Neuroimaging findings in alcohol-related encephalopathies

Toxic and Drug-Related White Matter Diseases of the Brain and Spine

Toxic leukoencephalopathy and myelopathy are common neurologic complications of a wide range of chemotherapeutic and substance abuse agents. During the last decade, there has been a significant change in the profile of white matter toxins, primarily driven by the development and usage of new chemotherapeutic and immunotherapeutic agents and by the continuous increase in illicit drug abuse with contaminants. Neuroimaging in the form of MR imaging forms the cornerstone in the diagnosis of these entities, many of which are reversible and amenable to rapid correction. Chronic white matter changes are also seen with these toxins with gradually progressive clinicoradiological findings.

Sequential Brain Perfusion Findings in a Case of Osmotic Demyelination Syndrome

ABSTRACT

A 60-year-old man with chronic alcoholism for 30 years was admitted to the hospital for an acute alcoholic syndrome with global confusional state, cognitive disorders, and ataxia. MRI detected bilateral mamillary bodies T 2 hypersignal related to Wernicke encephalopathy. It was treated by oral thiamine supplementation with clinical improvement. Two months later, he was rehospitalized for rapidly progressive dementia symptoms. Brain perfusion scintigraphy revealed pontine hyperperfusion and right hippocampal hypoperfusion. One month after IV thiamine supplementation, brain perfusion scintigraphy showed normalization of perfusion abnormalities in the pons and right hippocampus, leading to the diagnosis of alcoholic-related osmotic demyelination syndrome.

MRI Spectrum of Toxic Encephalopathy-An Institutional Experience

Background

There are numerous toxins that affect our nervous system, both central and peripheral. Innumerable differentials exist in patients of acute encephalopathy and the list can be narrowed down with appropriate imaging. Specific neuroradiological features point to a particular diagnosis in a substantial number of cases.

Objective

Through this study, we aimed to demonstrate the varied imaging findings of toxic encephalopathy on MRI encountered at our institute.

Material and Methods

A retrospective analysis of the patients clinically diagnosed as toxic encephalopathy and referred for imaging between March 2015 and December 2019 was done. A total of 25 patients were included. Patient records were reviewed for clinical details, laboratory investigations, and treatment; the institute Picture Archiving and Communication System provided the imaging findings.

Results

Patients presenting were aged between 22 and 55 years (mean-34.3 years). Four patients (16%) presented with imaging findings characteristic of Marchiafava-Bignami disease and six patients (24%) had MRI findings of Wernicke encephalopathy. Three patients (12%) had methanol poisoning sequelae while imaging findings of nitroimidazole drug toxicity were observed in another three patients (12%). Two patients (8%) each of carbon monoxide poisoning and lead toxicity were seen. We had one patient (4%) each of isoniazid, methyl iodide, dextropropoxyphene toxicity, chronic toluene abuse, and hyperglycemia-induced hemiballismus-hemichorea.

Conclusion

Our study illustrates the amalgamated spectrum of MRI appearances in various subgroups of toxic encephalopathies. Imaging substantiated by relevant history and clinical manifestations can accurately diagnose the possible causative agent in the majority of the cases.

Diverse MRI findings and clinical outcomes of acute Marchiafava-Bignami disease

BACKGROUND

The acute onset of Marchiafava-Bignami disease (MBD) is difficult to capture, and its clinical manifestations are overlapped. Magnetic resonance imaging (MRI) is very useful in the diagnosis of acute MBD.

PURPOSE

To investigate the MRI features and clinical outcomes of acute MBD.

MATERIALS AND METHODS

Sagittal T2-weighted (T2W) or T1-weighted (T1W) imaging, axial T1W and T2W imaging, and axial FLAIR and diffusion-weighted imaging (DWI) sequences were performed in 17 patients with acute MBD on 1.5-T MR. According to the different ranges of callosal restricted diffusion, MBD was divided into Type I (n = 7, the completely involved), Type II (n = 5, the mostly involved), and Type III (n = 5, the partly involved). The MRI findings and outcomes of each type were retrospectively analyzed.

RESULTS

With the reduced range of the callosal restricted diffusion, the callosal atrophy or cavitation was more common: no case of Type I; 1 (20%) case of Type II; and 3 (60%) cases of Type III. With the increased range of callosal restricted diffusion, the extracallosal involvement was more common: 6 (86%) cases of Type I; 3 (60%) cases of Type II; and 1 (20%) case of Type III. During the follow-up, five cases had neuropsychiatric sequelae: 1 (14%) case of type I; 1 (20%) case of Type II; 3 (60%) cases of Type III.

CONCLUSION

The MRI findings and clinical outcomes of acute MBD are regular. The extensive restricted diffusion of acute MBD may present the curable condition. Callosal heterogeneity may affect the outcome of acute MBD.

Effect of alcohol on the central nervous system to develop neurological disorder: pathophysiological and lifestyle modulation can be potential therapeutic options for alcohol-induced neurotoxication

The central nervous system (CNS) is the major target for adverse effects of alcohol and extensively promotes the development of a significant number of neurological diseases such as stroke, brain tumor, multiple sclerosis (MS), Alzheimer's disease (AD), and amyotrophic lateral sclerosis (ALS). Excessive alcohol consumption causes severe neuro-immunological changes in the internal organs including irreversible brain injury and it also reacts with the defense mechanism of the blood-brain barrier (BBB) which in turn leads to changes in the configuration of the tight junction of endothelial cells and white matter thickness of the brain. Neuronal injury associated with malnutrition and oxidative stress-related BBB dysfunction may cause neuronal degeneration and demyelination in patients with alcohol use disorder (AUD); however, the underlying mechanism still remains unknown. To address this question, studies need to be performed on the contributing mechanisms of alcohol on pathological relationships of neurodegeneration that cause permanent neuronal damage. Moreover, alcohol-induced molecular changes of white matter with conduction disturbance in neurotransmission are a likely cause of myelin defect or axonal loss which correlates with cognitive dysfunctions in AUD. To extend our current knowledge in developing a neuroprotective environment, we need to explore the pathophysiology of ethanol (EtOH) metabolism and its effect on the CNS. Recent epidemiological studies and experimental animal research have revealed the association between excessive alcohol consumption and neurodegeneration. This review supports an interdisciplinary treatment protocol to protect the nervous system and to improve the cognitive outcomes of patients who suffer from alcohol-related neurodegeneration as well as clarify the pathological involvement of alcohol in causing other major neurological disorders.

Potentially Reversible and Recognizable Acute Encephalopathic Syndromes: Disease Categorization and MRI Appearances

"Encephalopathy" is a vague term that encompasses varying definitions, often with a nonspecific clinical presentation and numerous possible pathophysiologic causes. Hence, MR imaging plays a crucial role in the early diagnosis and treatment by identifying imaging patterns when there is limited clinical history in such patients with acute encephalopathy. The aim of this review was to aid in remembrance of etiologies of potentially reversible acute encephalopathic syndromes on MR imaging. The differential includes vascular (reversible cerebral vasoconstriction syndrome, transient global amnesia, disseminated intravascular coagulation, and thrombotic microangiopathy), infection (meningitis, encephalitis), toxic (posterior reversible encephalopathy syndrome, acute toxic leukoencephalopathy; carbon monoxide, alcohol-related, medication- and illicit drug-related toxic encephalopathies), autoimmune, metabolic (osmotic demyelination syndrome, uremic, acute hepatic encephalopathy), idiopathic/inflammatory (stroke-like migraine attacks after radiation therapy syndrome), neoplasm-related encephalopathy, and seizure-related encephalopathy.

Alcohol use disorders and the brain

A diagnosis of alcohol use disorder is associated with a higher risk of dementia, but a dose-response relationship between alcohol intake consumption and cognitive impairment remains unclear. Alcohol is associated with a range of effects on the central nervous system at different doses and acts on a number of receptors. Acute disorders include Wernicke's encephalopathy (WE), traumatic brain injury, blackouts, seizures, stroke and hepatic encephalopathy. The most common manifestations of chronic alcohol consumption are Korsakoff's syndrome (KS) and alcohol-related dementia (ARD). There is limited evidence for benefit from memantine in the treatment of ARD, but stronger evidence for the use of high-dose parenteral thiamine in the progression of neuropsychiatric symptoms for WE. Accumulating evidence exists for pharmacological treatment in the prevention of hepatic encephalopathy. Rehabilitation of people with ARD may take several years, and requires an approach that addresses physical and psychosocial factors.

Comprehensive review of Wernicke encephalopathy: pathophysiology, clinical symptoms and imaging findings

Wernicke's encephalopathy (WE) is a severe and life-threatening illness resulting from vitamin B1 (thiamine) deficiency. The prevalence of WE has been estimated from 0.4 to 2.8%. If not treated properly, severe neurologic disorders such as Korsakoff psychosis and even death may occur. The classical triad of clinical symptoms (abnormal mental state, ataxia, and ophthalmoplegia) is found in only 16-33% of patients on initial examination. The originally described underlying condition of WE is alcoholism, but it accounts for about 50% of causes of WE. Nonalcoholic patients are also affected by WE and likely to present symptoms and radiological imaging findings different from patients with alcoholism, which further complicates the diagnosis of WE. Being familiar with predisposing causes, symptoms and radiological imaging findings of WE is important for radiologists and clinicians when making the diagnosis to start immediate treatment. This review discusses pathophysiologies, underlying causes, clinical symptoms, imaging findings and their mimics.

Region-specific interneuron demyelination and heightened anxiety-like behavior induced by adolescent binge alcohol treatment

Adolescent binge drinking represents a major public health challenge and can lead to persistent neurological and mental conditions, but the underlying pathogenic mechanisms remain poorly understood. Using a mouse model of adolescent binge ethanol treatment (ABET), we found that this treatment induced behavioral changes associated with demyelination in different brain regions. After ABET, adolescent mice exhibited anxiogenic behaviors with no change in locomotion on the elevated plus maze, and impaired spatial memory indicated by a significant reduction in spontaneous alternation in the Y maze test. Both effects persisted into adulthood. Anatomical studies further showed that ABET induced a significant reduction of parvalbumin-positive (PV+) GABAergic interneurons and myelin density in the hippocampus and medial prefrontal cortex (mPFC). While these deficits in PV+ interneurons and myelin persisted into early adulthood in the hippocampus, the myelin density recovered in the mPFC. Moreover, whereas ABET mainly damaged myelin of PV+ axons in the hippocampus, it primarily damaged myelin of PV-negative axons in the mPFC. Thus, our findings reveal that an adolescent binge alcohol treatment regimen disrupts spatial working memory, increases anxiety-like behaviors, and exerts unique temporal and spatial patterns of gray matter demyelination in the hippocampus and mPFC.

Serum iron, Magnesium, Copper, and Manganese Levels in Alcoholism: A Systematic Review

The aim of this paper was to review recent literature (from 2000 onwards) and summarize the newest findings on fluctuations in the concentration of some essential macro- and microelements in those patients with a history of chronic alcohol abuse. The focus was mainly on four elements which the authors found of particular interest: Iron, magnesium, copper, and manganese. After independently reviewing over 50 articles, the results were consistent with regard to iron and magnesium. On the other hand, data were limited, and in some cases contradictory, as far as copper and manganese were concerned. Iron overload and magnesium deficiency are two common results of an excessive and prolonged consumption of alcohol. An increase in the levels of iron can be seen both in the serum and within the cells, hepatocytes in particular. This is due to a number of factors: Increased ferritin levels, lower hepcidin levels, as well as some fluctuations in the concentration of the TfR receptor for transferrin, among others. Hypomagnesemia is universally observed among those suffering from alcoholism. Again, the causes for this are numerous and include malnutrition, drug abuse, respiratory alkalosis, and gastrointestinal problems, apart from the direct influence of excessive alcohol intake. Unfortunately, studies regarding the levels of both copper and manganese in the case of (alcoholic) liver disease are scarce and often contradictory. Still, the authors have attempted to summarize and give a thorough insight into the literature available, bearing in mind the difficulties involved in the studies. Frequent comorbidities and mutual relationships between the elements in question are just some of the complications in the study of this topic.

Simultaneous acute Marchiafava-Bignami disease and central pontine myelinolysis: A case report of a challenging diagnosis

RATIONALE

Marchiafava-Bignami disease (MBD) is a rare disease characterized by demyelination of the corpus callosum. It is most commonly seen in patients with chronic alcoholism. The clinical diagnosis of MBD can be difficult due to its nonspecific manifestation. Central pontine myelinolysis (CPM) occurs mostly as a complication of severe and prolonged hyponatremia, especially when corrected too rapidly. However, CPM can be associated with chronic alcoholism and its clinical presentation can be heterogeneous. Because both MBD and CPM can have fatal outcomes, early recognition and treatment can result in a better prognosis. We present a very rare case of simultaneous acute Marchiafava-Bignami disease and central pontine myelinolysis in a patient with chronic alcoholism who was diagnosed unexpectedly using brain magnetic resonance imaging and improved after proper treatment.

PATIENT CONCERNS

We presented a case of a 39-year-old patient who visited the hospital with general weakness and an altered neurologic condition after a week of vomiting.

DIAGNOSIS

The patient was diagnosed with simultaneous acute Marchiafava-Bignami disease and central pontine myelinolysis using brain magnetic resonance imaging.

INTERVENTION

Administration of a high dose of thiamine.

OUTCOMES

The neurologic signs improved after a week of thiamine administration.

LESSONS

This case suggests that Marchiafava-Bignami disease and central pontine myelinolysis might have a common pathogenesis, and brain magnetic resonance imaging is of crucial importance in chronic alcoholic patients presenting with nonspecific neurological deterioration. The appropriate administration of thiamine may prevent poor outcomes.

Long-term alcohol exposure elicits hippocampal nonsynaptic epileptiform activity changes associated with expression and functional changes in NKCC1, KCC2 co-transporters and Na+/K+-ATPase

Nonsynaptic mechanism changes, particularly the enhancement of NKCC1 expression in the dentate gyrus (DG) after 4weeks of ethanol consumption, motivate the present work, in which rats were submitted to a period of chronic consumption (12weeks). Four groups of six animals (6-week-old male Wistar rats) were formed, including the control (C), ethanol 1 (E1), ethanol 2 (E2) and ethanol 3 (E3) groups. The rats in the E1, E2 and E3 groups were treated daily with a 30% v/v solution of ethanol, administered via oral gavage (1.0, 2.0 and 3.0g/kg, respectively). Nonsynaptic epileptiform activities (NEA) were induced by means of the zero-Ca2+ and high-K+ model using hippocampal slices and were recorded in the DG. The presence of NKCC1, KCC2, α1-Na+/K+-ATPase and GFAP immunoreactivity was analyzed. The results demonstrate that alcohol consumption changes NEA, and these changes are more prominent at the lower dosage. An increase in the DC shifts associated with epileptiform discharges was present with the low dose. This increase was correlated with the increment of NKCC1 expression. Confocal microscopy images indicate the NKCC1 increase was pronounced in the initial axonal segment of granule cells. The blockage of these cotransporters during NEA induction with bumetanide suppressed the DC shift increase and diminished all parameters of NEA that were quantified for all groups treated with ethanol. Therefore, the increase in NKCC1 expression and the effective activity of this cotransporter, which were observed in the treated groups, suggest that drugs that act for block NKCC1 represent promising strategies for diminishing the effects of alcohol damage on the brain.

Neuroimaging of chronic alcohol misuse

Alcohol is one of the most commonly abused substances worldwide. It results in a wide range of diseases and disorders affecting many organ systems. Alcohol-related nutritional deficiencies and electrolyte disturbance leave chronic abusers at risk of a range of demyelinating conditions to which the radiologist and clinician should always be alert. These include Wernicke's encephalopathy, Korsakoff's syndrome, Marchiafava-Bignami disease and osmotic demyelination. Cerebral volume loss is also a commonly encountered neuroimaging phenomenon in chronic alcohol abusers. Neuroimaging with CT and MR, with a focus on FLAIR and diffusion-weighted MR sequences, play an important role in the diagnosis and often monitoring of these conditions. We present an educational review of these entities in terms of their clinical features, neuropathology and imaging features along with a case example of each condition.

Neuroimaging features in subacute encephalopathy with seizures in alcoholics (SESA syndrome)

PURPOSE

To describe the neuroimaging findings in subacute encephalopathy with seizures in alcoholics (SESA syndrome).

METHODS

We reviewed all cases reported previously, as well as 4 patients diagnosed in our center. We included a total of 8 patients. All subjects had clinical and EEG findings compatible with SESA syndrome and at least one MRI study that did not show other underlying condition that could be responsible for the clinical presentation.

RESULTS

Initial MRI studies revealed the following features: cortical-subcortical areas of increased T2/FLAIR signal and restricted diffusion (6 patients), hyperperfusion (3 patients), atrophy (5 patients), chronic microvascular ischemic changes (4 patients). Follow-up MRI was performed in half of the patients, all showing a resolution of the hyperintense lesions, but developing focal atrophic changes in 75%.

CONCLUSIONS

SESA syndrome should be included among the alcohol-related encephalopathies. Its radiological features include transient cortical-subcortical T2-hyperintense areas with restricted diffusion (overlapping the typical findings in status epilepticus) observed in a patient with atrophy and chronic multifocal vascular lesions.

Toxic and metabolic encephalopathies: iconographic essay

Generally, toxic-metabolic diseases affecting the central nervous system can hardly be differentiated just on the basis of their clinical presentation. However, some typical neuroradiological features can guide the correct diagnosis. In this context, magnetic resonance imaging is an important tool which, in association with clinical and laboratory data, can establish an early and specific treatment. The present pictorial essay with selected cases from the archives of the authors' institution describes imaging findings which might help in the etiologic diagnosis of toxic-metabolic diseases.

Neurologic Manifestations of Chronic Liver Disease and Liver Cirrhosis

The normal functioning of brain is intimately as well as intricately interrelated with normal functioning of the liver. Liver plays a critical role of not only providing vital nutrients to the brain but also of detoxifying the splanchnic blood. Compromised liver function leads to insufficient detoxification thus allowing neurotoxins (such as ammonia, manganese, and other chemicals) to enter the cerebral circulation. In addition, portosystemic shunts, which are common accompaniments of advanced liver disease, facilitate free passage of neurotoxins into the cerebral circulation. The problem is compounded further by additional variables such as gastrointestinal tract bleeding, malnutrition, and concurrent renal failure, which are often associated with liver cirrhosis. Neurologic damage in chronic liver disease and liver cirrhosis seems to be multifactorial primarily attributable to the following: brain accumulation of ammonia, manganese, and lactate; altered permeability of the blood-brain barrier; recruitment of monocytes after microglial activation; and neuroinflammation, that is, direct effects of circulating systemic proinflammatory cytokines such as tumor necrosis factor, IL-1β, and IL-6. Radiologist should be aware of the conundrum of neurologic complications that can be encountered in liver disease, which include hepatic encephalopathy, hepatocerebral degeneration, hepatic myelopathy, cirrhosis-related parkinsonism, cerebral infections, hemorrhage, and osmotic demyelination. In addition, neurologic complications can be exclusive to certain disorders, for example, Wilson disease, alcoholism (Wernicke encephalopathy, alcoholic cerebellar degeneration, Marchiafava-Bignami disease, etc). Radiologist should be aware of their varied clinical presentation and radiological appearances as the diagnosis is not always straightforward.

Wernicke encephalopathy and ethanol-related syndromes

Ethanol causes diverse neurologic conditions caused by acute and chronic brain damage. This review provides an overview of Wernicke encephalopathy and other ethanol-related brain changes, such as chronic brain atrophy, Marchiafava-Bignami disease, osmotic demyelination syndrome, chronic hepatic encephalopathy, and acute alcohol withdrawal. As clinical symptoms of this spectrum of diseases have nonspecific neurologic alterations, radiologists should have current radiologic information and understand the imaging findings pertaining to the pathophysiology to support diagnosis.

Magnetic resonance imaging in marchiafava-bignami syndrome: a cornerstone in diagnosis and prognosis

Marchiafava-Bignami syndrome is a rare condition. However, with the advent of MRI, more and more of these cases are being diagnosed. Thus, it becomes essential for a radiologist to be familiar with its imaging features as well as clinical presentation. A 50-year-old chronic alcoholic presented to the emergency room with history of 3 episodes of seizures 2 days earlier. The patient had gait disturbances for the last few days. On examination, the patient was in a state of stupor. No neck rigidity was elicited. On MRI, the corpus callosum appeared diffusely hypointense on T1 weighted images and hyperintense on T2 weighted sequences without any evident enhancement after intravenous administration of Gadolinium. On fluid attenuation and inversion recovery images, central hypointensity with surrounding hyperintense rim involving the genu, body, and splenium of corpus callosum was noted. Additionally, cortical-subcortical signal intensity changes were also noted predominantly involving the right frontal lobe. On diffusion weighted imaging, all the above mentioned lesions showed restriction of diffusion. I am presenting here a case of Marchiafava-Bignami syndrome highlighting the role of MR imaging in diagnosing, prognosticating as well as in understanding the underlying pathophysiology of this rare clinical entity.

Brain and behavioral pathology in an animal model of Wernicke's encephalopathy and Wernicke-Korsakoff Syndrome

Animal models provide the opportunity for in-depth and experimental investigation into the anatomical and physiological underpinnings of human neurological disorders. Rodent models of thiamine deficiency have yielded significant insight into the structural, neurochemical and cognitive deficits associated with thiamine deficiency as well as proven useful toward greater understanding of memory function in the intact brain. In this review, we discuss the anatomical, neurochemical and behavioral changes that occur during the acute and chronic phases of thiamine deficiency and describe how rodent models of Wernicke-Korsakoff Syndrome aid in developing a more detailed picture of brain structures involved in learning and memory.

Reversible cytotoxic edema in TPN-related hepatic encephalopathy

Hepatic encephalopathy (HE) is an uncommon complication of total parenteral nutrition (TPN). Cytotoxic edema has not been reported in children with TPN-related HE. We describe a case of TPN-related HE presenting with diffuse cytotoxic edema which reversed after liver transplantation.

Evaluation of genotoxicity after application of Listerine(R) on human lymphocytes by micronucleus and single cell gel electrophoresis assays

Listerine (LN) is one of the most commonly used mouth rinses worldwide although very limited information is available concerning its genotoxicity. In another view, the biological safety profile of oral care products is frequently assumed on the basis of simplistic test models. Therefore, the present study was undertaken to investigate the in vitro genotoxic potential of LN using micronucleus and single cell gel electrophoresis tests as genetic endpoints. Different concentrations of LN (0-100% of ml/culture, v/v) were applied to whole human blood cultures (n = 5). The result of the present study showed that there were no statistically significant differences (p > 0.05) between the control group and the groups treated with LN alone in both analysed endpoints. In conclusion, our result first demonstrated the absence of genotoxicity of LN on human lymphocytes.

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.