Diffusion weighted MR imaging of acute Wernicke's encephalopathy

Pediatric thiamine deficiency disorders in high-income countries between 2000 and 2020: a clinical reappraisal

Often thought to be a nutritional issue limited to low- and middle-income countries (LMICs), pediatric thiamine deficiency (PTD) is perceived as being eradicated or anecdotal in high-income countries (HICs). In HICs, classic beriberi cases in breastfed infants by thiamine-deficient mothers living in disadvantaged socioeconomic conditions are thought to be rare. This study aims to assess PTD in HICs in the 21st century. Literature searches were conducted to identify case reports of PTD observed in HICs and published between 2000 and 2020. The analyzed variables were age, country, underlying conditions, clinical manifestations of PTD, and response to thiamine supplementation. One hundred and ten articles were identified, totaling 389 PTD cases that were classified into four age groups: neonates, infants, children, and adolescents. Eleven categories of PTD-predisposing factors were identified, including genetic causes, lifestyle (diabetes, obesity, and excessive consumption of sweetened beverages), eating disorders, cancer, gastrointestinal disorders/surgeries, critical illness, and artificial nutrition. TD-associated hyperlactatemia and Wernicke encephalopathy were the most frequent clinical manifestations. The circumstances surrounding PTD in HICs differ from classic PTD observed in LMICs and this study delineates its mutiple predisposing factors. Further studies are required to estimate its magnitude. Awareness is of utmost importance in clinical practice.

The Relevance of Thiamine Evaluation in a Practical Setting

Thiamine is a crucial cofactor involved in the maintenance of carbohydrate metabolism and participates in multiple cellular metabolic processes. Although thiamine can be obtained from various food sources, some common food groups are deficient in thiamine, and it can be denatured by high temperature and pH. Additionally, different drugs can alter thiamine metabolism. In addition, the half-life of thiamine in the body is between 1 and 3 weeks. All these factors could provide an explanation for the relatively short period needed to develop thiamine deficiency and observe the consequent clinical symptoms. Thiamine deficiency could lead to neurological and cardiological problems. These clinical conditions could be severe or even fatal. Marginal deficiency too may promote weaker symptoms that might be overlooked. Patients undergoing upper gastrointestinal or pancreatic surgery could have or develop thiamine deficiency for many different reasons. To achieve the best outcome for these patients, we strongly recommend the execution of both an adequate preoperative nutritional assessment, which includes thiamine evaluation, and a close nutritional follow up to avoid a nutrient deficit in the postoperative period.

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.

MR imaging findings in alcoholic and nonalcoholic acute Wernicke's encephalopathy: a review

Wernicke's encephalopathy (WE) is a severe neurological syndrome caused by thiamine (vitamin B1) deficiency and clinically characterized by the sudden onset of mental status changes, ocular abnormalities, and ataxia. Apart from chronic alcoholism, the most common cause of WE, a lot of other conditions causing malnutrition and decreasing thiamine absorption such as gastrointestinal surgical procedures and hyperemesis gravidarum must be considered as predisposing factors. Due to its low prevalence and clinical heterogeneity, WE is often misdiagnosed, leading to persistent dysfunctions and, in some cases, to death. Nowadays, MR imaging of the brain, showing T2 and FLAIR hyperintensities in typical (thalami, mammillary bodies, tectal plate, and periaqueductal area) and atypical areas (cerebellum, cranial nerve nuclei, and cerebral cortex), is surely the most important and effective tool in the diagnostic assessment of WE. The aim of this paper is to propose a state of the art of the role of MR imaging in the early diagnosis of this complex disease.

The neurological effects of methyl bromide intoxication

Used primarily as a fumigant or as a substrate in chemical processes, methyl bromide is a highly toxic gas. The gas is usually absorbed by inhalation and effects on the lungs, gastrointestinal tract, skin, and brain are seen. Numerous instances of acute and chronic neurologic injury have been reported: acute poisoning results in seizures, myoclonus, ataxia or cerebral oedema beginning as early as 30 min after exposure while subacute or chronic intoxication presents with diverse slowly progressive neurological and neurobehavioral symptoms. Serum bromide levels may be elevated, but often return rapidly to normal. Electroencephalography may show frontally-predominant slow waves or polyspikes with following slow wave, and MRI reveals characteristic involvement in the dentate nucleus of the cerebellum, the brainstem, and the splenium of the corpus callosum. Symmetric and selective lesions in characteristic sites are observed on imaging and on histopathological examination. These are likely produced by methylation of intracellular lipids, protein and glutathione; production of toxic metabolites; defective neurotransmitter function; and abnormal oxidative phosphorylation. This article reviews the toxic effects of this gas, the pathophysiology and symptoms of its effects on the nervous system, and characteristic findings on MRI; and presents an illustrative case of methyl bromide intoxication due to exposure at a factory producing the compound commercially.

Wernicke's encephalopathy following Hyperemesis gravidarum. A report of three cases

Wernicke's encephalopathy (WE) due to causes other than chronic alcohol abuse is an uncommon and often misdiagnosed condition. In the setting of hyperemesis gravidarum, an acute deficiency of thiamine results from body stores being unable to meet increased metabolic demands. The condition produces typical clinical and radiological findings and when diagnosed early and treated promptly has a good prognosis. Magnetic resonance imaging (MRI) is sensitive and specific for diagnosis. We describe three patients with hyperemesis gravidarum who developed WE, and highlight a range of clinical and imaging features important for appropriate diagnosis. A high degree of clinical suspicion is essential. Treatment is often empirical pending results of investigation, and consists of parenteral repletion of thiamine stores. Reversal of MRI findings parallels clinical improvement. Neurologic outcomes are usually good, but half the pregnancies complicated by this condition do not produce healthy children.

Neuroimaging of Wernicke's encephalopathy and Korsakoff's syndrome

There is considerable evidence that neuroimaging findings can improve the early diagnosis of Wernicke's encephalopathy (WE) in clinical settings. The most distinctive neuroimaging finding of acute WE are cytotoxic edema and vasogenic edema, which are represented by bilateral symmetric hyperintensity alterations on T2-weighted MR images in the periphery of the third ventricle, periaqueductal area, mammillary bodies and midbrain tectal plate. An initial bout of WE can result in Korsakoff's syndrome (KS), but repeated bouts in conjunction with its typical comorbidity, chronic alcoholism, can result in signs of tissue degeneration in vulnerable brain regions. Chronic abnormalities identified with neuroimaging enable examination of brain damage in living patients with KS and have expanded the understanding of the neuropsychological deficits resulting from thiamine deficiency, alcohol neurotoxicity, and their comorbidity. Brain structure and functional studies indicate that the interactions involving the thalamus, mammillary bodies, hippocampus, frontal lobes, and cerebellum are crucial for memory formation and executive functions, and the interruption of these circuits by WE and chronic alcoholism can contribute substantially to the neuropsychological deficits in KS.

Wernicke's encephalopathy: expanding the diagnostic toolbox

Wernicke's encephalopathy (WE) is a life threatening neurological disorder that results from thiamine (Vitamin B1) deficiency. Clinical signs include mental status changes, ataxia, occulomotor changes and nutritional deficiency. The conundrum is that the clinical presentation is highly variable. WE clinical signs, brain imaging, and thiamine blood levels, are reviewed in 53 published case reports from 2001 to 2011; 81 % (43/53) were non-alcohol related. Korsakoff Syndrome or long-term cognitive neurological changes occurred in 28 % (15/53). Seven WE cases (13 %) had a normal magnetic resonance image (MRI). Four WE cases (8 %) had normal or high thiamine blood levels. Neither diagnostic tool can be relied upon exclusively to confirm a diagnosis of WE.

Atypical Wernicke's encephalopathy showing involvement of substantia nigra

CASE HISTORY

Wernicke's encephalopathy is a metabolic disorder caused by deficiency of thiamine (vitamin B1) seen in alcoholics and even in nonalcoholic patients, classically presenting with a triad of ataxia, ophthalmoplegia, and altered mental status. Typical findings in magnetic resonance imaging are represented by symmetric signal alterations in medial thalami, mamillary bodies, tectal plate, and periaqueductal area and atypical findings involve lesions in cerebellum, midline vermis, red nuclei, dentate, caudate, cranial nerve nuclei, splenium and cerebral cortex. We report here a case of nonalcoholic starvation induced atypical WE showing symmetrical lesions in substantia nigra in addition to the classical neuroradiological findings.

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.

[Wernicke encephalopathy after subtotal gastrectomy for morbid obesity]

Wernicke's encephalopathy (WE) is one of the potential complications of obesity surgery. It is an acute neuropsychiatric syndrome resulting from thiamine deficiency often associated with repeated vomiting. The classic triad is frequently reported in these patients (optic neuropathy, ataxia and confusion), associated with uncommon features. Cerebral impairment affects the dorsal medial nucleus of the thalamus and the periaqueductal grey area, appearing on MRI, as hyperintense signals on T2, Flair and Diffusion weighted imaging. Early diagnosis and parenteral thiamine are required to decrease morbidity and mortality. We report a case of WE and Korsakoff's syndrome in a young obese patient after subtotal gastrectomy, who still has substantial sequelae. The contribution of MRI with diffusion-weighted imaging is illustrated. The interest of nutritional supervision in the first weeks and preventive thiamine supplementation in case of repeated vomiting are of particular importance in these risky situations.

A case report of Wernicke's encephalopathy in a pediatric patient with anorexia nervosa--restricting type

PURPOSE

To describe a case of Wernicke's encephalopathy in a 15-year-old female patient with anorexia nervosa--restricting type.

METHOD

The patient and family were interviewed. Literature relevant to the case was reviewed prior to diagnosis.

RESULTS

The patient reported a 30-kg weight loss over a 6-month period, following a strict diet deplete in thiamine without vitamin supplementation. The patient reported a carbohydrate binge for 5 days prior to admission. Her clinical presentation, confusion, ataxia, nystagmus, and magnetic resonance imaging demonstrating bilateral subthalamic hyperdensities were consistent with Wernicke's encephalopathy. Nutritional stabilization and parenteral thiamine replacement resulted in rapid improvement of her ataxia and nystagmus and contributed to her recovery.

CONCLUSIONS

Wernicke's encephalopathy should be considered in patients with anorexia nervosa. Thiamine therapy could be considered in cases of anorexia nervosa with significant confusion.

Hyperemesis gravidarum complicated by Wernicke encephalopathy: background, case report, and review of the literature

Wernicke encephalopathy (WE) is a rare but known complication of severe hyperemesis gravidarum caused by thiamine deficiency. This article presents an unusual case that occurred at our institution and reviews the 48 previously published cases of WE in pregnancy. Considering all the 49 cases, the mean (+/-standard deviation) patients' age was 26.7 +/- 4.9 years, the mean gestational age when WE manifested was 14.3 +/- 3.4 weeks, and the mean duration of vomiting and feeding difficulties was 7.7 +/- 2.8 weeks. Wernicke's classic triad (confusion, ocular abnormalities, and ataxia) manifested in only 46.9% (23 of 49) of the patients. Confusion affected 63.3% (31 of 49) of the patients, ocular signs 95.9% (47 of 49) and symptoms 57.1% (28 of 49), and ataxia 81.6% (40 of 49). Deterioration of consciousness affected 53.1% (26 of 49) of the subjects and memory impairment 61.2% (30 of 49). Complete remission of the disease occurred in only 14 of 49 cases. Symptom resolution required months and permanent impairments were common. The overall pregnancy loss rate, directly (spontaneous fetal loss) and indirectly (planned abortion) attributable to WE, was 47.9% (23 of 49). The diagnosis of WE is clinical and can be rapidly confirmed by magnetic resonance imaging. We emphasize the importance of thiamine supplementation to women with prolonged vomiting in pregnancy, especially before intravenous or parenteral nutrition. We also underline the necessity to promptly replace vitamin B1 when neurologic symptoms and/or signs develop in a patient with hyperemesis gravidarum.

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.

MRI findings of Wernicke encephalopathy revisited due to hunger strike

BACKGROUND AND PURPOSE

The purpose of this study was to determine the characteristic magnetic resonance imaging (MRI) findings among a group of patients who presented with Wernicke encephalopathy (WE) due to the neurological complications of a long-term hunger strike (HS).

METHODS

MRI studies also including the fluid-attenuated inversion recovery (FLAIR) sequence and diffusion-weighted imaging (DWI) of six male patients with WE aged from 25 to 38 years (mean age 31 years) were evaluated.

RESULTS

In all subjects, T2-weighted sequences, FLAIR and DWI revealed a signal hyperintensity within the posteromedial thalami and surrounding the third ventricle. In particular, on coronal images, the hyperintense areas around the third ventricle showed a suggestive "double wing" configuration. We observed an increased signal on proton-density and T2-weighted images in the mamillary bodies of three patients. Four patients demonstrated additional hyperintensities within the periaqueductal region and/or the tectal plate. At least one lesion area in five of six patients demonstrated contrast enhancement.

CONCLUSION

The consistent imaging findings of our study suggest that MRI is a reliable means of diagnosing WE. Acute WE is sometimes underdiagnosed, yet early diagnosis and treatment of WE is crucial in order to avoid persistent brain damage. MRI, including postcontrast T1-weighted imaging, DWI beneath standardized T2-weighted imaging, and FLAIR sequences may prove to be a valuable adjunct to clinical diagnosis and to provide additional information in acute and/or subacute WE.

Imaging of acute neurological conditions in pregnancy and the puerperium

Eclampsia is one of the most common acute neurological events occurring during pregnancy. However, there are many other conditions that can present during pregnancy and the puerperium and that may either mimic eclampsia or produce other acute neurological manifestations. Frequently the symptoms and signs are non-specific, and it can be difficult to differentiate between these conditions on clinical grounds alone. Neuroradiological studies can provide valuable diagnostic information, and interventional radiological procedures may play a part in the subsequent management of these conditions. This review focuses on the imaging of acute neurological conditions which may be associated with, or present during, pregnancy and the puerperium.

Correlation of magnetic resonance images with neuropathology in acute Wernicke's encephalopathy

We correlated serial brain MRIs with neuropathological findings in a 16-year-old female whose autopsy was consistent with Wernicke's encephalopathy (WE). Diffusion-weighted imaging, diffusion coefficients mapping and neuropathology findings were suggested vasogenic edema in the periaqueductal and peri-the-fourth ventricular areas. This is the first documented case report to make this direct comparison. The characteristic WE changes in the mammillary body was also correlated with the findings of MRI with contrast enhancement. Bilateral cortical lesions revealed by MRI were atypical and rare in WE and were not evidenced by pathological changes.