Neuroanatomy and neuropathology associated with Korsakoff's syndrome.

Although the neuropathology of Korsakoff's syndrome (KS) was first described well over a century ago and the characteristic brain pathology does not pose a diagnostic challenge to pathologists, there is still controversy over the neuroanatomical substrate of the distinctive memory impairment in these patients. Cohort studies of KS suggest a central role for the mammillary bodies and mediodorsal thalamus, and quantitative studies suggest additional damage to the anterior thalamus is required. Rare cases of KS caused by pathologies other than those of nutritional origin provide support for the role of the anterior thalamus and mammillary bodies. Taken together the evidence to date shows that damage to the thalamus and hypothalamus is required, in particular the anterior thalamic nucleus and the medial mammillary nucleus of the hypothalamus. As these nuclei form part of wider memory circuits, damage to the inter-connecting white matter tracts can also result in a similar deficit as direct damage to the nuclei. Although these nuclei and their connections appear to be the primary site of damage, input from other brain regions within the circuits, such as the frontal cortex and hippocampus, or more distant regions, including the cerebellum and amygdala, may have a modulatory role on memory function. Further studies to confirm the precise site(s) and extend of brain damage necessary for the memory impairment of KS are required.

Influence of liver pathology on markers of postmortem brain tissue quality.

BACKGROUND: Postmortem brain tissue provides an important resource to investigate various brain disorders, including those resulting from the effects of alcohol abuse. Unlike the traditionally recognized confounders to tissue quality (e.g., coma, hypoxia), our understanding of the effects of liver disease is incomplete. The aim of this study was to determine the effects of liver pathology, and in particular cirrhosis resulting in hepatic encephalopathy (HE), on 2 postmortem brain tissue quality markers, brain pH and RNA integrity. METHODS: We measured tissue quality markers in a cohort of alcohol abuse and control cases collected by the NSW Tissue Resource Centre. Cerebellar tissue was used to evaluate both brain pH and RNA quality (as indicated by the RNA integrity number: RIN). A histological assessment was performed on each case to exclude coexisting pathologies (e.g., cerebrovascular disease, hypoxic encephalopathy, neurodegenerative disease) and to assess the presence or absence of HE. Autopsy reports were reviewed for liver pathology and toxicology. RESULTS: Analysis revealed that cases of alcohol abuse had a lower mean (±SD) brain pH, 6.46 (±0.3) as compared with the control mean 6.64 (±0.2). The mean RIN for the alcohol abuse group was 6.97 (±1.3) and controls 7.66 (±0.5). The severity of liver pathology affected both brain pH (p < 0.0001) and RIN (p < 0.0001). The comparison between cirrhotic cases highlighted increased degradation of RNA in cases with cirrhosis resulting in HE (p = 0.0095). A similar effect was seen on brain pH (p = 0.0019). CONCLUSIONS: The results show that the presence of cirrhosis and, more so, HE reduces the pH and RIN of postmortem brain tissue.

Clinical and pathological features of alcohol-related brain damage.

One of the sequelae of chronic alcohol abuse is malnutrition. Importantly, a deficiency in thiamine (vitamin B(1)) can result in the acute, potentially reversible neurological disorder Wernicke encephalopathy (WE). When WE is recognized, thiamine treatment can elicit a rapid clinical recovery. If WE is left untreated, however, patients can develop Korsakoff syndrome (KS), a severe neurological disorder characterized by anterograde amnesia. Alcohol-related brain damage (ARBD) describes the effects of chronic alcohol consumption on human brain structure and function in the absence of more discrete and well-characterized neurological concomitants of alcoholism such as WE and KS. Through knowledge of both the well-described changes in brain structure and function that are evident in alcohol-related disorders such as WE and KS and the clinical outcomes associated with these changes, researchers have begun to gain a better understanding of ARBD. This Review examines ARBD from the perspective of WE and KS, exploring the clinical presentations, postmortem brain pathology, in vivo MRI findings and potential molecular mechanisms associated with these conditions. An awareness of the consequences of chronic alcohol consumption on human behavior and brain structure can enable clinicians to improve detection and treatment of ARBD.

Neuroimaging findings in alcohol-related encephalopathies.

OBJECTIVE: Our aim was to review the emergent neuroimaging findings of alcohol-related CNS nontraumatic disorders. Alcohol (ethanol) promotes inflammatory processes, increases DNA damage, and creates oxidative stress. In addition, the accompanying thiamine deficiency may lead to Wernicke encephalopathy. Associated changes in serum osmolarity may lead to acute demyelination. CONCLUSION: Alcohol-related encephalopathies can be life-threatening conditions but can be prevented or treated, if recognized.

The importance of brain banks for molecular neuropathological research: The New South Wales Tissue Resource Centre experience.

New developments in molecular neuropathology have evoked increased demands for postmortem human brain tissue. The New South Wales Tissue Resource Centre (TRC) at The University of Sydney has grown from a small tissue collection into one of the leading international brain banking facilities, which operates with best practice and quality control protocols. The focus of this tissue collection is on schizophrenia and allied disorders, alcohol use disorders and controls. This review highlights changes in TRC operational procedures dictated by modern neuroscience, and provides examples of applications of modern molecular techniques to study the neuropathogenesis of many different brain disorders.

Interaction of thiamine deficiency and voluntary alcohol consumption disrupts rat corpus callosum ultrastructure.

The relative roles of alcohol and thiamine deficiency in causing brain damage remain controversial in alcoholics without the Wernicke-Korsakoff syndrome. Experimental control over alcohol consumption and diet are impossible in humans but can be accomplished in animal models. This experiment was designed to differentiate the separate and combined effects on the macro- and ultrastructure of the corpus callosum of thiamine deficiency and voluntary alcohol consumption. Adult male alcohol-preferring (P) rats (9 chronically alcohol-exposed and 9 water controls) received a thiamine-deficient diet for 2 weeks. There were four groups: five rats previously exposed to alcohol were treated with pyrithiamine (a thiamine phosphorylation inhibitor); five rats never exposed to alcohol were treated with pyrithiamine; four alcohol-exposed rats were treated with thiamine; and four rats never exposed to alcohol were treated with thiamine. On day 14, thiamine was restored in all 18 rats; 2 weeks later the 10 pyrithiamine-treated rats received intraperitoneal thiamine. The rats were perfused 61 days post-pyrithiamine treatment at age 598 days. Brains were dissected and weight and volumes were calculated. Sagittal sections were stained to measure white matter structures. The corpus callosum was examined using transmission electron microscopy to determine density of myelinated fibers, fiber diameter, and myelin thickness. The corpus callosum in the alcohol/pyrithiamine group was significantly thinner, had greater fiber density, higher percentage of small fibers, and myelin thinning than in the alcohol/thiamine and water/thiamine groups. Several measures showed a graded effect, where the alcohol/pyrithiamine group had greater pathology than the water/pyrithiamine group, which had greater pathology than the two thiamine-replete groups. Across all 16 rats, thinner myelin sheaths correlated with higher percentage of small fibers. Myelin thickness and axon diameter together accounted for 71% of the variance associated with percentage of small fibers. Significant abnormalities in the alcohol/pyrithiamine group and lack of abnormality in the alcohol-exposed/thiamine-replete group indicate that thiamine deficiency caused white matter damage. The graded abnormalities across the dually to singly treated animals support a compounding effect of alcohol exposure and thiamine depletion, and indicate the potential for interaction between alcohol and thiamine deficiency in human alcohol-related brain damage.

Localised reductions in gyrification in the posterior cingulate: schizophrenia and controls.

UNLABELLED: Several authors report changes in the volume and degree of cortical folding in several presumptive regions of schizophrenia patients. However, no research, to our knowledge, has looked for schizophrenia related differences in cortical volume and degree of cortical folding in post-mortem posterior cingulate cortex (PCCx). METHOD: Brain tissues from 9 people who suffered from schizophrenia (DSM-IV) and 9 controls were cut into 3 mm coronal slices. Three alternative PCCx blocks were available for research. The 3 PCCx blocks were cut into 50 microm sections. The volume and gyrification index (GI) were measured in 15 tissue sections per brain (5 sections per block). RESULTS: People who suffered with schizophrenia showed significant reductions in GI in rostral PCCx, trend reductions were seen in medial and caudal PCCx. In addition, the average volume of the rostral tissue sections was significantly lower in the schizophrenia cohort, suggesting that schizophrenia is associated with reduced volume in the rostral PCCx. However, a true volumetric assessment of the whole PCCx, rather than a limited number of sections from three alternative blocks, is needed to confirm such a hypothesis.

Myosin storage (hyaline body) myopathy: a case report.

Myosin storage myopathy/hyaline body myopathy is a rare congenital myopathy, with less than 30 cases reported in the literature. It is characterised by the presence of subsarcolemmal hyaline bodies in type 1 muscle fibres and predominantly proximal muscle weakness. Recently, a single mutation (Arg1845Trp) in the slow/beta-cardiac myosin heavy chain gene (MYH7) was identified in four unrelated probands from Sweden and Belgium. The clinical severity and age of onset was variable, despite the same disease-causing mutation and similar histological findings. Here, we report the clinical and morphological findings of two brothers of English/Scottish background with the Arg1845Trp mutation in MYH7. This case report adds to the clinical description of this rare disorder and confirms that Arg1845Trp is a common mutation associated with this phenotype, at least in the White European population.

GABA(A) receptor beta isoform protein expression in human alcoholic brain: interaction with genotype.

Chronic alcohol misuse by human subjects leads to neuronal loss in regions such as the superior frontal cortex. Reduced GABA transmission may mediate this. The expression of GABA(A) receptor beta(1), beta(2), and beta(3) isoform proteins was analyzed by western blotting in vulnerable (superior frontal cortex) and spared (primary motor cortex) cortical tissue obtained at autopsy from Caucasian subjects, and the effect of genotypes of candidate genes for alcoholism assessed. There was a significant regional difference in global isoform expression, but no significant overall group difference in beta(2) or beta(3)expression between controls and alcoholics undifferentiated by genotype in either cortical region. There were significant, regionally selective, interactions of DRD2B, SLC1A2 and APOE genotypes with beta protein expression when alcoholics were compared with controls. In each instance possession of the alcoholism-associated allele increased the beta(2):beta(3) ratio in the pathologically vulnerable region, by two distinct mechanisms. The SFC beta(2):beta(3) ratio in DRD2B-B2,B2 alcoholics was 22% higher than that in DRD2B-B1,B1 alcoholics, and 17% higher than that in DRD2B-B2,B2 controls. The SFC beta(2):beta(3) ratio in SLC1A2A603 homozygote alcoholics was 25% higher than that in alcoholics with at least one 603G allele, and 75% higher than that in SLC1A2A603 homozygote controls. The SFC beta(2):beta(3) ratio in alcoholics lacking an APOE epsilon3 allele was 73% higher than that in alcoholics with at least one epsilon3 allele, and 70% higher than that in controls without an epsilon3 allele. ADH1C genotype also differentiated cases and controls, but the effect was not localized. GABRB2 and GRIN2B genotypes were associated with significant regional differences in the pattern of beta subunit expression, but this was not influenced by alcoholism status. DRD2A and SLC6A4 genotypes were without significant effect. A restricted set of genotypes may influence subunit expression in this group of high-consumption alcoholics.

No differences in calcium-binding protein immunoreactivity in the posterior cingulate and visual cortex: schizophrenia and controls.

UNLABELLED: Schizophrenia-specific alterations in the densities of interneurons immunoreactive (ir) to the calcium binding proteins are reported for several cortical regions. However, no reported studies have searched for such differences within the posterior cingulate cortex using antibodies to a specific calcium binding protein, calbindin (Cb). AIMS: Compare the (a) relative density of Cb-ir neurons (ratio of labeled neurons to total neurons), (b) relative width of cortical layers II/III and (c) somal areas of Cb-ir neurons in people with schizophrenia and non-psychiatric age-, gender- and postmortem index-matched controls (9 per group). METHOD: Tissue from Brodmann's area (BA) 30 and 23 and an internal control region, the visual cortex (BA 18) were labeled with polyclonal Cb antibodies then Nissl counter-stained. Cb-ir neurons as well as counter-stained neurons with clearly visible nucleoli were plotted and counted within their area 1 and laminar boundaries. RESULTS: No qualitative or statistical differences in the relative density of Cb-ir neurons were observed. A trend towards a significant effect was detected in BA 30, the relative density of Cb-ir neurons for controls was greater than for schizophrenics (P=0.0518). There were no significant differences in the relative cortical widths or somal areas. The data from this study suggest that the posterior cingulate cortex may not be involved in schizophrenia, at least not as far as Cb-ir neurons are concerned.

Expression of MBP, PLP, MAG, CNP, and GFAP in the Human Alcoholic Brain.

BACKGROUND: Chronic and excessive alcohol misuse results in neuropathological damage in the cerebral cortex. The damage includes white matter loss, brain atrophy, and selective loss of neurons in the superior frontal gyrus. Chronic alcohol misuse also results in alterations in the expression of a number of genes, including a selective reprogramming of myelin gene expression in the frontal cortex. METHODS: The expression of cyclic nucleotide phosphodiesterase, glial fibrillary acidic protein, myelin-associated glycoprotein, myelin basic protein, and myelin proteolipid protein were assessed in the superior frontal gyrus and the primary motor cortex of control, uncomplicated alcoholic, and cirrhotic alcoholic cases. RESULTS: Overall, the expression of cyclic nucleotide phosphodiesterase, glial fibrillary acidic protein, myelin-associated glycoprotein, and myelin basic protein were significantly lower in the cirrhotic alcoholic cases compared with controls, with a similar tendency for myelin proteolipid protein. There was a strong correlation between the expression of the proteins studied and the brain weight of the individual case, but this interaction did not confound the overall analysis. There was no significant difference between controls and uncomplicated alcoholics. CONCLUSIONS: The loss of myelin proteins occurred without gross changes in brain pathology or brain weight and was not restricted to pathologically susceptible brain regions. It is not possible to determine whether the loss of myelin proteins in cirrhotic alcoholics is the result of cirrhosis per se or the combination of alcohol misuse and liver cirrhosis. Future studies comparing cases with alcoholic and nonalcoholic cirrhosis of the liver disease are required to elucidate this further.

No evidence for selective GABAergic interneuron deficits in the anterior thalamic complex of patients with schizophrenia.

Fewer neurons have been reported in the anterior thalamic complex (AT) of individuals diagnosed with schizophrenia in comparison to control tissue. In addition, the density of presumptive thalamo-cortical relay neurons of the AT is reported to be significantly decreased in schizophrenia compared with controls whilst total AT neuron density appears unchanged. We have investigated whether schizophrenia alters either the density of presumptive interneurons or the ratio between the two fundamental neuron types within the AT by immunohistochemically visualizing GABAergic neurons in post-mortem brain tissue from individuals with a diagnosis of schizophrenia pair-matched to tissue from normal individuals. Qualitative observations indicated no obvious differences between the two cohorts in the morphology of neurons exhibiting a GABAergic phenotype. A cell counting analysis of AT neurons revealed: (1) a non-significant 1% increase in density of GABAergic neurons in schizophrenia compared with controls and (2), a non-significant 6% increase in the percentage of neurons with a GABAergic phenotype in the schizophrenia group compared with controls. These findings suggest that a reduction of AT neuron number in schizophrenia does not alter either the morphology of neurons with a GABAergic phenotype or the ratio of neuronal phenotypes within AT.

Cytoplasmic expression of nm23 predicts the potential for cerebral metastasis in patients with primary cutaneous melanoma.

The nm23 gene is a putative tumour and metastasis suppressor gene. A number of studies have found that reduction of its expression is associated with increased metastatic potential in several human malignancies. Similarly, clinical studies have shown correlation between reduced nm23 protein expression and a poor prognosis. The aim of this study was to determine if a relationship exists between nm23 expression in primary cutaneous melanomas with or without cerebral metastases. Paraffin-embedded tissues were retrieved from 21 patients with primary cutaneous melanomas (n=21) and who subsequently developed cerebral metastases (n=24). Primary cutaneous melanomas with no regional or organ metastases within a 10 year period were used as control cases (n=34). Nm23 staining was localized in the cytoplasm of the tumour cells. Most of the control cases showed strong expression, whereas the majority of the primary melanomas with cerebral metastases showed no or weak expression of nm23. The cerebral metastases mostly showed strong expression. In summary, the results of this study may have significant prognostic implications for patients presenting with cutaneous melanoma. Patients with cutaneous melanomas with a low expression of nm23 appear to be more at risk of developing brain metastases.

Induction of HO-1 in tissue macrophages and monocytes in fatal falciparum malaria and sepsis.

BACKGROUND: As well as being inducible by haem, haemoxygenase -1 (HO-1) is also induced by interleukin-10 and an anti-inflammatory prostaglandin, 15d PGJ2, the carbon monoxide thus produced mediating the anti-inflammatory effects of these molecules. The cellular distribution of HO-1, by immunohistochemistry, in brain, lung and liver in fatal falciparum malaria, and in sepsis, is reported. METHODS: Wax sections were stained, at a 1:1000 dilution of primary antibody, for HO-1 in tissues collected during paediatric autopsies in Blantyre, Malawi. These comprised 37 acutely ill comatose patients, 32 of whom were diagnosed clinically as cerebral malaria and the other 5 as bacterial diseases with coma. Another 3 died unexpectedly from an alert state. Other control tissues were from Australian adults. RESULTS: Apart from its presence in splenic red pulp macrophages and microhaemorrhages, staining for HO-1 was confined to intravascular monocytes and certain tissue macrophages. Of the 32 clinically diagnosed cerebral malaria cases, 11 (category A) cases had negligible histological change in the brain and absence of or scanty intravascular sequestration of parasitized erythrocytes. Of these 11 cases, eight proved at autopsy to have other pathological changes as well, and none of these eight showed HO-1 staining within the brain apart from isolated moderate staining in one case. Two of the three without another pathological diagnosis showed moderate staining of scattered monocytes in brain vessels. Six of these 11 (category A) cases exhibited strong lung staining, and the Kupffer cells of nine of them were intensely stained. Of the seven (category B) cases with no histological changes in the brain, but appreciable sequestered parasitised erythrocytes present, one was without staining, and the other six showed strongly staining, rare or scattered monocytes in cerebral vessels. All six lung sections not obscured by neutrophils showed strong staining of monocytes and alveolar macrophages, and all six available liver sections showed moderate or strong staining of Kupffer cells. Of the 14 (category C) cases, in which brains showed micro-haemorrhages and intravascular mononuclear cell accumulations, plus sequestered parasitised erythrocytes, all exhibited strong monocyte HO-1 staining in cells forming accumulations and scattered singly within cerebral blood vessels. Eleven of the available and readable 13 lung sections showed strongly staining monocytes and alveolar macrophages, and one stained moderately. All of the 14 livers had strongly stained Kupffer cells. Of five cases of comatose culture-defined bacterial infection, three showed a scattering of stained monocytes in vessels within the brain parenchyma, three had stained cells in lung sections, and all five demonstrated moderately or strongly staining Kupffer cells. Brain sections from all three African controls, lung sections from two of them, and liver from one, showed no staining for HO-1, and other control lung and liver sections showed few, palely stained cells only. Australian-origin adult brains exhibited no staining, whether the patients had died from coronary artery disease or from non-infectious, non-cerebral conditions CONCLUSIONS: Clinically diagnosed 'cerebral malaria' in children includes some cases in whom malaria is not the only diagnosis with the hindsight afforded by autopsy. In these patients there is widespread systemic inflammation, judged by HO-1 induction, at the time of death, but minimal intracerebral inflammation. In other cases with no pathological diagnosis except malaria, there is evidence of widespread inflammatory responses both in the brain and in other major organs. The relative contributions of intracerebral and systemic host inflammatory responses in the pathogenesis of coma and death in malaria deserve further investigation.

Tissue distribution of migration inhibitory factor and inducible nitric oxide synthase in falciparum malaria and sepsis in African children.

BACKGROUND: The inflammatory nature of falciparum malaria has been acknowledged since increased circulating levels of tumour necrosis factor (TNF) were first measured, but precisely where the mediators downstream from this prototype inflammatory mediator are generated has not been investigated. Here we report on the cellular distribution, by immunohistochemistry, of migration inhibitory factor (MIF) and inducible nitric oxide synthase (iNOS) in this disease, and in sepsis. METHODS: We stained for MIF and iNOS in tissues collected during 44 paediatric autopsies in Blantyre, Malawi. These comprised 42 acutely ill comatose patients, 32 of whom were diagnosed clinically as cerebral malaria and the other 10 as non-malarial diseases. Another 2 were non-malarial, non-comatose deaths. Other control tissues were from Australian adults. RESULTS: Of the 32 clinically diagnosed cerebral malaria cases, 11 had negligible histological change in the brain, and no or scanty intravascular sequestration of parasitised erythrocytes, another 7 had no histological changes in the brain, but sequestered parasitised erythrocytes were present (usually dense), and the remaining 14 brains showed micro-haemorrhages and intravascular mononuclear cell accumulations, plus sequestered parasitised erythrocytes. The vascular walls of the latter group stained most strongly for iNOS. Vascular wall iNOS staining was usually of low intensity in the second group (7 brains) and was virtually absent from the cerebral vascular walls of 8 of the 10 comatose patients without malaria, and also from control brains. The chest wall was chosen as a typical non-cerebral site encompassing a range of tissues of interest. Here pronounced iNOS staining in vascular wall and skeletal muscle was present in some 50% of the children in all groups, including septic meningitis, irrespective of the degree of staining in cerebral vascular walls. Parasites or malarial pigment were rare to absent in all chest wall sections. While MIF was common in chest wall vessels, usually in association with iNOS, it was absent in brain vessels. CONCLUSIONS: These results agree with the view that clinically diagnosed cerebral malaria in African children is a collection of overlapping syndromes acting through different organ systems, with several mechanisms, not necessarily associated with cerebral vascular inflammation and damage, combining to cause death.

Changing trends in heroin-related deaths in Sydney, Australia-1995 to 1999.

This 1997-1999 study replicates an earlier one (1995-1997) in which coronial cases were reviewed at the Department of Forensic Medicine in Australia. Ten percent of the 2945 cases were considered accidental illicit drug deaths, compared to 4% in the previous study. Heroin was associated with 90% of the deaths, but in only 17% of these cases as a single drug. Concomitant drug use, in particular alcohol, benzodiazepines, and antidepressants, has increased considerably. The combined effects of these substances might play a role in the disturbingly large increase in heroin (morphine) related deaths during this period.