Vermal atrophy of alcoholics correlate with serum thiamine levels but not with dentate iron concentrations as estimated by MRI

Background characteristics and neuropathology findings of medico-legal autopsy cases with and without β-amyloid precursor protein positive diffuse traumatic axonal injury

The postmortem diagnosis of diffuse traumatic axonal injury (dTAI) relies on β-amyloid precursor protein (β-APP) immunohistochemistry. Most reports of factors associating with dTAI are decades old. We compared background characteristics and neuropathology findings of today's Finnish medico-legal autopsy cases with and without β-APP-positive dTAI (dTAI+ and dTAI-, respectively). The cases had suffered a head injury prior to death and underwent a full neuropathological examination including β-APP stain. Background and circumstantial data as well as neuropathology findings were collected from police documents, medical records, and autopsy and neuropathology reports. Prevalence ratios were calculated for each factor to facilitate comparisons between the dTAI+ and dTAI- groups. The dataset comprised 57 cases (66.7% males), with 17 classified as dTAI+ and 40 as dTAI-. Based on prevalence ratios, the factors that had at least two-fold prevalence among dTAI+ cases compared to dTAI- cases were: an unknown injury mechanism; concurrent epidural or subdural haemorrhage; and an accidental manner of death. In contrast, the factors that had at least two-fold prevalence among dTAI- cases compared to dTAI+ cases were: a short postinjury survival (<30 min); concurrent intracerebral/ventricular haemorrhage or contusion; vermal atrophy; and a natural or homicidal manner of death. This study revealed differences in circumstantial features and neuropathology findings between dTAI+ and dTAI- cases in today's medico-legal autopsy material. Data on typical case profiles may help estimate the prior probability of dTAI not only in medico-legal autopsies but also among living patients with head injuries.

Race explains substantial variance in whole blood thiamine diphosphate concentrations

Deficiency for thiamine (vitamin B1), traditionally assessed via the activity of the thiamine-dependent enzyme erythrocyte transketolase, has been reported in individuals with alcohol use disorder (AUD) and in people with HIV; concentrations of the metabolically active diphosphate form, however, have yet to be reported in HIV cohorts and results in AUD are equivocal. In this cross-sectional study, samples from 170 AUD, 130 HIV, and 100 healthy control individuals were analyzed to test the hypothesis that AUD and HIV groups relative to healthy controls would show low whole blood thiamine diphosphate (TDP) concentrations related to peripheral neuropathy. TDP concentrations were not different in the 3 study groups (P = .6141) but were lower in Black (n = 172) relative to White (n = 155) individuals (P < .0001) regardless of group. In a multiple regression, race relative to diagnoses explained more than 10 times the variance in whole blood TDP concentrations (F4,395 = 3.5, P = .0086; r2 = 15.1]. Performance on a measure of peripheral neuropathy (2-point discrimination) was worse in the HIV and AUD cohorts relative to the healthy control group (P < .0001) but was not associated with TDP concentrations. These findings suggest that Black individuals carry a heightened vulnerability for low whole blood TDP concentrations, but the clinical significance and mechanisms underlying these results remain to be determined.

Further Evidence of Relationship Between Thiamine Blood Level and Cognition in Chronic Alcohol-Dependent Adults: Prospective Pilot Study of an Inpatient Detoxification with Oral Supplementation Protocol

BACKGROUND

The relationship between thiamine blood level (TBL) and cognition remains uncertain including amongst alcohol-dependent persons (ADP) AIM: To evaluate this relationship during protocol-driven inpatient alcohol detoxification treatment including thiamine supplementation (AD+Th) METHODS: Prospective 3-week study with 100 consecutively admitted detoxification-seeking ADP (47.7±11 years-old, 21% females) without superseding comorbidities requiring treatment. TBL and Montreal Cognitive Assessment (MoCA) were measured at admission (t₁, pre-AD+Th) and discharge (t₃, post-AD+Th). Frontal Assessment Battery (FAB) was performed at t₁. AD+Th included abstinence, pharmacological alcohol withdrawal syndrome treatment and oral thiamine supplementation (200 mg/day for 14 days). Regression and mediation analyses assessed TBL-cognition relationships.

RESULTS

We found no cases of Wernicke Encephalopathy (WE) and only one case of thiamine deficiency. Both MoCA and TBL significantly improved across AD+Th (with medium-to-large effect sizes). At t₁, TBL significantly predicted MoCA and FAB sum scores (medium effect sizes; extreme and very strong evidence, respectively). The clear TBL-MoCA association disappeared at t₃. In multivariate regression and mediation analyses exploring key influential factors of cognition (identified by LASSO regression), the TBL-MoCA interactions did not relevantly change at t₁ and t₃. Age, serum transaminases, vitamin D levels, drinking-years and depression score weakly modified the relationship.

CONCLUSION

TBL was a robust predictor of pre-detoxification cognitive impairment, and both TBL and cognition improved significantly during AD+Th (including abstinence) in our ADP population, supporting routine thiamine supplementation for ADP, even those at low WE-risk. TBL-cognition relationship was minimally confounded by age, alcohol-toxicity proxies, mood, and vitamin D levels.

CLINICAL TRIALS REGISTRATION

https://osf.io/b54eh/.

High-dose thiamine strategy in Wernicke-Korsakoff syndrome and related thiamine deficiency conditions associated with alcohol use disorder

Thiamine is essential for the activity of several enzymes associated with energy metabolism in humans. Chronic alcohol use is associated with deficiency of thiamine along with other vitamins through several mechanisms. Several neuropsychiatric syndromes have been associated with thiamine deficiency in the context of alcohol use disorder including Wernicke-Korsakoff syndrome, alcoholic cerebellar syndrome, alcoholic peripheral neuropathy, and possibly, Marchiafava-Bignami syndrome. High-dose thiamine replacement is suggested for these neuropsychiatric syndromes.

Long-Term Mortality of Patients with an Alcohol-Related Wernicke–Korsakoff Syndrome

Aims

To characterize a series of contemporary patients with alcohol-related Wernicke's encephalopathy (WE) or Korsakoff's syndrome (KS) and to update the current prognosis of disease.

Methods

Retrospective and prospective study of patients diagnosed with an alcohol-related WE or KS between 2002 and 2011 in a tertiary hospital. Socio-demographic, alcohol use characteristics, signs and symptoms, co-morbidity and blood parameters were obtained at admission. Patients were followed up until 2013 and causes of death were ascertained through the review of charts.

Results

Sixty-one patients were included (51 with WE and 10 with KS). Among patients with WE, 78% were men and age at diagnosis was 57 years (interquartile range (IQR): 49–66). Twenty-three percent fulfilled the classic WE triad. Regarding Caine's criteria for WE, 70.6% presented with at least two out of four signs or symptoms. Median follow-up of patients with WE syndrome was 5.3 years (IQR: 2.6–8.8), the cumulated mortality was 45% and death rate of 7.4 × 100 person-years (95% confidence interval (CI): 4.8–10.9). Overall, 50% of patients would be expected to die within 8 years of WE episode and main causes of death included serious bacterial infections (44.5%) and cancer (33.3%).

Conclusions

Survival of patients with an alcohol-related Wernicke–Korsakoff syndrome is poor; pursuing treatment of alcohol use disorder and early diagnosis of thiamine deficiency is a priority for improving clinical outcomes.

Direct voxel-based comparisons between grey matter shrinkage and glucose hypometabolism in chronic alcoholism

Alcoholism is associated with widespread brain structural abnormalities affecting mainly the frontocerebellar and the Papez's circuits. Brain glucose metabolism has received limited attention, and few studies used regions of interest approach and showed reduced global brain metabolism predominantly in the frontal and parietal lobes. Even though these studies have examined the relationship between grey matter shrinkage and hypometabolism, none has performed a direct voxel-by-voxel comparison between the degrees of structural and metabolic abnormalities. Seventeen alcoholic patients and 16 control subjects underwent both structural magnetic resonance imaging and (18)F-2-fluoro-deoxy-glucose-positron emission tomography examinations. Structural abnormalities and hypometabolism were examined in alcoholic patients compared with control subjects using two-sample t-tests. Then, these two patterns of brain damage were directly compared with a paired t-test. Compared to controls, alcoholic patients had grey matter shrinkage and hypometabolism in the fronto-cerebellar circuit and several nodes of Papez's circuit. The direct comparison revealed greater shrinkage than hypometabolism in the cerebellum, cingulate cortex, thalamus and hippocampus and parahippocampal gyrus. Conversely, hypometabolism was more severe than shrinkage in the dorsolateral, premotor and parietal cortices. The distinct profiles of abnormalities found within the Papez's circuit, the fronto-cerebellar circuit and the parietal gyrus in chronic alcoholism suggest the involvement of different pathological mechanisms.

Vitamin B status in patients with type 2 diabetes mellitus with and without incipient nephropathy

AIM

To investigate the vitamin B status, with particular focus on vitamin B6, in adults with and without incipient nephropathy secondary to type 2 diabetes mellitus.

METHODS

Plasma and/or urine concentrations of vitamins B₆, B₁, B₁₂, related vitamers and biomarkers (including total homocysteine, methylmalonic acid) were measured in 120 adults with type 2 diabetes (including 46 patients with microalbuminuria) and 52 non-diabetic control subjects.

RESULTS

Plasma concentrations of pyridoxal 5'-phosphate (PLP) were significantly lower in patients with type 2 diabetes than in control subjects (median: 22.7 nmol/L, diabetes with microalbuminuria; 26.8 nmol/L, diabetes without microalbuminuria; 39.5 nmol/L, non-diabetic control; p<0.0001). The prevalence of low PLP (<30 nmol/L) was 63%, 58%, and 25% in the diabetes groups with and without microalbuminuria and the control group, respectively. Plasma levels of pyridoxine and pyridoxal were also lower (p<0.0001), but levels of pyridoxamine, pyridoxamine 5'-phosphate, and pyridoxic acid were higher in both groups with diabetes compared to the control group (p<0.001). Thiamine deficiency was highly prevalent in all groups, whereas low vitamin B₁₂ and elevated methylmalonic acid were rare. Increased levels of C-reactive protein and soluble vascular cell adhesion molecule-1 were observed in the groups with diabetes (p<0.05, versus healthy control).

CONCLUSIONS

Deficiency of vitamin B₆ (PLP, pyridoxine, pyridoxal) and vitamin B₁ (thiamine) was prevalent in type 2 diabetes. Incipient nephropathy was associated with more pronounced alterations in vitamin B₆ metabolism and stronger indications of endothelial dysfunction and inflammation.

Metabolische Störungen

Im folgenden Kapitel werden die verschiedenen metabolischen Störungen betrachtet. Zunächst wird auf die allgemeinen und spezifischen neurologischen Komplikationen bei Organtransplantation eingegangen. Dann geht es um die metabolischen Enzephalopathien: Störungen der Gehirntätigkeit bei angeborenen und erworbenen Stoffwechselerkrankungen im engeren Sinn, Elektrolytstörungen, Hypovitaminosen, zerebrale Folgen einzelner Organdysfunktionen, zerebrale Hypoxien, Endotheliopathien und Mitochondropathien. Anschließend werden das Alkoholdelir und die Wernicke-Enzephalopathie erörtert. Bei zahlreichen akuten Erkrankungen von Gehirn, Rückenmark und peripherem Nervensystem treten typische Störungen vegetativer Systeme auf, deren Erkennung und Therapie insbesondere bei Intensivpatienten eine vitale Bedeutung haben kann: die autonomen Störungen. Bei der zentralen pontinen Myelinolyse kommt es zu einer akuten, vorwiegend fokal-symmetrischen Demyelinisierung im Hirnparenchym. Auch Basalganglienerkrankungen können intensivmedizinisch relevant werden. Und schließlich wird die akute Stressreaktion betrachtet, die aufgrund der vielfältigen metabolischen und endokrinen Veränderungen bei kritischen Erkrankungen entsteht. Gerade das RCVS als neuere Krankheitsentität und wichtige Differenzialdiagnose zur Vaskulitis des ZNS verdient einen eigenen Platz, in diesem Unterkapitel werden ebenfalls verwandte Syndrome wie die hypertensive Enzephalopathie und das PRES abgehandelt.

Alcoholism: A systemic proinflammatory condition

Excessive ethanol consumption affects virtually any organ, both by indirect and direct mechanisms. Considerable research in the last two decades has widened the knowledge about the paramount importance of proinflammatory cytokines and oxidative damage in the pathogenesis of many of the systemic manifestations of alcoholism. These cytokines derive primarily from activated Kupffer cells exposed to Gram-negative intestinal bacteria, which reach the liver in supra-physiological amounts due to ethanol-mediated increased gut permeability. Reactive oxygen species (ROS) that enhance the inflammatory response are generated both by activation of Kupffer cells and by the direct metabolic effects of ethanol. The effects of this increased cytokine secretion and ROS generation lie far beyond liver damage. In addition to the classic consequences of endotoxemia associated with liver cirrhosis that were described several decades ago, important research in the last ten years has shown that cytokines may also induce damage in remote organs such as brain, bone, muscle, heart, lung, gonads, peripheral nerve, and pancreas. These effects are even seen in alcoholics without significant liver disease. Therefore, alcoholism can be viewed as an inflammatory condition, a concept which opens the possibility of using new therapeutic weapons to treat some of the complications of this devastating and frequent disease. In this review we examine some of the most outstanding consequences of the altered cytokine regulation that occurs in alcoholics in organs other than the liver.

Magnetic resonance imaging biomarkers in patients with progressive ataxia: current status and future direction

A diagnostic challenge commonly encountered in neurology is that of an adult patient presenting with ataxia. The differential is vast and clinical assessment alone may not be sufficient due to considerable overlap between different causes of ataxia. Magnetic resonance (MR)-based biomarkers such as voxel-based morphometry, MR spectroscopy, diffusion-weighted and diffusion-tensor imaging and functional MR imaging are gaining great attention for their potential as indicators of disease. A number of studies have reported correlation with clinical severity and underlying pathophysiology, and in some cases, MR imaging has been shown to allow differentiation of conditions causing ataxia. However, despite recent advances, their sensitivity and specificity vary. In addition, questions remain over their validity and reproducibility, especially when applied in routine clinical practice. This article extensively reviews the current literature regarding MR-based biomarkers for the patient with predominantly adult-onset ataxia. Imaging features characteristic of a particular ataxia are provided and features differentiating ataxia groups and subgroups are discussed. Finally, discussion will turn to the feasibility of applying these biomarkers in routine clinical practice.

Magnetic resonance and nuclear medicine imaging in ataxias

Imaging techniques including computed tomography (CT), magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT), and positron emission tomography (PET) have been widely applied to the investigation of patients with acute or chronic ataxias. Fundamentally, CT has a role in the emergency evaluation of the patient with acute ataxia to ascertain brainstem or cerebellar hemorrhage and to exclude a mass lesion in the posterior cranial fossa. Conventional MRI is the most frequently performed imaging investigation in patients with ataxia. It can support the diagnosis of acute cerebellitis and Wernicke encephalopathy by revealing T2 signal changes with a typical distribution. In patients with inherited or sporadic chronic ataxia it reveals three fundamental patterns of atrophy of the brainstem, cerebellum, and spinal cord which match the gross neuropathological descriptions. These are represented by olivopontocerebellar atrophy (OPCA), cortical cerebellar atrophy (CCA), and spinal atrophy (SA). A substantial correspondence exists among these patterns of atrophy shown by MRI and the etiological classification of inherited or acquired chronic ataxias. This, along with demonstration of T2 signal changes characteristic of some diseases, makes conventional MRI potentially useful for the diagnostic work-up of the single patient, especially in the case of a sporadic disease. Non-conventional MR techniques including diffusion MR, spectroscopy, and functional MR have been used in patients with acute or chronic ataxia, but their exact role in the evaluation of the single patient is not established yet. They are currently investigated as potential tools to monitor progression of neurodegeneration in chronic ataxia and to serve as "surrogate markers" in clinical trials. Several radiotracers have been utilized in combination with SPECT and PET in patients with ataxia. Perfusion SPECT can reveal cerebellar blood flow abnormalities early in the course of cerebellitis. It has also been utilized to investigate perfusion of the brain in several inherited or sporadic chronic ataxic diseases, contributing to improved understanding of the pathophysiology of these conditions. Recently, perfusion SPECT has been tested as a "surrogate marker" to verify the effects of newly developed therapies in patients with a variety of chronic ataxias. Whole-body FDG-PET is recommended in patients with suspected paraneoplastic cerebellar degeneration to detect the primary malignancy. Brain FDG-PET has provided important information on the pathophysiology of several acquired and inherited conditions. PET and SPECT with radiotracers able to assess the nigrostriatal system or the density of D2 dopamine receptors in the striatum are increasingly used in patients with adult-onset sporadic ataxia for the differential diagnosis between multiple system atrophy in which overt striatal abnormalities are found and idiopathic late-onset cerebellar ataxia in which no abnormality is detected.

Association of SOD2, a mitochondrial antioxidant enzyme, with gray matter volume shrinkage in alcoholics

Chronic alcoholism leads to gray matter shrinkage and induces the formation of superoxide anions (O(2)(-)) that can cause neuronal cell death. The mitochondrial superoxide dismutase 2 (SOD2) enzyme is critical in the metabolism of superoxide. An Ala16Val polymorphism putatively affects SOD2 enzyme activity in vivo. Brain volumes of 76 treatment-seeking alcohol-dependent individuals were measured with a 1.5T MRI. Intracranial tissue margins were manually outlined on coronal sections. Gray matter, white matter, sulcal, and ventricular CSF volumes were estimated using intensity-based K-means clustering. Ala16Val (rs4880) and a second haplotype tagging SNP, rs10370, were genotyped. The q-value package was used to correct for multiple comparisons. In the alcoholics, cerebrospinal fluid and intra-cranial volumes showed significant differences across the six diplotype categories. The homozygous Ala16-containing diplotype rs10370TT-rs4880GG was associated with lowest gray matter ratio (greater shrinkage; p=0.005). Presence of one or two copies of the low activity Ala16 allele was a risk factor for lower gray matter volume in alcoholics below the median alcohol consumption (p=0.03) but not in alcoholics above this level. White matter ratio was associated with sex (p=0.002) and lifetime total alcohol consumption (p=0.01) but not with diplotypes. In this exploratory analysis, a putative functional missense variant of SOD2 appears to influence gray matter loss in alcoholics. This may be due to impaired clearance of reactive oxygen species formed as a result of alcohol exposure. The risk/protective effect was observed in alcoholics with lower levels of lifetime alcohol consumption. Highest levels of exposure may overwhelm the protective action of the SOD2 enzyme.

Neurologic presentations of nutritional deficiencies

Optimal functioning of the central and peripheral nervous system is dependent on a constant supply of appropriate nutrients. The first section of this review discusses neurologic manifestations related to deficiency of key nutrients such as vitamin B(12), folate, copper, vitamin E, thiamine, and others. The second section addresses neurologic complications related to bariatric surgery. The third sections includes neurologic presentations caused by nutrient deficiencies in the setting of alcoholism. The concluding section addresses neurologic deficiency diseases that have a geographic predilection.

Ethanol promotes thiamine deficiency-induced neuronal death: involvement of double-stranded RNA-activated protein kinase

BACKGROUND

Heavy alcohol consumption causes cerebellar degeneration, and the underlying mechanism is unclear. Chronic alcoholism is usually associated with thiamine deficiency (TD) which is known to induce selective neurodegeneration in the brain. However, the role of TD in alcohol-induced cerebellar degeneration remains to be elucidated. The double-stranded RNA-activated protein kinase (PKR) is a potent antiviral protein. Viral infection or binding to dsRNA causes PKR autophosphorylation and subsequent phosphorylation of the alpha-subunit of eukaryotic translation factor-2alpha, leading to inhibition of translation or apoptosis. PKR can also be activated by cellular stresses.

METHODS

In this study, we used an in vitro model, cultured cerebellar granule neurons (CGNs), to investigate the interaction between TD and ethanol and evaluate the contribution of their interaction to neuronal loss. TD was induced by treatment with amprolium in association with ethanol. Cell viability was determined by 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide assay. PKR expression/phosphorylation and subcellular distribution was analyzed with immunoblotting and immunocytochemistry.

RESULTS

Thiamine deficiency caused death of CGNs but ethanol did not. However, TD plus ethanol induced a much greater cell loss than TD alone. TD-induced PKR phosphorylation and ethanol exposure significantly promoted TD-induced PKR phosphorylation as well as its nuclear translocation. A selective PKR inhibitor not only protected CGNs against TD toxicity, but also abolished ethanol potentiation of TD-induced loss of CGNs.

CONCLUSIONS

Ethanol promoted TD-induced PKR activation and neuronal death. PKR may be a convergent protein that mediates the interaction between TD and ethanol.

Magnetic resonance imaging in occupational chronic solvent encephalopathy

PURPOSE

The aim of this study was to characterize the magnetic resonance imaging (MRI) findings in chronic solvent encephalopathy (CSE) patients and to study whether the findings are associated with solvent exposure indices.

METHODS

The brain MRI scans of 71 CSE patients were independently re-evaluated and rated by two experienced neuroradiologists. All the work tasks were analyzed and the chemical composition of lifetime exposure was categorized.

RESULTS

The MRI scans of 27/71 CSE patients (38%) were classified as abnormal. Brain atrophy in any brain area was found in 17/71 CSE patients (24%). Abnormal white matter hyperintensities (WMH) were found in 20/71 CSE patients (28%). Cerebral and cerebellar brain atrophy was associated with the duration of exposure in years, and vermian atrophy was associated with alcohol consumption. Periventricular and brainstem WMH were related to age.

CONCLUSIONS

Slight brain atrophy is associated with CSE and there is a correlation between brain atrophy and the duration of exposure in years. However, all the MRI findings in CSE are non-specific and thus MRI is useful mainly in the differential diagnosis of CSE.

Cerebellar gray matter volume correlates with duration of cocaine use in cocaine-dependent subjects

This study was conducted to explore differences in gray and white matter volume between cocaine-dependent and healthy comparison subjects using optimized voxel-based morphometry (VBM). Brain magnetic resonance imaging (MRI) and neuropsychological function tests were performed for 40 cocaine-dependent subjects (41.4+/-6.9 years, 27 men) and 41 healthy age- and sex-matched comparison subjects (38.7+/-8.8 years, 26 men). Optimally normalized whole brain MR images were segmented, modulated, smoothed, and compared between groups with statistical parametric mapping. The cocaine-dependent group had lower gray matter volumes in bilateral premotor cortex (Brodmann area (BA) 6, 8; 16.6%), right orbitofrontal cortex (BA 10, 15.1%), bilateral temporal cortex (BA 20, 38; 15.9%), left thalamus (12.6%), and bilateral cerebellum (13.4%) as well as lower right cerebellar white matter volume (10.0%) relative to the comparison group at a corrected p<0.05 for multiple comparisons. Duration of cocaine use negatively correlated with right and left cerebellar gray matter volumes (r=-0.37, r=-0.39, respectively). In cocaine-dependent subjects, lower cerebellar hemispheric gray and white matter volumes were correlated with deficits in executive function and decreased motor performance. This study reports that cocaine-dependent subjects have lower gray matter volumes in cerebellar hemispheres as well as in frontal, temporal cortex, and thalamus. These findings are the first to suggest that the cerebellum may be vulnerable to cocaine-associated brain volume changes, and that cerebellar deficits may contribute to neuropsychological deficits and motor dysfunction frequently observed in cocaine-dependent subjects.

Cerebellar Vermis Proteome of Chronic Alcoholic Individuals

BACKGROUND

Cerebellar changes are commonly associated with alcoholism and chronic alcohol consumption can produce profound impairments in motor functioning and various aspects of cognition. Although the mechanisms underlying alcohol-induced changes in the cerebellar vermis are poorly understood, observations in the alcoholic vermis are thought to be consequential to common alcohol-related factors, particularly thiamine deficiency.

METHODS

In the present study, we used a proteomics-based approach to compare protein expression profiles of the cerebellar vermis from human alcoholic individuals (both neurologically uncomplicated and alcoholic individuals complicated with liver cirrhosis) and healthy control brains. This article complements our recent studies performed on alcoholic prefrontal gray and white matter and splenium of the corpus callosum (CC).

RESULTS

Like the CC study, several liver cirrhosis-specific proteins were identified in the vermis, perhaps indicating the effects of liver dysfunction in this brain region. Among other protein expression changes observed are disturbances in the levels of thiamine-dependent enzymes. A derangement in energy metabolism perhaps related to thiamine deficiency seems to be important in both alcoholic groups, even where there are no clinical or pathological findings of Wernicke-Korsakoff syndrome.

CONCLUSIONS

These results suggest that clinically and pathologically uncomplicated alcoholic cases may not in fact be "uncomplicated," as at the proteome level we seem to be isolating the confounding effects of nutritional deficiencies and liver dysfunction and perhaps their role in alcohol-related vermis damage. Together, these results indicate that the alcohol-related pathology of the vermis is more multifactorial than other brain regions examined previously (prefrontal region and CC splenium).

Alcoholic cerebellar degeneration: A clinicopathological study of six Japanese autopsy cases and proposed potential progression pattern in the cerebellar lesion

Alcoholic cerebellar degeneration (ACD) is one of the most common neurological complications in alcoholics. As far as we know, however, only four Japanese autopsy cases of ACD have been reported, and only limited clinicopathological data on this disease are now available in Japan. The aims of this study were: (i) to examine the clinicopathological correlation of six Japanese autopsy cases of ACD, including three asymptomatic cases; and (ii) to elucidate the pattern of progression of the cerebellar lesion in ACD. All six alcoholics were histopathologically diagnosed as having "pure" ACD without Wernicke's encephalopathy. The characteristics of the topographical distribution of the cerebellar lesion were as follows. Symptomatic cases (cases 1-3) showed more severe and widespread change than asymptomatic cases (cases 4-6). Even in case 6, which had the mildest lesion, the anterior vermis developed a moderate change (Purkinje cell loss and narrowing of the molecular layer). In cases 4 and 5 with more severe and widespread lesions, the superior and posterior vermis and the adjacent regions of the superior hemisphere, including the anterior lobe and simple lobule, were involved. In all symptomatic cases, the anterior superior hemisphere had severe lesions involving the granular cell layer. In contrast to asymptomatic cases, all symptomatic cases also had severe to moderate lesions in the anterior inferior hemisphere. In cases 1 and 2 with the most severe lesions, the moderate to severe changes were distributed in the posterior and inferior portions of both the vermis and hemisphere. These findings suggest that in ACD, severe lesions successively develop: (i) in the anterior superior vermis; (ii) anterior superior hemisphere; (iii) anterior inferior hemisphere; and (iv) anterior inferior vermis. In addition, cerebellar symptoms may frequently occur if the anterior superior hemisphere and anterior inferior hemisphere, in addition to the anterior superior vermis, are involved.

Thiamine deficiency induces endoplasmic reticulum stress in neurons

Thiamine (vitamin B1) deficiency (TD) causes region selective neuronal loss in the brain; it has been used to model neurodegeneration that accompanies mild impairment of oxidative metabolism. The mechanisms for TD-induced neurodegeneration remain incompletely elucidated. Inhibition of protein glycosylation, perturbation of calcium homeostasis and reduction of disulfide bonds provoke the accumulation of unfolded proteins in the endoplasmic reticulum (ER), and cause ER stress. Recently, ER stress has been implicated in a number of neurodegenerative models. We demonstrated here that TD up-regulated several markers of ER stress, such as glucose-regulated protein (GRP) 78, growth arrest and DNA-damage inducible protein or C/EBP-homologus protein (GADD153/Chop), phosphorylation of eIF2alpha and cleavage of caspase-12 in the cerebellum and the thalamus of mice. Furthermore, ultrastructural analysis by electron microscopic study revealed an abnormality in ER structure. To establish an in vitro model of TD in neurons, we treated cultured cerebellar granule neurons (CGNs) with amprolium, a potent inhibitor of thiamine transport. Exposure to amprolium caused apoptosis and the generation of reactive oxygen species in CGNs. Similar to the observation in vivo, TD up-regulated markers for ER stress. Treatment of a selective inhibitor of caspase-12 significantly alleviated amprolium-induced death of CGNs. Thus, ER stress may play a role in TD-induced brain damage.

Clinical heterogeneity of recessive ataxia in the Mexican population

Approximately 75% of Indo-European patients with recessive ataxia are homozygous for frataxin gene (FXN) mutations and have either typical or atypical Friedreich ataxia (FRDA). Our previous analysis of 134 Mexican Mestizo recessive ataxia patients showed that FRDA is relatively uncommon in the Mexican population (10.4%). This article reports the evaluation of the phenotypes of these patients. Over half of the patients with clinical diagnostic criteria for FRDA did not carry FXN mutations, constituting a "FRDA-like" phenotypic subgroup. Analysis of non-FRDA patients revealed a subgroup with early onset recessive cerebellar ataxia and cognitive deficit. These two phenotypic subgroups accounted for approximately 60% of all patients, indicating that the cause for recessive ataxia in the Mexican population is distinct from other populations and remains largely unknown.

Frequency and clinicopathological characteristics of alcoholic cerebellar degeneration in Japan: a cross-sectional study of 1,509 postmortems

Alcoholic cerebellar degeneration (ACD) is a pivotal neurological complication in alcoholics. However, although there are a few autopsy reports and some data on its frequency, it is considered very rare in Japan. The aims of this study were (1) to estimate the frequency of the disease in Japanese autopsy cases, and (2) to examine the clinicopathological features of symptomatic and asymptomatic cases of ACD. We reviewed the records of 1,509 Japanese autopsies obtained from three autopsy series in Japan, and selected all 55 cases (3.6%) with alcoholism. On neuropathological reexamination, ACD was confirmed in six male alcoholics [0.4% of all subjects; 10.9% of all alcoholics; mean age at death 59.3+/-13.4 years (+/- SD)], including three asymptomatic cases. These frequencies were much lower than some previous Western findings, but more common than that has been expected in Japan. The frequencies of memory impairment and ataxia in ACD cases were significantly higher than those in alcoholics without any alcohol-related pathologies. In ACD cases, loss of Purkinje cells, narrowing of the width of the molecular layer, and tissue rarefaction in the granular layer were observed in the anterior and superior portions of the vermis of the cerebellum. In adjacent regions, the Purkinje cell and molecular layers were more mildly affected. The distribution of severely affected regions was more restricted in the asymptomatic cases than in the symptomatic cases. This study confirmed the frequency of asymptomatic cerebellar degeneration in alcoholics, suggesting that early intervention in alcoholism in the subclinical phase is important to prevent the development of cerebellar symptoms.

Susceptibility of the cerebellum to thiamine deficiency

Thiamine or vitamin B(1), an essential nutrient absorbed from the diet, is involved in vital brain metabolic and cellular functions, including carbohydrate metabolism and neurotransmitter production. Diencephalic regions and, in particular, the cerebellum demonstrate lesions in cases of prolonged thiamine deficiency, such as that observed in alcohol-dependent individuals or in patients with cancer or AIDS. The purpose of this review is to demonstrate recent evidence of cerebellar dysfunction resulting from thiamine deficiency and to assemble theories as to why the cerebellum may be sensitive to this type of insult. A brief outline on cerebellar structure and function, as well as a short discussion on thiamine and thiamine deficiency are provided before detailing the conditions and mechanisms underlying thiamine deficiency-induced cerebellar dysfunction. Although much is known regarding cell loss from a lack of thiamine, further work is still required to identify the sequelae of events leading to the susceptibility of the cerebellum to injury stemming from a thiamine deficient diet or impaired thiamine utilization.

The treatment of patients at risk of developing Wernicke's encephalopathy in the community

AIM

To review the process of identifying alcohol-dependent patients at risk of developing Wernicke's encephalopathy (WE) in the community, and prophylactic treatment options.

METHODS

Non-systematic literature review of the diagnosis of thiamine deficiency and of its treatment in the community. The role of supplementation of beer and bread with thiamine was evaluated.

RESULTS

The diagnosis of thiamine deficiency is not always made, and treatment apparently may sometimes be inadequate.

CONCLUSIONS

Alcohol-dependent patients in the community who are at risk of developing WE should be given thiamine 250 mg, intramuscularly, daily for 3-5 days as part of a community detoxification programme. Further work is essential to determine the optimum dose of thiamine required to prevent permanent brain damage (Korsakoff's Psychosis). Neurotoxicity, due to the metabolism of excessive alcohol in patients with chronic and severe alcohol dependence, must be considered as an important factor in determining the long-term outcome of treatment.