolic state characteristic of AIDS. In view of (i) the confirmed neuropathological evidence of Wernicke's Encephalopathy in AIDS patients, (ii) the significant thiamine deficiency in these patients and (iii) the difficulties of clinical diagnosis of Wernicke's Encephalopathy, it is recommended that dietary thiamine supplementation be initiated in all newly diagnosed cases of AIDS or AIDS-related complex.

Wernicke's encephalopathy in an autopsy material obtained over a one-year period

In a material comprising 279 consecutive autopsies obtained over a one-year period there were four cases of Wernicke's encephalopathy (WE), of which three were inactive (chronic) and one was active (acute). The latter was not related to chronic alcoholism. Our findings show that WE may be regularly present in a routine autopsy series. In only one case was WE suspected clinically and none of the cases revealed macroscopic brain changes indicative of WE. We therefore suggest that sections of the mammillary bodies should be taken routinely to detect all possible cases of WE.

Cerebral lesions and causes of death in male alcoholics. A forensic autopsy study

Autopsies on 195 male alcoholics aged 30-64 years who died outside hospitals and nursing homes in Oslo from 1984 to 1988, were carried out at the Institute of Forensic Medicine, Rikshospitalet. In 127 cases brain tissue was examined neuropathologically, 86 (67.7%) showed abnormalities and 28 contained lesions of more than one type. Lesions associated with alcoholism were found in 61 cases (48%), 18 (14.2%) showed Wernicke's encephalopathy, 47 (37%) cerebellar atrophy, 2 central pontine myelinolysis and 1 hepatic encephalopathy. Subdural haematoma and/or cortical contusions were found in 30 cases (23.6%) and cerebrovascular lesions in 19 (15%). Of the 195 cases, 22 had a history of recurrent convulsive attacks of which 19 were examined neuropathologically and 13 had focal damage that could have caused epileptic fits. Although cerebral damage was more frequent among vagrants and other persons dependent on social support, 50% of the alcoholics living in their own homes were also affected. Alcohol-related disease was considered the cause of death in 15 of 127 cases examined neuropathologically and 9 of these died from acute Wernicke's encephalopathy all of whom were sober at death. Although the post mortem analyses included neuropathological examination of the brain, the cause of death remained unknown in 27 (21%) of the 127 cases.

Increased central immunoreactive beta-endorphin content in patients with Wernicke-Korsakoff syndrome and in alcoholics

beta-endorphin, adrenocorticotrophin, and alpha-melanocyte stimulating hormone were measured by radioimmunoassay in three areas of human brain at necropsy in seven subjects with Wernicke-Korsakoff syndrome and in 52 controls. Thiamin concentration in six brain areas was also measured. Mamillary body beta-endorphin concentrations were significantly increased in those with the syndrome compared with controls, and those controls with high alcohol intake showed increased mamillary body beta-endorphin compared with controls with low alcohol intake. Brain thiamin concentration was similar in both groups, with the exception of the brainstem, where it was reduced in subjects with Wernicke-Korsakoff syndrome. Thalamic beta-endorphin in controls was inversely correlated with thiamin in frontal white matter, frontal cortex, parietal white matter and parietal cortex, while beta-endorphin in the hypothalamus of patients was inversely correlated with thiamin in frontal cortex, parietal white matter, thalamus and brainstem. These results suggest that there is a disturbance of the endorphinergic system in Wernicke-Korsakoff syndrome which may be related to alcohol intake.

Progression of neurological disease in thiamin-deficient rats is enhanced by ethanol

The clinical and neuropathological consequences of either ethanol consumption or thiamin deficiency or both were examined in Wistar rats aged nine weeks divided into five groups and fed one of the following diets: a thiamin-replete (control) diet (A): a thiamin-fortified diet with water (B) or 15% ethanol (C); or a thiamin-deficient diet with water (D) or 15% ethanol (E). Rats fed diets A, B or C for 35 weeks showed no clinical signs of neurological disease at any stage and no significant brain pathology when harvested. Rats fed diets D and E progressed through a common sequence of clinical signs of neurological disease typical of acute thiamin deficiency, viz loss of coat condition, ataxia, opisthotonus and ultimately death within 10-23 weeks. The onset and progression of these stages of neurological disease were significantly earlier and faster (p less than 0.001 for proportion of opisthotonic and ataxic animals at weeks 10 and 15) in the thiamin-deficient rats that received ethanol than in those that did not. At death, the brain pathology in these two groups was limited and similar.

Thiamin status of a sample of homeless clinic attenders in Sydney

Thiamin is one of the marginally adequate nutrients in the Australian diet. The incidence and prevalence of Wernicke-Korsakoff syndrome in this country may be the highest in the world. Homeless men could be at risk for low intakes of thiamin in association with irregular high alcohol intakes. A sample of 107 homeless men from two hostels and one clinic for homeless persons in inner Sydney was investigated for nutritional status; their thiamin status is reported here. By means of 24-hour recall methods, their mean dietary thiamin intake--0.76 mg per day--was less than the National Health and Medical Research Council's recommended dietary intake of 1.1 mg per day; at 0.076 mg/MJ it was even less than the minimal requirement of 0.08 mg/MJ. It was much lower than the mean intake of 1.38 mg per day that was found in the 1983 National Dietary Survey of adults and the distribution of thiamin intakes in this study was skewed positively, with the largest intake being in the range of 0-0.1 mg per day. On clinical examination we found a high prevalence of signs that were consistent with thiamin deficiency. Twenty-four per cent of the subjects showed three-or-more of the signs of the Wernicke-Korsakoff syndrome (ophthalmoplegia, nystagmus, ataxia, peripheral neuropathy and global confusion). In assaying for red-cell transketolase levels, this subgroup showed higher thiamin pyrophosphate effects than did the whole sample. Thirty-six per cent of the whole sample showed subnormal thiamin status by the thiamin pyrophosphate effect. Thus, in this sample, homeless men showed a high prevalence of dietary, biochemical and clinical features to indicate subclinical or early clinical thiamin deficiency.

Wernicke's encephalopathy in non-alcoholics. An autopsy study

In a 5-year autopsy material constituting 6,964 autopsies, there were 52 cases of Wernicke's encephalopathy of which 12 (23%) occurred in non-alcoholics. Among 18 cases with active (acute) disease, 7 cases (39%) were found in non-alcoholics. Only 4 cases of active Wernicke's disease were diagnosed clinically, all of them in alcoholics. The predominant clinical symptoms were disorientation and depressed levels of consciousness, whereas eye symptoms were recorded in only 3 cases. None of the non-alcoholics were given specific thiamine therapy, whereas some alcoholics received large doses of the vitamin as a routine procedure. However, the thiamine therapy was often instituted too late. It is concluded that active Wernicke's encephalopathy should be considered in all patients with prolonged malnutrition and that disorientation and depressed levels of consciousness may be the predominating symptoms of the disease. Even the slightest suspicion of Wernicke's encephalopathy should prompt immediate administration of large doses of thiamine parenterally.

[Central pontine myelosis. Morphology and forensic importance]

Central pontine myelinolysis (CPM) evidently occurs more frequently than had been assumed up to now owing to the cases that have been substantiated solely on the basis of pathological anatomy. Its genesis is still unclarified. Computed tomography and magnetic resonance methods allow detection of the foci while the affected person is still alive. They are clearly capable of regression and are not automatically accompanied by a poor prognosis. Since an iatrogenic factor (forced compensation of hyponatremia) is increasingly under discussion as the cause of CPM, the condition also has substantial significance from a forensic point of view. On the basis of a prospective study on CPM confirmed in 100 brains of alcoholics, as well as 4 further cases from the forensic autopsy material, it is shown that hyponatremia is not likely to be the sole triggering factor. The course of the condition in the cases investigated shows that the capacity for action may be preserved up to death (which has occurred for other reasons) in not very pronounced CPM. In questionable violent and other unclear deaths, CPM must also be considered a possible cause of death. The various hypotheses on its etiology in the extensive literature are compared with the findings in our own cases and discussed.

The diet of steady drinkers with special reference to social variables

The influence of a number of variables on the diets of 65 steady drinkers from alcohol rehabilitation units on Merseyside, United Kingdom was investigated. All drank principally beer or spirits. Social variables studied included age, sex, living alone or with others, employment status and socio-economic status. Alcohol-related variables included quantity consumed and preferred beverage. Dietary outcome was assessed in terms of the variety of foods and the number of meals eaten per week. Living alone proved by far the most important determinant of reduced diet. Spirit drinkers ate more meals than beer drinkers, but only if living with others. Increased alcohol consumption related modestly to fewer foods and meals being consumed. Drinkers living alone constitute a much larger proportion of those entering rehabilitation programmes in Queensland, Australia than in the United Kingdom. The present findings may help to explain the high incidence in Queensland of thiamin deficiency syndromes including the Wernicke-Korsakoff syndrome.

The prevalence of the Wernicke-Korsakoff syndrome in Sydney, Australia: a prospective necropsy study

In a prospective necropsy study, the prevalence of the Wernicke-Korsakoff syndrome (WKS) in Sydney, Australia was 2.1% of adults over the age of 15 years. The population studied encompassed a wide spectrum of socio-economic and cultural backgrounds. Abuse of alcohol appeared to be the major predisposing factor to the development of the WKS in cases which were adequately documented. This high prevalence rate is in line with other clinical and pathological Australian studies and provides additional support for the idea of prevention of the WKS by the use of thiamin supplements in the Australian diet in flour, bread and perhaps alcoholic beverages.

Diencephalic amnesia: a reorientation towards tracts?

The principal thalamic and hypothalamic structures implicated in mnemonic information processing are the mediodorsal nucleus of the thalamus, the pulvinar, anterior thalamus, and laterodorsal nucleus, the mamillary body, and the mamillothalamic tract and internal medullary lamina. Determining the contribution of an individual region in memory is quite difficult as it is nearly impossible to find a circumscribed damage of only one region. On the contrary, some illnesses affecting primarily the diencephalon, such as Korsakoff's disease, tend to involve several structures together. Furthermore, even when cases with similar circumscribed diencephalic damage can be found, these will not necessarily demonstrate the same outcome on the behavioral level. Therefore, the role or contribution of individual memory-related diencephalic structures has to be inferred by comparing a number of cases and by then extracting distinct features common to a given group. Such an approach revealed that the contributions of the two fiber systems mentioned above, mamillothalamic tract and internal medullary lamina, might be more important in processing information long-term than had been acknowledged previously and might be more important than that of the nuclear masses mentioned, especially of the mediodorsal thalamus. This outcome underlines the view that emphasizing interactions between brain regions rather than single static masses will provide a more realistic picture of how the nervous system acts in information processing.

Thiamine status after major trauma

A prospective study of thiamine status in patients with severe injuries (injury severity scores greater than 12) showed that they all developed signs of severe thiamine deficiency on the basis of transketolase activity, the standard biochemical test for thiamine deficiency. This occurred within the first week after their injuries despite routine enteral or parenteral feeding including vitamin supplements. This may be due to increased requirements secondary to increased metabolic activity or increased cellular losses. An increased awareness of thiamine requirements and metabolism is essential to avoid the appearance of deficiency syndromes.

Alcohol and brain damage

1. The safe limits of alcohol intake are difficult to define because of individual variations in susceptibility to damage. The present recommendations are based largely on epidemiological studies of liver damage. 2. Recent investigations indicate that alcoholic brain damage is much more common than previously suspected. More information is required about its natural history and the characteristics of individuals most likely to suffer damage. 3. Thiamin (vitamin B1) deficiency has long been associated with brain damage and may result from a number of additive causes in the alcoholic patient. New information indicating damage to the protein moeity of some of the thiamin-using enzymes has been reviewed, as have possible mechanisms of brain cell necrosis.

Two cases of Wernicke's encephalopathy in children: an underdiagnosed complication of poor nutrition

We describe the occurrence of Wernicke's encephalopathy in two children in whom the diagnosis was not suspected during life. Postmortem examination showed changes characteristic of the disease. This preventable and treatable condition is probably underdiagnosed in poorly nourished, nonalcoholic patients of all ages.